Note: Descriptions are shown in the official language in which they were submitted.
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REGENERATIVE VALVE HYDRAULIC ACTUATOR
The present invention relates to a regenerative valve hydraulic actuator which
is
particularly intended for use in reciprocating internal combustion engines.
Since the early days of internal combustion engines, numerous devices have
been
designed to actuate opening and closing of the intake and exhaust valves of
the
most widely used internal combustion engines, that is to say those employing a
Beau de Rochas, Otto or Diesel cycle.
However, because of its reliability, its robustness, its simplicity and its
moderate
unit cost, the camshaft has been imposed as the virtually universal valve
actuator
equipping almost all four-travel engines produced worldwide.
For all that, the cams which said camshaft includes have a profile fixed by
their
design which leaves no freedom to change the valve lift laws that said cams
actuate.
A first step toward more flexibility was made by inserting a phase-shifter
between
the camshaft(s) and the crankshaft of reciprocating internal combustion
engines,
said phase-shifter allowing advancing or retarding of the opening - relative
to the
angular position of the crankshaft - either of the intake valves or of the
exhaust
valves, or both. Said phase-shifter is used as part of the strategy known as
VVT
(which stands for "Variable Valve Timing").
A second step consisted in making variable the opening time and/or the lift
height
of the valves, this strategy being better known by the abbreviation WA (which
stands for "Variable Valve Actuation"). In this regard, a number of devices
have
been or are being marketed under various brands and/or various trade names.
A distinction is made between discretely variable valve lifters which have at
least
two selectable cam profiles and continuously variable lifters generally based
on a
single cam and a continuously variable ratio transmission. Discretely variable
lifters include for example the "VTec 0" device from "Honda 0", the "Variocam
Plus 0" device from "Porsche 0", the "Valvelift system 0" from "Audi 0" and
the
"VVTL-i 0" device from "Toyota 0".
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Continuous variation valve lifter devices include the "Valvetronic 8" device
developed by "BMW 8" which is based on a variable ratio lever and the
"Multiair
e" device from "FIAT 0", the latter providing a hydraulic transmission between
the
cam and the valve pushrod while a hydraulic fluid tank return solenoid valve
enables the lift of said valve to be truncated to a greater or lesser degree.
To go further toward flexibility of control in opening, closing and lifting of
the valves
of reciprocating internal combustion engines, numerous devices have been
conceived purely and simply to replace the camshaft and its invariable profile
cams with more or less variable devices. These devices without cams are known
as "camless" devices.
The aim of said "camless" devices is to procure great variety in the laws for
opening, lifting and closing the valves, within the limits allowed by physics
and
geometry. Numerous "camless" devices have been produced which for the most
part have stalled at the prototype stage. This is the case for example of the
"electromagnetic camless" device from "Valeo 0", the "Free Valve e" device
from
"Cargine 8", the hydro-electric device developed by the American company
"Sturman e" in collaboration with "Siemens OD" or the "Active Valve Train
(AVTTm)"
device from the company "Lotus 0".
A wide variety of devices have stalled at the design stage and have been
implemented only partially, if at all. In this regard note the patents
belonging to the
applicant that describe hydromechanical or electrohydraulic "camless" devices.
The first of these devices was published under the number FR 2 842 867 and
describes a valve hydraulic actuator for piston engines, while the second was
published under the number FR 2 980 516 and discloses a reciprocating cam
electrohydraulic valve actuator.
At present, no "camless" type device has been mass produced for motor
vehicles.
This is because, compared to "camless" devices, valve actuators based on at
least
one cam remain more competitive and less adventurous and have a more
advantageous cost-benefit ratio.
Moreover, the energy balance of numerous "camless" devices is in the final
analysis mediocre because either the energy invested to accelerate the valve
and
to compress the return spring is not recovered at all or only too little or
the energy
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efficiency of the hydraulic, electromagnetic or mechanical "camless" actuator
is
insufficient.
For example, US patent 5,410,994 from inventor Michael M. Schechter does not
recover the hydraulic energy invested to open the valve, to the point that the
inventor even specifies in the text of said patent that the flow rate of
hydraulic fluid
feeding the valve is the main factor determining the energy consumption of the
system.
Apart from leading to high energy consumption, non-recovery of the kinetic
energy
of the valve or of the valve return spring compression energy ¨ whatever the
nature of said spring ¨ implies great instability of said valve, which forms
with the
hydraulic fluid a mass-spring system subjected to high excitation if the non-
recovered energy is not entirely dissipated in the form of heat.
This is why many "camless" devices are imprecise and lead to unstable lifting
and
holding opening of the valve, which is subject to parasitic movements. This
leads
in particular to the necessity to damp the movement of said valve to render it
more
precise whereas by its very nature damping dissipates energy in the form of
heat,
which is unfavorable in terms of efficiency.
Note also the difficulty that most "camless" devices encounter in slowing the
valve
sufficiently during its closure, when said valve arrives in the vicinity of
its seat. This
slowing is necessary to limit the power of the impact between said valve and
said
seat, both to confer on said seat a normal service life and to prevent
excessive
acoustic emission. This slowing strategy known as "soft landing" is naturally
implemented by the cams which, in the prior art, have a profile that
terminates with
what is known in the art as a "ramp of silence", which moreover assures the
recovery of the kinetic energy of the valve under excellent conditions in
terms of
efficiency.
Note also in this regard that US patent 5,410,994 does not include either any
cam
or any mechanical device for slowing the valve in the vicinity of its seat,
any more
than for example US patent 2008/0251041 Al from inventor Zheng Lou.
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Such devices therefore necessarily lead to unacceptable acoustic emissions, to
hammering of the valve seat, and to an energy expenditure compromising the
overall efficiency of the internal combustion engine equipped therewith.
Accordingly, until now, and taking account of the state of the art and
technology,
the technological, economic and industrial effort to be accepted to maximize
the
energy efficiency of an internal combustion engine by means of "camless" type
valve actuators is not justified in that simpler and more robust means based
on
one or more camshafts can achieve most of the efficiency gains theoretically
acceptable for said engine without recourse to the "camless" technology.
In other words, to be imposed for the mass production of motor vehicles, the
unit
cost in manufacture, the reliability and the overall size of a "camless" type
valve
actuator must be at least comparable to those of a cam type actuator, or even
more competitive.
However, recourse to a "camless" valve actuator may be justified if it is
impossible
to have recourse to a cam type actuator for functional reasons. This is the
case in
particular for example of the cam shaft internal combustion engine on which
the
French patent belonging to the applicant was published under the number
FR 3 032 236. In fact, the intake metering valve of said engine must be lifted
in
such a short time ¨ of the order of a few hundred microseconds ¨ that a cam
type
actuator can in no case assure the opening of said valve under the required
conditions. The same applies in respect of the closing of said valve. A
classic
actuator could therefore not open the metering valve of the engine according
to
patent number FR 3 032 236 unless said engine were turning only at very low
speed, which cannot be the case if the latter actuator is employed in the
field of
motor vehicles or heavy goods vehicles.
Moreover, the particular architecture of the transfer-expansion and
regeneration
engine according to FR 3 032 236 and particularly that of the cylinder heads
of the
double-acting expansion cylinder of said engine is only with difficulty
compatible
with a camshaft. In fact, the assembly that the cylinder barrel, the lower
cylinder
head and the upper cylinder head of said expansion cylinder constitute is
adapted
to be suspended on hollow pillars as French patent application No. 1558585 of
14 September 2015 describes, said application also belonging to the applicant.
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Given that the hollow pillars rest on ball-joint connections, on the one hand,
and
that said assembly is at a high temperature, on the other hand, it is
impossible to
= fix to the lower cylinder head and/or the upper cylinder head that said
assembly
comprises a belt or chain transmission of whatever type of camshaft. It is
therefore
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pertinent to provide ¨ as patent number FR 3 032 236 proposes ¨ cartridges
ready
to be mounted in said cylinder heads, said cartridges including in particular
the
metering valve actuator and the metering valve itself, whilst said cartridges
are not
connected to each other and/or to the energy source that feeds said actuator
except by cables and/or lines that are sufficiently flexible.
In the application field of reciprocating piston compressors and engines and
in
accordance with one particular embodiment, there results from the invention a
regenerative valve hydraulic actuator that is:
= extremely fast to the point of enabling valve opening times of a few hundred
microseconds and opening durations close to one millisecond, thus
addressing in particular the function of requirement of the transfer-expansion
and regeneration engine as described in the French patent published under
the number FR 3 032 236;
= precise and induces little parasitic movement of the valve that it
actuates,
despite virtual absence of damping of said valve;
= suitable for equipping any prior art piston compressor or any
reciprocating
internal combustion engine, and notably installable on the transfer-expansion
and regeneration engine that French patent published under number
FR 3 032 236 describes thanks to the possibility of producing an independent
cartridge ready to be mounted independently for each valve, the orientation of
which relative to said engine is non-constraining, and which is not connected
to the energy source of the actuator except by a line sufficiently flexible to
be
able to accommodate thermal expansion of the cylinder head on which said
cartridge is mounted;
= of high energy efficiency comparable to that of a cam type actuator, said
high
efficiency being obtained in particular by recovering virtually all of the
kinetic
energy of all the moving parts of said actuator, in addition to that of the
valve;
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= silent in that it enables the valve to be returned to its seat at very
low speed
despite the high speed that said valve acquires during its closing travel;
= of long service life, compatible with that of any reciprocating internal
combustion engine;
= if necessary adapted to enable any valve to be opened to the exterior of
the
compression or combustion chamber of any reciprocating piston compressor
or engine without this allowing escape of the pressurized gas that said
chamber contains via said valve, and which by virtue of this prevents having
to
provide valve recesses on the cap of the piston of said compressor or engine
to prevent any collision between said piston and said valve, whilst any flow
of
gas via said valve is facilitated;
= economically feasible to manufacture.
In this regard, the regenerative valve hydraulic actuator according to the
invention
is in particular intended to implement on any reciprocating internal
combustion
engine most of the strategies that make it possible to maximize torque and
power,
on the one hand, and to reduce fuel consumption and emission of pollutants, on
the other hand, said strategies being based on precise and flexible control of
the
intake and/or exhaust valves of said engine.
Thanks to the regenerative valve hydraulic actuator according to the
invention, this
significant improvement in the performance of said engines can be obtained
without significantly increasing either the acoustic emissions or the
manufacturing
unit cost thereof.
It is also understood that the regenerative valve hydraulic actuator according
to the
invention is in particular designed to enable the production under optimum
conditions of the transfer-expansion and regeneration engine as described in
the
French patent published under the number FR 3 032 236, the latter promising a
drastic reduction in fuel consumption and emission of pollutants compared to
conventional reciprocating internal combustion engines.
It is understood that although the regenerative valve hydraulic actuator
according
to the invention is primarily intended for reciprocating piston compressors
and
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engines, said actuator can be applied to any other application field, machine
or
apparatus that includes at least one line in which a gas or a fluid of any
kind
circulates, whilst said actuator advantageously makes it possible to open and
to
close any valve of any type in said line in order to allow or to block the
flow of said
gas or fluid in said line.
Moreover, said actuator may be used with the valve that it actuates replaced
by
any other object necessitating rapid movement between at least two positions.
The other features of the present invention have been described in the
description
and in the secondary claims depending directly or indirectly on the main
claim.
