Four-stroke And Two-stroke Rotary Internal Combustion Engine

Abstract

A rotary internal combustion engine including a stator having a circular chamber within which is coaxially disposed a shaft supporting an off-center circular rotor, the diameter of the rotor being such that the distance between the center of the shaft and the zenith on the rotor periphery is substantially equal to the radius of the chamber whereas the distance between the center of the shaft and the nadir on the periphery is substantially equal to half this radius. Extending into the chamber are slide plates which are urged into continuous contact with the rotor surface to divide the chamber into operating zones of varying volume into which fuel charges are admitted for compression and ignition to produce gas expansion creating torque forces, the spent gases being exhausted from the zones.

Parent Case Text

RELATED APPLICATION

This application is a continuation-in-part of my copending application Ser. No. 280,733, filed Aug. 14, 1972 for ROTARY INTERNAL COMBUSTION ENGINE.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to rotary internal combustion engines, and more particularly to a rotary engine wherein an eccentrically-mounted rotor sweeps cyclically through a circular stator chamber and cooperates with slider plates which continuously engage the rotor surface to define operating zones to carry out a four-stroke or two-stroke internal combustion action that directly generates a rotational force.

In a standard internal combustion gasoline engine of the reciprocating-piston type, a combustible mixture is compressed in a cylinder and ignited. The gases which are produced in the cylinder by the combustion of the gasoline-air mixture, expand and thrust the piston downwards. Acting through a connecting rod, the piston imparts a rotary motion to the crankshaft. The spent burned gases must then be removed from the cylinder and replaced by a fresh fuel charge, so that a new cycle can begin. The energy for effecting this change in the contents of the cylinder, is supplied by a flywheel which stores some of the released energy.

A distinction must be drawn between four-stroke and two-stroke operation in an internal combustion engine. To carry out a full cycle of operations, including changing the contents of the cylinder and effecting combustion, the four-stroke engine requires four strokes of the piston, whereas the two-stroke engine entails only two piston strokes.

The present invention makes use of a continuously rotating rotor supported eccentrically on an output shaft coaxially mounted within a circular stator chamber to directly produce a rotational force. This rotary engine goes through the equivalent of a four-stroke or two-stroke action, but since no piston is involved, there is no reversal of direction, as in a piston-engine, where the piston must come to a complete halt before changing direction.

Because the present invention provides the equivalent of a four-stroke or two-stroke internal combustion piston action without the drawbacks incident thereto, a brief review of the standard four-stroke and two-stroke piston actions may be helpful.

In a four-stroke, reciprocating piston engine, the first stroke is an induction stroke in which the descending piston draws a fresh gasoline-air mixture from the carburetor through the then open intake valve into the cylinder. The exhaust valve is closed during the first stroke.

In the second or compression stroke, both the intake and exhaust valves are closed, and the rising piston acts to compress the mixture to a predetermined pressure level (i.e., 7 to 8 atmospheres), at which point the compressed mixture is ignited by the spark plug.

In the third or power stroke, both valves are still closed, and the pressure developed by the gases of combustion acts to force the piston downwards. In the fourth or exhaust stroke, the exhaust valve is open, but the intake valve is closed, and as the piston again rises, it discharges the spent gases from the cylinder.

Since power is developed during only the third stroke, the single-cylinder, four-stroke reciprocating engine has a low degree of uniformity, for the rotation of the crankshaft is subject to acceleration and deceleration during an operating cycle. A smoother running action is obtained with multi-cylinder engines wherein the cranks of the crankshaft are staggered in relation to one another.

In the two-stroke, reciprocating-piston engine, the piston periodically covers and uncovers inlet and exhaust ports in the cylinder wall, thereby obviating the need for valves. At the start of the first stroke, the piston is at its highest position, and when the gasoline-air fuel mixture, which is compressed in the space above the piston, is ignited, the piston is thrust downwards and, in the course of travel, opens up the exhaust port.

The burnt gases in the cylinder, which are still under high pressure, escape through the open exhaust port. When the piston descends further, its upper edge releases the inlet port which admits a fresh fuel charge into the cylinder so that the remaining burnt gases are flushed out, thereby completing the first stroke. When, in the next stroke, the piston rises again, all ports are again closed for a time, and during this period the fresh charge is compressed so that a new cycle can begin.

