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.

An improved screw-spindle pump, particularly for cooling systems, includes a first screw, a second screw and a pump housing, inside which the first screw and the second screw are rotatably housed between the first screw, the second screw and the pump housing, being defined pumping chambers adapted to move, as a consequence of the rotation of the first screw and the second screw, a fluid from a suction area to a delivery area of the pump.

The pump housing housing the first screw and the second screw is made in one piece.

The present disclosure relates to a two-stage rotary vane vacuum pump casing 200 that comprises an exterior surface 202 and a first plurality of cooling fins 204 (214) protruding from the exterior surface 202, wherein each cooling fin 204 (214) extends along the exterior surface 202 between a first and second cooling fin end 201a, 201b, and is a non-planar element that forms an at least partially enclosed cooling channel 206 (216) between the first and second ends 201a, 201b of the cooling fin 204 (214b). The present disclosure also provides a method of making a two-stage rotary vane vacuum pump casing 200 using extrusion and providing a removable end plate for a two-stage rotary vane vacuum pump casing 200.

An electric hydraulic actuator is provided with an electric motor and a gear pump driven in rotation by the electric motor. The electric motor includes a motor housing and a rotating shaft supported by the motor housing so as to be freely rotatable. The gear pump has a drive gear into which the rotating shaft of the electric motor is inserted and a driven gear meshed with the drive gear. A pump housing is configured to accommodate the drive gear and the driven gear on one end and has an installation concave portion open at the other end for accommodating part of the motor housing. The motor housing is attached to the pump housing with a gap formed between the motor housing and the pump housing in a radial direction of the rotating shaft. The gap includes an O-ring to elastically support the motor housing in the radial direction.

A cycle residual boost and two release cavities are provided on a cylinder wall. Wankel cycle air pump is provided with additional cavities which allow the pressure output higher than its fixed compression ratio and further increase compression efficiency. An apex seal active tracking mechanism is also provided. Wankel cycle air pump rotor plates passage makes apex seals keep firmly contact against a cylinder.

A cycle residual boost and two release cavities are provided on a cylinder wall. Wankel cycle air pump is provided with additional cavities which allow the pressure output higher than its fixed compression ratio and further increase compression efficiency. An apex seal active tracking mechanism is also provided. Wankel cycle air pump rotor plates passage makes apex seals keep firmly contact against a cylinder.

A scroll compressor has a drive shaft which drives a scroll compression mechanism housed in a housing and a drive shaft support member which supports the drive shaft. The drive shaft support member includes a plate portion having a predetermined thickness in an axial direction of the drive shaft. One side end surface of the plate portion has thereon a sliding support surface which supports the sliding movement of an orbiting scroll. Another side end surface of the plate portion has formed thereon a protruding portion which, protruding toward the other side in the axial direction, is fitted onto an inner peripheral surface of the housing. The protruding portion is interference fitted onto the inner peripheral surface of the housing, and thereby the drive shaft support member is fixed to the housing.

An electric compressor, an inverter assembly jig and an inverter manufacturing method, an inverter of the compressor includes a frame coupled to a circuit board, the frame includes a base plate opposite the circuit board, fixing means protruding from the base plate and supporting an outer periphery of the circuit board, and a through-hole formed at a position corresponding to the fixing means, the inverter assembly jig includes an expansion pin inserted into the through-hole, and an expansion pin actuation mechanism moving the expansion pin closer to and away from the fixing means, the inverter method includes inserting the expansion pin into the through-hole, manipulating the expansion pin actuation mechanism to deform the fixing means, seating the circuit board on the base plate, and manipulating the expansion pin actuation mechanism so that the fixing means is restored and coupled to the circuit board.

The invention relates to a screw pump (1), in particular a double screw pump, s comprising a multiple-piece housing (2, 7, 15, 21) and at least two coupled rotors (3, 3a) which form chambers with in each case at least one thread-shaped profile (4, 4a) which is configured at least in regions with helical channels (5, 5a) and with dividing walls (6, 6a) which delimit the channels (5, 5a), wherein the rotors (3, 3a) perform an opposed rotor rotation, and the dividing walls (6, 6a) engage into one another in a gearwheel-like manner, a running housing part (7), wherein the running housing part (7) encloses the rotors (3, 3a) without contact, wherein the rotors (3, 3a) form, with the running housing part (7), at least one conveying chamber (8, 8a) for the fluid to be conveyed, wherein the conveying chamber (8, 8a) migrates axially along the rotor axis (10, 10a) and conveys the fluid from a suction chamber (11) into a pressure chamber (12), a suction-side connector element (13) which is connected fluidically to the suction chamber (11), and a pressure-side connector element (14) which is connected fluidically to the pressure chamber (12), wherein the suction-side connector element (13) and the pressure-side connector element (14) are arranged on a connector housing part (15) of the multiple-piece housing (2, 7, 15, 21), wherein the housing (2, 7, 15, 21) has a planar dividing plane (16) which runs parallel to the rotor axes (10, 10a) between the running housing part (7) and the connector housing part (15).