US3927647A

US3927647A - Rotary internal combustion engine

Info

Publication number: US3927647A
Application number: US388985A
Authority: US
Inventors: William A Blackwood
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-08-16
Filing date: 1973-08-16
Publication date: 1975-12-23
Anticipated expiration: 1992-12-23

Abstract

A rotary engine for two cycle operation having arcuate combustion chambers formed in a rotor and correspondingly arcuate pistons mounted for swinging reciprocation in the combustion chambers on connecting rods pivoted to the rotor. The housing contains the rotor and provides an oblong inner periphery forming a raceway for cam followers mounted on the pistons so that, when ignition of the fuel mixture occurs at the beginning of a power stroke, the pistons are forced outwardly against the relative incline of the raceway in such a manner as to cause the pistons to impart rotary motion to the rotor. At about the end of the power stroke, the movement of the rotor causes recesses formed in the rotor at the inner end of the combustion chamber to communicate with exhaust and intake ports formed in the housing on opposite sides of the rotor for venting the spent gasses through one of the recesses and receiving a fresh charge of fuel mixture under pressure through the other recess in a scavenging fashion. The momentum of the rotor tends to cause it to rotate through the compression cycle wherein the cam followers riding on the raceway force the pistons into the combustion chambers to compress the air-gas mixture for ignition at approximately the innermost retracted position and thus initiate the next power stroke.

Description

United States Patent [191 Blackwood ROTARY INTERNAL COMBUSTION ENGINE [76] Inventor: William A. Blackwood, 295 Polaris Ave., Mountain View, Calif. 94040 [22] Filed: Aug. 16, 1973 [21] Appl. No.: 388,985

[52] US. Cl. 123/43 C; 123/44 C, 123/44 D [51] Int. F02]! 57/00; F02B 57/04 [58] Field of Search... 123/43 C, 44 C, 44E, 44 D;

[56] References Cited UNITED STATES PATENTS Primary Examiner-John J. Vrablik Attorney, Agent, or F irmSchapp and Hatch 1 1 ABSTRACT A rotary engine for two cycle operation having arcu- 51 Dec.23, 1975 ate combustion chambers formed in a rotor and correspondingly arcuate pistons mounted for swinging reciprocation in the combustion chambers on connecting rods pivoted to the rotor. The housing contains the rotor and provides an oblong inner periphery forming a raceway for cam followers mounted on the pistons so that, when ignition of the fuel mixture occurs at the beginning of a power stroke, the pistons are forced outwardly against the relative incline of the raceway in such a manner as to cause the pistons to impart rotary motion to the rotor. At about the end of the power stroke, the movement of the rotor causes recesses formed in the rotor at the inner end of the combustion chamber to communicate with exhaust and intake ports formed in the housing on opposite sides of the rotor for venting the spent gasses through one of the recesses and receiving a fresh charge of fuel mixture under pressure through the other recess in a scavenging fashion. The momentum of the rotor tends to cause it to rotate through the compression cycle wherein the cam followers riding on the raceway force the pistons into the combustion chambers to compress the air-gas mixture for ignition at approximately the innermost retracted position and thus initiate the next power stroke.

38 Claims, 9 Drawing Figures US. Patent Dec. 23, 1975 Sheet 1 of4 3,927,647

U.S. Patent Dec. 23, 1975 Sheet 2 of4 3,927,647

PIE- .4.

U.S. Patcent Dec. 23, 1975 Sheet 4 of4 3,927,647

ROTARY INTERNAL COMBUSTION ENGINE BACKGROUND OF THE INVENTION The present invention relates to a ROTARY EN- GINE and more particularly to a two cycle internal combustion rotary engine with pivotally swingable pis- 00118.

Prior art internal combustion engines typically have a plurality of pistons each mounted in a separate cylindrical combustion chamber in parallel alignment. Each piston has a separate piston rod connected thereto and the piston rods are connected through a crankshaft and train of gears to impart rotational energy. These devices generate a substantial amount of friction and consume excessive power for various other reasons.