In an attempt to overcome the serious drawbacks of reciprocating-piston engines, rotary internal combustion engines have been developed, the best known of which is the so-called "Wankel" engine. In the Wankel engine, a triangular rotor carries out essentially the same functions as a piston in a reciprocating engine. That is to say, the rotor acts to draw a fresh fuel charge into the engine chamber to compress the charge and after ignition thereof, to capture the force of the expanding gases, the rotor serving finally to sweep the exhausted gases out of the engine housing.

In a Wankel-type engine, the triangular rotor operates within a chamber whose epitrochoid shape is dictated by the complex motion of the rotor as it revolves about an eccentric on a rotating main shaft. This motion is usually produced by means of a gear rotating about an off-center axis, causing the triangular rotor to travel with a non-uniform or wobbling motion. In some Wankel-type engines, an equivalent motion is obtained by a cam and roller, or by a linkage mechanism.

As compared to a conventional reciprocating piston engine, relatively little energy is wasted in a Wankel-type engine, for while the piston in a four-stroke or two-stroke engine must come to a complete halt at the end of each stroke, the rotor of a Wankel engine is never arrested, and functions continuously to convert the force of the expanding gases into a torque that is applied directly to the main shaft.

One reason why the Wankel engine has not received widespread acceptance despite its low cost and other significant advantages, lies in its inherent wobbling motion, which gives rise to energy-dissipating forces that not only materially affect the efficiency of the engine, but also produces objectionable vibrations and unacceptable noise levels.

Moreover, this wobbling action of the rotor in traversing the epitroichoid chamber quickly degrades and wears out the engine parts, particularly those fabricated of standard materials. It is for this reason that expensive wearing surfaces made of exotic metal have in recent years been introduced in Wankel engines, but these materials offer no solution to deficiencies inherent in the standard design of a Wankel-type and other known forms of rotary engines.

SUMMARY OF THE INVENTION

In view of the foregoing, it is the main object of this invention to provide a rotary engine capable of operating on the four-stroke or two-stroke principle without, however, at any time reversing direction, to convert the thrust of the expanding gases directly into rotary motion.

More particularly, it is an object of this invention to provide a rotary engine of the above-type wherein a circular rotor eccentrically mounted on an output shaft coaxially positioned within a circular stator chamber, is caused by forces produced by internal combustion to rotate with substantially uniform motion.

A significant advantage of the invention is that, as compared to a Wankel-type rotary engine, it is of simple construction, for it dispenses with the usual eccentric gearing and makes use of a circular stator chamber rather than a chamber having a complex shape which dictates a wobbling rotor motion. Not only is an engine according to the present invention less costly than a Wankel engine of equivalent horsepower, but it also has a longer life, for with a circular sweeping action of the rotor within a circular chamber, no actual point of wear contact exists between the rotor and the wall of the chamber.

Also an object of this invention is to provide a rotary engine of the above-type, in which the stator chamber is divided by slide plates engaging the rotor surface, into operating zones, the slide plates being tracked and sealed to avoid leakage from the zones and to thereby maintain the efficiency of the engine.

A salient feature of the present invention is that the rotor, in the course of movement, brings about a change in volume in the operating zones defined by the slide plates engaging the rotor, which changes in volume are comparable to those produced by movement of a piston within a cylinder without however going through changes in direction as in the case of a piston.

Yet another object of the invention is to provide a low-cost, efficient rotary engine which is substantially free of vibration, noise and other objectionable factors.

Briefly stated, these objects are attained in a rotary internal combustion engine wherein a circular rotor is eccentrically mounted on an output shaft disposed coaxially within a circular chamber, the diameter of the rotor being such that the distance between the shaft center and the zenith point on the rotor periphery is substantially equal to the radius of the chamber, whereas the distance between the shaft center and the nadir point on the periphery is substantially equal to half this radius, whereby as the rotor sweeps the chamber the zenith travels in a circular scan path without actually making contact with the wall of the chamber.

In the four-stroke embodiment of the engine, the chamber is divided into four operating zones by four slide plates arranged in quadrature and extending radially into the chamber, the plates being urged into continuous engagement with the rotor surface. Each zone operates with a combustion cavity containing the gap electrodes of a sparkplug as well as intake and exhaust valves, whereby in the course of two full revolutions of the rotor, a fuel mixture is induced into the zone, compressed therein, ignited to undergo power expansion generating a thrust force on the rotor, after which the spent gases are exhausted.

In the four-stroke arrangement, ignition in the four zones is effected in a timed sequence wherein ignition takes place in the course of the first revolution in one pair of opposing zones, and in the course of the second revolution in the other pair of opposing zones, whereby four power pulses are generated at quadrature positions during the two revolutions to complete a full operating cycle imparting a high torque to the shaft and giving rise to a smooth-running, substantially uniform rotary output motion.

