A rotary piston engine having a rotor with an output shaft and a plurality of longitudinally extending cylinder-forming bores, each having a slidable piston disposed therein. The rotor is contained in a housing that contains an elliptical cam track that interacts with the pistons, upon combustion, to cause rotation of the rotor. An opening in the housing end cap admits air into the cylinders on the rear side of the pistons and a port delivers air driven by the rear side of the pistons to an intake port in the side of the housing where, in response to the angular position of the rotor, the air is admitted to the front side of a piston for compression with injected fuel. The compressed fuel-air mixture is ignited and an exhaust port in the side of the housing opens to discharge the products of combustion.

A rotational engine system comprises a rotational engine and a propulsion system. The rotational engine includes an outer ring enclosure, an inner ring component, and a drive gear. The inner ring component includes a piston and a drive gear engagement portion. The piston is configured to travel within the outer ring enclosure along a circumference of the outer ring enclosure. The drive gear engagement portion is configured to rotate as the piston travels along the circumference of the circular shape of the outer ring enclosure. The drive gear is coupled to the drive gear engagement portion of the inner ring component such that rotation of the drive gear engagement portion rotationally drives the drive gear. The propulsion system is configured to deliver propulsive energy to propel the piston along the circumference of the outer ring enclosure.

A rotational engine system comprises a rotational engine and a propulsion system. The rotational engine includes an outer ring enclosure, an inner ring component, and a drive gear. The inner ring component includes a piston and a drive gear engagement portion. The piston is configured to travel within the outer ring enclosure along a circumference of the outer ring enclosure. The drive gear engagement portion is configured to rotate as the piston travels along the circumference of the circular shape of the outer ring enclosure. The drive gear is coupled to the drive gear engagement portion of the inner ring component such that rotation of the drive gear engagement portion rotationally drives the drive gear. The propulsion system is configured to deliver propulsive energy to propel the piston along the circumference of the outer ring enclosure.

A split-cycle internal combustion engine includes a variable displacement compressor having two or more cylinders, an adjustment mechanism for varying the displacement volume of the compressor and possibly the phase between the compressor and the motor, and a rotary motor having two or more expansion chambers. A passage valve system located between the compressor and the motor transfers working fluid and combustion exhaust products, and, in addition, mechanically and thermally isolates the compressor from the high pressures and temperatures present in the motor.

A split-cycle internal combustion engine includes a variable displacement compressor having two or more cylinders, an adjustment mechanism for varying the displacement volume of the compressor and possibly the phase between the compressor and the motor, and a rotary motor having two or more expansion chambers. A passage valve system located between the compressor and the motor transfers working fluid and combustion exhaust products, and, in addition, mechanically and thermally isolates the compressor from the high pressures and temperatures present in the motor.

A Circle-Ellipse Engine comprises a stationary circular outer Housing having a fixed elliptical inner cam surface, and a separate internal round Rotor partitioned into equal segments that are populated by identical movable radial Vanes. During rotation, the end of the Vanes are positioned a constant distance from the elliptical inner cam surface of the Housing. The internal round Rotor has the same radius as the minor axis of the elliptical inner cam surface. During rotation, a variable height cavity is created representing the difference between the major and minor axes of the elliptical inner cam surface and the Rotor face.

The position of the radial Vanes is guided by the slots in the symmetrical Rotor, extending to the elliptical inner cam surface of the Housing. The precise extension is governed by a pin track machined into the dual End Plates.

There are no pistons, camshaft, timing chains, valves, valve lifters, rocker arms, connecting rods, or wrist pins. As a benefit, size and weight are significantly reduced when compared to a reciprocating engine of similar horsepower. Normal aspirated air is continuously drawn into the engine when an adjacent pair of radial Vanes passes the air inlet port. Similarly, exhaust products are expelled after a combustion event when the pair of adjacent Vanes passes over the exhaust port.

The resultant geometer results in a continuous implementation of the Otto Cycle; namely intake, compression, expansion or power stroke, and exhaust during a single rotation of the internal round Rotor.

Because the Otto Cycle is executed each revolution of the Rotor, the Circle-Ellipse Engine achieves the same power as a conventional reciprocating engine of the same displacement and compression ratio, at half the RPM. This implementation greatly reduces component ware and extends the life and maintenance cycle by a factor of four. As a side benefit, the power losses and vibration common to all reciprocating engines are eliminated.

A Circle-Ellipse Engine comprises a stationary circular outer Housing having a fixed elliptical inner cam surface, and a separate internal round Rotor partitioned into equal segments that are populated by identical movable radial Vanes. During rotation, the end of the Vanes are positioned a constant distance from the elliptical inner cam surface of the Housing. The internal round Rotor has the same radius as the minor axis of the elliptical inner cam surface. During rotation, a variable height cavity is created representing the difference between the major and minor axes of the elliptical inner cam surface and the Rotor face.

The position of the radial Vanes is guided by the slots in the symmetrical Rotor, extending to the elliptical inner cam surface of the Housing. The precise extension is governed by a pin track machined into the dual End Plates.

There are no pistons, camshaft, timing chains, valves, valve lifters, rocker arms, connecting rods, or wrist pins. As a benefit, size and weight are significantly reduced when compared to a reciprocating engine of similar horsepower. Normal aspirated air is continuously drawn into the engine when an adjacent pair of radial Vanes passes the air inlet port. Similarly, exhaust products are expelled after a combustion event when the pair of adjacent Vanes passes over the exhaust port.

The resultant geometer results in a continuous implementation of the Otto Cycle; namely intake, compression, expansion or power stroke, and exhaust during a single rotation of the internal round Rotor.

Because the Otto Cycle is executed each revolution of the Rotor, the Circle-Ellipse Engine achieves the same power as a conventional reciprocating engine of the same displacement and compression ratio, at half the RPM. This implementation greatly reduces component ware and extends the life and maintenance cycle by a factor of four. As a side benefit, the power losses and vibration common to all reciprocating engines are eliminated.

A method of controlling an air intake flow in a rotary engine having primary and secondary inlet ports, including positioning the secondary inlet port rearwardly of the primary inlet port and forwardly of the exhaust port along a direction of a revolution of the rotor, providing independently closable communications between an air source and the primary and secondary inlet ports, and controlling air intake flows between the air source and the primary and secondary inlet ports. Controlling air intake flows includes simultaneously allowing the air intake flow between the primary inlet port and the air source and between the secondary inlet port and the air source. Exhaust gases of the engine are purged with the air intake flow of the secondary inlet port. A rotary engine is also discussed.

A method of controlling an air intake flow in a rotary engine having primary and secondary inlet ports, including positioning the secondary inlet port rearwardly of the primary inlet port and forwardly of the exhaust port along a direction of a revolution of the rotor, providing independently closable communications between an air source and the primary and secondary inlet ports, and controlling air intake flows between the air source and the primary and secondary inlet ports. Controlling air intake flows includes simultaneously allowing the air intake flow between the primary inlet port and the air source and between the secondary inlet port and the air source. Exhaust gases of the engine are purged with the air intake flow of the secondary inlet port. A rotary engine is also discussed.

A variable volume chamber device is disclosed. The chambers may be defined by the space between four pivotally connected vanes contained within two side plates. The vanes may be connected so as to create a sealed interior chamber that may be used as a combustion chamber in an internal combustion engine, or as a pumping chamber in a pump or compressor. The four vane assembly may also form additional variable volume chambers between the vanes and a surrounding structure. The plurality of variable volume chambers may be interconnected to progressively act on a working fluid.