Note: Descriptions are shown in the official language in which they were submitted.
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ROTARY VALVE CONSTRUCTION UTILIZING
A COMPRESSED GAS AS LUBRICANT AND COOLANT ~-
Background of the Invention
I. Field of the Invention ~ -
The present invention relates generally to internal ;
combustion engines and, more particularly, to an improved
rotary intake and exhaust valve construction utilizing a
compressed fuel/air mixture as coolant, a lubricant, and to
provide a gas bearing.
II. Description of the Prior Art ~-
Conventional internal combustion engines include a
housing with at least one piston member reciprocally mounted
within a cylinder formed in the housing. Fuel intake
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passage means formed in the housing supply fuel to the
cylinder for combustion while, similarly, the exhaust gases
from the cylinder pass through exhaust passage means formed
in the housing and to the engine exhaust system.
In order to permit the intake of fuel into the
cylinder and the expulsion of exhaust gases from the
cylinder at the desired engine cycles, an intake valve and
an exhaust valve are provided in the intake and exhaust
passage means, respectively. These valves permit fluid flow
or communication through their respective passage means upon
opening and, conversely, when closed prohibit such fluid
flow.
There are many different types of previously-known
intake and exhaust valves. One type of previously-known
valve member employs a circular closure plate with an
axially attached elongated stem. The plate cooperates with
a valve seat formed in the housing while a spring attached
to the elongated stem normally urges the valve to its closed
position. Conversely, opening of the valve is accomplished
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by depression of the valve stem by a cam, rocker arm, or
other appropriate means. This simple type of engine valve,
however, is disadvantageous due to its high cost which, in
turn, results primarily from the multiplicity of components ~;
required for the valve and its actuation. Moreover, these
previously known engine valve systems are both heavy and ~ ;
bulky in construction. -
A rotary engine valve forms another previously
known engine valve in which an elongated cylindrical valve ~-
member is rotatably mounted within the engine housing in the
fuel intake or exhaust passage means for at least one, and
preferably several, engine cylinders. Diametric
throughbores are provided through the cylindrical valve
member so that upon rotation in synchronism with the
internal combustion engine, the valve members permit fluid
flow through the intake or exhaust passage means via the
diametric throughbore at preselected rotational positions of
the valve member.
An improved rotary valve construction is disclosed
in my earlier patent, United States Patent No. 4,198,946 as
having a valve with internal cooling and improved seals
between the engine housing and the rotary valve. More `
specifically, each valve member of that reference includes
at least one axial passageway which is fluidly connected at
both ends to the fluid coolant system of the internal ~;~
combustion engine so that a flow of coolant axially through
both valve members is obtained. ~
Despite the advantages of rotary valves in general ~'i
and U.S. Patent No. 4,198,946 specifically, a more efficient
-and advantageous structure for cooling and lubricating is
desirable which would eliminate the need for providing a
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flow of coolant through the valve members. By eliminating
the flow-through of coolant, additional steps related to
machining and construction can be eliminated. -
Furthermore, the bearing construction of known - -
rotary valves is very expensive and subject to considerable `;~
wear. Thus an improved bearing is desirable. ~ -~
Summary of the Present Invention
The present invention overcomes the above-mentioned
disadvantages of the previously-known rotary engine valves
by providing such a valve with a compressed gas which
circulates in the space between the valve and its bore to
act both as a lubricant and a coolant.
In brief, the rotary valves according to the
present invention are both elongated and cylindrical in
shape with one valve disposed through the inlet and the
other through the exhaust passage means in the engine 1~ l
housing. Each rotary valve is rotatably journalled in its l ;
respective passage means and includes a diametric opening
for each passageway in the passage means. Consequently, ~``
upon rotation, the rotary valve establishes fluid
communication through passageways via the diametric openings
at predetermined rotational positions of the rotary valve.
The rotary valve of the present invention is fitted
; into the bore journalled into the valve housing so that a
clearance of between .0007 and .0015 is established. With
such a clearance a compressed fuel/air mixture is allowed to
circulate within the gap. The circulating gas functions as
a "gas bearing" to assist in the free rotation of the rotary
valve. In essence, the rotary valve is allowed to "float" ~;
in the valve bore.