In the two-stroke embodiment of this engine, one pair of opposing zones cooperates with combustion cavities containing the gap electrodes of two sparkplugs, there being a lateral exhaust port in each of these zones whose opening and closing is determined by the position of the rotor relative thereto. The other half of opposing zones operates with respective lateral fuel supply ports whose openings and closings are determined by the position of the rotor relative thereto.

In this two-stroke arrangement, ignition takes place alternately one-hundred eighty degrees apart in the course of each revolution of the rotor, the air-fuel mixture taken into a zone which includes a supply port being compressed in the next zone and ignited therein to produce power expansion, the spent gases being discharged through the exhaust port.

Where fuel injection is used rather than carburetion, air is taken in instead of an air-fuel mixture and fuel is injected directly into the combustion chamber in timed sequence during or after compression of the air charge.

Where fuel-air mixture charging is effected by auxiliary means such as a pump, blower or compressor, all four zones defined by the four slide plates can be utilized as power chambers, with lateral ports for intake and exhaust, suitably manifolded. In such an arrangement, two-stroke combustion cycling takes place in each of the four zones sequentially, ignition occurring each 90.degree. revolution or four power pulses per revolution. This provides the equivalent power of a four-cylinder, two-stroke engine or of an eight-cylinder, four-stroke engine. It is also to be understood that rotary engines according to the invention are operable with combustible gases such as hydrogen or butane.

OUTLINE OF THE DRAWINGS

For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description to be read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a longitudinal section taken through a four-stroke rotary engine in accordance with the invention;

FIG. 2 is a transverse section taken in the plane indicated by line 2--2 in FIG. 1; FIG. 2A is a section taken in the plane indicated by line 2A--2A in FIG. 2.

FIG. 3 is a top view of the engine;

FIG. 4 is a side view of the valve mechanism in the engine;

FIG. 5 is a view taken in the plane indicated by line 5--5 in FIG. 1;

FIGS. 6, 7, 8 and 9 respectively show in schematic form the operating phases I, II, III and IV of the four-stroke engine illustrated in FIG. 1;

FIG. 10 is a longitudinal section taken through a two-stroke rotary engine according to the invention;

FIG. 11 is a top view of the engine shown in FIG. 10;

FIGS. 12, 13, 14 and 15 respectively show in schematic form the operating phases I, II, III and IV of the two-stroke engine illustrated in FIG. 10.

DESCRIPTION OF THE INVENTION

Referring now to FIGS. 1 to 5, there is shown a preferred embodiment of a four-stroke rotary engine in accordance with the invention. The main components of the engine are a rotor, generally designated by numeral 10, and a stator, generally designated by numeral 11.

Rotor 10 has a perfectly circular configuration, and is directly mounted off-center on an output shaft 12, coaxially supported within the circular chamber of stator 11. The diameter of the rotor is such that the distance D.sub.z between the center X of shaft 12 and the zero degree or zenith point Z on the periphery of the rotor, is substantially equal to the radius of the chamber, whereas the distance D.sub.n between shaft center and the 180.degree. or nadir point N on the rotor periphery, is substantially equal to one-half the radius of the chamber.

There is minimal clearance between zenith point Z on the rotor and the wall of the stator chamber. Though there is no point of contact between the rotor and stator in the course of revolution, the minimal clearance therebetween does not constitute a leakage or loss path for it is part of the chamber and its clearance volume.

The zenith of the rotor sweeps through a circular scanning path that is concentric with the wall of the stator chamber. The zenith arc segment of the rotor acts in a manner equivalent to that of a piston blade whose top surface moves in one phase of the operating cycle toward the chamber wall to compress a fuel mixture in the associated chamber zone to an extent determined by the clearance volume afforded by the engine design. In this context, the wall of the chamber effectively acts as a cylinder head (again using the piston-cylinder analogy) while the side plates of the chamber function as the cylinder wall. However though the present rotary engine is in some respects analogous to a reciprocating piston engine, it must always be borne in mind that the operating strokes in the present engine are carried out in the course of rotor revolution always in the same direction without any reversal or deceleration.

The chamber of stator 11 is divided into four distinct quadrature zones A, B, C and D, by radially extensible slide plates P.sub.1, P.sub.2, P.sub.3 and P.sub.4, each of which is spring-biased to urge the free end of the plate to engage the surface of rotor 10 and maintain continuous contact therewith. In practice this bias may be obtained by gas or hydraulic pressure. Formed in the stator and communicating with zone A, is a combustion cavity C.sub.a, within which are disposed the gap electrodes 16 of a sparkplug 13.