The regenerative valve hydraulic actuator according to the present invention
for a
reciprocating piston compressor or engine which comprises at least one piston
connected to transmission means to reciprocate in a cylinder closed by a
compressor or engine cylinder head, said piston, said cylinder and said
cylinder
head forming a compression or combustion chamber into which opens at least one
intake line and at least one exhaust or discharge line, one or both of said
two lines
being connected to said chamber by a line orifice that a valve can block when
it
rests on a valve seat, said actuator comprising:
= At least one high-pressure hydraulic feed pump that can admit a hydraulic
fluid from a low-pressure accumulator or a fluid tank via a low-pressure feed
line to discharge said fluid to a high-pressure accumulator via a high-
pressure feed line;
= At least one actuator which comprises an actuator cylinder capped by an
actuator cylinder head, said cylinder being attached directly or indirectly to
the compressor or engine cylinder head whereas said cylinder and the
actuator cylinder head form with an actuator piston an actuator hydraulic
chamber, said piston being mechanically connected by transmission means
to the valve, said means being such that if the actuator hydraulic chamber
is subjected to a pressure exerted by the hydraulic fluid, the actuator piston
tends to move said valve away from the valve seat with which it cooperates;
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= At least one valve return device which exerts on the valve a force
opposite
that which the actuator is able to produce, said device therefore tending to
return the valve into contact with the valve seat with which it cooperates;
= At least one valve lifter hydraulic valve that can open or close a high-
pressure lifter line which connects the high-pressure accumulator to the
actuator hydraulic chamber;
= At least one lifter check valve placed in an inertial lifter line that
connects
the low-pressure accumulator or the fluid tank to the actuator hydraulic
chamber, said check valve allowing the hydraulic fluid - via said line - to
flow from the low-pressure accumulator or the fluid tank to the actuator
hydraulic chamber, but not in the opposite direction;
= At least one valve closure hydraulic valve that can open or close a closure
and regeneration line which connects the actuator hydraulic chamber with a
fluid intake which a closure and regeneration hydraulic motor includes, a
fluid outlet which said motor also includes being connected with the low-
pressure accumulator or with the fluid tank by a hydraulic motor low-
pressure return line;
At least one progressive lever arm ratio lever constituting all or part of the
transmission means, said lever exposing at least one point of application of
the
force of the actuator to which the actuator piston can apply directly or
indirectly a
driving or resisting force, at least one point of application of the force of
the valve
to which the valve can apply directly or indirectly a driving or resisting
force, and at
least one point of application of the reaction force on the cylinder head at
which a
force is applied directly or indirectly to the compressor or engine cylinder
head.
The regenerative valve hydraulic actuator according to the present invention
comprises means for moving the application point which move the point of
application of the force of the actuator and/or the point of application of
the force of
the valve and/or the point of application of the reaction force on the
cylinder head
along the progressive lever arm ratio lever during the opening travel of the
valve.
The regenerative valve hydraulic actuator according to the present invention
comprises a point of application of the force of the actuator and/or a point
of
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application of the force of the valve and/or a point of application of the
reaction
force on the cylinder head which respectively form directly or indirectly with
the
actuator piston and/or with the valve and/or with the compressor or engine
cylinder
head with which it cooperates either at least one pivot connection or at least
one
.. rolling-sliding connection, the latter constituting the means for moving
the
application point.
The regenerative valve hydraulic actuator according to the present invention
comprises a rolling-sliding connection which consists of at least one lever
contact
track provided on the progressive lever arm ratio lever at the level of the
point of
application of the force of the actuator and/or the point of application of
the force of
the valve and/or the point of application of the reaction force on the
cylinder head,
said track cooperating with a lever reaction surface respectively formed
directly or
indirectly on the actuator piston and/or on the valve and/or on the compressor
or
engine cylinder head, said piston and/or said surface having a curved contact
profile on which is established the contact between said track and said
surface.
The regenerative valve hydraulic actuator according to the present invention
comprises a valve return device which consists of a valve return actuator
which
comprises a return actuator cylinder capped by a return actuator cylinder
head,
said cylinder being attached directly or indirectly to the cylinder head of
the
compressor or engine whereas said cylinder and the return actuator cylinder
head
form with a return actuator piston a return actuator hydraulic chamber, said
piston
being mechanically connected to the valve by return transmission means.
The regenerative valve hydraulic actuator according to the present invention
comprises a return actuator hydraulic chamber which is connected to the high-
pressure accumulator by a return pressure line.
In the regenerative valve hydraulic actuator according to the present
invention the
level and the pressure of the hydraulic fluid that the low-pressure
accumulator
contains are maintained within a certain range of values by a low-pressure
force-
feed hydraulic pump which can transfer said fluid from the fluid tank to said
accumulator via a low-pressure force-feed line.
The regenerative valve hydraulic actuator according to the present invention
comprises at least one valve with or without the valve seat with which it
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cooperates, an actuator, transmission means, a valve return device, a lifter
check
valve, a valve lifter hydraulic valve and a valve closure hydraulic valve are
together
accommodated in an actuator cartridge which exposes at least one hydraulic
connector.
5
The regenerative valve hydraulic actuator according to the present invention
comprises a valve lifter hydraulic valve and/or a valve closure hydraulic
valve
which consists of a tubular valve which comprises a blocking tube which can be
moved in longitudinal translation by a tube actuator, said tube being
10 accommodated in fluid-tight manner in a blocking tube bore and ending at
a tube
sealing bearing surface that can either rest on a tube seat to form with the
latter a
continuous line of fluid-tight contact or be maintained at a certain distance
from
said seat to allow the hydraulic fluid to pass from a tube internal volume to
a tube
external collector-distributor or vice versa.
The regenerative valve hydraulic actuator according to the present invention
comprises a tube actuator which is a hydraulic amplification piezoelectric
actuator
which comprises a stack of ceramic elements that are deformed mechanically
when they are subjected to an electric field, the end of said stack being
connected
to an actuator sender piston of large diameter which forms - with an actuator
sender cylinder - an actuator sender chamber which communicates with at least
one actuator receiver chamber, the latter being formed on the one hand by an
actuator receiver piston of small diameter which is directly or indirectly
connected
to the blocking tube with which it cooperates so as to be able to move the
latter in
longitudinal translation and on the other hand by an actuator receiver
cylinder.
The regenerative valve hydraulic actuator according to the present invention
comprises an actuator sender chamber and an actuator receiver chamber which
are together connected with a pressurized hydraulic fluid source by an
actuator
force-feed check valve which allows the hydraulic fluid to go from said source
to
said chambers and not vice versa.
The regenerative valve hydraulic actuator according to the present invention
comprises an actuator sender piston which receives a pressure compensation
spring which tends to move it toward the actuator sender chamber, the force
which
said spring exerts on said piston being less than or equal to the force which
the
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hydraulic fluid exerts on said piston when the piston in the actuator sender
chamber is equal to that in the pressurized hydraulic fluid source.
The regenerative valve hydraulic actuator according to the present invention
comprises an actuator receiver piston which receives a pressure compensation
spring which tends to move it toward the actuator receiver chamber, the force
which said spring exerts on said piston being less than or equal to the force
which
the hydraulic fluid exerts on said piston when the pressure in the actuator
receiver
chamber is equal to that in the pressurized hydraulic fluid source.
The regenerative valve hydraulic actuator according to the present invention
comprises an actuator sender chamber which communicates via a receiver
chamber common manifold with a plurality of actuator receiver chambers, the
actuator receiver piston forming each of said receiver chambers being able to
move in longitudinal translation a blocking tube that is its own.
The regenerative valve hydraulic actuator according to the present invention
comprises an actuator receiver chambers which are each put into communication
or not with the receiver chamber common manifold by a selection valve the
opening of which is commanded by a selection valve actuator.
The regenerative valve hydraulic actuator according to the present invention
comprises a receiver chamber common manifold which accommodates in non-
fluid-tight manner at least one solid or hollow incompressible cylindrical
element
which is maintained centered in the vicinity of a certain longitudinal
position
relative to the receiver chamber common manifold by at least two oppositely
acting
centering springs.
The regenerative valve hydraulic actuator according to the present invention
comprises a closure and regeneration hydraulic motor which comprises a closure
and regeneration cam mounted on a hydraulic motor shaft which is driven -
directly
or indirectly - in rotation by the reciprocating piston compressor or engine,
a
closure and regeneration piston bearing directly or indirectly on said cam and
forming - with a closure and regeneration cylinder - a closure and
regeneration
chamber which communicates with the fluid intake.
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The regenerative valve hydraulic actuator according to the present invention
comprises a closure and regeneration cam which exposes a closure and
regeneration cam profile which includes at least one regeneration angular
sector R
on which the closure and regeneration piston bears to return the valve to the
valve
seat.
The regenerative valve hydraulic actuator according to the present invention
comprises a closure and regeneration cam which exposes a closure and
regeneration cam profile which includes at least one pre-compression angular
sector P on which the closure and regeneration piston bears to pre-compress
the
closure and regeneration line between two returns of the valve to the valve
seat.
The regenerative valve hydraulic actuator according to the present invention
comprises a closure and regeneration cam which can be offset angularly
relative
to the hydraulic motor shaft by cam phase-shifting means.
The regenerative valve hydraulic actuator according to the present invention
comprises a cam phase-shifting means which consist of at least one male
helical
spline formed on the cylindrical external face of the hydraulic motor shaft
which
cooperates with at least one female helical spline formed inside the closure
and
regeneration cam, the latter being able to be moved or retained in place
axially
relative to the hydraulic motor shaft by a cam phase-shifting actuator.
The regenerative valve hydraulic actuator according to the present invention
comprises a cam phase-shifting actuator which is connected to the closure and
regeneration cam by a phase-shifting fork which cooperates with a phase-
shifting
groove on the closure and regeneration cam.
The regenerative valve hydraulic actuator according to the present invention
comprises a closure and regeneration line which includes an end of expansion
check valve which allows hydraulic fluid coming from the low-pressure
accumulator, from the fluid tank, or from a pressurized hydraulic fluid source
to
enter said line via a freewheel channel, but not to leave it.
The regenerative valve hydraulic actuator according to the present invention
comprises a closure and regeneration line which includes a precompression
valve
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which allows hydraulic fluid coming from the low-pressure accumulator, the
fluid
tank, or a pressurized hydraulic fluid source to enter said line and/or to
leave it.
The regenerative valve hydraulic actuator according to the present invention
comprises a point of application of the force of the actuator and/or a point
of
application of the force of the valve and/or a point of application of the
reaction
force on the cylinder head which includes play compensation means.
The regenerative valve hydraulic actuator according to the present invention
comprises play compensation means which consist of a play compensation
actuator inside which a play compensation chamber includes a play compensation
check valve which allows hydraulic fluid coming from the low-pressure
accumulator, the high-pressure accumulator, the fluid tank or a pressurized
hydraulic fluid source to enter said chamber, but not to leave it.
The regenerative valve hydraulic actuator according to the present invention
comprises play compensation means which consist of a play compensation
actuator inside which a play compensation chamber includes a play compensation
nozzle which allows hydraulic fluid coming from the low-pressure accumulator,
the
high-pressure accumulator, the fluid tank or a pressurized hydraulic fluid
source to
enter said chamber and to leave it.
The regenerative valve hydraulic actuator according to the present invention
comprises a progressive lever arm ratio lever which is accommodated in a lever
chamber into which also opens the actuator piston, said chamber being
connected
with the low-pressure accumulator, the fluid tank or a pressurized hydraulic
fluid
source by a lever chamber check valve which allows hydraulic fluid to leave
said
lever chamber but not to enter it, or by a lever chamber calibrated nozzle
which
allows hydraulic fluid to leave and to enter said lever chamber, or again by
both
said valve and said nozzle, the latter then being placed in parallel with the
lever
chamber check valve.
The following description with reference to the appended drawings provided by
way of nonlimiting example will enable a better understanding of the
invention, its
features, and the advantages that it is able to procure:
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Figure 1 is a theoretical diagram of the regenerative valve hydraulic actuator
according to the invention which includes by way of one variant an end of
expansion check valve and a freewheel channel, said diagram utilizing the
symbols usually employed to describe hydraulic circuits and units.
Figure 2 is a diagrammatic sectional view of a reciprocating internal
combustion
engine receiving the regenerative valve hydraulic actuator according to the
invention.
Figure 3 is a three-dimensional view of the expansion cylinder assembly of the
transfer-expansion and regeneration engine as described in the French patent
published under the number FR 3 032 236 and belonging to the applicant, in its
improved version according to the French patent application number 1558585 of
14 September 2015 also belonging to the applicant, the lower cylinder head of
the
expansion cylinder and the upper cylinder head of the expansion cylinder that
said
assembly comprises each receiving four actuator cartridges which are pressed
via
presser abutments onto the cylinder head with which they cooperate on the one
hand via a lower cartridge retention plate consisting of the expansion
cylinder
lower cylinder head and on the other hand via an upper cartridge retention
plate
consisting of the expansion cylinder upper cylinder head, said plates tending
to be
moved toward one another by plate tie-rods.
Figure 4 is a three-dimensional view of the expansion cylinder assembly shown
in
Figure 3 from which various members have been removed so as to be able to
distinguish more clearly the actuator cartridges of the regenerative valve
hydraulic
actuator according to the invention, the lower and upper cartridge retention
plates,
and the plate tie-rods which tend to move said retention plates toward one
another
so as to hold said actuator cartridges pressed onto their respective cylinder
head
via the plate abutment with which they cooperate.