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The circulating fuel/air mixture, in addition to
providing a "gas bearing", also provides lubrication and
cooling.
Beyond the circulating compressed fuel/air mixture
providing lubrication and cooling, the present invention
~ also teaches a novel means for providing peripheral spiral
¦ channels grooved or knurled about the valve to act as a
labyrinth gland or seal. By selectively defining the
channels about the periphery of the valve at strategic
intervals, glands or seals may be achieved.
To minimize wear and the general effects of heat
expansion, a ceramic sleeve is provided in the valve bore at
regions facing the channels.
The present invention also discloses a novel means
for rotatably driving the rotary valve. In particular, a
rotatably mounted shaft is coupled directly to the engine
crankshaft by an appropriate gearing arrangement whereby a
single gear face simultaneously drives a pair of rotary
valves.
As will be more fully understood as the description
proceeds, the rotary valve of the present invention is of
simple, lightweight, and inexpensive construction.
Moreover, due to the peripherally circulating fuel/air
mixture, the valve can be directly and effectively cooled
and lubricated without liquids. Additionally, because of
this construction, bearings may be minimized. Furthermore,
the labyrinthine channel construction further requires only
minimal use of seals. In addition, the channels aid in
lubrication. -
Brief Description of the Drawin~s
The present invention will be more clearly
understood upon reference to the following detailed
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description when read in conjunction with the accompanying
drawing, wherein like reference characters refer to like
parts throughout the several views, and in which~
FIG. 1 is a fragmentary sectional view showing the ~
rotary valve construction of the present invention in an -
engine housing; ~`
FIG. 2 is a fragmentary, partial sectional top view
illustrating an internal combustion engine employing the
rotary valve of the present invention; ~-
FIG. 3 is a fragmentary, partial sectional view
illustrating the rotary valve of the present invention in ~ -
detail;
FIG. 4 is a view detailing the configuration of the
rotary valve's fuel/air channel according to the present `~
invention;
FIG. 5 is a fragmentary, raised elevational view
illustrating the means for driving a pair of rotary valves
by a common take off shaft according to the present
invention;
FIG. 6 is a fragmentary, partial sectional side
view showing the means for rotatably driving the rotary
valve of the present invention and enlarged for clarity;
FIG. 7 is a view detailing the seal construction of
an alternate embodiment of the present invention in partial -
sectional view; '.
FIG. 8 is a cross-sectional view along line 8-8 of
Figure 7; and
FIG. 9 is a cross-sectional view along line 9-9 of
Figure 8.
Detailed Description of the
Present Invention ~;
With reference first to Figures 1 and 2, a portion ;
of an internal combustion engine 10 is thereshown having a -~
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housing 12. The housing 12 further comprises a block 14 and ~
an upper head assembly 16 detachably connected by means, not `;,",'!'~
shown, to the engine block 14. Typically, the engine valve
means which will subsequently be described in greater ...
detail, are contained within the head assembly 16 while one
or more cylinders 18 are formed within the engine block 14 .
and are adapted to reciprocally receive a piston member 20
therein. Each piston member 20 in turn is connected at its .. ~ `
lower end to a crankshaft (not shown) by appropriate piston
rod means (not shown). Moreover, by way of example only, . .
the internal combustion engine 10 shown in Figures 1 and 2 .
of the drawing incorporates four in-line cylinders 18, it -~
being understood, of course, that the.provision of more or ~-
less cylinders 18 remains within the scope and spirit of the ..
invention. .~s
A fuel intake passage means 22 comprising a first
section 24 and a second section 26 is formed through the ~.
head assembly 16 with a rotary intake valve 28, according to `.
the present invention, disposed between the intake passage `
sections 24 and 26. The passage section 24 is coupled at ..
its outer end to appropriate carburetor means 30 while the .
inner end of the passage section 26 is open to the cylinder
18. Thus, with the valve 28 in its open position, the .... i
piston 20 inducts a fuel mixture from the carburetor means :.. ;
30 into the cylinder 18 during the conventional downward
intake cycle of the piston 20. Conventional ignition means ~ .~
31 are provided for igniting the fuel mixture in the ; -.
cylinder 18. .. ~-
Exhaust passage means 32 comprising a first section ~.
