A displacement type rotary machine with non-rotatable housing, two mutually movable co-axial rotors includes an outer rotor movable along housing inside wall, and an inner rotor movable relative to an inner circumferential face of the outer rotor. The outer rotor has radially inwardly directed wings. The inner rotor has a hub with radially outwardly directed wings. Each inner rotor wing is movable between a pair of the outer rotor wings to create chambers. A free end of the inner rotor wings is movable adjacent a curved inside wall of the outer rotor. A free end of the outer rotor wings is movable adjacent the hub. Both rotors are movable adjacent a first cover on the housing. The inner rotor is in movable adjacent a second cover on the outer rotor. Controlling gears control movement of the rotors, the gears including elliptical gearwheels and circular gearwheels.

One embodiment may include a rotary engine, whose cylinder is in doughnut-shape. A cross-section of the cylinder is circular. The engine includes a pair of rotation disks, a power disk and passive disk. A power-output shaft is coaxial with an axis of the cylinder. A power piston and passive piston rotate around an axis of the power-output shaft. A space between the power piston in front and the passive piston at the back is a working chamber. When combustion and expansion take place in the working chamber, the power piston will be pushed forward continuously by the expanding gases, and output power via the power-output shaft. The passive piston relies on a driving system to drive it moving forward. Volume of the working chamber varies within one revolution of rotation. Larger volume of the working chamber causes combustion and expansion. Smaller volume of the working chamber causes compression and emission.

One embodiment may include a rotary engine, whose cylinder is in doughnut-shape. A cross-section of the cylinder is circular. The engine includes a pair of rotation disks, a power disk and passive disk. A power-output shaft is coaxial with an axis of the cylinder. A power piston and passive piston rotate around an axis of the power-output shaft. A space between the power piston in front and the passive piston at the back is a working chamber. When combustion and expansion take place in the working chamber, the power piston will be pushed forward continuously by the expanding gases, and output power via the power-output shaft. The passive piston relies on a driving system to drive it moving forward. Volume of the working chamber varies within one revolution of rotation. Larger volume of the working chamber causes combustion and expansion. Smaller volume of the working chamber causes compression and emission.

A rotary pump is provided for fluid transfer. The pump includes a planar housing, an elongated rotor, a pair of double-concave blades, fore and aft cover plates, and a gear box. The housing has a circular center cavity, and a pair of circular lateral cavities overlapping the center cavity and disposed along a longitudinal axis. The rotor is disposed on a rotor shaft along a rotation axis perpendicular to the longitudinal axis within the center cavity. The blades flank the rotor and are disposed within their corresponding lateral cavity and turn on corresponding blade shafts parallel to the rotor shaft. The fore and aft cover plates flank the housing along the rotation axis to cover the center and lateral cavities. The blades turn opposite from the rotor.

A rotary pump is provided for fluid transfer. The pump includes a planar housing, an elongated rotor, a pair of double-concave blades, fore and aft cover plates, and a gear box. The housing has a circular center cavity, and a pair of circular lateral cavities overlapping the center cavity and disposed along a longitudinal axis. The rotor is disposed on a rotor shaft along a rotation axis perpendicular to the longitudinal axis within the center cavity. The blades flank the rotor and are disposed within their corresponding lateral cavity and turn on corresponding blade shafts parallel to the rotor shaft. The fore and aft cover plates flank the housing along the rotation axis to cover the center and lateral cavities. The blades turn opposite from the rotor.

A method of operating an internal combustion engine having pilot subchambers communicating with main combustion chambers, the internal combustion engine configured in use to deliver a main fuel injection of a maximum quantity of fuel to the main combustion chambers when the internal combustion engine is operated at maximum load. The method includes delivering a pilot fuel injection of at most 10% of the maximum quantity to the pilot subchambers, igniting the pilot fuel injection within the pilot subchambers, directing the ignited fuel from the pilot subchambers to the main combustion chambers, and delivering a main fuel injection of a main quantity of fuel to at least one of the main combustion chambers receiving the ignited fuel, with the main quantity being at most 10% of the maximum quantity.

A rotary engine includes a housing and elliptical rotors mounted to rotor shafts for rotation within a chamber of the housing. A valve disk mounted to a rotor shaft includes a port passing between first and second sides. A valve plate includes a bore defining a cylindrical sidewall for rotationally receiving the valve disk. The valve disk includes a groove disposed in a wall, and includes a ring member disposed in the groove that contacts the sidewall of the bore when the valve disk is disposed in the bore. The apparatus may include multiple valve disks disposed in separate bores to operate as exhaust or intake valves. Circumferential channels may be included in the bore sidewalls within which the ring members are disposed.

A rotary engine includes a housing and elliptical rotors mounted to rotor shafts for rotation within a chamber of the housing. A valve disk mounted to a rotor shaft includes a port passing between first and second sides. A valve plate includes a bore defining a cylindrical sidewall for rotationally receiving the valve disk. The valve disk includes a groove disposed in a wall, and includes a ring member disposed in the groove that contacts the sidewall of the bore when the valve disk is disposed in the bore. The apparatus may include multiple valve disks disposed in separate bores to operate as exhaust or intake valves. Circumferential channels may be included in the bore sidewalls within which the ring members are disposed.

A method of combusting fuel, e.g. heavy fuel, in a rotary engine, including injecting a main quantity of fuel directly into a combustion chamber to form a first fuel-air mixture having a first air-fuel equivalence ratio higher than 1, injecting a pilot quantity of fuel into a pilot subchamber to form a second fuel-air mixture having a second air-fuel equivalence ratio smaller than the first air-fuel equivalence ratio, igniting the second fuel-air mixture within the pilot subchamber, using the ignited second fuel-air mixture from the pilot subchamber to ignite the first fuel-air mixture, and injecting a supplemental quantity of fuel directly into the combustion chamber after igniting the first fuel-air mixture, upstream of an exhaust port of the rotary engine with respect to a direction of rotation of the rotor. A rotary engine with interburner fuel injector 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.