An engine comprises a compression portion and a combustion portion. The compression portion comprises twin-screw rotors, male engaged with female. The combustion portion comprises twin-screw rotors, male engaged with female. The male compression rotor and the male combustion rotor share a same longitudinal axis, and the female compression rotor and the female combustion rotor share a same longitudinal axis. A combustion plate is disposed between the compression portion and the combustion portion, and prevents flow of gas from the compression portion to the combustion portion, except through a small orifice centrally located on the combustion plate. A valve is affixed to the male rotors adjacent to the combustion plate, covering the lobes of the male rotors and extending beyond the lobes of the male rotors. The valve controls the flow of gas from the compression portion to the combustion portion.

A vacuum pump for pumping a gas includes a pump housing which defines a pump cavity, a shiftable vane, a pump rotor body, a separate axial rotor retaining arrangement, and a radial friction bearing. The pump housing includes a closed housing wall. The pump rotor body includes a vane slit which supports the shiftable vane to define rotating pumping chambers, an axial low-pressure end which is axially supported by the closed housing wall so that a gas pressure inside the pumping chambers is present at the low-pressure end, and an axial high-pressure end. The pump housing is fluidically open at the axial high-pressure end so that atmospheric pressure is present. The axial rotor retaining arrangement includes a retaining sheet body arranged in a transversal plane which axially in part blocks the axial high-pressure end. The radial friction bearing is arranged axially between the vane slit and the axial high-pressure end.

A rotary internal combustion motor has a stator that houses a compartment defined by two opposite planar surfaces and by an annular surface with elliptical profile, inside which a rotor rotates, which includes a cylindrical drum surrounded by an annular chamber, which is divided into multiple portions by a regularly spaced set of radial blades that are slidingly housed in the cylindrical drum. The motor also has at least one pair of inlet openings, at least one pair of outlet openings, at least one pair of injectors, at least one pair of spark plugs, and at least one pair of pre-heating spark plugs.

A rotary engine casing having at least one end wall of an internal cavity for a rotor including a seal-engaging plate sealingly engaging the peripheral wall to partially seal the internal cavity and a member mounted adjacent the seal-engaging plate outside of the internal cavity. The member and seal-engaging plate having abutting mating surfaces which cooperate to define between them at least one fluid cavity communicating with a source of liquid coolant. When the casing includes a plurality of rotor housings, the end wall may be between rotor housings. A method of manufacturing a rotary engine casing is also discussed.

A vane cell pump, including: a rotor, which can be rotated about a rotational axis, and a plurality of vanes which are guided by the rotor such that they can be shifted, wherein the rotor includes a sub-vane chamber for each vane, and each vane forms a shifting wall of the sub-vane chamber assigned to it; a first end-facing wall which adjoins the rotor on an end-facing side on a first side of the rotor and which, in order to control pressure to the sub-vane chamber, includes a sub-vane cavity which extends in the circumferential direction and includes a control edge as viewed in the circumferential direction; a second end-facing wall which adjoins the rotor on an end-facing side on a second side of the rotor and which, in order to control pressure to the sub-vane chamber, includes a sub-vane cavity which extends in the circumferential direction and lies opposite the sub-vane cavity of the first end-facing wall and includes a control edge, as viewed in the circumferential direction, which is similar to the control edge of the sub-vane cavity) of the first end-facing wall, wherein the control edge of the sub-vane cavity of the first end-facing wall, and the control edge of the sub-vane cavity of the second end-facing wall which is similar to it, are formed differently from each other and/or are arranged offset, in particular angularly offset about the rotational axis as the apex, with respect to each other.

A gear pump includes: an inner rotor having external teeth; an outer rotor having a tubular inner housing portion in which the inner rotor is rotatably housed in an eccentric state, and internal teeth meshing with the external teeth; a first core having a tubular rotor housing portion in which the inner and outer rotors are housed, and a flange portion projecting radially outward from a tube wall of the rotor housing portion; a board-shaped second core having a contact portion in contact with the flange portion in an axial direction, and closing an opening of the rotor housing portion; and a housing opposing the second core and made of a resin. A gap is formed between opposing surfaces of the second core and the housing in a state where the flange portion is in contact with the contact portion and the housing opposes the second core.

Provided is a variable displacement vane pump which is capable of reducing fluctuation in discharge rate. In the variable displacement vane pump, a first straightening vane 33 closest to one end-side opening 14a of a discharge passage 14 among a plurality of straightening vanes 33, 34 and 35 arranged within the discharge pressure chamber 202 is located so as not to face a communication hole 32 of a pressure plate 2c.

A cam ring is capable of moving while rolling on a cam support surface. The cam ring is provided such that within a range in which the cam ring can move on the cam support surface, an eccentricity amount increasing-side angle is always greater than an eccentricity amount decreasing-side angle. On a plane perpendicular to the rotation axis of a driving shaft, the eccentricity amount increasing-side angle is an angle, in a direction opposite to a rotation direction of the driving shaft, from a first reference line, which connects a tangent point between the cam ring and the cam support surface to a rolling center of the cam ring, to a starting end of a first discharge port. The eccentricity amount decreasing-side angle is an angle, in the rotation direction of the drive shaft, from the first reference line to a terminal end of the first discharge port.

The pump device includes a motor portion that includes a shaft rotating about a central axis and a pump portion that is driven by a motor portion via the shaft. The pump portion includes a pump rotor that rotates along with the shaft and a pump housing that includes an accommodation portion that accommodates the pump rotor. The pump housing includes a pump body that includes a first bearing portion that supports the shaft and a pump cover with an accommodation portion disposed between the pump cover and the pump body. The pump cover includes a flow path through which oil is discharged and suctioned, and includes a second bearing portion that rotatably supports the shaft and that communicates with the flow path. An end portion of the shaft on one side in the axial direction is disposed at the second bearing portion or inside the flow path.

Disclosed herein is a rotary engine a supply flow passage provided in the housing to allow the lubricating oil to move therethrough, a sealing part arranged to contact the rotor to selectively close the supply flow passage, and an elastic part configured to press the sealing part toward the combustion chamber.