Figures 5 to 12 are diagrammatic sectional views of the regenerative valve
hydraulic actuator according to the invention and according to one particular
embodiment in which the flow of hydraulic fluid that the lifter check valve
can allow
to flow from the low-pressure accumulator to the actuator hydraulic chamber
passes entirely through the end of expansion check valve, said two check
valves
being placed in series, each of said views being linked to a hydraulic diagram
utilizing the symbols usually employed to describe hydraulic circuits and
units, said
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figures enabling explanation ¨ figure by figure ¨ of the sequencing of the
operation
of said hydraulic actuator according to the invention.
Figure 13 is a simplified diagrammatic sectional view of the progressive lever
arm
5 ratio lever and of the pistons with which it cooperates according to one
particular
embodiment of the regenerative valve hydraulic actuator according to the
invention
which provides a play compensation actuator which supports the lever reaction
surface, and which is inserted between said surface and the cylinder head.
10 Figure 14 is a simplified sectional view of a variant of the play
compensation
actuator which, in accordance with the regenerative valve hydraulic actuator
of the
invention, provides a play compensation actuator which includes a play
compensation check valve and a play compensation nozzle in parallel, said
actuator further including a play compensation spring that tends to cause it
to
15 advance.
Figure 15 is a graph which shows the drift in compression or in extension of
the
play compensation actuator as shown in Figure 14, as a function of the
evolution
of the force exerted at the point of application of the force of the actuator
in
accordance with the regenerative valve hydraulic actuator according to the
invention.
Figure 16 is a simplified sectional diagram of one particular embodiment of
the
regenerative valve hydraulic actuator according to the invention in which the
valve
opens toward the interior of the compression or combustion chamber, the valve
return device consisting of a coil spring known in itself.
Figure 17 is a simplified sectional diagram of one particular embodiment of
the
regenerative valve hydraulic actuator according to the invention in which the
valve
opens toward the interior of the compression or combustion chamber, the valve
return device consisting of a valve return actuator which is coaxial with said
valve
and the return actuator piston of which is fastened to the valve stem.
Figure 18 is a simplified diagrammatic view of one particular embodiment of
the
regenerative valve hydraulic actuator according to the invention in which the
valve
opens toward the interior of the compression or combustion chamber, the valve
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return device consisting of a valve return actuator which returns the valve to
the
closing position by means of a return lever.
Figure 19 is a simplified diagrammatic view of one particular embodiment of
the
regenerative valve hydraulic actuator according to the invention particularly
suited
to reciprocating piston compressors in which the valve opens toward the
exterior
of the compression or combustion chamber, the valve return device consisting
of a
coil spring accommodated as appropriate in the intake line or in the exhaust
line or
discharge line.
Figure 20 is a diagrammatic view of one particular embodiment of the
regenerative
valve hydraulic actuator according to the invention in which the valve opens
toward the interior of the compression or combustion chamber, the valve return
device consisting of a valve return actuator which is coaxial with said valve
and the
return actuator piston of which is fastened to the valve stem whilst valve
actuator
tongue forms a part of the progressive lever arm ratio lever.
Figures 21 and 22 are diagrammatic sectional views of the hydraulic
amplification
piezoelectric actuator provided as a variant of the tube actuator by the
regenerative valve hydraulic actuator according to the invention, said Figures
21
and 22 representing the blocking tube respectively resting on the tube seat
with
which it cooperates, then held at a certain distance from said seat to allow
the
hydraulic fluid to pass from the internal volume of the tube to the tube
external
collector-distributor.
Figure 23 is a diagrammatic sectional view of the hydraulic amplification
piezoelectric actuator that the regenerative valve hydraulic actuator
according to
the invention can comprise, the actuator sender chamber of said piezoelectric
actuator being able to communicate via a lever chamber common manifold with a
plurality of actuator receiver chambers which can each be put into
communication
or not with said manifold by a selection valve.
Figure 24 is a three-dimensional phantom view of the actuator cartridge of the
regenerative valve hydraulic actuator according to the invention, the valve
lifter
hydraulic valve and the valve closure hydraulic valve consisting of a tubular
valve
moved in the longitudinal translation by a hydraulic amplification
piezoelectric
actuator.
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17
Figure 25 is a three-dimensional sectional view of the regenerative valve
hydraulic
actuator according to the invention in the particular configuration shown in
Figure
24, said section particularly highlighting the main mobile or non-mobile
components which cooperate directly with the valve, and the lifter check
valve.
Figure 26 is a three-dimensional sectional view of the regenerative valve
hydraulic
actuator according to the invention in the particular configuration shown in
Figure 24, said section particularly highlighting the main mobile or non-
mobile
components which cooperate directly with the valve, and the lifter check
valve.
Figure 27 is a view in cross section of the regenerative valve hydraulic
actuator
according to the invention in accordance with the particular configuration
shown in
Figure 24, said section being perpendicular to that shown in Figure 26 and
.. highlighting the actuator hydraulic chamber.
Figure 28 is a diagrammatic sectional view of the closure and regeneration cam
that the closure and regeneration hydraulic motor of the regenerative valve
hydraulic actuator according to the invention can comprise, said figure
showing the
various angular sectors that the closure and regeneration cam profile can
expose
on which the closure and regeneration piston bears.
Figures 29 to 33 are diagrammatic sectional views illustrating by successive
steps
the operation of one particular configuration of the closure and regeneration
hydraulic motor of the regenerative valve hydraulic actuator according to the
invention in which a closure and regeneration cam is mounted on a hydraulic
motor shaft driven in rotation by the reciprocating piston compressor or
engine by
means of a hydraulic motor pulley, said cam being able to be offset angularly
relative to said shaft by cam phase-shifting means consisting of male helical
splines formed on the cylindrical external face of said shaft which cooperate
with
female helical splines formed on the inside of said cam, the latter being
movable
or retainable axially relative to the hydraulic motor shaft by a cam phase-
shifter
actuator via a phase-shifter form.
Figure 34 is a three-dimensional phantom view of the closure and regeneration
hydraulic motor of the regenerative valve hydraulic actuator according to the
invention shown in Figures 29 to 33.
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18
Figure 35 is a three-dimensional and cut away exploded view of the closure and
regeneration hydraulic motor of the regenerative valve hydraulic actuator
according to the invention shown in Figures 29 to 33.
DESCRIPTION OF THE INVENTION
There have been shown in Figures 1 to 35 the regenerative valve hydraulic
actuator 1, various details of its components, its variants, and its
accessories.
As Figure 2 illustrates, the regeneration valve hydraulic actuator 1 is
particularly
intended for a reciprocating piston compressor or engine 100 which comprises
at
least one piston 101 connected to transmission means 102 to reciprocate in a
cylinder 103 closed by a compressor or engine cylinder head 104.
Still in Figure 2, it is seen that the piston 101, the cylinder 103 and the
compressor
engine cylinder head 104 form a compressor or combustion chamber 105 into
which open at least one intake line 106 and at least one exhaust or discharge
line
107, one or both of said lines 106, 107 being connected to said chamber 105 by
a
line orifice 10 which a valve 8 is able to block when it rests on a valve seat
11.
As Figure 1 and Figures 5 to 12 particularly illustrate, the regenerative
valve
hydraulic actuator 1 according to the invention comprises at least one high-
pressure hydraulic feed pump 2 which is able to admit a hydraulic fluid 3 from
a
low-pressure (BP) accumulator 4 or a fluid tank 46 via a low-pressure feed
line 47
and to discharge said fluid 3 to a high-pressure (HP) accumulator 5 via a high-
pressure feed line 48.
Note that the high-pressure hydraulic feed pump 2 can for example be driven in
rotation by transmission means 102 as shown in Figures 2 to 4. Said pump 2 may
further be a piston type pump, a gear type pump, a vane type pump or a pump of
any other type known to the person skilled in the art, whilst the high-
pressure
accumulator 5 can be of the piston type, the membrane type, the mechanical or
pneumatic spring type, or of any type also known to the person skilled in the
art.
Figures 1 and 2, Figures 5 to 12, Figures 16 to 20, and Figures 25 and 26 also
illustrate that the regenerative valve hydraulic actuator 1 according to the
invention
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19
comprises at least one actuator 6 which comprises an actuator cylinder 25
capped
by an actuator cylinder head 49, said cylinder 25 being fixed directly or
indirectly to
the compressor or engine cylinder head 104.
In said figures, it is seen that the actuator cylinder 25 and the actuator
cylinder
head 49 form with an actuator piston 26 an actuator hydraulic chamber 7, said
piston 26 being mechanically connected by transmission means 9 to the valve 8,
said means 9 being such that if the actuator hydraulic chamber 7 is subjected
to a
pressure exerted by the hydraulic fluid 3, the actuator piston 26 tends to
move said
valve 8 away from the valve seat 11 with which is cooperates or vice versa, to
move said valve 8 toward the valve seat 11.
Note that the line orifice 10 may be interchangeably provided in the intake
line 106
and/or in the exhaust or discharge line 107 so that the valve 8 prevents the
passage of any gas in said line 106, 107 when it is resting on its valve seat
11.
As shown in a particularly clearly visible manner in Figures 1 and 2, in
Figures 5 to
12, and in Figures 16 to 20, the regenerative valve hydraulic actuator 1
according
to the invention comprises at least one valve return device 12 which exerts on
the
valve 8 a force in the opposite direction to that which the actuator 6 is able
to
produce, said device 12 therefore tending to return the valve 8 into contact
with
the valve seat 11 with which it cooperates or, according to the circumstances,
to
move it away from said seat 11, said return device 12 being able to be for
example
a helical spring known in itself as ordinarily used to return to contact with
their seat
the valves of reciprocating internal combustion engines.
In Figure 1, in Figures 5 to 12 and in Figure 20, it is seen that the
regenerative
valve hydraulic actuator 1 according to the invention comprises at least one
valve
lifter hydraulic valve 13 which is able to open or close a high-pressure
lifter line 14
which connects the high-pressure accumulator 5 to the actuator hydraulic
chamber
7.
It is moreover seen that opening the valve lifter hydraulic valve 13 enables
the
valve 8 to be lifted off the valve seat 11 with which it cooperates, and said
valve 8
then to be moved away from said seat 11 until the required flow section is
attained
at the level of the line orifice 10.
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By way of example, the valve lifter hydraulic valve 13 may be a solenoid valve
of
any type known to the person skilled in the art, controlled by a computer.
Note also
that if a plurality of valves 8 must be lifted simultaneously from their seat
following
the simultaneous connection of their respective actuator hydraulic chamber 7
with
5 the same high-pressure accumulator 5 by their respective valve lifter
hydraulic
valve 13, said valves 8 may be connected in common to said accumulator 5 via a
flow divider known in itself which guarantees that said valves 8 are each
lifted from
the valve seat 11 with which it cooperates at the same speed, and at the same
time.
Figure 1, Figures 5 to 12, Figure 20 and Figures 24 to 27 moreover illustrate
that
the regenerative valve hydraulic actuator 1 according to the invention
comprises at
least one lifter check valve 15 in an inertial lifter line 16 which connects
the low-
pressure accumulator 4 or the fluid tank 46 to the actuator hydraulic chamber
7,
said valve 15 allowing the hydraulic fluid 3 ¨ via said line 16 ¨ to flow from
the low-
pressure accumulator 4 or the fluid tank 46 to the actuator hydraulic chamber
7,
but not in the opposite direction, said valve 15 being able to consist of a
ball held
pressed onto its seat by a spring.
In Figure 1, in Figures 5 to 12 and in Figure 20, it is seen that the
regenerative
valve hydraulic actuator 1 according to the invention comprises at least one
valve
closure hydraulic valve 17 which is able to open or to close a closure and
regeneration line 18 which connects the actuator hydraulic chamber 7 with a
fluid
intake 19 which a closure and regeneration hydraulic motor 20 includes, a
fluid
outlet 21 which said motor 20 also includes being connected with the low-
pressure
accumulator 4, or with the fluid tank 46, or with any type of low-pressure
accumulator by a hydraulic motor low-pressure return line 22.
It is seen that opening the valve closure hydraulic valve 17 allows the valve
8 to
replace the valve 8 on the valve seat 11 with which it cooperates. By way of
example, said valve 17 may be a solenoid valve of any type known to the person
skilled in the art, controlled by a computer.
Note that the closure and regeneration hydraulic motor 20 may be of piston
type,
gear type, vane type, or of any type known to the person skilled in the art.
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21
Note also that if a plurality of valves 8 must be simultaneously replaced on
their
seat by the closure and regeneration hydraulic motor 20, said valves 8 may be
connected in common to said motor 20 via flow divider known in itself which
guarantees that said valves 8 all return into contact with the valve seat 11
with
which they cooperate at the same speed, and at the same time.