Disposed on either side of sparkplug 13 are two valves, one of which functions as an intake valve 14 leading to a fuel inlet port 15. The second valve functions as an exhaust valve 17 leading to an exhaust port 18. The valve and sparkplug structures are similar to those in a conventional piston engine.

Similarly, a combustion chamber C.sub.b communicates with zone B, within which are disposed the gap electrodes of a sparkplug 19. Associated with this cavity are an intake valve 20 leading to fuel inlet port 21, and an exhaust valve 22 leading to exhaust port 23. A combustion cavity C.sub.c communicates with zone C, within which are disposed the gap electrodes of a sparkplug 28. Associated with this cavity are intake valve 24 leading to fuel inlet port 25, and exhaust valve 26 leading to exhaust port 27.

Zone D communicates with combustion cavity C.sub.d, within which are disposed the gap electrodes of sparkplug 29, and associated with this cavity are intake valve 30 leading to inlet port 31, and exhaust valve 32 leading to exhaust port 33.

We shall at this point not further consider the mechanical details of the engine, including the means by which the components thereof are sealed to prevent leakage from the four zones, nor the manner in which the valves are manipulated in the course of an operating cycle, for these will be analyzed after the basic operating principles are explained and clearly understood.

It will be seen that in the course of a single, 360-degree, clockwise revolution of the rotor from the zenith position Z shown in FIG. 1, the zenith of the rotor will initially engage slide plate P.sub.1 to force this plate fully out of the stator chamber, and that as this zenith Z scans the wall, it will successively engage slide plates P.sub.2, P.sub.3, P.sub.4, and back again to plate P.sub.1, forcing each plate in turn into its fully retracted position.

As the zenith Z moves clockwise away from each plate, the plate, which always engages the periphery of the rotor, proceeds to move radially into the chamber until it reaches the nadir N on the rotor periphery, at which point the plate has its maximum extension from the stator wall, after which the plate is progressively pushed out of the chamber until it again reaches rotor zenith Z. Hence the zone established between any two slide plates has a changing volume determined at any instant by the relative degree to which the related plates are extended into the chamber.

Each zone has it minimum volume its zenith A of rotor 10 is exactly midway between the pair of associated plates defining the zone. Maximum volume is attained when nadir N is at this midway position. Between the maximum and minimum levels, the volume undergoes changes as the rotor turns. This change in volume is known in engine parlance as the displacement.

When a mixture compressed in an operating zone is ignited, the expanding gases produce a torque force just as soon as the center of gas pressure on the arced surface of the rotor passes the point of alignment with the shaft center X. This point of alignment in piston engines is referred to as top dead center.

Referring now to FIGS. 6 to 9 which respectively consist of sketches showing operating Phases I, II, III and IV, we shall now outline the operation of the four-stroke rotary internal combustion gasoline engine having zones A, B, C and D. The engine completes a full operating cycle in the course of two full revolutions of the rotor. We shall therefore with respect to each zone, consider what happens during the successive phases in both the first and second revolutions.

FIRST REVOLUTION -- ZONE A

Phase I

Both the intake and exhaust valves 14 and 17 are closed. Zone A is filled with a fuel charge under full compression. Zenith Z of the rotor is at the midway position in the zone and sparkplug 13 is ignited to explode the charge.

Phase II

Both intake and exhaust valves 14 and 17 are closed. The expanding combustion gases produce a force on the rotor surface between plates P.sub.1 and P.sub.2, the resultant of which is displaced from the center of the shaft to create a torque to cause zenith Z to move toward zone B.

Phase III

Intake valve 14 is closed, but exhaust valve 17 is now open. This phase occurs at the end of the expansion of the gases and the beginning of the exhaust of the spent gases through the open exhaust valve 17.

Phase IV

In this phase, intake valve 14 is still closed and exhaust valve 17 is still open to permit continuing exhaust of the spent gases and sweep out by the piston-like action of the rotor surface as the Z point approaches its original position in Phase I. FIGS. 6 to 9 illustrate the rotor and valve positions for Phases I to IV of the first revolution but not for the second revolution which will now be described but not illustrated.

SECOND REVOLUTION -- ZONE A

Phase I

Exhaust valve 17 is still open but just about to close and intake valve 14 is re-opened to permit the completion of exhaust and the start of fuel intake.

Phase II

The exhaust valve 17 is now fully closed, and intake valve 14 is now fully opened to permit further fuel intake.

