Note: Descriptions are shown in the official language in which they were submitted.
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~A CEI? ~tCI'A'~Y INTERNAL CC~ ITSTI~N'
ENGINE ~1~ CYCLING V~LLdME CHINE
This invention relates in general to rotary internal
combustion engines and more specifically to engines
utilizing variable shape rotor known from the earliest
prior art as Werner (U.S. Pat. No. 716,970) type and
opposite to the Wankel type rotary engines with fixed shape
rotor and epitrochoidal shape stator. The device also
relates to compressors, pumps, vacuum machines, steam or
compressed gas engines and other cycling machines.
In present invention, during the rotation cycle, the
rotor pivoting blades or pistons al-ign alternatively in a
lozenge and a square configuration so that the volume
between the blades itself, side walls and the stator is
changing which allows to create a cycling machine.
Rotary engines and cycling machines based on the
principle of Edward H. Werner's invention (FIG. 9) of 1902
(U.S. Pat. No. 716,970) and further inventions developed in
greater details (FIG. 7) by Alfred Jordan (U. S. Pat. Nos.
3,295,505; 3,369,529; 4,181,481) as we.l.l as other cycling
machines with variable shape rotors are well known from the
prior art.
According to the German Pat. No. 1,295,569 a rotary
internal combustion engine is known, in which two pistons
are provided, which are connected to the shaft by means of
two diametrically opposite arms f-xedly connected to the
shaft.
Most recent realization of such cycling machine
utilizing Werner's principle and described in U.S. Pat,. No.
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6,164,263 (FIG. 8) employs roll carriages pivotally
connected to the ends of the blades and therefore creating
a lateral support for the rotor and simultaneously
providing a cam surface for the rotor shape deformation. In
this device an additional variation of the volume between
the bl ades, side covers and a stator is achievable due to
variation in relative position of the carriages and blades.
Similar configuration indeed is well known from the
prior art including U.S. patents by Jordan, Ishida and
Niemland. These devices however do not employ rolls at the
end of sealing carriages except as in the U.S., Pat. No.
3, 387, 596 by Niemand where ro-i_ls are used in combination
with cam surface for deformation of the shape of four link
blades' parallelogram. This cam though was not part of the
combustion chamber which provided improved reliability of
the device compared to U.S. Pat. No. 6,:L64,263.
Parallelogram mechanisms for creating reciprocating
movement of the pistons are known from the U.S. Pat. No.
5,203,295 by Alexander. Multiple application of unique
properties of the parallelogram mechanism are also known,
for instance from PCT WO 09105990 A1 by Okulov. However the
common disadvantage exists that the pivoting blades or
links arranged in such configuration are extremely
difficult to seal at the pivoting ends.
Different sealing techniques and methods arE: described
in details in the U.S. Pat. Nos. 3'950,017; 3,690,791;
3,918,41; 4,296,936, etc. Particularly,. several different
types of seals are needed to provide adequate sealing of
the device similar to U.S. Pat. No. 6,164,263 which greatly
complicates design and makes it unreliable. In addition,
the complicated shape of the parts and greater surface area
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of combustion chamber both determine high thermal losses
and lower efficiency for this type of engines. Eliminating
roll carriages in order to create simpler shape for the
combustion chamber (or considering its size near zero)
brings such design back to the devices like ones described
in a U.S. Pat. No. 3,918,415.
The geometry and numerous configurations of the rotor
and stator. shapes were detailed in U.S. Pat. Nos. 3,950,117
and 5,288,217 for different types of Variable shape rotors.
The shape employed in the U.S. Pat. No. 6,=L64,2o3 is
generally described in prior art and employing non
deformable rotor (FIG. 10) having one to four pivoted
carriages running in a stator of square or other polygon
like with rounded corners shape.
All these engines have an advantage of being near
vibrations free contrary to the Wankel and other type of
engines with fixed shape rotor or unbalanced pistons.
Disadvantages of the engines however exists that seals at
the pivoting ends of the blades are complicated and there
are still high friction losses due to the significant
stress produced by gas pressure and complex shape of the
seals and joints.
