A first communication groove (38) extending from a start point of a discharge port (36) in a direction opposite to rotation direction of vanes (22) is formed. A first end portion (38E) of this groove is connected to the start point of the discharge port (36). When a front-side vane in a rotation direction of a driving shaft (11) is positioned at the start point of the discharge port (36), a second end portion (38S) of the groove is positioned at a rear side in the rotation direction with respect to a rear-side vane coming immediately after the front-side vane, and communicates with a suction port (35). A part of working fluid in a front-side pump chamber (27-1) can therefore be introduced into a rear-side pump chamber (27-2) that communicates with the suction port (35), thereby lessening excessive pressure increase of the front-side pump chamber (27-1) and suppressing pulsation phenomenon.

A vane cell pump, includes a rotatable rotor having vanes which can be moved back and forth; an end plate with a pressure passage for discharging pressure fluid and a supply passage for supplying a sub-vane region with pressure fluid; a flow channelling device on an end face of the end plate facing axially away from the rotor; a first outlet region for discharging a first partial flow of the pressure fluid; a second outlet region for discharging a second partial flow of the pressure fluid; a first flow path along which the first partial flow flows through the first outlet region; a second flow path connecting the pressure passage to the supply passage, diverges from the first flow path and is delineated by the flow channelling device; and a third flow path connecting the supply passage to the second outlet region and delineated by the flow channelling device.

A stacked gerotor pump is provided. The stacked gerotor pump includes a first gerotor pump defining a first inlet section and a first outlet section, a second gerotor pump defining a second inlet section and a second outlet section and a plate. The plate is interposed between the first and second gerotor pumps and defines upstream cavities respectively communicative with the first and second inlet sections, downstream cavities respectively communicative with the first and second outlet sections and a pre-pressurization hole by which the second outlet section is communicative with the first inlet section.

A rotary compressor may include a cylinder having an inner peripheral surface defined in an annular shape to define a compression space, and a suction port that extends in a lateral direction to communicate with the compression space and through which refrigerant is suctioned into the compression space; a roller rotatably provided in the compression space of the cylinder, and having a plurality of vane slots that provides a back pressure at one side thereinside provided at a predetermined interval along an outer peripheral surface of the roller; a plurality of vanes slidably inserted into the plurality of vane slots, respectively, to rotate together with the roller, front end surfaces of which come into contact with the inner peripheral surface of the cylinder due to the back pressure to partition the compression space into a plurality of compression chambers; and a main bearing and a sub bearing provided at ends of the cylinder and in contact with surfaces of the plurality of vanes, respectively, and spaced apart from each other to define surfaces of the compression space, respectively. At least one surface of the vane in contact with the main bearing and the sub bearing may be a curved surface having a predetermined curvature.

A rotary vane pump includes a housing that includes first and second plates respectively secured to first and second opposing sides of an intermediate plate. The intermediate plate includes a bore and inlet and outlet ports. The first and second sides respectively have first and second passages that are respectively in fluid communication with the inlet and outlet ports. The first and second passages are in fluid communication with the bore. The intermediate plate is reversible with respect to the first and second plates. A rotor is arranged in the bore. The rotor supports slidable vanes that are configured to pump fluid between the inlet and outlet ports.

A delivery port of a rotary-screw compressor includes: a first opening having a profile configured to interrupt communication with a second working chamber of a suction process that opens only in the axial direction; a second opening connected to the first opening; and a third opening connected to the first opening and the second opening. The profile of the first opening includes: a first profile line that forms one of a pair of lateral edges of a lingulate protrusion configured to close off the second working chamber and extends toward a reference point; a second profile line that forms another one of the pair of the lateral edges of the protrusion; a third profile line that extends toward the reference point along the root circle of the female rotor; and a second connection line that connects the first profile line with the second profile line. The second opening is a first groove that opens into the first opening at the second connection line and extends toward a reference line. The third opening is a second groove that opens into the first groove and extends in an open state along the first profile line.

A rotary compressor may include a rotational shaft, a first bearing and a second bearing each supporting the rotational shaft in a radial direction, a cylinder disposed between the first bearing and the second bearing and forming a compression space, a roller disposed in the compression space to form a contact point spaced at a predetermined interval from the cylinder and coupled to the rotational shaft to compress a refrigerant in response to rotation of the roller, and at least one vane slidably inserted into the roller and in contact with an inner circumferential surface of the cylinder and dividing the compression space into a plurality of compression chambers.

Provided is a rotary pump including: a pump rotor having a flat first rotor side surface facing one side in an axial direction, and a flat second rotor side surface facing the other side in the axial direction; and a housing configured to rotatably house the pump rotor. The housing includes: a ring member having a hollow tubular shape and openings at both ends in the axial direction; a first side member detachably mounted to one end in the axial direction of the ring member to slide and guide the first rotor side surface by using a first crosslinked fluororesin flat surface formed of a crosslinked fluororesin; and a second side member detachably mounted to the other end in the axial direction of the ring member to slide and guide the second rotor side surface by using a second crosslinked fluororesin flat surface formed of the crosslinked fluororesin.

A pump device includes a rotating body, a pump housing including a suction port and a discharge port, and a relief valve. In the pump device, a fluid is sucked from the suction port and discharged from the discharge port by rotation of the rotating body. The relief valve includes a valve body and a biasing member. The discharge port includes an one end in a direction in which the discharge port extends. The one end is shallower than a middle portion of the discharge port. The pump housing includes a relief flow path through which the fluid flows when the relief valve opens. The relief flow path is provided so as to be open to a groove bottom surface of the one end of the discharge port.

A rotary internal combustion engine has: a rotor; a housing circumscribing a rotor cavity, the rotor received within the rotor cavity, the housing having a peripheral wall and a side housing assembly secured to the peripheral wall, the side housing assembly having plates located at spaced apart ends of the peripheral wall, the plates defining seal running surfaces in sealing engagement with opposed end faces of the rotor, the plates made of silicon carbide.