The shaft or mechanical transmission device which drives the closure and
regeneration hydraulic motor 20 may advantageously and simultaneously drive
the
high-pressure hydraulic feed pump 2 and/or the low-pressure hydraulic force-
feed
pump 45, said two pumps 2, 45 being for example able to consist of at least
one
cam which cooperates with at least one piston which forms with a cylinder a
chamber provided with intake and discharge valves.
In Figure 2, in Figures 5 to 13, in Figures 16 to 20 and in Figures 24 to 26,
it is
seen that the regenerative valve hydraulic actuator 1 according to the
invention
comprises at least one progressive lever arm ratio lever 27 constituting in
part or in
their entirety the transmission means 9, said lever 27 exposing at least one
point
28 of application of the force of the actuator at which the actuator piston 26
is able
to apply a driving or resisting force either directly or indirectly, at least
one point 29
of application of the force of the valve at which the valve 8 can apply
directly or
indirectly a driving or resisting force, and at least one point 30 of
application of the
reaction force on the cylinder head at which is applied directly or indirectly
a force
on the compressor or engine cylinder head 104.
As Figure 9 clearly shows, this configuration makes it possible to define
firstly an
actuator piston lever arm LP either between the point 28 of application of the
actuator force and the point 29 of application of the valve force or between
said
point 28 of application of the actuator force and the point 30 of application
of the
reaction force on the cylinder head, and secondly a valve action lever arm LS
between the point 29 of application of the valve force and the point 30 of
application of the reaction force on the cylinder head.
It is seen in Figure 20 in particular that the progressive lever arm ratio
lever 27
may consist of a plurality of parts. In this instance, said lever 27 comprises
a valve
actuator tongue 70 which is articulated in the compressor or engine cylinder
head
104.
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22
As is seen in Figures 5 to 13 and in Figures 16 to 20, the regenerative valve
hydraulic actuator 1 according to the invention may include means for moving
the
point 31 of application which move the point 28 of application of the actuator
force
and/or the point 29 of application of the valve force and/or the point 30 of
.. application of the reaction force on the cylinder head along the
progressive lever
arm ratio lever 27 during the opening travel of the valve 8.
According to this particular configuration, the ratio between the length of
the
actuator piston lever arm LP and the length of the valve action lever arm LS
varies
as a function of the lift of the valve 8.
For example, the actuator piston lever arm LP to which the actuator piston 26
applies a force can have its greatest length when the valve 8 is near the
valve seat
11 and a shorter length when said valve 8 is further away from said seat 11,
the
.. situation being exactly the opposite in the case of the valve action lever
arm LS.
In other words, the progressive lever arm ratio lever 27 may advantageously be
such that for a given constant speed of the actuator piston 26, the speed of
lifting
or of replacing the valve 8 is lower when said valve 8 is positioned in the
vicinity of
.. its position in contact with its valve seat 11 than when said valve 8 is
farther away
from said seat 11.
Note that in the embodiment illustrated in Figures 2, 5 to 13, 16 to 19 and 24
to 27,
the means for moving the application point 31 may take the form of a cam-lever
.. 71.
Note that, according to variants of the regenerative valve hydraulic actuator
1
according to the invention, the point 28 of application of the force of the
actuator
and/or the point 29 of application of the force of the valve and/or the point
30 of
application of the reaction force on the cylinder head respectively form
directly or
indirectly with the actuator piston 26, and/or with the valve 8 and/or with
the
compressor or engine cylinder head 104 with which it cooperates either at
least
one pivot connection 34, or at least one rolling-sliding connecting 35, the
latter
constituting the means for moving the application point 31.
As an alternative, said application points 29, 29, 30 can also form a rolling
connection the kinematic of which can be imposed by any type of gear device.
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23
As seen in Figures 5 to 13, in Figures 16 to 20, and in Figures 25 and 26, the
rolling-sliding connecting 35 may consist of at least one lever contact track
36
formed on the progressive lever arm ratio lever 27 at the level of the point
28 of
application of the force of the actuator and/or the point 29 of application of
the
force of the valve and/or the point 30 of application of the reaction force on
the
cylinder head, said track 36 cooperating with a lever reaction surface 37
respectively formed directly or indirectly on the actuator piston 26 and/or on
the
valve 8 and/or on the compressor or engine cylinder head 104, said track 36
and/or said surface 37 having a curved contact profile 38 on which is
established
the contact between said track 36 and said surface 37.
A result of the curved contact profile 38 is that when the valve 8 moves
toward or
away from the valve seat 11 with which it cooperates, the rolling-sliding
connection
35 is moved along the progressive lever arm ratio lever 27 which for example
and
as illustrated in Figure 9 increases the actuator piston lever arm LP and/or
reduces
the valve action lever arm LS, or vice versa.
Note that as shown more particularly in Figures 5 to 12, 17 to 20 and 25 and
26 ¨ the valve return device 12 of the regenerative valve hydraulic actuator 1
according to the invention may consist of a valve return actuator 39 which
comprises a return actuator cylinder 40 capped by a return actuator cylinder
head
50, said cylinder 40 being fixed directly or indirectly to the compressor or
engine
cylinder head 104 whilst said cylinder 40 and the return actuator cylinder
head 50
form with a return actuator piston 41 a return actuator hydraulic chamber 42,
said
piston 41 being mechanically connected to the valve 8 by return transmission
means 43.
According to this variant, the return actuator hydraulic chamber 42 can be
connected to the high-pressure accumulator 5 by a return pressure line 44.
Alternatively, the valve return device 12 may consist of a valve return spring
known in itself.
Note in Figure 1, in Figures 5 to 12 and in Figure 20 that the level and the
pressure of the hydraulic fluid 3 that the low-pressure accumulator 4 contains
can
be maintained within a certain range of values by a force-feed low-pressure
CA 03077379 2020-03-30
24
hydraulic pump 45 which is able to transfer said fluid 3 from the fluid tank
46 to
said accumulator 4 via a low-pressure force-feed line 60.
Note that the fluid tank 46 can be a non-pressurized tank known in itself into
which
flow in particular leaks of hydraulic fluid 3 from any part of the
regenerative valve
hydraulic actuator 1 according to the invention.
Figures 2 to 12 and Figures 24 to 27 show that at least the valve 8 with or
without
the valve seat 11 with which it cooperates, the actuator 6, the transmission
means
9, the valve return device 12, the lifter check valve 15, the valve lifter
hydraulic
valve 13, and the valve closure hydraulic valve 17 may be accommodated
together in an actuator cartridge 52 which exposes at least one hydraulic
connector 53.
Note that if ¨ as shown in Figures 3 and 4 ¨ the actuator cartridge 52 is
mounted
on the expansion cylinder assembly 54 of the transfer-expansion and
regeneration
engine the French patent on which belonging to the applicant has been
published
under the number FR 3 032 236, the actuator cartridge 52 may notably include a
valve cage 56 accommodated in the expansion cylinder lower cylinder head 33
and the expansion cylinder upper cylinder head 61 which said assembly 54
comprises.
In this case, the valve 8 may be guided directly or indirectly in said cage 56
which
moreover accommodates the valve seat 11, the latter and/or the part of the
valve
cage 56 which guides the valve 8 being able to be cooled by a valve cooling
circuit
32 in which a heat transfer fluid circulates as shown in Figures 5 to 12.
Note that in this context, and as also represented in Figures 5 to 12, a valve
stem
51 which the valve 8 includes may advantageously be protected by a valve
thermal screen 58 which limits the quantity of heat received by the valve 8,
said
heat having to be evacuated by the heat transfer fluid.
As Figures 5 to 12 and 21 to 24 show, the valve lifter hydraulic valve 13
and/or the
valve closure hydraulic valve 17 may consist of a tubular valve 130 which
comprises a blocking tube 131 which can be moved in longitudinal translation
by a
tube actuator 137, said tube 131 being accommodated in fluid-tight manner in a
blocking tube bore 181 and ending at a tube sealing bearing surface 135 which
CA 03077379 2020-03-30
can either rest on a tube seat 136 to form with the latter a continuous line
of fluid-
tight contact or be maintained at a certain distance from said seat 136 to
allow
hydraulic fluid 3 to flow from a tube internal volume 133 to a tube external
collector-distributor 134 or vice versa.
5
Note that the tube sealing bearing surface 135 can be maintained either in
contact
with the tube seat 136 or at a distance from said seat 136 by a tube return
spring
138 depending on whether the tubular valve 130 is respectively of "normally
closed" or "normally open" type. Note also that the tube actuator 137 can be
10 interchangeably electrical, electromagnetic, piezoelectric, pneumatic,
hydraulic, or
of any type known to the person skilled in the art.
As has been shown in Figures 21 to 27, the tube actuator 137 can be a
hydraulic
amplification piezoelectric actuator 139 which comprises a stack of ceramic
15 elements 140 that are deformed mechanically when they are subjected to an
electric field, the end of said stack 140 being connected to an actuator
sensor
piston 141 of large diameter which forms ¨ with an actuator sender cylinder
142 ¨
an actuator sender chamber 143 which communicates with at least one actuator
receiver chamber 144, the latter being formed on the one hand by an actuator
20 receiver piston 145 of small diameter which is connected directly or
indirectly to
the blocking tube 131 with which it cooperates so as to be able to move the
latter
in longitudinal translation and on the other hand by an actuator receiver
cylinder
142.
25 Note that the ratio between the section of the actuator sender piston
141 and the
section of the actuator receiver piston 145 determines the ratio of
amplification of
the movement of the hydraulic amplification piezoelectric actuator 139.
According to this variant of the regenerative valve hydraulic actuator 1
according
to the invention, the actuator sender chamber 143 and the actuator receiver
chamber 144 may be together connected with a pressurized hydraulic fluid
source
147 by an actuator force-feed check valve 148 which allows hydraulic fluid 3
to
flow from said source 147 to said chambers 143, 144 and not vice versa. The
pressurized hydraulic fluid source 147 can advantageously be the low-pressure
accumulator 4.
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26
As Figures 21 to 23 show, an anti-drift nozzle 150 can be placed in parallel
with
the actuator force-feed check valve 148, said nozzle 150 allowing the
hydraulic
fluid 3 to flow from the pressurized hydraulic fluid source 147 to said
chambers
143, 144 or vice versa, whilst said nozzle 150 forms a constriction through
which
only a low flow rate of hydraulic fluid 3 can pass.
It is seen in Figures 21 to 24 that the actuator sender piston 141 can receive
a
pressure compensation spring 149 which tends to move it toward the actuator
sender chamber 143, the force that said spring 149 exerts on said piston 141
being less than or equal to the force that the hydraulic fluid 3 exerts on
said piston
141 when the pressure in the actuator sender chamber 143 is equal to that in
the
pressurized hydraulic fluid source 147.
In the same said Figures 21 to 24, it is seen that the actuator receive piston
145 is
able to receive a pressure compensation spring 149 which tends to move it
toward
the actuator receiver chamber 144, the force that said spring 149 exerts on
said
piston 145 being less than or equal to the force which the hydraulic fluid 3
exerts
on said piston 145 when the pressure in the actuator receiver chamber 144 is
equal to that in the pressurized hydraulic fluid source 147.
Figure 23 shows that according to one variant of the regenerative valve
hydraulic
actuator 1 according to the invention, the actuator sender chamber 143 is able
to
communicate via a common receiver chamber manifold 151 with a plurality of
actuator receiver chambers 144, the actuator receiver piston 145 forming each
of
said receiver chambers 144 being able in this case to move a blocking tube 131
of
its own in longitudinal translation.
Note that, according to the variant shown in Figure 23, the actuator receiver
chambers 144 can each be placed in communication or not with the receiver
chamber common manifold 151 by a selection valve 152 the opening of which is
controlled by a selection valve actuator 153.
Accordingly, for the stack of ceramic elements 140 to be able to move in
longitudinal translation the blocking tube 131 corresponding to an actuator
receiver
chamber 144, it is necessary that beforehand the selection valve 152 that
cooperates with said chamber 144 places the latter in communication with the
receiver chamber common manifold 151.
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27
This particular configuration of the regeneration valve hydraulic actuator 1
according to the invention enables for example the use of only one stack of
ceramic elements 140, very fast but deemed costly and bulky to maneuver in
succession a plurality of blocking tubes 131, said tubes 131 being selected by
means of selection valve actuators 153 that are undoubtedly slower, but less
costly and less bulky, such as solenoid actuators 182.