Phase III

Exhaust valve 17 is still closed, and intake valve 14 is still partially open, to permit completion of fuel intake.

Phase IV

Both exhaust valve 17 and intake valve 14 are closed as the fresh fuel charge undergoes compression before ignition. This last phase of the second revolution leads into Phase I of the first revolution to initiate the next two-revolution cycle. It will be seen that this Zone-A operation is equivalent to that of a four-stroke piston engine, in which the successive operating phases are induction, compression, power and exhaust.

FIRST REVOLUTION -- ZONE B

Phase I

In this phase, intake valve 20 is closed and exhaust valve 22 is open to initiate exhaust from zone B.

Phase II

In this phase, intake valve 20 is now open and exhaust valve 22 is still open to complete exhaust and to start fuel intake.

Phase III

In this phase, intake valve 20 is still open to continue fuel intake, while exhaust valve 22 is closed.

Phase IV

Intake valve 20 is still open to complete intake, while exhaust valve 22 is closed. FIGS. 6 to 9 show rotor and valve positions for the operating phases of Zone B for the first revolution but not for the second revolution which is described.

SECOND REVOLUTION -- ZONE B

Phase I

In this phase, both intake valve 20 and exhaust valve 22 are closed, while the gasoline-air charge introduced during Phases II, III and IV of the first revolution, is compressed.

Phase II

In this phase, intake and exhaust valves 20 and 22 are still closed, and the compressed fuel mixture is ignited by sparkplug 19. It is to be noted that ignition in Zone B takes place in Phase II of the second revolution, whereas in Zone A, it takes place in Phase I of the first revolution. The timing of the sparkplug distributor is adjusted for sequential ignition in accordance with this requirement.

Phase III

In this phase, the previously ignited mixture undergoes power expansion while both valves 20 and 22 are closed, to cause the zenith Z of rotor 10 to travel toward Zone C.

Phase IV

In this final phase, valves 20 and 22 are still closed while expansion is completed, after which the rotor returns to the Phase I position of Zone B in the first revolution, to exhaust the spent gases resulting from power expansion.

FIRST REVOLUTION -- ZONE C

Phase I

In this phase, fuel intake has been completed and exhaust valve 26 and intake valve 24 are both closed in preparation for compression.

Phase II

While both valves 26 and 24 are closed, the fuel mixture in Zone C is compressed.

Phase III

With both valves closed, the compressed fuel is ignited by sparkplug 28. It will be seen that ignition in Zone C takes place in Phase III of the first revolution, whereas ignition in Zone B occurs in phase II of the second revolution.

Phase IV

Valves 26 and 24 are still closed and the expanding gases produce power to push the zenith of rotor 10 toward Zone D. FIGS. 6 to 9 illustrate the phases of the first revolution of Zone C but not that of the second revolution to be now described.

SECOND REVOLUTION -- ZONE C

Phase I

With valves 26 and 24 still closed, expansion is completed.

Phase II

Exhaust valve is opened, while intake valve 24 is held closed, to initiate exhaust of the spent gases.

Phase III

Exhaust valve 26 remains open while intake valve 24 remains closed to complete exhaustion.

Phase IV

With exhaust valve 26 still closed and intake valve 24 now open, fuel intake into Zone C is commenced, this intake being continued in Phase I of the first revolution of the next cycle. FIGS. 6 to 9 show the phases of Zone D for the first revolution but not for the second revolution to be now described.

FIRST REVOLUTION -- ZONE D

Phase I

With intake valve 30 open and exhaust valve 32 closed, fuel is drawn into Zone D.

Phase II

With intake valve 30 still open and exhaust valve 32 closed, fuel intake is completed.

Phase III

In this phase, both valves 30 and 32 are closed while the fuel is compressed.

Phase IV

In this phase, with both valves still closed, the compressed fuel is ignited by sparkplug 29. It will be seen that in Zone D, ignition takes place in Phase IV of the first revolution, whereas in Zone C, ignition takes place in Phase III of the first revolution. FIGS. 6 to 9 show the phases of Zone D in the first revolution but not the second revolution to be now described.

SECOND REVOLUTION -- ZONE D

Phase I

In this phase, both valves 30 and 32 are still closed, and the ignited fuel undergoes power expansion to force zenith D of rotor 10 toward Zone A.

Phase II

In this phase, with both valves 30 and 32 still closed, power expansion is completed.

Phase III

In this phase, with exhaust valve 32 open and intake valve 30 closed, the spent gases are exhausted.