In addition the rolls of the carriages being part of
the combustion chamber are exposed to high temperature
combustion gases and are suffering deposition of residue
products or plaque from the combustion process. Very
complicated configuration of tL:e combustion chamber creates
excessive heat transfer to its parts c'.ue to large surface
area~predetermined by the geometry of the pistons (blades.)
Due to the higher surface area of the combustion chambers
relatively to its volumes, there is more residue from the
CA 02465472 2004-04-28
non burnt film of the fuel on it. As in most rotary
engines, due to centrifugal action of the rotating rotor
forcing the lubricator oil to enter the exhaust, a tendency
of having higher overall engine emissions still exists.
There are also well known devices (so-called '°cat and
mouse" or scissors type engines) realized in a variety of
configurations and utilizing principle of creating cycling
volumes between rotating inside the circular or tor_oidal
housing pistons or blades. The disadvantage of these
engines is a necessity fo:r creating an external mechanism
for variation of the relative position of the pistons.
These devices include cams, oval gears, rotating links
mechanisms (Rice), etc. Another known type o:f balanced
rotary engines are devices employing cylinders and pistons
arranged in a circle and having an activating pistons
movement cam with rotating shaft.
Other engines are represented by concepts proposed in
a prior art and including a pressure energy converter,
rotary engine or compressor as in U.S. Pat. Nos. 4,068,985,
3,996,899; a rotary disk engine as in the U.S. Pat. No.
5,404,850 a rotary planetary motion engine as in U.S. Pat.
No. 5,399,078; a rotary detonatior_ engine as in the U.S.
Pat. 4, 741, 154; a rotary combustion engine as ire DE patent
2,448,828, U.S. Pat. Nos. 3,933,131, 4,548,171, 5,036,809;
the Wankel type engine as in the U.S. Pat. Nos. 3,228,183,
4,308,002, 5,305,721, and a continuous combustion engine as
in the U.S. Pat. No. 3,996,899. Most rotary engines, and
particularly the Wankel and those described in the U.S.
Pat. Nos. 3,442,257, 3,614,277, 4,144,866, 4,434,757, DE
Patent No. 3,027,208 are based on the principles of volume
variation between a curve and a moving cord of fixed length
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as a single sliding piston and have the common disadvantage
of not being balanced.
One aspect of the present inventicn is to provide an
engine or fully balanced cycling volume machine with
variable shape rotor and low internal friction. It is also
ar_ objective to provide a rotor engine with reduced
negative effect of the centrifugal forces on the oil or
lubricant distribution and utilize a conventional oil pan
(pool) design solution proved to be superior to other types
of lubrication systems,. part~_cularly the ones used in
conventional automobile engines. Still another objective of
present invention _~s to create an effective and simplified
engine sealing system.
A further aspect of the present invention is to create
the possibility of using a simple circular shape stator and
an efficient combustion chamber. Another objects are to
create a system for direct and linear transmission of
mechanical torque from all four pistons to 'the shaft,
remove roll cams and pivoting parts from the action of
combustion gases, reduce the weigh of the engine and
provide cleaner exhaust. Still another object is to provide
engine configuration capable of creating a jet propulsory
system and creating an engine for water crafts employing
polymer plastic or composite parts cocl_ed directly in the
water.
Another aspect of the present invention is to provide
a lower rpm engine, utilizing more efficient and less NOx
producing (asymmetric) pressure cycle. i.e. giving less
time to the compression and exhaust st=rokes, and allowing
more time to the combustion stroke. Another object of this
invention is to provide lower dead time, and to provide an
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_..
engine tolerant to different fuels as well suitable for
photc-detonation mode and hydrogen combustion.
Alternatively~ a further aspect of the present
invention is to create an ignition device amplifying the
internal pressure during compression cycle to the point of
ignition of air-fuel mixture and to provide a:n external
combustion engine utilizing compressor and expansion
machines as per present invention.