By way of nonlimiting example, this particular strategy is of full benefit in
the
context of a Diesel or Beau de Rochas cycle reciprocating internal combustion
engine with multiple cylinders in which the intake and/or exhaust valves 8 are
actuated in succession with a high angular offset. Said offset is for example
of one
hundred and eighty degrees of rotation of the crankshaft in the case of a four-
cylinder engine.
Still in accordance with the variant shown in Figure 23, note that the
receiver
chamber common manifold 151 is able to accommodate in non-fluid tight manner
at least one solid or hollow non-compressible cylindrical element 156 which is
maintained centered in the vicinity of a certain longitudinal position
relative to the
receiver chamber common manifold 151 by at least two oppositely acting
centering springs 157.
Note that said element 156 preferably consists of a material that is both
relatively
non-compressible ¨ that is to say the modulus of elasticity of which is high,
and of
low density. Said element 156 in particular enables the use of a receiver
chamber
common manifold 151 of large inside diameter which enables limitation of the
head loss that said manifold 151 produces when the hydraulic fluid 3 flows,
and
this without having to suffer the high compressibility that would otherwise be
induced by a large volume of hydraulic fluid 3 inside said manifold 151.
Accordingly, when the actuator sender piston 141 expels hydraulic fluid 3 from
the
actuator sender chamber 143, the non-compressible cylindrical element 156
accompanies the hydraulic fluid 3 in at least part of its movement by moving
freely
in the receiver chamber common manifold 151. Once the maneuver of opening
and/or closing the corresponding blocking tube 131 has been completed, the non-
compressible cylindrical element 156 is returned to the vicinity of its
initial position
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28
by the conjugate action of the two oppositely acting centering springs 157
with
which it cooperates.
In Figures 28 to 35, it has been shown that the closure and regeneration
hydraulic
motor 20 of the regenerative valve hydraulic actuator 1 according to the
invention
may comprise a closure and regeneration cam 158 mounted on a hydraulic motor
shaft 163 which is driven ¨ directly or indirectly ¨ in rotation by the
reciprocating
piston compressor or engine 100 or by any means associated with said
compressor or engine 100, a closure and regeneration piston 159 bearing
directly
or indirectly on said cam 158 and forming ¨ with a closure and regeneration
cylinder 160 ¨ a closure and regeneration chamber 161 which communicates with
the fluid intake 19.
As shown in Figures 34 and 35, the hydraulic motor shaft 163 can be driven in
rotation by the reciprocating piston compressor or engine 100 via a hydraulic
motor pulley 170 driven by a belt or a chain, by gears or by any mechanical,
electrical or hydraulic transmission whether of fixed or variable ratio.
Note also that ¨ as shown in Figures 29 to 35 ¨ the closure and regeneration
piston 159 can bear on the closure and regeneration cam 158 via a closure and
regeneration tongue 173.
Figure 28 shows that the closure and regeneration cam 158 can expose a closure
and regeneration cam profile 162 which includes at least one regeneration
angular
sector R on which the closure and regeneration piston 159 bears to return the
valve 8 onto the valve seat 11.
Moreover, the closure and regeneration cam 158 can expose a closure and
regeneration cam profile 162 which includes at least one precompression
angular
sector P on which the closure and regeneration piston 159 bears to precompress
the closure and regeneration line 18 between two returns of the valve 8 onto
the
valve seat 11.
In Figures 29 to 35, it has been shown that the closure and regeneration cam
158
can be offset angularly relative to the hydraulic motor shaft 163 by cam phase-
shifting means 164.
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29
In these same figures, note that the cam phase-shifting means 164 may consist
of
at least one male helical spline 165 formed on the cylindrical external face
of the
hydraulic motor shaft 163 which cooperates with at least one female helical
spline
166 formed inside the closure and regeneration cam 158, the latter being
movable
and then retained in place axially relative to the hydraulic motor shaft 163
by a
cam phase-shifting actuator 167 which may be a linear or rotary electric
stepper
motor, a hydraulic actuator, or any actuator known or not to the person
skilled in
the art.
It is seen in Figures 29 to 35 that the cam phase-shifting actuator 167 can be
connected to the closure and regeneration cam 158 via a phase-shifting fork
168
which cooperates with a phase-shifting groove 169 which the closure and
regeneration cam 158 includes.
In Figures 29 to 33 and in Figure 35, it is seen that the closure and
regeneration
line 18 can include an end of expansion check valve 171 which allows hydraulic
fluid 3 coming from the low-pressure accumulator 4, from the fluid tank 46, or
from
a pressurized hydraulic fluid source 147 to enter said line 18 via a freewheel
channel 24, but not to leave it.
Note that the end of expansion check valve 171 can consist of a ball held
pressed
onto its seat by a spring. It will also be noted that according to a
particular
configuration shown in Figures 5 to 12 of the regenerative valve actuator 1
according to the invention, the flow of hydraulic fluid 3 that the lifter
check valve 15
can allow to flow from the low-pressure accumulator 4 to the actuator
hydraulic
chamber 7 can pass entirely through the end of expansion check valve 171, the
two check valves 15, 171 then being placed in series.
This particular arrangement has no significant consequence for the operation
of
the regenerative valve hydraulic actuator 1 and in particular enables a saving
by
eliminating the need for a hydraulic connector 53 to connect the actuator
hydraulic
chamber 7 with the low-pressure accumulator 4.
In Figures 29 to 35, it is seen that the closure and regeneration line 18 can
include
a precompression valve 172 which allows hydraulic fluid 3 coming from the low-
pressure accumulator 4, from the fluid tank 46, or from a pressurized
hydraulic
fluid source 147 to enter said line 18 and/or to leave it.
CA 03077379 2020-03-30
According to one particular embodiment of the regenerative valve hydraulic
actuator 1 according to the invention, the precompression valve 172 may
consist
of a tubular valve 130.
5
In figures 13, 14, 20, 25 et 26, it is seen that the point 28 of application
of the force
of the actuator and/or the point 29 of application of the force of the valve
and/or
the point 30 of application of the reaction force on the cylinder head may
include
play compensation means 174.
It is also seen that the play compensation means 174 can advantageously
consist
of a play compensation actuator 175 inside which a play compensation chamber
176 includes a play compensation check valve 177 which allows hydraulic fluid
3
coming from the low-pressure accumulator 4, from the high-pressure accumulator
5, from the fluid tank 46, or from a pressurized hydraulic fluid source 147 to
enter
said chamber 176, but not to leave it.
As Figure 13 clearly shows, the play compensation actuator 175 can be inserted
between the lever reaction surface 37 which its supports at one of its ends
and via
a fixed ball-joint connection 68, and the compressor or engine cylinder head
104.
Note also in Figure 13 that at its other end, the lever reaction surface 37 is
preferably supported by a sliding ball-joint connection 69 which is
substantially
able to move on the compressor or engine cylinder head 104 parallel to the
lever
reaction surface 37.
In Figure 14, it has been shown that the play compensation means 174 can
consist of a play compensation actuator 175 inside which a play compensation
chamber 176 includes a play compensation nozzle 178 which allows hydraulic
fluid 3 coming from the low-pressure accumulator 4, from the high-pressure
accumulator 5, from the fluid tank 46, or from a pressurized hydraulic fluid
source
147 to enter said chamber 176, and to leave it.
As Figure 15 particularly illustrates, this particular configuration of the
regenerative
valve hydraulic actuator 1 according to the invention allows the play
compensation
actuator 175 to retract when the actuator 6 exerts a high force on the
progressive
lever arm ratio lever 27.
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This enables counterbalancing of the drift in the opposite direction ¨ that is
to say
in extension ¨ of the play compensation actuator 175 which then occurs on
lifting
the valve 8, at the moment when ¨ when said valve 8 decelerates at the end of
its
lifting travel ¨ the force to which said actuator 175 is objected is low or
even zero.
In particular, said configuration prevents it from being impossible ¨ the play
compensation actuator 175 having drifted excessively in extension ¨ to return
said
valve 8 onto the valve seat 11 with which it cooperates.
It will be noted that the play compensation nozzle 178 can advantageously be
incorporated into the play compensation check valve 177, which can for example
¨
as Figure 14 shows ¨ consist of a ball pressed onto its seat by a spring, the
seal
between said ball and said seat being intentionally imperfect. Figure 14 also
shows that a play compensation spring 179 can be provided that tends to move
forward the play compensation actuator 175.
In Figures 25 and 26, it is seen that according to one variant of the
regenerative
valve hydraulic actuator 1 according to the invention, the progressive lever
arm
ratio lever 27 can be accommodated in a lever chamber 23 to which the actuator
piston 26 also leads, said chamber 23 being connected with the low-pressure
accumulator 4, with the fluid tank 46, or with a pressurized hydraulic fluid
source
147, by a lever chamber check valve 59 which allows hydraulic fluid 3 to leave
said lever chamber 23 but not to enter it, or by a calibrated lever chamber
nozzle
67 which allows hydraulic fluid 3 to leave and to enter said lever chamber 23,
or
again both by said valve 59 and said nozzle 67, the latter then being placed
in
parallel with the lever chamber check valve 59.
Note moreover that the lever chamber check valve 59 and the lever chamber
calibrated check nozzle 67 may be one and the same, in particular by using as
said valve 59 a ball pressed by a spring onto a seat, said ball with said seat
allowing passage of a leak of hydraulic fluid 3 that serves as the lever
chamber
calibrated nozzle 67.
As Figures 25 and 26 particularly illustrate, this particular configuration of
the
regenerative valve hydraulic actuator 1 according to the invention enables
exploitation of the variation of the volume of the hydraulic fluid 3 contained
in the
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lever chamber 23 to hold the actuator piston 26 pressed onto the transmission
means 9 with which it cooperates, at the moment when the valve 8 is replaced
on
its valve seat 11, or when said valve 8 returns to the vicinity of said seat
11.
Alternatively, the actuator piston 26 can cooperate with braking means
provided
for example in or on the actuator cylinder 25 with which it cooperates, said
means
being able to consist of a shape generating a castor effect, said shape being
fastened to said cylinder 25 or free relative to the latter and spring-loaded
or not.
OPERATION OF THE INVENTION
The operation of the regenerative valve hydraulic actuator 1 according to the
invention is easily understood from Figures 1 to 35.
It will be noted beforehand that the diagrammatic sections shown in the
figures are
merely explanatory and do not reflect the construction details to be given to
the
person skilled in the art that will in particular enable the various parts to
be
assembled.
The basic principle of said actuator 1 is shown in Figure 1. During the
following
explanation, it is possible to refer to said figure to situate the
understanding of said
actuator 1 and the various components that it combines into one and the same
system.
As Figure 2 illustrates, said actuator 1 is addressed in particular to
reciprocating
piston compressors or engines 100 of a type known in itself, without this
application being limiting on the invention, however, said actuator 1
advantageously being able to find other fields of application.
Figures 3 and 4 detail the fitting of the regenerative valve hydraulic
actuator 1
according to the invention to the expansion cylinder assembly 54 of the
transfer-
expansion and regeneration engine the French patent on which belonging to the
applicant has been published under the number FR 3 032 236, and particularly
to
the improved version of said engine as presented in the French patent
application
number 1558585 of 14 September 2015 also belonging to the applicant.
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It is deduced from said Figures 3 and 4 that an actuator cartridge 52 has
advantageously been provided in which are together accommodated the main
members of the regenerative valve hydraulic actuator 1 according to the
invention
and in particular those represented in the diagrammatic section shown in
Figures 5
to 12, that is to say the valve 8 and the valve seat 11 with which it
cooperates, the
actuator 6, the transmission means 9, the valve return device 12, the lifter
check
valve 15, the valve lifter hydraulic valve 13, and the valve closure hydraulic
valve
17.
It is seen that in this nonlimiting embodiment the expansion cylinder assembly
54
includes eight actuator cartridges 52 each having a valve cage 56 cooled by a
valve cooling circuit 32 in which a heat transfer fluid circulates. Note that
in this
context, as represented in Figures 5 to 12, the valve stem 51 can
advantageously
be protected by a valve heat shield 58 which limits the quantity of heat
received by
the valve 8, said heat having to be evacuated by the heat transfer fluid.
It is also seen in Figure 3 that the expansion cylinder assembly 54 includes a
cylinder barrel 55, an expansion cylinder lower cylinder head 33 and an
expansion
cylinder upper cylinder head 61 which can for example be made of ceramic and
suspended on hollow pillars 62 as described by the French patent application
number 1558585 of 14 September 2015 which belongs to the applicant.
