A multi-stage dry Roots vacuum pump, including a pump body, multi-stage Roots working units and a plurality of drive components. The pump body is provided with a plurality of independent working chambers, and airflow channels communicating the various working chambers; the airflow channels are communicated with outside; the Roots working units of each stage include driving Roots rotors and driven Roots rotors; the driving Roots rotors and driven Roots rotors are positioned in the working chambers; and the various drive components are respectively used for driving the driving Roots rotors and driven Roots rotors positioned in the various working chambers to rotate towards opposite directions at the same rotating speed. The Roots working units of various stages may be randomly distributed at various positions of the pump body on premise of ensuring that the airflow channels can communicate the working chambers of each stage.

An electric refrigerant drive, in particular a refrigerant compressor for an air conditioner of a motor vehicle, has an electric motor drive module and a compressor module coupled to the drive module. The drive module has a motor housing which houses an electric motor with a rotatable motor shaft and is joined to an end shield. The drive module also comprises a fluid-tight housing partition opposite the end shield, thereby forming an electronic housing that receives an electronic motor unit and is closed by a housing cover. The compressor module has a compressor housing which is attached to the end shield of the motor housing of the drive module and which receives a compressor part that is coupled or can be coupled to the drive module so as to be driven.

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): I(b/a)k and Formula (2): I(c/a)j is satisfied, where a represents a height of the pump chamber, b represents a height of the rotor, c represents a height of the vane in a rotation axis direction of the rotor, and where I represents a linear expansion coefficient of the casing in the rotation axis direction, k represents a linear expansion coefficient of the rotor in the rotation axis direction, and j represents a linear expansion coefficient of the vane in the rotation axis direction.

Provided is a co-rotating scroll compressor comprising a synchronous drive mechanism that can achieve a long life. The compressor comprises a driving side scroll member (90) driven to rotate about a driving side rotation axis CL1, a driven side scroll member (70) driven to rotate about a driven side rotation axis CL2, a hollowed drive shaft (6) that is connected to the driving side scroll member (90), and driven by a motor (5) to rotate, and a driven shaft (20) that is disposed inside the drive shaft (6), and has one end connected to the drive shaft (6) via a first flexible coupling (21) and the other end connected to the driven side scroll member (70) via a second flexible coupling (22).

A permanent magnet electric motor includes a shaft extending along a longitudinal axis, wherein the shaft defines a shaft jacket extending along a first direction, a rotor mounted on the shaft, a stator disposed about the rotor. The rotor defines a plurality of longitudinal channels each with the shaft jacket. The longitudinal channels are part of a rotor jacket. The rotor jacket includes a plurality of inlets fluidly interconnecting the shaft jacket and the plurality of the longitudinal channels. The rotor jacket includes an inner edge and an outer edge opposite the inner edge. The rotor jacket includes a plurality of outlets each in fluid communication with the plurality of longitudinal channels. Each of the outlets is closer to the inner edge than to the outer edge of the rotor jacket.

There is provided a co-rotating scroll compressor in which a driving-side scroll member including a spiral wall between facing end plates can be manufacturable at low cost. A driving-side scroll member (70) includes a first driving-side scroll portion (71), a second driving-side scroll portion (72), and a bolt (31). The first driving-side scroll portion (71) includes a first driving-side end plate (71a) and a first driving-side wall (71b), and is driven by a motor (5). The second driving-side scroll portion (72) includes a second driving-side end plate (72a) and a second driving-side wall (72b). The bolt (31) performs fixing while a front end in a rotation axis direction of the first driving-side wall (71b) and a front end in the rotation axis direction of the second driving-side wall (72b) face each other.

A compressor is provided and may include a shell, a hub, an insert, and at least one collar. The hub may be disposed within the shell and define an axis of rotation. The hub may include an axially extending aperture. The insert may be disposed within the aperture. The at least one collar may be disposed about the hub.

A fluid ring compressor comprises a first single-acting compression stage having a first impeller eccentrically mounted in a housing and a second single-acting compression stage having a second impeller eccentrically mounted in a housing. The first compression stage and the second compression stage are separated from one another by a sealing gap. The sealing gap is arranged between a suction section of the first compression stage and a suction section of the second compression stage.

To provide a displacement pump that can be assembled while properly maintaining side clearances. The displacement pump (100, 101, 102, 103, 104, 105) of the present invention for sucking and discharging a fluid such as gasoline vapor by changing pressure in a space constituted by an outer peripheral surface of a rotor (1) and an inner wall surface of a casing (2), comprising a side clearance adjusting member (4), rotating with respect to the pump main body (6), for moving a shaft (3) integrally formed with the rotor (1) in an axial direction of the shaft (3).

A single-screw compressor includes a screw rotor with helical grooves, a gate rotor assembly including first and second gate rotors, and a casing housing the screw rotor and the gate rotor assembly. A rotor support member is attached to the first and second gate rotor rotors, and is rotatably supported by the casing. Each of the helical grooves of the screw rotor has a front sidewall surface and a rear sidewall surface. Each of the gates of the first gate rotor slides only on the front sidewall surface of the helical groove in which the gate has entered. Each of the gates of the second gate rotor slides only on the rear sidewall surface of the helical groove in which the gate has entered. The first and second gate rotors of the gate rotor assembly are coaxially arranged and relatively displaceable in a circumferential direction.