Rotary engines have been therefore relied upon to reduce friction and thereby increase efficiency. They can be made lightweight and compact and have desirable power-to-weight ratios. Furthermore, they are characteristically simple to cast and fabricate.

Rotary engines have been developed which act against a single cam track to convert lineal reciprocating motion of pistons mounted in combustion chambers formed on a rotor to rotary motion of the rotor. US. Pat. No. 2,439,150 to Smith is typical of such devices. The combustion chambers and pistons in these engines are uniformly cylindrical in shape. As the rotor rotates, the reciprocal movement of the piston and connecting piston rod imparts an undesirable lateral cocking moment on the piston sliding against the cylindrical wall as the followers move on the relative incline of the cam surface. This moment causes unbalanced stresses between the piston and cylindrical chamber wall and increases friction between them. This friction results in a reduction in efficiency of the engine and excessive stress and wear on the materials of the piston and cylinder wall.

SUMMARY OF THE INVENTION The general purpose of the present invention is to provide an improved rotary engine in which the rotor is mounted in a housing providing a cam surface having an oblong or generally elliptical inner periphery. The engine has arcuate combustion chambers formed in the rotor and arcuate pistons each mounted for swinging reciprocation in one of the chambers on a connecting rod pivoted to the rotor. Each piston is formed in mating configuration with the associated combustion chamber. The arcuate shape of the pistons and combustion chambers and the pivoted connecting rods eliminates the lateral bending and torque forces inherent in prior rotary engines having cylindrical pistons and combustion chambers. These factors further reduce the friction between the pistons and combustion chambers to thereby increase efficiency.

Cam rollers or followers are mounted on each piston so that when a piston is retracted inwardly at the beginning of a power stroke, as ignition of the fuel mixture occurs in the associated combustion chamber, the piston is forced outwardly against the oblong cam surface to cause the piston to impart rotary motion to the rotor. The piston is also urged outwardly by centrifugal force as the rotor rotates during the power stroke.

Each combustion chamber has its end relieved to form a pair of recesses separated by a protuberance. Approximately at the end of the power stroke, the combustion chamber communicates with exhaust and intake ports formed in the housing sidewalls on opposite sides of the rotor to exhaust the spent gases through one of the recesses and receive a charge of the fuel mixture into the chamber through the other recess, in a scavenging fashion. The exhaust port is positioned so that it comes into communication with the combustion chamber slightly before the intake port for improved scavenging. The cam surface is formed to accommodate the burn characteristics of the particular fuel mixture.

The angular momentum of the rotor tends to cause it to continue to rotate through the compression cycle. In this cycle, each cam follower being mounted on a piston head, travels up the relative incline of the cam surface and forces the piston to swing into the inward retracted position, compressing the fuel mixture. Ignition occurs when the piston is at approximately the innermost retracted position, beginning the power stroke once more. The rotation of the rotor at the beginning of the power stroke has been augmented by centripetal force due to the radially inward retraction of the pistons into the combustion chambers at the end of the compression stroke.

In one form, the engine is cooled by air cooling fins mounted on the rotor. The air passed through the air cooling fins as well as blowby and exhaust gases may be vented to an afterburner which burns this mixture of gases. The burnt gases may be used to drive a turbine to impart rotational energy to a blower to blow air onto the fins.

Accordingly, an object of the present invention is to provide a rotary engine with pivotally swingable pistons.

Another object of the present invention is to provide rotary engine means having at least one arcuate combustion chamber and at least one arcuate piston formed in mating configuration.

A further object of the present invention is to provide a housing for a rotary engine having an elliptical or oblong inner periphery providing a cam surface shaped for accommodating the burn characteristics of an airgas fuel mixture ignited in the combustion chambers.

Still another object of the present invention is to provide an intake and an exhaust port each positioned on sealing plates on opposite sides of a rotary engine and aligned slightly askew relative to each other for improved scavenging.

Yet another object of the present invention is the provision of a pair of recesses separated by a wall in a combustion chamber of a rotary engine for communicating with exhaust and intake ports for improved scavenging.