Given that the hollow pillars 62 rest on ball-joint connections, on the one
hand, and
that the expansion cylinder assembly 54 is heated to a high temperature, on
the
other hand, it would be impossible to fix to the expansion cylinder lower
cylinder
head 33 and/or the expansion cylinder upper cylinder head 61 a transmission by
belt, by gears or by chains of any camshaft whatsoever.
It is therefore pertinent to provide ¨ as the patent number FR 3 032 236 and
the
present invention propose ¨ actuator cartridges 52 ready to be mounted in said
cylinder head 33, 61, said cartridges 52 being connected to one another and/or
to
the energy source that powers them only by flexible lines and/or cables.
In Figures 3 and 4, it is also seen that the actuator cartridges 52 of the
expansion
cylinder lower cylinder head 33 are advantageously pressed onto the latter by
a
lower cartridge retention plate 57 whilst the actuator cartridges 52 of the
expansion
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cylinder upper cylinder head 61 are pressed onto the latter by an upper
cartridge
retention plate 63.
As seen in said Figures 3 and 4, said two plates 57, 63 are held in contact
with the
actuator cartridges 52 with which they cooperate by means of plate abutments
64
that said plates 57, 63 include facing each of said cartridges 52.
Moreover, said two plates 57, 63 tend to be moved toward one another by plate
tie
rods 65 of which there are four in this example and which consist of long
screws
that cooperate with a spring 66 for moving the plates toward one another
placed
under the head of said screws. It is seen in Figures 3 and 4 that¨ according
to this
nonlimiting embodiment, said spring 66 consists of a stack of three
"Belleville" type
washers known in themselves.
Clearly, in accordance with this particular configuration, the lower cartridge
retention plate 57, the upper cartridge retention plate 63 and the plate tie
rods 65
with which they cooperate remain at relatively low temperatures compared to
the
expansion cylinder assembly 54.
In fact, said plates 57, 63 do not touch said assembly 54 directly whilst the
actuator cartridges 52 are maintained at low temperatures ¨ for example of the
order of one hundred degrees Celsius ¨ by the valve cooling circuit 32 which
their
valve cage 56 includes, on the one hand, and by the circulation of the
hydraulic
fluid 3 in the regenerative valve hydraulic actuators 1 according to the
invention,
on the other hand.
There can be seen in Figure 3 a centering gantry 72 which cooperates in
orienting
the expansion cylinder assembly 54 relative to a transmission casing 73 that
the
transfer-expansion and regeneration engine that is the subject matter of the
French patent published under the number FR 3 032 236 includes. It will be
noted
that a link that is not shown can advantageously be provided to connect said
gantry 72 directly or indirectly with the lower cartridge retention plate 57,
with the
upper cartridge retention plate 63, or both of them, in order to maintain the
expansion cylinder assembly 54 correctly oriented about its vertical axis
relative to
the transmission casing 73.
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To describe in detail the operation of the regenerative valve hydraulic
actuator 1
according to the invention, there will be employed here the nonlimiting
embodiment illustrated in Figures 5 to 12 in which said actuator 1 is able to
pull on
a valve stem 51 that the valve 8 includes, the latter ¨ when it is opened by
being
5 lifted off its valve seat 11 ¨ moving toward the interior of the intake
line 106 with
which it cooperates, the bearing surface of said seat 11 being oriented toward
the
interior of said line 106.
This configuration is particularly well suited to the intake metering valve of
the
10 expansion cylinder assembly 54 shown in Figures 3 and 4 of the transfer-
expansion and regeneration engine that is the subject matter of the French
patent
published under the number FR 3 032 236. Assume therefore that it is on the
same said motor and to be more precise on its expansion cylinder assembly 54
that the regenerative valve hydraulic actuator 1 according to the invention is
15 installed, as shown in Figures 5 to 12.
Note that in Figures 5 to 12 the compressor or engine cylinder head 104 is
referenced. This is purely terminological with the sole objective of
facilitating the
understanding of the operation of the regenerative valve hydraulic actuator 1
20 according to the invention. In fact, the part of said cylinder head 104
that is
represented in said figures is here an integral part of the actuator cartridge
52, in
particular with the valve seat 11. The resulting assembly can be designed to
be
introduced into the rest of the cylinder head 104 in which the compression or
combustion chamber 105, the intake line 106, and the exhaust or discharge line
25 107 of any reciprocating piston compressor or engine 100 which receives
said
cartridge 52 are formed.
It will be noted in Figures 5 to 12 that the valve lifter hydraulic valve 13
and the
valve closure hydraulic valve 17 each consist of a tubular valve 130 identical
to
30 that which is the subject matter of the French patent application number
FR 1659096 of 27 September 2016 relating to a hydraulically controlled tubular
valve, said application belonging to the applicant.
Figures 5 to 12 also illustrate that the progressive lever arm ratio lever 27
takes
35 the form of a cam-lever 71 which forms one of the components of the
transmission
means 9. Said cam-lever 71 exposes a point 28 of application of the actuator
force
at which the actuator piston 26 can apply a driving or resisting force, a
point 29 of
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application of the valve force to which the valve 8 can apply a driving or
resisting
force, and a point of application of the reaction force on the cylinder head
30 at
which a force is applied to the cylinder head 104. These various said
application
points 28, 29, 30 are specifically referenced in Figure 9.
Note that according to this particular embodiment of the regenerative valve
hydraulic actuator 1 according to the invention as illustrated in Figures 5 to
12, the
point 28 of application of the actuator force and the point 29 of application
of the
valve force form a pivot connection 34 whilst the point of application of the
reaction
force on the cylinder head 30 forms a rolling-sliding connection 35 which in
itself
constitutes means for moving the application point 31.
Figures 5 to 12 further show that the rolling-sliding connection 35 is in
particular
formed by a lever contact track 36 which has a curved contact profile 38 along
which is moved the point 30 of application of the reaction force on the
cylinder
head during maneuvers of opening and closing the valve 8, said profile 38
cooperating with a lever reaction surface 37 formed on the cylinder head 104.
In Figure 9, there has been represented the actuator piston lever arm LP and
the
valve action lever arm LS. This representation facilitates understanding that
when
the valve 8 is close to the valve seat 11 with which it cooperates, the
actuator
piston lever arm LP has its greatest length. Also, said arm LP has its
shortest
length when the valve 8 is opened to the maximum. The situation is exactly the
opposite in the case of the valve action lever LS.
Figure 13 is used to describe in detail one particular and nonlimiting
strategy for
operation of the cam-lever 71 and in particular to describe in detail the
consequences of moving the point 30 of application of the reaction force on
the
cylinder head.
In particular, it is seen in Figure 13 that the cam-lever 71 can
advantageously have
a concentric neutral angular sector NC that holds the valve 8 immobile when
said
cam-lever 71 turns. This sector makes it possible to accompany the
deceleration
in rotation of the cam-lever 71 after the valve 8 has been replaced on its
valve seat
11.
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According to this nonlimiting example illustrated in Figure 13, the cam-lever
71
also has a tangential neutral angular sector NT which does not lift the valve
8, but
which enables propositioning of the point 30 of application of the reaction
force on
the cylinder head in the vicinity of the commencement of the lifting of the
valve 8
when between two openings of the valve 8 the cam-lever 71 is no longer driven
with any rotation whatsoever.
The slow lift angular sector LL for its part approximately reproduces what the
person skilled in the art terms the "ramp of silence" provided on the cams
usually
employed in reciprocating internal combustion engines. Said sector LL on the
one
hand enables high acceleration of the valve 8 at the start of lifting it, for
example
over the first tenths of a millimeter and, on the other hand, to replace said
valve 8
on its valve seat 11 slowly, for example at a speed less than one meter per
second ¨ at the end of the closing travel of said valve 8.
The cam-lever 71 also includes a fast lift angular sector LR which ends the
acceleration of the valve 8 when it is lifted, after which it accompanies it
over its
second lift half-travel whereas the valve lift hydraulic valve 13 is closed
and
whereas the lift check valve 15 introduces hydraulic fluid 3 coming from the
low-
pressure accumulator 4 into the actuator hydraulic chamber 7.
It will be seen that during the return of the valve 8, the rapid lift angular
sector LR
precedes the slow lift angular sector LL, the actuator piston 26 then
expelling
hydraulic fluid 3 toward the closure and regeneration hydraulic motor 20 via
the
valve closure hydraulic valve 17.
In Figures 5 to 12, it is seen that the valve return device 12 consists of a
valve
return actuator 39 which comprises a return actuator cylinder 40 capped by a
return actuator cylinder head 50, said cylinder 40 and said cylinder head 50
forming a return actuator hydraulic chamber 42 with a return actuator piston
41
connected to the valve 8 by return transmission means 43.
Figures 5 to 12 also show diagrammatically that the return actuator hydraulic
chamber 42 is connected to the high-pressure accumulator 5 by a return
pressure
line 44.
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It will be seen in Figures 5 to 12 that the actuator piston 26 and the return
actuator
piston 41 can be equipped with the piston sealing device the patent on which
belonging to the applicant has been published under the number FR 3 009 037,
said device guaranteeing a strong seal at high operating pressures, being
compatible with high speeds, and enabling the production of short and light
pistons
26, 41.
It will also be seen that according to this nonlimiting embodiment, the
section of
the actuator piston 26 is approximately twice that of the return actuator
piston 41.
To describe in detail the operation of the regenerative valve hydraulic
actuator 1
according to the invention, it will be assumed that the hydraulic fluid 3 is
maintained at a pressure of twenty bar in the low-pressure accumulator 4 and
at a
pressure of five hundred bar in the high-pressure accumulator 5.
Figure 5 shows the regenerative valve hydraulic actuator 1 according to the
invention at rest, the valve 8 resting on its valve seat 11 and closing the
line orifice
10 so that the intake line 106 does not communicate with the compression or
combustion chamber 105 into which it opens.
At this stage, the valve lifter hydraulic valve 13 and the valve closure
hydraulic
valve 17 are closed. The pressure in the actuator hydraulic chamber 7 is
twenty
bar whilst that in the return actuator hydraulic chamber 42 is five hundred
bar, said
chamber being connected directly to the high-pressure accumulator 5.
In the closed position represented in Figure 5, the force that holds the valve
8 in
contact with the valve seat 11 is the equivalent of the product of the section
of the
return actuator piston 41 by the pressure of five hundred bar, less the
product of
the section of the actuator piston 26 by the pressure of twenty bar by the
quotient
of the length of the actuator piston lever arm LP by the length of the valve
action
lever arm LS as denoted in Figure 9.
To open the valve 8, a computer that is not shown commands opening of the
valve
lifter hydraulic valve 13. This situation is represented in Figure 6. Said
valve 13
being open, a pressure of five hundred bar continues to be exerted on the
return
actuator piston 41 whilst the same pressure of five hundred bar is also
exerted on
the actuator piston 26.
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The section of the actuator piston 26 being twice that of the return actuator
piston
41 and said actuator piston 26 having a long lever arm, said piston 26
accelerates
up to speed. In doing this, said piston 26 exerts a high force on the valve 8
which
accelerates and starts to be lifted off the valve seat 11 with which it
cooperates.
Figure 7 shows how the regenerative valve hydraulic actuator 1 according to
the
invention advantageously enables exploitation of the kinetic energy stored by
the
actuator piston 26, the transmission means 9, the return actuator piston 41
and the
valve 8 to perfect the lifting of said valve 8.
At the stage shown in Figure 7, the valve 8 has already covered approximately
half
its opening travel. The computer that is not shown has commanded closing of
the
valve lifter hydraulic valve 13. Driven by its inertia, the assembly
consisting of the
actuator piston 26, the transmission means 9, the cam-lever 71, the return
actuator piston 41, and the valve 8 has continued to move, which has led to a
drop
in pressure in the actuator hydraulic chamber 7 to the point that the pressure
in
said chamber 7 has fallen below twenty bar.
A result of this situation is that the lifter check valve 15 has been lifted
off its seat
whilst hydraulic fluid 3 coming from the low-pressure accumulator 4 has begun
to
be introduced into the actuator hydraulic chamber 7 via said valve 15.
In parallel with this, the return actuator piston 41 has expelled hydraulic
fluid 3 at
approximately five hundred bar to the high-pressure accumulator 5 whilst
braking
the valve 8.