The rotor as per present invention comprises of an
assembly of four pistons or blades suitable for creation of
variable volumes during its rotation cycle and having
sealed gaps between themselves and a:n oval o:r circular
shape stator, where the opposite pistons are pivotally
linked to each other creating parallelogram mechanism and
where (in basic configuration) the crop>sings of said links
are connected to the rotor shape deforming mechanism and
are also coupled with the output shaft.
The pistons can have individual seals with stator and
side covers creating variable volume chambers or have seals
between them, preferably at the centers of their relative
rotation. 'Ihe variable chambers can be composed as shown in
the drawings and diagrams below. Intake ports, spark plug
and exhaust ports are provided either radial in the stator
housing, or axial in the side covers, or both.
Different sealing techniques are further presented
where sealing between pistons and side walls of the stator
generally constitute simple linear or curved semicircular
spring loaded seals similar to the Wankel type engine
seals. Apex seals are arranged either between pistons, or
between pistons and stator contour circular or oval wall,
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or comprising additional seals supported in the mid angle
between adjacent pistons and having apex seals with them.
Another type of continuos seal when used in combination
with toroidal shape stator are also disclosed as well as
seals employing rollers and supporting roll bearings at the
ends of the pistons.
Rotation of the rotor provides tle pistons of the
variable rotor to generate.cycling volumes thus enabling to
provide compression, expansion or vacuum. The engine with
four pivoting pistons would have four strokes cycle firing
four times per every revolution, wits. v.irtuall_y no dead
time.
Having thus generally described the invention,
reference will now be made to the accompanying drawings
illustrating preferred embodiments and s_n which:
FIGS. 1, 2, 3, 5, 6, 13 show one preferred embodiment
employing four segmental pistons arranged in lozenge
configuration.
FIGS. 4, 12, i4 illustrate the same ,embodiment with
pistons arranged in a square configuration.
FIGS. 7-10 illustrate prior art.
FIG. 11 is a cross section of the engine from FIG. 12.
FIG. 12 shows plan view of the preferred embodiment
with part of the engine side cover not .shown.
FIG. 15 details the extreme positions of. the links
between pistons relative to the piston during engine
operation, and FIG. 16 provides a cross sec~t:ion of the
piston side wall in assembly with its side wall.
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FIGS. 17, 23, 27 illustrate engine configuration with
lubricating oil pan (pool) and pistons aligned in a square
configuration and surrounding the stator.
FIGS. 22, 26, 29 show the same engine with pistons
arranged in a square configuration.
FIG. 18 is a cross section of the engine as per FIG.
17.
FIG. 24 is a cross section of the engine as per FIG.
23.
FIG. 28 is a cross section of the engine as per FIG.
27.
FIGS. 19-21 illustrate details of the sealing with
side seals positioned in side covers and °'apex" seals at
the edges of the bed.
FIG. 25 shows kinematic scheme o:~ the engine as per
FIG. 23.
FIG. 30 details geometry of the cycling machine with
"oval" shape stator.
FIGS. 31 and 32 illustrate pistons with supporting
wheels (rolls) positioned in the central part of pistons.
FIG. 33 illustrates the geometry of the circular
stator shape and "ideal" segmental pistons.
FIGS. 34 and 35 provide the geometry of segmental
outer portion of the piston creating minimum volume between
pistons and a contour wall.
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FIG. 36 illustrates method of determining of the
geometrical shape of the contour wall of "oval" shape.
FIG. 37 illustrates variations of possible shapes of
"oval" contour wall.
FIGS. 38-40 provide illustration to the method of
finding mathematical solution for the definition of contour
wall curve.
FIG. 41, 42 provide diagrams of minimum and maximum
volume of chambers for "oval" type contour wall.
FIGS. 43, 44 provide diagrams of :minimum a.nd maximum
volume of chambers for circular type contour wall.
FIGS. 45-55 show a variety of rotor and stator
configurations determining the shape of-_ the cycling volume
chambers.
FIGS. 56-63 describe principles of determination of
engine internal loads and torque.
FIGS. 64-75 show a variety of cam mechanisms for
piston rotor assembly shape deformation.