An additional object of the present invention is to provide fins mounted on the periphery of a rotary engine for cooling thereof.

Further objects and advantages of the present invention will become apparent as the specification proceeds, and the new useful features will be fully defined in the claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred form of the present invention is illustrated in the accompanying drawings, in which,

FIG. 1, is a side elevational view of a rotary engine constructed in accordance with the present invention, with portions removed to show internal mechanism;

FIG. 2, is a side elevational view on a reduced scale of the engine of FIG. 1 at a different point in its operat- 3 ing cycle;

FIG. 3, is a view similar to that of FIG. 2 but at another point in its operating cycle;

FIG. 4, is a cross-sectional view taken along the plane of line 44 of FIG. 2;

FIG. 5, is a cross-sectional view taken along the plane of line 5-5 of FIG. 4;

FIG. 6, is a cross-sectional view taken along the plane of line 6-6 of FIG. 1;

FIG. 7, is a cross-sectional view taken along the plane of line 77 of FIG. 3;

FIG. 8, is a partially exploded perspective view of the rotor and pistons of the rotary engine of the present invention; and

FIG. 9, is a schematic diagram of a carburetion and exhaust system for the engine of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is shown a rotor 11 having

arcuate pistons

12 and 13 mounted thereon for reciprocal curvilinear movement in

arcuate combustion chambers

14 and 16 respectively. The rotor is mounted on a central drive shaft 17 for transmitting rotational energy from the movement of the rotor 11 to a load. The rotor and piston assembly is mounted in a housing 18 having an oblong or elliptical inner peripheral surface 19. The

pistons

12 and 13 are connected to connecting

rods

21 and 22 respectively, and the connecting rod and piston assemblies have

rollers

23 and 24 respectively formed for following the contour of the cam surface or raceway provided by inner periphery 19. The profile of the cam surface 19 may be modified to accommodate the burn characteristics of the particular fuel mixture being used. The connecting

rods

21 and 22 are journalled for swinging movement on pivot pins 26 and 27, respectively, carried by rotor 11 shown in FIG. 8.

The

arcuate combustion chambers

14 and 16 have seals 28 as shown for slidably sealing the

pistons

12 and 13 in the chambers. The combustion chambers are further sealed on the sides by

end plates

29 and 31 each secured on opposite sides of the rotor 11 by screws as shown in FIG. 4. Side plates and 30 are stationary with the housing and reduce the tolerances between the end plates and the housing. The

side plates

25 and 30 have ports and respectively formed thereon. The end plate 29 has intake ports 33 as shown in dotted lines in FIG. 5 and the end plate 31 has exhaust ports 32 shown in solid lines in FIG. 5. The exhaust ports 32 are slightly misaligned from the intake ports 33 on the opposite faces to permit a combustion chamber to communicate with the exhaust ports slightly before communication with the intake ports. This permits the venting of the exhaust gas out of the combustion chamber to begin slightly before the beginning of the injection of the fresh fuel mixture through the intake port and into the chamber to improve scavenging.

As shown in FIGS. 4 and 7, the interior end of the combustion chamber 14 is relieved to provide an intake recess 43 and an exhaust recess 48 separated by a protuberance 46. Similarly, the interior end of the combustion chamber 16 is also relieved to provide an intake recess 44 and an exhaust recess 49 separated by a protuberance 47. As shown in FIG. 8, the head of each of the

pistons

12 and 13 is formed in mating configuration with the associated ends of the

combustion chambers

14 and 16 to accommodate the described recesses and protuberances.

As may best be seen in FIG. 4, air is here injected under pressure through passages 34 and fuel is introduced through

fuel injectors

36 and 37 to form a fuel mixture which is forced into the combustion chambers through ports 35 in side plate 25, intake ports 33 and recesses 43 and 44. The fuel mixture in the combustion chambers is compressed during the compression stroke of the pistons which begins approximately when the pistons are at their outermost position as shown in FIG. 2. As the rotor rotates in the clockwise direction, the fuel mixture is compressed by the forcing inwardly of the

pistons

12 and 13 into

combustion chambers

14 and 16 respectively as the

rollers

23 and 24 are deflected inwardly by cam surface 19. The retraction of the pistons toward the center of gravity of the rotor during the compression stroke generates a centripetal force to enhance the rotation of the rotor 11.