As Figure 8 illustrates, this situation continues until all the kinetic energy
of the
assembly consisting of the actuator piston 26, the transmission means 9, the
cam-
lever 71, the return actuator piston 41, and the valve 8 has been converted
into a
flow of hydraulic fluid 3 at five hundred bar produced by the return actuator
piston
41, said energy being stored in the high-pressure accumulator 5.
During this movement and whilst the valve 8 is beginning to reach the end of
its
opening movement, the actuator piston lever arm LP has been considerably
shortened whilst in parallel the valve action lever arm LS has been
lengthened.
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Figure 9 illustrates the equilibrium situation encountered at the end of the
opening
travel of the valve 8. The mobile members having ceded all their kinetic
energy to
the high-pressure accumulator 5, the return actuator piston 41 has tended to
push
the valve 8 toward the valve seat 11. The lifter check valve 15 has then been
5 closed immediately, trapping hydraulic fluid 3 in the actuator hydraulic
chamber 7,
in which the pressure has risen until the force produced by the return
actuator
piston 41 on the valve 8 via the return transmission means 43 is exactly
countered
by a force of the same intensity produced by the actuator piston 26 on said
valve 8
in particular via the point 29 of application of the valve force, this
allowing for the
10 section ratios of said pistons 41, 26 and of the ratio between the
actuator piston
lever arm LP and that of the valve action lever arm LS.
The equilibrium pressure in the actuator hydraulic chamber 7 is therefore the
result
of these various section ratios and lever ratios. According to the example
taken
15 here, let us consider that said equilibrium pressure in Figure 9 is then
approximately three hundred bar.
It can moreover be specified here that at the moment the pressure of twenty
bar is
reached in the actuator hydraulic chamber 7 and just after the lifter check
valve 15
20 has been closed, the computer that is not represented can open the valve
lifter
hydraulic valve 13 briefly to increase intentionally the pressure in the
actuator
hydraulic chamber 7 to three hundred bar, to maintain the actuator piston 26
immobile when the valve 8 has reached its maximum opening.
25 This strategy enables cancellation of the effects of the compressibility of
the
hydraulic fluid 3 and prevents the actuator piston 26 from advancing again in
its
actuator cylinder 25 and partially closing the valve 8.
Figure 10 shows what happens when the decision is taken to close the valve 8
30 starting from the equilibrium situation as illustrated in Figure 9.
However, before describing in more detail the sequence of closing said valve
8, it
is useful to consider in more detail the operation of the high-pressure
hydraulic
feed pump 2, on the one hand, and the closure and regeneration hydraulic motor
35 20, on the other hand, starting from the diagram in the top right part
of Figures 5 to
12.
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According to the example taken here to illustrate the operation of the
regenerative
valve hydraulic actuator 1 according to the invention, it will be considered
that the
high-pressure hydraulic feed pump 2 is designed to maintain a pressure set
point
in the high-pressure accumulator 5 of five hundred bar with a latitude of plus
or
minus three bar. Said pump 2 is for example of variable cubic capacity so that
its
cubic capacity is automatically adapted so that said set point is complied
with.
Here, and by way of example, said pump 2 is driven directly by the crankshaft
102
of the reciprocating piston compressor or engine 100 which in this instance
consists of a transfer-expansion and regeneration engine that is the subject
matter
of the French patent published under the number FR 3 032 236.
The closure and regeneration hydraulic motor 20 is also mechanically connected
to said crankshaft 102 so that its rotation speed is proportional to that of
said
crankshaft 102.
In Figures 5 to 12, it is clear that when the valve lifter hydraulic valve 13
and the
valve closure hydraulic valve 17 are closed, the pressure of twenty bar in the
low-
pressure accumulator 4 is applied both to the fluid intake 19 and to the fluid
outlet
21 of the closure and regeneration hydraulic motor 20.
This results in circulation of hydraulic fluid 3 through said motor 20, the
latter on
the one hand admitting said fluid 3 via its fluid intake 19 via the freewheel
channel
24 which includes an end of expansion check valve 171 and, on the other hand,
discharging said fluid 3 via its fluid outlet 21 via the hydraulic motor low-
pressure
return line 22. To summarize, said closure and regeneration hydraulic motor 20
is
looped on itself, being driven for this by the crankshaft 102.
When - as Figure 10 illustrates - the computer that is not shown opens the
valve
closure hydraulic valve 17, said computer connects the actuator hydraulic
chamber 7 with the closure and regeneration line 18. The hydraulic fluid 3
contained in said chamber is expanded suddenly in said line 18 the pressure in
which rises virtually instantaneously to - for example - two hundred and
eighty bar.
A few microseconds later, the actuator piston 26 has moved rapidly when pushed
by the return actuator piston 41, said push being exerted in particular via
the
transmission means 9. In doing this, the actuator piston 26 has restored a
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pressure of approximately three hundred bar both in the actuator hydraulic
chamber 7 and in the closure and regeneration line 18.
Almost instantaneously after the valve closure hydraulic valve 17 has been
.. opened, the pressure on the downstream side of the end of expansion check
valve
171 has become very much higher than that of twenty bar on the upstream side
of
said valve 171. Said valve 171 is therefore closed so that the pressure
firstly of
two hundred and eighty bar and then a few seconds later of three hundred bar
is
applied to the fluid intake 19 of the closure and regeneration hydraulic motor
20.
A result of this has been that the closure and regeneration hydraulic motor 20
has
immediately applied a driving torque to the crankshaft 102 of the
reciprocating
piston compressor or engine 100.
The closure and regeneration hydraulic motor 20 being in this example of the
positive displacement type known in itself, it has imposed a certain flow rate
on the
hydraulic fluid 3 flowing from now on in the closure and regeneration line 18,
said
flow rate being determined by the rotation speed of said motor 20 itself fixed
by the
rotation speed of the crankshaft 102.
Accordingly, the speed at which the actuator piston 26 advances in the
actuator
cylinder 25 with which it is cooperating is at this stage determined directly
by the
rotation speed of the crankshaft 102.
As is seen in Figure 11, oppositely relative to what occurred on lifting the
valve 8,
the actuator piston lever arm LP length increases again as and when the valve
8 is
moved toward the valve seat 11 whereas, in a correlative manner, the valve
action
lever arm length LS decreases. This is because the point of application of the
reaction force on the cylinder head 30 at which a force is applied to the
compressor or engine cylinder head 104 is moved along the curved contact
profile
38 which the lever contact track 36 formed on the cam-lever 71 includes.
The force that the return actuator piston 41 exerts on the valve 8 being
approximately constant, the increase in the ratio of the actuator piston lever
arm
.. LP to the length of the valve action lever arm LS leads to a gradual
reduction of
the force applied by the progressive lever arm ratio lever 27 which
constitutes the
cam-lever 71 on the actuator piston 26 and therefore of the pressure of the
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43
hydraulic fluid 3 at the fluid intake 19 of the closure and regeneration
hydraulic
motor 20. This remains true despite the deceleration of the valve 8 which
generates an additional force on the actuator piston 26 via the cam-lever 71.
When the valve 8 is a few tenths of a millimeter from the valve seat 11, the
cam-
lever 71 travels its slow lift angular sector LL as represented in Figure 13
and the
quotient of the actuator piston lever arm LP divided by the length of the
valve
action lever arm LS becomes high. The ratio between the speed at which the
actuator piston 26 advances and that of the valve 8 is proportional to said
quotient.
The pressure in the closure and regeneration line 18 is from now on relatively
low.
It follows that the speed of replacing said valve 8 is very low - for example
a few
tens of centimeters per second ¨ which guarantees a soft landing of said valve
8
on the valve seat 11 with which it cooperates. Said landing guarantees silence
and
long-term operation of the valve 8 and of the valve seat 11, and guarantees
that
the valve 8 cedes virtually all of its kinetic energy to the hydraulic fluid 3
admitted
to the fluid intake 19 of the closure and regeneration hydraulic motor 20.
Once the valve is totally closed and replaced perfectly on its valve seat 11,
as
Figure 12 shows, the actuator piston 26 has when launched been able to
continue
its travel of a few tenths of a millimeter without consequence for the
position of the
valve 8, accompanied in its movement by the transmission means 9, thanks in
particular to the concentric neutral angular sector NC of the cam-lever 71.
Said
piston 26 has then been returned to the rest position by the pressure with
which it
is faced. This additional micro-travel has enabled the actuator piston 26 and
the
transmission means 9 with which it cooperates also to cede their kinetic
energy to
the hydraulic fluid 3 introduced into the fluid intake 19 of the closure and
regeneration hydraulic motor 20.
Then, as the closure and regeneration hydraulic motor 20 continues to be
turned
by the crankshaft 102 to which it is mechanically connected, the pressure in
the
closure and regeneration line 18 progressively returns to the pressure of
twenty
bar in the low-pressure accumulator 4 as and when the hydraulic fluid 3
compressed remaining in the closure and regeneration line 18 is expanded.
Once a pressure very substantially less than twenty bar is reached in the
closure
and regeneration line 18, the closure and regeneration motor 20 again loops on
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44
itself as explained above, to this end admitting hydraulic fluid 3 at the
level of its
fluid intake 19 via the end of expansion check valve 171 and the free wheel
channel 24.
The description that has just been given of the operation of the closure and
regeneration hydraulic motor 20 is theoretical, however. In practice, it is
necessary
to manage the compressibility of the hydraulic fluid 3 contained in the
closure and
regeneration line 18 as otherwise the valve 8 will be closed too violently. In
fact,
the violent expansion of the hydraulic fluid 3 contained in the actuator
hydraulic
chamber 7 in the closure and regeneration line 18 when the valve closure
hydraulic valve 17 is closed can only produce rapid depressurization of said
chamber 7 with ¨ apart from excitation and instability of the valve 8 -
serious
energy loss by turbulence in the hydraulic fluid 3 as it passes through said
valve
17.
Note moreover that the larger the internal volume of the closure and
regeneration
line 18 relative to that of the actuator hydraulic chamber 7, the greater the
instability of the valve 8 and the associated energy loss.
It is to prevent these two undesirable effects that according to one
particular
embodiment of the regenerative valve hydraulic actuator 1 according to the
invention, the closure and regeneration hydraulic motor 20 can consist of a
closure
and regeneration cam 158 as shown in Figure 28. According to this nonlimiting
example, said cam includes a closure and regeneration cam profile 162 divided
into a plurality of angular sectors each having a particular role.
There are clearly seen in Figure 28 the regeneration angular sector R, the
expansion angular sector D, the maneuvering angular sector M, the
precompression angular sector P, and the stabilization angular sector S.
The role of each angular sector R, D, M, P and S is shown in detail in Figures
29
to 33, which are diagrammatic sectional views illustrating by successive steps
the
operation of the closure and regeneration hydraulic motor 20 of the
regenerative
valve hydraulic actuator 1 according to the invention.
It is seen that the closure and regeneration cam 158 is mounted on a hydraulic
motor shaft 163 that is assumed here to be driven in rotation by the
crankshaft 102
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of the transfer-expansion and regeneration engine the French patent on which
belongs to the applicant has been published under the number FR 3 032 236 by
means of a hydraulic motor pulley 170 such as can be seen in Figures 34 and
35.
5 It is also seen that said cam 158 can be offset angularly relative to the
hydraulic
motor shaft 163 by cam phase-shifting means 164 consisting of male helical
splines 165 formed on the cylindrical external face of said shaft 163 which
cooperate with female helical splines 166 formed inside said cam 158, the
latter
being movable axially relative to the hydraulic motor shaft 163 by a cam phase-
10 shifting actuator 167 which acts via a phase-shifting fork 168.
Figures 29 to 33 show clearly that on turning the closure and regeneration cam
158 causes a closure and regeneration piston 159 to move in its closure and
regeneration cylinder 160, via a closure and regeneration tongue 173. As seen,
15 said piston 159 and said cylinder 160 together form a closure and
regeneration
chamber 161.
It is moreover clear that the closure and regeneration cam 158 is made
sufficiently
long so that, whatever its axial position relative to the hydraulic motor
shaft 163, it
20 always exposes its closure and regeneration cam profile 162 to the closure
and
regeneration tongue 173.
Figures 29 to 33 show the hydraulic connector 53 that is connected to the
closure
and regeneration line 18, said connector 53 forming the fluid intake 19 of the
25 closure and regeneration hydraulic motor 20. Note also in said Figures 29
to 33
the hydraulic connector 53 that is connected to the hydraulic motor low-
pressure
return line 22 which is in direct communication with the low-pressure
accumulator
4. The latter said connector 53 forms the fluid outlet 21 of the closure and
regeneration hydraulic motor 20.