34 and a second section 36 are also formed through the head .
assembly 16 with a rotary exhaust valve 38 according to the .~ ;
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present invention, disposed between the exhaust passage
sections 34 and 36. The outer end of the exhaust passage
section 34 is coupled to an appropriate engine exhaust
system 40 while the inner end of the exhaust section 36 is
open to the cylinder 18. Thus, with the exhaust rotary
valve 38 in its open position, exhaust fumes from the fuel
combustion are expelled through the exhaust passageway 32
and exhaust valve 38 during the conventional upward exhaust
cycle of the piston 20.
With reference now to Figures 1, 2 and 3, the
intake rotary valve 28 and exhaust rotary valve 38 are
substantially identical to each other so that, for brevity,
only the intake rotary valve 28 will be described in detail,
it being understood, of course, that the description also
applies to the exhaust rotary valve 38. The rotary valve 28
is elongated and cylindrical in cross-sectional shape and
includes a cylindrical valve portion 42 respectively
disposed in the intake passage means 22 for each cylinder
18. The rear end 48 of the rotary valve 28 protrudes
outwardly from the housing 12 while the other axial end 50
of the valve 28 protrudes into a cavity 52 formed in the
housing 12.
As best shown in Figures 1 and 3, each valve
portion 42 includes an axially oblong diametric throughbore
54 so that the valve 28 permits fluid communication between
the intake passage sections 24 and 25 when the throughbore
54 is in alignment with the sections 24 and 26, as best
shown in Figure 1. The throughbore 54 is particularly wide
to provide a better fuel/air mix because the charge is more
directed into the combustion chamber. Conversely, of
course, the rotary valve 28 obstructs and prohibits fluid
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flow from the passage section 24 to the section 26 when the
rotary valve 28 is rotated to a position in which the oblong
throughbore 54 is not in registry with the passage sections -`
24 and 26. It will also be appreciated that the angular -~
positions of the throughbores 54 relative to each other will .
vary from one valve portion 42 to the other as required by
the cylinder combustion sequence of the particular internal
combustion engine 10. ..
The valve 28 is disposed within the head assembly :~
16 such that a clearance of between .0007 and .0015 is
provided between the bores of the head assembly 16 and the
periphery of the valve 28. By the provision of such a .
clearance compressed fuel/air, piloted from the fuel/air .. .
mixture compressed by the compression stroke of a cylinder .~
via fuel/air lines 121, is able to circulate around the ~;.
periphery of the valve 28, thereby providing a compressed ..
lubricating and cooling fuel/air mixture which acts as an `
air bearing to assist in the proper free rotation of the
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valve 28.
To provide seals between the valve portions 42 and .~:
to thereby limit the travel of combusting fuel/air about the :.. ;~i
valve, spiral channels are selectively defined in the valve i~
28. With particular reference to Figure 3, a spiral channel ;
122 is illustrated defined about the periphery of the valve
28. With reference to Figure 4, a pair of channels 124,
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124' are provided. The channels 122, 124, 124' may be
either knurled or grooved. ~
Although as illustrated in Figure 3 the fuel/air . i
line 121 is not venting compressed gas into the channel, as .
can be seen by channel 122, if the valve 28 was to be
rotated 180~, the line 121 would be venting directly into l` `
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the channel 122. Referring to Figure 4, an intersection of
channels 124 and 124', generally indicated as "A", is the
position on the rotating face of the valve 28 wherein the
line 121 would vent into the channels 124, 124'.
The construction of channels 122 or 124, 124' are
provided to minimize leakage of the fuel/air mixture
longitudinally along the valve 28 from one valve portion 42
to the next. The labyrinthine design of the channels 122
and 124, 124' acts as a seal in that the compressed fuel/air
mixture is substantially trapped in the channels and a
turbulent mass of the mixture is created in the channels.
Accordingly, compressed fuel/air mixture piloted off from
one cylinder during its compression stroke does not leak
over into the neighboring valve portion 42.
Although the present construction provides a
particular advantage in that a seal is accomplished by the
channels 122, 124, 124', the turbulence created in the
channels 122, 124, 124' tends to create heat in the
intermediate environment. Accordingly, in the bore hole for
the valve 28 immediately about the channels 122, 124,124'
are provided a number of ceramic bushings 126.