When the pistons are approximately at their completely retracted position, as shown in FIG. 3, the power stroke is begun through ignition of the compressed mixture of air and fuel by

spark plugs

38, 39, 41 and 42 as shown in FIG. 7. The ignition and combustion of the compressed fuel-air mixture causes pressure to be exerted against the

pistons

12 and 13 to urge them outwardly. The

rollers

23 and 24 mounted on

pistons

12 and 13 respectively follow the cam surface 19 from the short diagonal at about the beginning of the power stroke, shown in FIG. 3, to the points on the profile surface intersecting the long diagonal. The centrifugal force urging the pistons outwardly as well as the inertia of the rotor 11 and the shaft 17, cause the rotor and shaft to rotate through the next compression stroke to thereby begin the venting of the exhaust gas through

recesses

48 and 49, exhaust ports 32 and ports 40 on side plate 30. Shortly thereafter, the venting of an airgas mixture is begun through intake ports 33 to begin the compression stroke once more. The recesses and protuberances cause a circulation path as shown by the arrows in FIG. 4 to improve scavenging action.

The engine here is shown as being cooled by rotor mounted fins 51 which are shown in greater detail in FIGS. 1 and 6. The fins 51 conduct air through suitable apertures 62 in the housing. A suitable shroud or manifold (not shown) is mounted on the back side of the housing to duct the air blown through the housing into an exhaust system (not shown).

In the carburetion and exhaust system shown schematically in FIG. 9, a blower 61 draws air through a carburetor 63 and propels the fuel-air mixture into the chambers for combustion. The exhaust gases are passed through line 66 and vented to a suitable afterburner 67. The mixture of exhaust gases are burned further in the afterburner 67. Energy from such combustion is imparted to a turbine 68 to drive the blower 61 through a suitable coupling 69.

The arcuate shape of the pistons and combustion chambers permit the engine to operate without severe stresses in the piston and rotor materials caused by misalignment of force trying to cock and bend the pistons in the cylinders, and the resulting reduction in friction improves efficiency. The rotor is preferably constructed of aluminum and the pistons are preferably formed of steel. This provides for better cooling of the rotor. The seals may be better placed in the rotor when formed of aluminum, and the pivoted construction of the piston assembly permits the use in the rotor of relatively soft, high heat dissipating metal such as aluminum.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. For example, the mass of the rotor 11 could be reduced by cutting out portions of the rotor which do not communicate with the

combustion chambers

14 and 16, the exhaust ports 32 or the intake port 33. Furthermore, although the preferred embodiment is constructed with two combustion chambers and pistons, the engine may be constructed with any number of combustion chambers to accommodate any desired utilization thereof.

Of course, it will be appreciated that more than one rotor assembly may be mounted on a single shaft with the cylinders of one rotor preferably oriented in angularly spaced relation to the others for multiplying the number of impulses delivered to the shaft.

The rotary engine of the present invention also is suitable for four-cycle mode of operation with relocation of the valve openings. The rotor and swinging piston structure may be adapted for use in a steam or fluid driven engine. it is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

l claim:

I. A rotary engine for two-cycle operation comprisa housing formed to provide an oblong inner cam surface,

a rotor carried for relative rotation in said housing,

walls in said rotor defining at least one arcuate combustion chamber,

a correspondingly arcuate piston mounted for curvilinear reciprocation in said combustion chamber inwardly toward the axis of rotation of said rotor and outwardly toward said cam surface such that the centerline of said chamber, if extended, would pass through the axis of said rotor,

and follower means for operatively connecting said piston to said oblong inner cam surface,

whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression stroke.

2. A rotary engine as described in claim 1 and further comprising means for injecting a mixture of air and fuel into said arcuate combustion chamber.