FIGS. 76-83 illustrate different types of supports for
pistons capable of direct receipt of loads from variation
of chamber pressures.
FIGS. 84-89 present different systems for mechanical
transfer of the torque to the output shaft, where FIGS. 84
and 85 describe prior art and illustrate its disadvantages.
FIGS. 90-96 are other illustrations of the methods of
deformation of piston assembly utilizing oval gears coupled
with oval rolls, and the devices with crank shafts.
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FIGS. 97-107 show a variety of possible pivoted links
between pistons.
FIGS. 108-111 are demonstrating details of variation
or cycling of internal volume between pistons.
FIGS. 112-117 present in greater details engines or
compressors with pistons surrounding tile stator or rotor,
particularly FIG. 114 illustrate a piston or a chain of
pistons surrounding a '°wavy'° stator or rotor and FIGS. 116-
117 present the variant of engine with blades or firs
associated directly with pistons.
FIGS. 118-157 illustrate in great: details different
types of seals, sealing methods and embodiments.
FIGS. 158-159 show a variant of the device with
circular deformable contour wall of flexible liner of the
stator.
FIGS. 160 and 161 illustrate rotary engine with "oval°'
shape rotor and stationary piston assembly.
FIGS. 162-164 further show the cycling sequence of
such device.
FIGS. 165-166 describe principle of external
combustion engine as per present invention,
FIG. 167 describes an amplified compression type
ignition plug and method of amplified pressure ignition.
FIG. 168 present a bcttom view of the plug showing
slots for gas passage, and
FIG. 169 provides explanation to method of
amplification of pressure inside ignition chamber of the
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plug by means of differential piston presented in the FIG.
170.
Preferred embodiment comprises a four pistons (each
generally of the in a form of a disk segment) variable
shape assembly where pistons are linked to each other
creating a parallelogram mechanism by means of at least
four pivoted links. The pistons are movably mounted inside
the engine housing comprising side walls and a stator_ of
generally circular or semicircular inner profile thus
providing a contour wall. (This shape can also be achieved
by using rigid or flexible (deformable) cylindrical liner,
which in addition can be deformed to match its
configuration to the ideal geometry of movement oa the
pistons and apex seals.)
The shape of the rotor assembly is alt:ernat=ively
changing from lozenge to square with the help of the piston
assembly deformation mechanisms which can be for instance a
cam mechanism having rolls with its axes corresponding to
the intersections of the pistons links and rocking against
the "oval'° shape or generally speaking about non-circular
orbit.
Diagrams of operation of the cycling volume machine as
a four cycle internal combustion engine are further
presented in the drawings. It is important to mention that
the engine can operate as a two cycle engine where two
intake ports and two exhaust ports can be provided.
Alternatively the inner cycling volume of the engine
(between pistons) or external blower also can be utilized
for fuel mixture compression or distribution. or as part of
the lubrication system, cooling, porting, etc.
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A distinct advantage of the engine as per present
invention is the fact that piston assembly deformation
mechanism is actually not a part of the contour wall or
stator or rotor configuration which makes it easy to adjust
its properties to different types of fuels, desired
compression ratios and ratios between the
combustion/intake/expansion chambers volumes and angles of
the rotor assembly rotation, thus providing greater
flexibility to the design of the device and providing
reduction of its cost.
Each piston's height can be approximately equal to the
half of its length which provides minimum variation of the
clearance between the top of the piston and contour of the
stator circular wall. For instance, with stator inner
diameter 4" (.about.100 mm) the length of the piston can be
2.13°' (54 mm) and the height-0.9," (23 mm) and the
variation of the gap between the top part of the of the
piston (at its apex seal) will be in a range of 0-0.012"
(0-0.3 mm.) This small variation or apex. seal normal
breathing can be easily accommodated by its sliding in the
seat.