From the foregoing, it can be seen that during
engine operation a continuous flow of circulating compressed
fuel/air mixture is piloted off from the cylinder to
circulate about the valve 28. Cooling and lubrication is
accomplished thereby, creating a cooled gas bearing within
which the valve 28 freely rotates. To seal one valve
portion 42 from another portion 42, the channels 122, 124,
124' are provided to create a labyrinth seal. This
construction prevents leakage of combusting fuel/air from
cylinder to cylinder.
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With reference now particularly to Figures 2 and 6,
the means for rotatably driving the intake and exhaust
rotary valves 28 and 38, respectively, is thereshown and
comprises a vertical shaft 72 having an upper end extending
into and rotatably journalled within the cavity 52. The
lower end of the shaft 72 is coupled with and rotatably
driven by the crankshaft (not shown) of the engine 10.
A bevel gear 74 is secured to the upper end of the
shaft 72 and meshes with a cooperating bevel gear 76 coupled
to a stub shaft 78 and rotatably journalled by ball bearing
means 80 within the housing cavity 52. Still referring to
Figures 2 and 6, a small spur gear 82 is likewise coupled to
the stub shaft 78 for rotation therewith immediately
adjacent the bevel gear 76. The spur gear 82 in turn meshes
with a pair of larger spur gears 84 secured onto the front
end 50 of both the intake and exhaust valves 28 and 38,
respectively.
By this arrangement, rotation of the shaft 72 by
the engine crankshaft in turn simultaneously rotatably
drives both the intake and exhaust valves 28 and 38.
It will also be appreciated that the proper gearing
ratios between the gears 74, 76, and 82 and 84 will, of
course, depend upon the particular type of internal
combustion engine 10- For example, in a conventional
four-cycle engine a one-half rotation of each rotary valve
28 and 38 would be required for every two rotations of the
engine crankshaft. It will also be appreciated that the
rotary valves 28 and 38 are rotatably driven in the opposite
rotational directions, but due to the diametric nature of
the oblong throughbores 54, the correct opening sequence for
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the valves 28 and 38 is obtained regardless of their
direction of rotation.
With reference to Figure 5, an alternate embodiment
of the means for rotatably driving the intake and exhaust
rotary valves 28 and 38, respectively, is thereshown and
comprises a vertical shaft 172 having an upper bevel gear
174 and a lower bevel gear 176. The lower bevel gear 176 is
rotatably driven by a crankshaft bevel gear 178 provided at
one end of the crankshaft (not shown).
The upper bevel gear 174 meshes with a pair of
cooperating valve bevel gears 128, 138, each provided at the
end of the intake and exhaust rotary valves 28 and 38,
respectively. By this arrangement, rotation of the
crankshaft bevel gear 178 by the engine crankshaft in turn
simultaneously rotatably drives both the intake and the
exhaust valves 28 and 38.
The rotary valve construction of the present
invention thus achieves severa] important advantages over
the previously-known rotary valves. In particular, the
peripheral cooling and lubricating of the valves 28 and 38
provide a simple and yet effective means for efficiently
providing a cooled valve and a lubricated compressed gas
bearing. As such, expensive and complex cooling and bearing
designs are effectively eliminated.
In addition, the labyrinth seal provided by the
spiral channels 122, 124, 124' eliminates spill-over of
compressed gas from one valve portion 42 to another.
To further prevent spill-over, an alternate
embodiment of the present invention is shown in Figures 7-9.
With reference thereto, a view is shown illustrating a
valve, such as the intake valve 28, rotatably housed within
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~; head assembly 16. The ceramic bushing 126 is also
illustrated. In this embodiment, a sealing ring 180 is ~.
included and is fitted in a channel defined in the head
assembly 16. The sealing ring 180 is preferably composed of
a carbon or a carbon compound to provide a high heat
resistance. Peripherally fitted about the sealing ring 180 -~ -
is a rubber or plastic ring washer 182 fitted within a .
channel 184 defined about the sealing ring 180.
Having described my invention, many modifications .~
thereto will become apparent to those skilled in the art to ;
which it pertains without deviation from the spirit of the
invention as defined by the appended claims.
I claim: ~.
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