3. A rotary engine as described in claim 1 and wherein said oblong cam surface of said housing is shaped to accommodate the burn characteristics of the fuel-air mixture in said arcuate combustion chamber.

4. The rotary engine as described in claim 1 and further comprising at least one seal circumferentially formed around the sides of said arcuate combustion chamber for slidably sealing said piston in said arcuate combustion chamber.

5. A rotary engine as described in claim 1 and further comprising an intake port formed on one side of said housing for communicating with said arcuate combustion chamber, and an exhaust port formed on the opposite side of said housing positioned slightly askew from said intake port for communicating with said combustion chamber to thereby improve scavenging in said combustion chamber.

6. A rotary engine as described in claim 5 and wherein said exhaust port is positioned for commencing communication with said arcuate combustion chamber prior to the commencement of communica tion between said arcuate combustion chamber and said intake port.

7. A rotary engine as described in claim 6 and wherein the internal end of said arcuate combustion chamber is relieved to provide a pair of recesses with one formed to communicate with said intake port and the second formed for communication with said exhaust port.

8. A rotary engine as described in claim 7 and wherein said arcuate combustion chamber is further formed with a protuberance separating said pair of recesses.

9. A rotary engine as described in claim 1 and further comprising a plurality of fins mounted on said rotor for deflecting air to cool the rotary engine.

10. A rotary engine as described in claim 9 and fur ther comprising venting means for venting blowby and exhaust gases.

1]. A rotary engine as described in claim 1 and further comprising a plurality of arcuate combustion chambers formed in said rotor and a plurality of arcuate pistons each mounted in one of said combustion chambers and communicating with said oblong inner cam surface.

12. A rotary engine as described in claim 11 and further comprising a plurality of intake ports formed on one side of said housing for communicating with said plurality of combustion chambers and an equal number of exhaust ports each formed on the opposite side of said housing and each positioned slightly askew from one of said intake ports for communicating with said plurality of combustion chambers to thereby improve scavenging in said plurality of combustion chambers.

13. A rotary engine as described in claim 12 and wherein each of said plurality of said exhaust ports is positioned for commencing communication with one of said plurality of arcuate combustion chambers prior to the commencement of communication between said one of said plurality of arcuate combustion chambers and the associated intake port of said plurality of intake ports on the opposite side of said housing.

14. A rotary engine as described in claim 13 and wherein each of said arcuate combustion chambers is formed with a pair of recesses with one formed to communicate with said plurality of intake ports and the second formed for communication with said plurality of exhaust ports.

15. A rotary engine as described in claim 14 and wherein each of said plurality of arcuate combustion chambers is formed with a protuberance separating said pair of recesses formed therein.

16. A rotary engine as described in claim 15 and wherein the head of each of said plurality of arcuate pistons is formed in mating configuration with the inner end of the associated combustion chamber.

17. A rotary engine as described in claim 16 in which said rotor is formed of aluminum.

18. A rotary engine as described in claim 17 in which said plurality of arcuate pistons are formed of steel.

19. The rotary engine as described in claim 1 and further comprising a connecting rod rigidly mounted on said piston and pivotally connected to said rotor so as to prevent cocking action of said piston in said combustion chamber.

20. The rotary engine as described in claim 19 and wherein said follower means is mounted on said connecting rod.

21. The rotary engine as described in claim 20 and wherein said connecting rod is arcuate in shape.

22. A rotary engine, comprising a housing having circumferential and end walls defining an enclosure providing an oblong inner cam surface on its inner periphery,

a rotor carried in said enclosure for rotation relative to said housing,

said rotor being formed to provide a combustion chamber having a head end near the axis of rotation of said rotor and curving along a circular arc from such head end outwardly to the outer periphery of said rotor such that extension of the center line are of the chamber passes through the axis of rotation,

a correspondingly arcuate piston slidably mounted in said combustion chamber for reciprocation therein toward and away from said head end,

23. A rotary engine as described in claim 22 and wherein said piston is swingably mounted for arcuate movement corresponding to the shape of said combustion chamber about a pivot point stationary with respect to said rotor.