The "ideal" geometrical configuration will involve
piston segments of twice less radius than the stator
contour wall and with any configuration of the piston
assembly it will be always a precise contact between the
piston's outer circular part and the circular contour wall
of the stator. Sealing will be a challenge though with
respect to this configuration, however in the high rpm
devices the '°close to zero" gap technique can be employed
where depending on the density of working fluid very
sufficient pressures can be achieved without seals at all,
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but with minimum clearance between parts. This particular
configuration will be preferable with ceramic, composite or
plastic parts employed which can be especially advantageous
for "lubricant free" engines as well as in ''micro°° engines
etched from the silicone based materials, etc.
In its preferable configuration the apex and side
seals are similar to the Wankel type seals with the
advantage of having much more favorable leaning angle of
apex seals (not more than 10 degrees compared to between 16
to 30 degrees for Wankel type engines.)
The geometry of other variations and details of
engines and Cycling volume machines is described in the
diagrams enclosed herein. The variations of shapes of the
°'oval" stator or geometry of the cam surfaces and other
parameters are numerous anal can be analyzed using standard
math analysis techniques. The geometry chosen will
determine the compression ratio and displacement of the
engine. The shape of the curve always has t.o conform with
two points: #1 and #2 (see FIG. 36), the distance between
them has to be equal to the side of the square 3(c), and a
polar angle (gamma) between them must be equal ~0 degrees.
Such curve has an indefinite amount of solutions {shapes)
predetermined by the ratio a/b and by at least one fragment
of the curve between points 4 or 5 and 6 which are the
reference points for all possible curves with similar ratio
°'a/b". However, points 5 stz.ll rema.i.n common reference
points for all possible curves.
Compression ratio ef present engine is not limited by
its geometry, contrary to the Wankel type engines where it
cannot exceed 15.5:1 (for three lobes rotor.) Displacement
of engines as per present invention has to be compared to
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eight cylinder four cycle engine, as it will have equal
number of power strokes per one shaft revolution. As an
example, the circular stator shape engine as per present
invention with displacement 2.? liters will have diameter
of the contour wall of approximately 12" and thickness of
3 . 3 °' only .
The central shaft can be linked with at least two
opposite pistons in a way described in a prior art, i.e. by
a coupling arm or two arms. However, as the angle between
arms changes during the rotation this method will prove
difficult to implement in terms of equal distribution of
the torque from all four pistons. Another disadvantage of
such solution will be an alternative di:Eficulty of rotating
the shaft during the starting procedure due to possibility
of cam rolls getting stuck when approaching lean angles
with the cam surface, especially in case of engines or
compressors with higher compression ratios.
As per preferable embodiment the central shaft has a
cross-like shape with four slots engaging with
corresponding axes of the parallelogram links at their
crossings. Thus, either the torque can be transferred to
the output shaft alone, or both: the torque and the lateral
force resulting from the internal chambers' pressure can be
transferred through the pistons depending on the
configuration chosen.
While the cam mechanism itself can withstand these
lateral forces and provide creation o:r the torque, it is
more advantageous to separate these two functions as it is
shown in the preferred embodiments. Several means as
illustrated can be employed for such configuration
including pivoted arms, rolls, etc. This solution will also
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provide better dynamical response to the pulsating loads
received during the power cycles and improve torque
creation and transmission system.
Because the duration of peak pressure at the top dead
center is much shorter than in the conventional piston or
Wankel type engines, the shape of the combustion chamber is
much less critical. It can be assumed however that the
least total surface area of the combustion chamber will be
desired in order to improve. thermal efficiency of the
engine. Two spark or glow plugs can be employed similar to
the approach used in Wankel type engine in order to improve
combustion.
Intake and exhaust ports can be located in the side
covers or in the stator or rotor, or in both. In order to
simplify the design, laminated structure for_ the stator or
rotor or both can be employed. Intake arid exhaust. ports can
then be provided in a form of slots or bunched openings
provided in the plates (lamellas) which, after putting them
together and tightening or sintering, will provide internal
2Q channels as well as any desirable outer or inner shape
configuration.
Distribution of the wear and heat will be expected to
be quite similar to the Wankel type engine with more
sealing capabilities for the apex seals due to the lower
lean angles of the seas.