Phase IV

In this final phase, with the exhaust valve 32 still open and intake valve 30 closed, the exhaustion of the gases is completed preparatory to Phase I of the first revolution, in which a fresh charge of fuel is induced.

Thus in a four-stroke rotary engine in accordance with the invention, each quadrature zone of the stator chamber through which the rotor sweeps, undergoes fuel induction, compression, ignition, power expansion, and exhaust, once every two revolutions of the rotor, in a sequence wherein during the first revolution, Zone A generates power in Phase II and Zone C in Phase IV, while in the second revolution, Zone D generates power in Phase I and Zone B in Phase III.

Thus the first revolution of the rotor is accompanied by two successive power pulses, and the second revolution by two successive power pulses which are in staggered time relation to the first two pulses, thereby avoiding deceleration of the rotor and producing a substantially uniform torque. As in a four-stroke four-cylinder piston engine, the firing order in the present invention is Zones A, C, D, B, equivalent to cylinders 1, 3, 4, 2 in a conventional four-cylinder engine.

It is to be understood that the invention is also applicable to a rotary engine operating on diesel principles, for diesel engines are also designed to operate on the four-stroke or two-stroke principle, just like gasoline engines. The combustion process in the diesel engine differs from that in a gasoline engine in that instead of drawing in a gasoline-air mixture, air alone is drawn and compressed to a relatively high ratio, as a result of which the air is heated to a temperature in excess of 700.degree.C. Only then is diesel fuel injected into the chamber. Because of the prevailing high temperature, the fuel ignites spontaneously. The injection nozzle is designed so that its spray pervades all the air in the combustion chamber.

In connection with FIG. 2, we shall now consider the manner in which the rotary engine is effectively sealed and the means by which wear is reduced. As pointed out previously, there is no actual point of contact between the periphery of the rotor and the inner surface of the stator chamber. The operating zones are defined by slide plates P.sub.1 to P.sub.4 which continuously engage the periphery of the rotor, these points of engagement representing the only points of wear. But wear at these points is minimized in that the periphery of the rotor does not undergo the same rotational motion as the rotor body, as will be explained hereinafter.

Shaft 12 of rotor 10 is supported on either end by sleeve bearings 34 and 35 fitted into the end plates 11A and 11B of the stator structure. Rotor 10 which is eccentrically mounted on shaft 12, is provided with a peripheral collar 10A whose width is such that it extends at either end beyond the edges of the rotor body. Peripheral collar 10A is freely mounted on rotor 10 and is capable of independent rotation thereon. Hence as eccentric rotor 10 turns about shaft 12, the peripheral collar, which is subjected to radial pressure by the slide plates P.sub.1 to P.sub.3, is carried through the rotor scanning circle but its rotation is resisted by the plates which in the course of a rotor revolution move in and out of the stator chamber and continuously engage the collar. As the rotor turns eccentrically on shaft 12, the peripheral collar thereon undergoes epicyclic motion in which sliding motion between the collar and plates is minimized although some degree of collar rotation will be experienced.

It will be noted that oil lubrication passages are provided in shaft 12 which lead to the interface of the rotor body and peripheral collar as well as to bearings 34 and 35. it is to be understood however that the invention is not limited to this collar arrangement and that in practice, particularly with low-cost motors, the peripheral collar may be omitted, in which event the plates bear directly against the rotor body.

Sealing of the rotor is effected by means of rings 36 and 37 each having a rectangular cross section. The rings are received within annular grooves formed in the left end of the peripheral collar 10A and are urged by suitable springs against the wall of the stator and plates 11B, the rings being in sliding contact therewith. A similar set of rings is provided for the right end of the collar.

Sealing the slide plates, such as plates P.sub.1 and P.sub.3 shown in FIG. 2, is effected by means of close-fitting rectangular shoes 38 and 39 slotted to receive the edges of the plates and riding within suitable slots in the end plates of the stator as the slide plates move up and down. Within shoe 38 is the right edge of plate P.sub.1 and spring 38A which presses shoe 38 against the stator slot in end plate 11A. Also in shoe 38 is a sealing block 38B with a fitted slot to receive the bottom edge of plate P.sub.1 which is urged by spring 38C against the side and edge of the rotor collar 10A.

Similarly with shoe 39, there is a spring 39A pressing against the edge of the associated slide plates P.sub.3, urging shoe 39 against the stator slot in end plate 11B. A sealing block 39B is urged by a spring 39C against the side and edge of the rotor collar. Sealing the clearance spaces between the sides of all slide plates and the slots in stator 11 is effected by means of lengths of rectangular cross section bars 44 (see FIG. 1) in rectangular grooves, the bars being urged by springs 45 against the plates in sliding contact therewith. The length of these bars is substantially equal to the width of the plates exposed between the edges of the sealing shoes.