24. A rotary engine as described in claim 22 and wherein a plurality of said combustion chambers are formed in equidistant circumferentially spaced relation in said rotor, and a plurality of said pistons are slidably mounted in said combustion chambers.

25. A rotary engine as described in claim 22 and wherein a control arm is journaled on said rotor for swinging movement of its distal end in an arc corresponding to the arc of said combustion chamber, said piston being rigidly mounted on said distal end of said control arm whereby cocking of said piston with respect to said combustion chamber is precluded.

26. A rotary engine as described in claim 25 and wherein said follower means comprises a cam roller journaled on said distal end of said control arm.

27. A rotary engine as described in claim 22 and further comprising an intake port formed through one of said end walls in position for communicating with said combustion chamber at specific angular positions of said rotor, and an exhaust port formed through the other of said end walls in position for communicating with said combustion chamber at specific angular positions of said rotor.

28. A rotary engine as described in claim 27 and wherein said intake port is positioned slightly circumferentially askew from said exhaust port for improving scavenging from said combustion chamber.

29. A rotary engine as described in claim 28 and wherein the internal end of said arcuate combustion chamber is relieved to provide a pair of recesses with one formed to communicate with said intake port and the second formed for communication with said exhaust port.

30. A rotary engine as described in claim 29 and wherein said arcuate combustion chamber is further formed with a protuberance separating said pair of recesses.

31. A rotary engine for two-cycle operation compris ing, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing,

walls in said rotor defining a plurality of arcuate combustion chambers, plurality of arcuate pistons each mounted in one of said combustion chambers for curvilinear reciprocation in said combustion chambers inwardly toward the axis of rotation of said rotor and outwardly toward said cam surfaces, each communicating with said oblong inner cam surface.

a plurality of intake ports formed on one side of said housing for communicating with said plurality of combustion chambers and an equal number of exhaust ports each formed on the opposite side of said housing and each positioned slightly askew from one of said intake ports for communicating with said plurality of combustion chambers to thereby improve scavenging in said plurality of combustion chambers,

each of said plurality of said exhaust ports being positioned for commencing communication with one of said plurality of arcuate combustion chambers prior to the commencement of communication between said one of said plurality of arcuate combustion chambers and the associated intake port of said plurality of intake ports on the opposite side of said housing,

each of said arcuate combustion chambers being formed with a pair of recesses with one formed to communicate with said plurality of intake ports and the second formed for communication with said plurality of exhaust ports,

each of said plurality of arcuate combustion chambers having a protuberance separating said pair of recesses formed therein, and

follower means for operatively connecting said pistons to said oblong inner cam surface,

whereby said arcuate pistons are urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chambers to provide the power stroke and are urged inwardly by travel along said inner cam surface to provide the compression stroke.

32. A rotary engine as described in claim 31 and wherein the head of each of said plurality of arcuate pistons is formed in mating configuration with the inner end of the associated combustion chamber.

33. A rotary engine as described in claim 32 in which said rotor is formed of aluminum.

34. A rotary engine as described in claim 33 in which said plurality of arcuate pistons are formed of steel.

35. A rotary engine for two-cycle operation comprising, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing,

walls in said rotor defining at least one combustion chamber of rectangular cross-section opening to the periphery of said rotor and extending into said rotor along an arcuate path having as its center of curvature a point on said rotor circumferentially spaced from said combustion chamber, the centerline of said path extended passing through the axis of said rotor,

a correspondingly arcuate piston mounted for curvilinear reciprocation in said combustion chamber inwardly toward the axis of rotation of said rotor and outwardly toward said cam surface,

an arm rigidly secured to the outer end of said piston and journalled to said rotor for swinging movement on one axis coinciding with the center of curvature of said combustion chamber,

and, a cam follower journalled on said arm adjacent to said outer end of said piston in position to track along said cam surface,

36. A rotary engine as described in claim 35 and wherein a plurality of said combustion chambers are formed in equally circumferentially spaced relation in said rotor, and a piston and arm and cam follower are provided for each of said combustion chambers.

