The present invention generally relates to rotary combustion engines, and more particularly to an axial vane rotary combustion engine that exhibits improved performance over presently known combustion engines of this type.
Combustion engines are used to generate and supply power in myriad environments. For example, combustion engines have been used in various types of automobiles, aircraft, and watercraft, just to name a few. One particular type of combustion engine that has been developed is an axial vane rotary combustion engine. A typical axial vane rotary combustion engine, such as the one disclosed in U.S. Pat. No. 5,429,084, includes multiple vanes that are actuated by stationary cam surface. Adjacent vanes create a cavity that is compressed and expanded as it rotates relative to the cam surface. Fuel that is injected into each cavity via the stationary cam is combusted to generate power.
Although presently known axial vane rotary combustion engines, such as the one described above, are generally safe, reliable, and robust, these engines do suffer certain drawbacks. For example, such engines may not be configured to sufficiently react the loads generated from compression and combustion events while generating power at certain desired levels and/or may not exhibit adequate operational efficiency. The present invention addresses one or more of at least these drawbacks.
In one exemplary embodiment, a rotary combustion engine includes an annular outer wall, a stator, a rotor, a plurality of vane openings, a plurality of actuator openings, a plurality of dual vane assemblies, and a plurality of vane actuators. The annular outer wall has an inner surface that defines a chamber. The stator is disposed within the chamber and includes at least two end walls. Each end wall has a vane cam surface and an actuator cam surface. The rotor is disposed within the chamber and is configured to rotate relative to the stator about a rotational axis. The vane openings extend through the rotor, with each vane opening disposed parallel to the rotational axis, and at least a portion of each vane opening having a cylindrical cross section. The actuator openings extend through the rotor, with each actuator opening disposed parallel to the rotational axis and radially inwardly of one of the plurality of vane openings. Each dual vane assembly is disposed within one of the plurality of vane openings, and includes first and second cylindrical sections, an actuator connection rod coupled between the first and second cylindrical section, a first substantially flat vane section extending from the first cylindrical section to a first vane end, and a second substantially flat vane section extending from the second cylindrical section to a second vane end. The first vane end and the second vane end each engage a vane cam surface. Each vane actuator is disposed within one of the plurality of actuator openings and is coupled to one of the dual vane assembly actuator connection rods. Each vane actuator has a first actuator end and a second actuator end, and the first actuator end and the second actuator end each engage an actuator cam surface.
In another exemplary embodiment, a rotary combustion engine includes an annular outer wall, a stator, a rotor, a plurality of vane openings, a plurality of actuator openings, a plurality of dual vane assemblies, and a plurality of vane actuators. The annular outer wall has an inner surface that defines a chamber. The stator is disposed within the chamber and includes at least two end walls. Each end wall has a vane cam surface and an actuator cam surface. The rotor is disposed within the chamber and is configured to rotate relative to the stator about a rotational axis. The vane openings extend through the rotor, with each vane opening disposed parallel to the rotational axis, and at least a portion of each vane opening having a cylindrical cross section. The actuator openings extend through the rotor, with each actuator opening disposed parallel to the rotational axis and radially inwardly of one of the plurality of vane openings. Each dual vane assembly is disposed within one of the plurality of vane openings and includes first and second substantially flat vane sections extending to first and second vane ends, respectively. The first vane end and the second vane end each engage a vane cam surface. Each vane actuator is disposed within one of the plurality of actuator openings, is coupled to one of the dual vane assemblies, and includes an actuating mechanism, a first cam follower, a second cam follower, a first hydraulic lifter, and a second hydraulic lifter. Each actuating mechanism is coupled to one of the dual vane assemblies and has a first end and a second end. The first and second cam followers each engage one of the actuator cam surfaces. The first hydraulic lifter is coupled between the actuating mechanism first end and the first cam follower, and the second hydraulic lifter is coupled between the actuating mechanism second end and the second cam follower.