Sealing of the zones at the surface of the rotor is accomplished by springs which urge the slide plates into engagement with the peripheral collar on the rotor. FIG. 2 shows a set of springs 40 for plate P.sub.1 and another set 41 for plate P.sub.3.

Thus the plates are urged into continuous contact with the rotor so as to prevent any leakage between the adjacent zones defined by each plate, and the edges of the plates, which move in and out, are sealed by the shoes to prevent leakage as a result of such movement.

Referring now to FIGS. 10 and 11, there is shown a rotary engine of essentially the same construction as the four-stroke internal combustion engine disclosed previously but instead of exhaust and intake valves, lateral ports are provided which are selectively opened and closed as the eccentrically-mounted rotor sweeps through the stator chamber which is divided into operating zones by the slide plates. But before considering the structure and function of this rotary engine, some aspects of a conventional two-stroke reciprocating piston engine will first be reviewed, for in such conventional engines the crankcase functions as a pump, whereas in the present engine there is no crankcase.

In a crankcase scavenged two-stroke reciprocating piston engine, the crankcase is hermetically sealed so that it can function as a pump in conjunction with the piston. When the piston ascends, a partial vacuum is produced in the crankcase, until the lower edge of the piston releases the inlet port to open the passage for the admission of a fresh gasoline and air mixture into the crankcase. When the piston descends, the mixture in the crankcase is compressed somewhat, so that as soon as the top of the piston releases the transfer port and overflow duct connecting the crankcase to the cylinder, it can enter the cylinder. In the present invention, similar functions are carried out within the stator zones.

In the two-stroke rotary engine shown in FIGS. 10 and 11, rotor 10 is again eccentrically mounted on shaft 12 to revolve within the circular chamber formed by stator 11. In this instance, the reciprocating slide plates P.sub.1, P.sub.2, P.sub.3 and P.sub.4 divide the stator chamber into two pairs of companion zones A and A' and B and B'.

Zone A' is provided with a transfer port A.sub.t which is coupled by a transfer duct D.sub.a to an inlet port A.sub.in located in companion zone A which includes an exhaust port A.sub.e. Zone B' is provided with a transfer port B.sub.t which is coupled by a transfer duct D.sub.b to an inlet port P.sub.in located in companion zone B which includes an exhaust port B.sub.e. The gas-air mixture from the carburetor goes through a pipe leading to a transfer port A.sub.t, the pipe being provided with a reed intake valve 44 which functions as a check valve. The carburetor input pipe to transfer port B.sub.t has a similar valve 45.

Communicating with zone A is a combustion cavity C.sub.a within which is located the electrodes of a spark plug 42 and communicating with zone B is a combustion cavity C.sub.b within which are disposed the electrodes of a spark plug 43. These spark plugs are diametrically opposed on the stator 2 and fired alternately, each 180 degrees of rotation.

The operation will now be explained in connection with FIGS. 12 to 15 which show successive operating Phases I, II, III and IV.

Phase I

In this phase, both intake port A.sub.in and exhaust port A.sub.e in zone A are closed and the rotor, moving clockwise, proceeds to compress the mixture in this zone. In zone B we are at the end of power expansion, with inlet port B.sub.in and exhaust port B.sub.e both closed. In zone B' the transfer port B.sub.t which communicates with the carburetor, is open at the end of intake, whereas transfer port A.sub.t in zone A is closed.

Phase II

In this phase, zone B is exhausting through port B.sub.e which is open while purging and intake takes place through transfer port B.sub.t in zone B', forcing the charge into zone B. Zone A is at the end of compression and at the start of ignition with both inlet port A.sub.in and exhaust port A.sub.e closed, while in zone A transfer port A.sub.t is being opened to commence induction.

Phase III

In this phase, ports A.sub.in and A.sub.e are closed in zone A where power expansion takes place. In zone A', transfer port A.sub.t is open while intake takes place. In zone B where ports B.sub.in and B.sub.e are closed, compression is in progress while in zone B', transfer valve B.sub.t is closed.

Phase IV

In this phase, we are at the end of compression in zone B where ports B.sub.e and B.sub.in are closed and at the start of combustion and power expansion. In zone B', the transfer port B.sub.t is being opened for intake while in zone A where port A and ports A.sub.in and A.sub.e are open, gas is being exhausted and purging and intake is in progress. In zone A' where transfer port A.sub.t is open, the mixture is being transferred to zone A.