The engine with "oval" stator configuration can be
provided with different types of chamber compositions. The
preferred embodiment includes a stator_ ring with pistons
surrounding it from the inner or outer portion of the
stator ring. In case of inner positicn of the pistons it
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becomes possible to employ a conventional oil pan (oil
pool) for lubrication which significantly simplifies the
overall design, improves reliability and provides low
emissions_
The number of pistons surrounding stator can vary from
application to application with minimum four pistons
employed. A "chain" like structure can be achieved with
multiple chambers or a "wavy" disk coupled with a single or
multiple tiltable chambers. This configuration can be
effectively used in pumps, pneumatic brakes for vehicles (a
pump with closed output and "wavy disk" like stator),
propulsors for water crafts etc.
In case of water craft engines, the parts can be made
of polymer plastic/composite and the whole engine can be
Submerged into the water for effective cooling. Each piston
can have a blade attached for it for direct propulsion. The
same configuration can be used for airplanes or ducked fan
engines.
Continuous seals are also described herein in
combination with toroidal stator or toroidal shape rotor
pistons. These seals are as high effective as conventional
piston engine seals. In addition, the °'one piece" molded,
extruded or etched rotor assembly with flexible seals is
shown.
In the instance of four stroke combustion engines, the
four chambers can be used in a close circuit and the cycles
are defined as followse intake-compression-expansion-
exhaust. Ports for intake can utilize a conventional
carburetor or can be fitted with gas or diesel fuel
injector. Alternatively, the fuel can be injected directly
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into the chamber. Also a continuous combustion can be
achieved by utilizing a flame pilot technique or providing
a channel between chambers. Alternatively, the compression
diesel igniter can be used as per preferred embodiment
where the pressure of air/fuel mixture is mechanically
multiplied by differential piston as per diagrams below.
Effective ignition timing advance can be achieved by
using electronic ignition or controlling the injection of
fuel directly into the combustion chamber. A spark plug
cavity can be exposed to the inner volume of the combustion
chamber by means of porting by rotating pistons themselves.
The engine as per preferred embodiment does not
require a fly wheel as the inertial capability of the four
piston assembly is sufficient for providing smooth rotation
even on low rpms. Projected highest rpm of the engine is
about 3000-5000 rpm due to four firings per revolution
which in many cases will require less complicated gear box
or no gear box at all.
Cooling of the engine can be done by air, water or oil
in a traditional for rotary (particularly Warakel type)
engines way. In case of employment of oil pan the intensive
circulation of the oil utilizing an external heat exchanger
for cooling and filter can be provided. Inner variable
volume of the engine also can be used for pumping the
cooling agent or fuel mixture into the engine.
Alternatively, the cooling and/or lubricating systems can
employ simply a mixture of the oil with fuel as well as
mare complex distribution systems. One of the systems
include an intake port opening connected with carburetor
through the inner volume of tlae rotor which can provide
effective cooling of the links and pistons by the intake
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air and/or fuel. The inner volume can be furnished with
valves for providing pumping/vacuum capabilities to it.
The engine as per present desicJn can work as an
expansion type machine with numerous t_y~oes of fluids like
steam, compressed/liquified gases, hydrogen and solid fuel
burners, etc.
As further illustrated in FIGS. 165, 166, two cycling
machines as per present invention can be arranged in a such
way that one machine will compress oxidizer (air, for
instance) and deliver it along with fuel into a high
pressure combustion chamber where the products of
combustion will be fed into expansion machine as per
present invention and part of the energy created can be fed
back to the compressor. The similar configuration of
external combustion engine can employ a hybrid system where
the compressor can be driven by electric motor, etc. it is
important to note that pract:~cal devices described and
provided herein are for illustrative purposes only and
should not limit the scope and intentions of present
2G invention.
Although embodiments of the invention have been
described above, it is not lim-ited thereto and it will be
apparent to those skilled in the art that numerous
modifications form part of the present invention insofar as
they do not depart from the spirit, nature and scope of the
claimed and described invention.