In still another exemplary embodiment, a rotary combustion engine includes an annular outer wall, a stator, a rotor, a plurality of vane openings, a plurality of actuator openings, a plurality of dual vane assemblies, a plurality of first fluid film bearings, a plurality of second fluid film bearings, and a plurality of vane actuators. The annular outer wall has an inner surface that defines a chamber. The stator is disposed within the chamber and includes at least two end walls. Each end wall has a vane cam surface and an actuator cam surface. The rotor is disposed within the chamber and is configured to rotate relative to the stator about a rotational axis. The vane openings extend through the rotor, with each vane opening disposed parallel to the rotational axis, and at least a portion of each vane opening having a cylindrical cross section. The actuator openings extend through the rotor, with each actuator opening disposed parallel to the rotational axis and radially inwardly of one of the plurality of vane openings. Each dual vane assembly is disposed within one of the plurality of vane openings and includes first and second cylindrical sections, an actuator connection rod coupled between the first and second cylindrical section, a first substantially flat vane section extending from the first cylindrical section to a first vane end, and a second substantially flat vane section extending from the second cylindrical section to a second vane end. The first vane end and the second vane end each engaging a vane cam surface. Each first fluid film bearing is disposed between the rotor and a dual vane assembly first cylindrical section. Each second fluid film bearing is disposed between the rotor and a dual vane assembly second cylindrical section. Each vane actuator is disposed within one of the plurality of actuator openings, is coupled to one of the dual vane assembly actuator connection rods, and includes an actuating mechanism, a first cam follower, a second cam follower, a first hydraulic lifter, a second hydraulic lifter, a first roller, and a second roller. The actuating mechanism is coupled to one of the dual vane assemblies, and has a first end and a second end. The first hydraulic lifter is coupled between the actuating mechanism first end and the first cam follower, and the second hydraulic lifter is coupled between the actuating mechanism second end and the second cam follower. The first roller is rotationally coupled to the first cam follower and engages one of the actuator cam surfaces, and the second roller is rotationally coupled to the second cam follower and engages one of the actuator cam surfaces.
Furthermore, other desirable features and characteristics of the rotary combustion engine will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the preceding background.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. In this regard, although the axial vane rotary combustion engine is described as being implemented as a diesel engine, it will be appreciated that it may also be readily implemented as a spark ignition engine.
Referring first to
The depicted stator 102 is mounted within the housing 101 and is also cylindrically shaped. The stator 102 is mounted to the end plates 107, 109 and includes two end walls 112, 114. The annular outer wall 108 has an inner surface 116 that, at least in part, defines a chamber 118 between the two stator end walls 112, 114. The end walls 112, 114 each have two cam surfaces. The cam surfaces may be integrally formed as part of the end walls 112, 114, or may be separately formed and then coupled to the end walls 112, 114. In either case, the two cam surfaces are referred to herein as a vane cam surface 122 and an actuator cam surface 204 (not shown in
The end plates 107, 109 each have a plurality of openings formed therein. The openings include at least an air intake opening 126 and an exhaust opening 128, and in the depicted embodiment additionally include a coolant inlet opening 132 and a coolant discharge opening 134. Although these openings are visible on only one of the end plates 107 in
The rotor 104 is disposed within the chamber 118 and is configured to rotate relative to the stator 102 about a rotational axis 136. More specifically, the rotor 104, which is also preferably cylindrically shaped, is mounted on a shaft 138. The shaft 138 is in turn rotationally mounted on the stator 102 via one or more bearing assemblies 142 (only one visible), and is used to supply output power to a load. Thus, the shaft 138 may be appropriately keyed or splined to couple to a non-illustrated component. It will be appreciated that the rotor 104 may be variously formed. For example, it may be formed as a hollow, unitary casting, or from a plurality of substantially identical castings. The rotor 104 may additionally be formed as a substantially solid piece.
No matter its shape or its specific manner of construction, the rotor 104 also includes two sets of openings. One set of openings are referred to herein as vane openings 144, and the other set of openings are referred to herein as actuator openings 206 (not visible in
Each dual vane assembly 106 is disposed within one of the plurality of vane openings 144 and, as shown more clearly in
As is shown most clearly in
Each vane actuator 202 is disposed within one of the plurality of actuator openings 206 and is coupled to one of the dual vane assembly actuator connection rods 212. Each vane actuator 202 has a first actuator end 226 that engages an actuator cam surface 204, and a second actuator end 228 that engages an opposed actuator cam surface 204. More specifically, the each vane actuator 202 includes an actuating mechanism 232, first and second cam followers 234 (234-1, 234-2), and first and second hydraulic lifters 236 (236-1, 236-2). The actuating mechanism 232 is coupled to a dual vane assembly 106 and includes a first end 238 and a second end 242. Although the manner in which each actuating mechanism 232 may be coupled to a dual vane assembly 106 may vary, in the depicted embodiment each actuating mechanism 232 includes a forked engagement mechanism 244 that engages one of the actuator connection stubs 216, and provides anti-rotation of the dual vane assembly 106.