37. A rotary engine for two-cycle operation comprising, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing,

walls in said rotor defining at least one arcuate combustion chamber,

an intake port formed on one side of said housing for communicating with said arcuate combustion chamber,

an exhaust port formed on the opposite side of said housing positioned slightly askew from said intake port for communicating with said combustion chamber to thereby improve scavenging in said combustion chamber, said exhaust port being positioned for commencing communication with said arcuate combustion chamber prior to the commencement of communication between said arcuate combustion chamber and said intake port, and,

the internal end of said arcuate combustion chamber being relieved to provide a pair of recesses with one formed to communicate with said intake port 10 and the second formed for communication with said exhaust port and having a protuberance separating said pair of recesses,

38. A rotary engine, comprising a housing having circumferential and end walls defining an enclosure providing an oblong inner cam surface on its inner periphery,

a rotor carried in said enclosure for rotation relative to said housing,

said rotor being formed to provide a combustion chamber having a head end near the axis of rotation of said rotor and curving along a circular are from such head end outwardly to the outer periphery of said rotor,

follower means for operatively connecting said piston to said oblong inner cam surface,

said housing end walls being parallel, said rotor being slidably mounted between said end walls,

an intake port formed through one of said end walls in position for communicating with said combustion chamber at specific angular positions of said rotor, and an exhaust port formed through the other of said end walls in position for communicating with said combustion chamber at specific angular positions of said rotor,

said intake port being positioned slightly circumferentially askew from said exhaust port for improving scavenging from said combustion chamber, and,

the internal end of said arcuate combustion chamber being relieved to provide a pair of recesses with one formed to communicate with said intake port and the second formed for communication with said exhaust port, said arcuate combustion chamber having a protuberance separating said pair of recesses,

whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression

Claims

1. A rotary engine for two-cycle operation comprising, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing, walls in said rotor defining at least one arcuate combustion chamber, a correspondingly arcuate piston mounted for curvilinear reciprocation in said combustion chamber inwardly toward the axis of rotation of said rotor and outwardly toward said cam surface such that the centerline of said chamber, if extended, would pass through the axis of said rotor, and follower means for operatively connecting said piston to said oblong inner cam surface, whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression stroke.

6. A rotary engine as described in claim 5 and wherein said exhaust port is positioned for commencing communication with said arcuate combustion chamber prior to the commencement of communication between said arcuate combustion chamber and said intake port.

10. A rotary engine as described in claim 9 and further comprising venting means for venting blowby and exhaust gases.

11. A rotary engine as described in claim 1 and further comprising a plurality of arcuate combustion chambers formed in said rotor and a plurality of arcuate pistons each mounted in one of said combustion chambers and communicating with said oblong inner cam surface.

22. A rotary engine, comprising a housing having circumferential and end walls defining an enclosure providing an oblong inner cam surface on its inner periphery, a rotor carried in said enclosure for rotation relative to said housing, said rotor being formed to provide a combustion chamber having a head end near the axis of rotation of said rotor and curving along a circular arc from such head end outwardly to the outer periphery of said rotor such that extension of the center line arc of the chamber passes through the axis of rotation, a correspondingly arcuate piston slidably mounted in said combustion chamber for reciprocation therein toward and away from said head end, and follower means for operatively connecting said piston to said oblong inner cam surface, whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression stroke.