It is to be noted that the inlet and exhaust ports in the zones A and B are on opposite side walls of the chamber. It is also possible to provide engines with combustion valves and passages and ports utilizing one pair of zones as an air or gas compressor for direct fuel injection of gasoline or oil fuel to carry out semi-diesel action in the other pair of zones. Also, the slide plates need not be in guadrature relation, for they may be more or less than in quadrature relation for variations of compression pressure and other precharging and supercharging requirements.

Thus for two-stroke semi-diesel operation, the oppositely disposed combustion chambers may be reduced to a 60.degree. to 80.degree. inclusive angle, thereby effectively enlarging the adjoining zones proportionately for supercharging air purposes. These zones as in the two-stroke gasoline reciprocating engine act to effect intake of air for a diesel fuel and air mixture or for a gasoline-air mixture in spark ignition engines. They then compress the air or the charge in the combustion zones and their relative displacement determines the charging pre-pressure before the compression stroke in the combustion zones.

While there have been shown and described preferred embodiments of rotary internal combustion engines in accordance with the invention, it will be appreciated that many changes and modifications may be made therein without, however, departing from the essential spirit thereof.

Claims

1. A rotary internal combustion engine comprising:

A. a stator having a substantially circular chamber defined by a pair of parallel end walls and a continuous side wall,

B. an output shaft coaxially mounted within said chamber,

C. a rotor having a circular cross-section mounted off-center on said shaft, said rotor having a diameter along which the distance between the center of the shaft and the zenith of the rotor is slightly less than the radius of the chamber, and the distance between the center of the shaft and the nadir of the rotor is no more than about half this radius, whereby as the rotor sweeps the chamber the zenith travels in a circular scan path concentric with the side wall of the chamber and there is no point of contact between the rotor and the side wall,

D. independently movable slide plates extending into the chamber at angular displaced positions therein to divide same into operating zones, the edges of said slide plates being received in guide slots formed in the end walls of the stator, the plates being urged into continuous contact with the surface of the rotor, whereby in the course of a full rotation of the rotor, each slide plate moves between a maximum retracted position and a maximum extended position, said guide slots having lengths extending between said maximum retracted and extended positions whereby at no point in the movement of a plate are the edges thereof unsupported or unsealed,

E. means in said guide slots sealing the edges of said plates, said means engaging the edges of said plates and being movable therewith within said guide slots, and means sealing the peripheral edges of said rotor with respect to the end walls of the chamber whereby the resultant volume of each zone is determined by the space enveloped by the associated slide plates and the related surfaces of said rotor and said stator and said volume continuously varies to a degree determined by the extent to which the associated plates are extended, and

F. means associated with said zones selectively to induce a combustible mixture therein, to compress and ignite said mixture, to produce power

2. A rotary combustion engine as set forth in claim 1, wherein said sealing means for said slide plates includes shoes which engage the edges of said plates and are movable within said slots in said stator, said shoes being

3. A rotary combustion engine as set forth in claim 1, wherein said rotor is provided with a peripheral collar which is freely mounted on said rotor whereby as said rotor turns on said shaft, said collar undergoes epicyclic

4. An engine as set forth in claim 3, wherein said collar is provided with sealing rings which are accommodated within annular grooves in the edges of said collar and are urged against the end walls of said stator to seal

5. An engine as set forth in claim 1, further including springs to urge

6. An engine as set forth in claim 1, wherein four of said slide plates are provided in a quadrature arrangement for four-stroke operation, each of the resultant zones including means for the intake of a gasoline-air mixture, means to ignite said mixture and means to exhaust the resultant

7. An engine as set forth in claim 6 wherein said means are constituted by

8. An engine as set forth in claim 1 including port means associated with said zones which are selectively opened and blocked by said rotor in the course of rotation to cause said engine to operate on a two-stroke

9. An engine as set forth in claim 8, wherein four slide plates are provided to divide said chamber into two pairs of companion zones, one zone in the first pair having a transfer port coupled by a pipe to a carburetor and communicating with an inlet port in the other zone which is further provided with an exhaust port and ignition means, one zone in the second pair having a transfer port coupled by a pipe to a carburetor and communicating with an inlet port in the other zone which is further

10. An engine as set forth in claim 9, further including unidirectional valves in said pipes to admit a gasoline-air mixture to the associated zone and to prevent discharge through said pipes.