The first cam follower 234-1 engages one of the actuator cam surfaces 204, and the second cam follower 234-2 engages the opposing actuator cam surface 204. Preferably, the first and second cam followers 234-1, 234-2 engage the associated actuator cam surfaces 204 via a first roller 246-1 and a second roller 246-2, respectively, that are rotationally coupled thereto. The first and second rollers 246-1, 246-2 may be variously implemented, but are preferably implemented using tapered rollers. The tapered rollers 246-1, 246-2 help eliminate potential skidding between the actuator cam surfaces 204 and the vane actuator 202.
The first hydraulic lifter 236-1 is coupled between the actuating mechanism first end 238 and the first cam follower 234-1. Similarly, the second hydraulic lifter 236-2 is coupled between the actuating mechanism second end 242 and the second cam follower 234-2. The hydraulic lifters 236-1, 236-2, together with the tapered rollers 246-1, 246-2, provide positive actuation of each dual vane assembly 106, while allowing the vane actuators 202 the ability to negotiate potential actuator cam surface 204 variations.
In addition to the above, the rotor 104 also includes a plurality of seals and a plurality of fluid film bearings. In particular, and with continued reference to
Referring briefly to
Returning once again to
Turning now to
From the point of view of
The second dual vane assembly 106-2 and the third dual vane assembly 106-3 are at approximately 90 degrees-of-rotation and 150 degrees-of-rotation, respectively, at the beginning of a compression stroke. As the rotor 104 rotates, the second and third vane actuators 202-2, 202-3 are moved from the low portion 502 of the actuator cam surface 204 to the high portion 504 of the actuator cam surface 204. The second and third vane actuators 202-2, 202-3 thus move the second and third dual vane assemblies 106-2, 106-3 from the low portion 506 of the vane cam surface 122 to the high portion 508 of the vane cam surface 122. The air that is between the second dual vane assembly 106-2 and the third dual vane assembly 106-3 is compressed due to the decreasing volume between these dual vane assemblies 106-2, 106-3. It is noted that from the viewpoint of
The air between two adjacent dual vane assemblies 106 is fully compressed at the positions that correspond to the third and fourth dual vane assemblies 106-3, 106-4. The third dual vane assembly 106-3, as noted above, is at 150 degrees-of-rotation while the fourth dual vane assembly 106-4 is at 210 degrees-of-rotation. The fuel, which is supplied via the fuel injector 135, is combusted at this position or, if implemented as a spark ignition engine, the fuel may be ignited when these dual vane assemblies 106-3, 106-4 are just past the depicted positions. For example, when the third dual vane assembly 106-3 is rotated, via its vane actuator 208-3, to about 180 degrees-of-rotation.
The expansion stroke of the engine 100, during which the combusted fuel/air mixture expands, occurs as the dual vane assemblies 106 move to the position of the fifth dual vane assembly 106-5. The exhaust stroke of the engine 100 also begins at the position of the fifth dual vane assembly 106-5, which is 270 degrees-of-rotation. At this position, exhaust gases are disposed between the fifth and sixth dual vane assemblies 106-5, 106-6. The exhaust gases are discharged out the exhaust port 128 as the fifth vane actuator 202-5 rotates the fifth dual vane assembly 106-5 to the right (from the point of view of
The axial vane rotary combustion engine 100 described herein provides improved performance over similar, presently known engines. This improved performance is provided via and improved configuration that results in a significant reduction in friction, with concomitant reduction in power loss and improved efficiency. These improvements are attributable to the configuration of the dual vane assemblies, which provides stiffness and contributes to load sharing and reduced deflections. The dual vane assembly shape reduces deflections and stress levels. The dual fluid film bearing arrangement supports large centrifugal loads and also helps reduce deflections. The vane actuator configuration results in proper positioning even with variations in cam profile tolerances.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.