31. A rotary engine for two-cycle operation comprising, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing, walls in said rotor defining a plurality of arcuate combustion chambers, a plurality of arcuate pistons each mounted in one of said combustion chambers for curvilinear reciprocation in said combustion chambers inwardly toward the axis of rotation of said rotor and outwardly toward said cam surfaces, each communicating with said oblong inner cam surface. a plurality of intake ports formed on one side of said housing for communicating with said plurality of combustion chambers and an equal number of exhaust ports each formed on the opposite side of said housing and each positioned slightly askew from one of said intake ports for communicating with said plurality of combustion chambers to thereby improve scavenging in said plurality of combustion chambers, each of said plurality of said exhaust ports being positioned for commencing communication with one of said plurality of arcuate combustion chambers prior to the commencement of communication between said one of said plurality of arcuate combustion chambers and the associated intake port of said plurality of intake ports on the opposite side of said housing, each of said arcuate combustion chambers being formed with a pair of recesses with one formed to communicate with said plurality of intake ports and the second formed for communication with said plurality of exhaust ports, each of said plurality of arcuate combustion chambers having a protuberance separating said pair of recesses formed therein, and follower means for operatively connecting said pistons to said oblong inner cam surface, whereby said arcuate pistons are urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chambers to provide the power stroke and are urged inwardly by travel along said inner cam surface to provide the compression stroke.

35. A rotary engine for two-cycle operation comprising, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing, walls in said rotor defining at least one combustion chamber of rectangular cross-section opening to the periphery of said rotor and extending into said rotor along an arcuate path having as its center of curvature a point on said rotor circumferentially spaced from said Combustion chamber, the centerline of said path extended passing through the axis of said rotor, a correspondingly arcuate piston mounted for curvilinear reciprocation in said combustion chamber inwardly toward the axis of rotation of said rotor and outwardly toward said cam surface, an arm rigidly secured to the outer end of said piston and journalled to said rotor for swinging movement on one axis coinciding with the center of curvature of said combustion chamber, and, a cam follower journalled on said arm adjacent to said outer end of said piston in position to track along said cam surface, whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression stroke.

37. A rotary engine for two-cycle operation comprising, a housing formed to provide an oblong inner cam surface, a rotor carried for relative rotation in said housing, walls in said rotor defining at least one arcuate combustion chamber, a correspondingly arcuate piston mounted for curvilinear reciprocation in said combustion chamber inwardly toward the axis of rotation of said rotor and outwardly toward said cam surface, and follower means for operatively connecting said piston to said oblong inner cam surface, an intake port formed on one side of said housing for communicating with said arcuate combustion chamber, an exhaust port formed on the opposite side of said housing positioned slightly askew from said intake port for communicating with said combustion chamber to thereby improve scavenging in said combustion chamber, said exhaust port being positioned for commencing communication with said arcuate combustion chamber prior to the commencement of communication between said arcuate combustion chamber and said intake port, and, the internal end of said arcuate combustion chamber being relieved to provide a pair of recesses with one formed to communicate with said intake port and the second formed for communication with said exhaust port and having a protuberance separating said pair of recesses, whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression stroke.

38. A rotary engine, comprising a housing having circumferential and end walls defining an enclosure providing an oblong inner cam surface on its inner periphery, a rotor carried in said enclosure for rotation relative to said housing, said rotor being formed to provide a combustion chamber having a head end near the axis of rotation of said rotor and curving along a circular arc from such head end outwardly to the outer periphery of said rotor, a correspondingly arcuate piston slidably mounted in said combustion chamber for reciprocation therein toward and away from said head end, follower means for operatively connecting said piston to said oblong inner cam surface, said housing end walls being parallel, said rotor being slidably mounted between said end walls, an intake port formed through one of said end walls in position for communicating with said combustion chamber at specific angular positions of said rotor, and an exhaust port formed through the other of said end walls in position for communicating with said combustion chamber at specific angular positions of said rotor, said intake port being positioned slightly Circumferentially askew from said exhaust port for improving scavenging from said combustion chamber, and, the internal end of said arcuate combustion chamber being relieved to provide a pair of recesses with one formed to communicate with said intake port and the second formed for communication with said exhaust port, said arcuate combustion chamber having a protuberance separating said pair of recesses, whereby said arcuate piston is urged outwardly to travel along said oblong inner cam surface and impart rotation to said rotor by combustion in said arcuate combustion chamber to provide the power stroke and is urged inwardly by travel along said inner cam surface to provide the compression stroke.