In the light of Figures 29 to 33, it is clear that providing communication of
the
hydraulic motor low-pressure return line 22 with the closure and regeneration
chamber 161 may be effected via the end of expansion check valve 171 and in
this case hydraulic fluid 3 can go only from said line 22 to said chamber 161
and
not vice versa, that is via the precompression valve 172 when the latter is
held
open by its tube actuator 137, said precompression valve 172 being mounted in
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46
parallel with said valve 171 and allowing the hydraulic fluid 3 to go from
said line
22 to said chamber 161 and vice versa.
Figure 29 shows the role of the regeneration angular sector R. The valve 8 is
in
the process of being replaced and the valve closure hydraulic valve 17 is
open.
The closure and regeneration piston 159 pushes on the closure and regeneration
tongue 159, which drives the hydraulic motor shaft 163 in rotation via the
closure
and regeneration cam 158. Said sector R therefore enables a large proportion
of
the kinetic energy of the valve 8 and of the mobile components that accompany
it
in its movement to be recovered.
Figure 30 shows what happens immediately after the valve 8 has laded on its
valve seat 11. In a first time denoted Da in Figure 30, the internal volume
filled with
hydraulic fluid 3 of the closure and regeneration line 18 is expanded until
its
pressure becomes less than twenty bar, that is to say less than that in the
low-
pressure accumulator 4. From this moment and therefore in a second time
denoted Db in Figure 30, the end of expansion check valve 171 has been opened
and has allowed hydraulic fluid 3 contained in the low-pressure accumulator 4
to
return to the closure and regeneration chamber 161.
There follows what is illustrated in Figure 31, the closure and regeneration
tongue
173 being in contact with the maneuvering angular sector M. In this figure, it
is
seen that the precompression valve 172 has been opened by its tube actuator
137
and that the closure and regeneration cam profile 162 causes the closure and
regeneration piston 159 to rise in its closure and regeneration cylinder 160
for as
long as necessary to position the beginning of the precompression angular
sector
P at the required angular position.
It is seen in Figure 32 that the precompression valve 172 has been closed
again.
The point of closure of said valve 172 has marked the beginning of the
precompression angular sector P which has no physical reality on the closure
and
regeneration cam profile 162. The moment when said valve 172 has actually been
closed again has been determined by a computer that is not represented taking
into account firstly the pressure there will be in the actuator hydraulic
chamber 7
when the valve 8 is held open as shown in Figure 9, secondly the
compressibility
of the hydraulic fluid 3, and thirdly the internal volume and the stiffness of
the
closure and regeneration line 18.
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47
The sooner the precompression valve 172 is closed when the closure and
regeneration tongue 173 travels over the precompression angular sector P, the
higher the pressure there will be in the closure and regeneration line 18 at
the
moment when the valve closure hydraulic valve 17 opens.
The aim is that when said valve 17 is opened, the pressure in the closure and
regeneration line 18 will be as close as possible to that in the actuator
hydraulic
chamber 7.
Once the target pressure is reached in the closure and regeneration line 18,
the
closure and regeneration tongue 173 will travel over the stabilization angular
sector S which is nothing other than a part of the closure and regeneration
cam
profile 162 that is concentric with the hydraulic motor shaft 163 and which
therefore generates no movement of the closure and regeneration piston 159 in
the closure and regeneration cylinder 160.
From this moment, the closure and regeneration hydraulic motor 20 is ready to
execute a new valve 8 closing cycle, the closure and regeneration cam 158
again
reaching the regeneration angular sector R as shown in Figure 29.
It is seen that, the regenerative valve hydraulic actuator 1 according to the
invention being totally flexible, it is necessary to be able to realign
angularly the
closure and regeneration cam 158 relative to the crankshaft 102 when the
angular
moment relative to said crankshaft 102 at which the valve 8 must be closed
again
changes.
To this end, said cam 158 includes female helical splines 166 that cooperate
with
male helical splines 165 formed on the hydraulic motor shaft 163.
Said splines 165, 166 offset said cam 158 angularly relative to the hydraulic
motor
shaft 163 when said cam 158 is moved axially along said shaft 163 by the cam
phase-shifting actuator 167 that has been shown in Figures 34 and 35, by means
of the phase-shifting fork 168 which cooperates with a phase-shifting groove
169
formed in the closure and regeneration cam 158.
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48
Note that by way of a variant that is not represented, the same closure and
regeneration cam 158 is able to actuate a plurality of closure and
regeneration
tongues 173 each dedicated to closing a valve 8. By way of another variant,
the
hydraulic motor shaft 163 can turn at twice the speed of the crankshaft 102
whilst
a single closure and regeneration tongue 173 can be made responsible for
returning two valves 8 which share the same closure and regeneration line 18,
the
closing of the first valve 8 being offset approximately one hundred and eighty
crankshaft 102 degrees relative to the closing of the second valve 8.
It is clear from the description of the operation of the regenerative valve
hydraulic
actuator 1 according to the invention that has just been given that said
actuator 1
constitutes a favorable response to virtually all of the objectives of
hydraulic
actuation of the valves 8 of any reciprocating piston compressor or engine
100.
These objectives include the recovery - by means of the closure and
regeneration
hydraulic motor 20 - of the kinetic energy of the mobile mechanical components
and of the hydraulic fluid 3 in motion. In fact, if it is not recovered, said
energy is
not only dissipated as a pure loss to the detriment of the final energy
balance of
the reciprocating piston compressor or engine 100, but is able to excite the
mass-
spring system constituted by the mobile but rigid mechanical components
considered separately, on the one hand, and the compressible hydraulic fluid
3, on
the other hand. This excitation produces functional instability and noise.
Said
excitation could be attenuated by damping, but this would be to the detriment
of
the final efficiency as damping is notorious for dissipating excitation energy
in the
form of heat.
Now, the regenerative valve hydraulic actuator 1 according to the invention
does
not induce dissipative damping, but instead regenerative damping through using
the kinetic energy stored by its main mobile components during the first half-
travel
of the valve 8 to move said valve 8 during its second half-travel.
Moreover, thanks to the advanced functions of its closure and regeneration
hydraulic motor 20, said actuator 1 according to the invention controls the
precompression of the hydraulic fluid 3 in the closure and regeneration line
18 to
provide in the regenerative part of the closing cycle of the valve 8 the best
stability
and the best energy efficiency possible.
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49
Moreover, and as is readily understood, the regenerative valve hydraulic
actuator
1 according to the invention enables extremely fast lifting of the valve 8
that it
would be difficult to produce using a conventional cam given the cam profile
to
which such lifts would lead. This said, said actuator 1 guarantees slow
replacement of the valve 8 on the valve seat 11 with which it cooperates, this
being necessary to guarantee silent operation and the required service life of
said
valve 8 and said seat 11.
Note also that the computer that is not represented can instruct the opening
and
the closing either of the valve lifter hydraulic valve 13 or of the valve
closure
hydraulic valve 17 at any time so as to trigger the opening or the closing of
the
valve 8 at any angular position during the rotation of said crankshaft 102.
This
possibility leaves complete freedom to adjust precisely the quantity of gas
admitted into the compression or combustion chamber 105 via the intake line
106,
and the moment at which said gases are admitted into said chamber 105.
Note also that the regenerative valve hydraulic actuator 1 according to the
invention offers the possibility of adjusting the lift height of the valve 8
by acting on
the open time of the valve lifter hydraulic valve 13. For a given pressure in
the
high-pressure accumulator 5, the longer said time, the higher the lift of said
valve
8.
Moreover, said actuator 1 also offers the possibility of locking the valve 8
open and
of maintaining it for as long as necessary in the position shown in Figure 9.
This
enables a valve lift 8 plateau to be produced, which can prove useful in
various
applications.
It will be noted that the particular configuration of the regenerative valve
hydraulic
actuator 1 according to the invention as shown in Figures 5 to 12
advantageously
makes it possible to adjust the pressure in the high-pressure accumulator 5.
Said
adjustment enables a choice of the speed of lifting and replacing the valve 8.
In
fact, the return actuator piston 41 being subjected to the pressure in the
high-
pressure accumulator 5, if the pressure in the latter is increased to open the
valve
8 more quickly by means of the actuator piston 26, the return force exerted on
said
valve 8 by the return actuator piston 41 will be increased in the same
proportions.
Consequently, the lifting speed and the replacement speed of the valve 8
always
remain approximately proportional.
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It will moreover be noted that various means enable variation of the pressure
in
the high-pressure accumulator 5. Said means include the possibility of
temporarily
increasing or decreasing the cubic capacity of the high-pressure hydraulic
feed
5 pump 2, or again of providing a non-compressible volume which may be
larger or
smaller introduced into the high-pressure accumulator 5 or into the circuit to
which
said accumulator 5 is connected.
The other advantages of the regenerative valve hydraulic actuator 1 according
to
10 the invention include the possibility ¨ as illustrated in Figures 5 to
12¨ of replacing
the springs normally used to return the valves 8 of the reciprocating piston
compressor or engine 100 onto their valve seat 11 with a valve return actuator
39.
This particular configuration made possible by the invention notably enables a
very
15 high return force to be exerted on the valve 8 without the penalty of the
large
dimensions and the high reciprocating mass of a steel spring as normally used
by
the person skilled in the art. In this sense, the regenerative valve hydraulic
actuator 1 according to the invention is able to offer return powers of the
valve 8
that are normally accessible only via desmodromic control known in itself.
This particular feature in particular enables rapid and short lifts of the
valve 8 to be
obtained as is for example necessary to produce the intake and exhaust
metering
valves of the transfer-expansion and regeneration engine the French patent on
which published under the number FR 3 032 236 belongs to the applicant.
In fact, said transfer-expansion and regeneration engine can preferably be
controlled not by gas pressure variation but rather by truncation of the
expansion
to generate more torque, or by extension of the expansion followed by quasi-
adiabatic recompression at the exhaust to produce less torque. Said motor then
operating at constant pressure no longer has virtually any delay responding to
load
transients.
Note that the regenerative valve hydraulic actuator 1 according to the
invention
can advantageously be applied to the compressors of said motor the load of
which
can also be controlled by means of their intake valves 8 thanks to said
actuator 1.
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The responsiveness and the speed of the regenerative valve hydraulic actuator
1
according to the invention also enables high-speed internal combustion engines
to
be equipped with valves 8 offering numerous control variants to optimize the
efficiency, torque, power and pollutant emissions of said engines.
The flexibility of control of the valve 8 offered by the regenerative valve
hydraulic
actuator 1 according to the invention further enablers multiple lifts to be
provided
during the same thermodynamic cycle, for example for fine adjustment of the
quantity of exhaust gas recirculated into the compression or combustion
chamber
105, and production of compression ignition internal combustion engines.
Note also the great flexibility of integration on the cylinder head of the
compressor
or engine 104 of any reciprocating piston compressor or engine 100 whatsoever
of
the regenerative valve hydraulic actuator 1 according to the invention, in
particular,
the absence of any mechanical connection between the energy source of the
regenerative valve hydraulic actuator 1 and the actuator cartridge 52 which
accommodates the valve 8 allows the latter to be oriented freely relative to
the
compression or combustion chamber 105. This in particular enables improvement
of the geometric qualities of said chamber 105, for example according to
permeability and/or combustion quality criteria.
By way of another advantage of the regenerative valve hydraulic actuator 1
according to the invention, note that the particular configuration of said
actuator 1
as shown in Figures 5 to 12 prevents as much as possible any cul-de-sac in
which
hydraulic fluid 3 could be trapped. In fact, said configuration ensures a
constant
circulation of hydraulic fluid 3 between the high-pressure accumulator 5 and
the
low-pressure accumulator 4 via the various circuits and volumes constituted
inside
the actuator cartridge 52. A cooler can moreover be provided on the path of
said
fluid 3. Accordingly, said cartridge 52 will be cooled by said hydraulic fluid
3, and
its temperature is stabilized. This arrangement finds its full benefit for
example in
the context of the transfer-expansion and regeneration engine the French
patent
on which published under the number FR 3 032 236 belongs to the applicant, the
expansion cylinder assembly 54 of said engine not including any external
cooling
circuit.
The other advantages of the regenerative valve hydraulic actuator 1 according
to
the invention include the tubular valve 130, especially when the latter
cooperates
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52
with the hydraulic amplification piezoelectric actuator 139 the operation of
which is
readily understood from Figures 21 and 22.
