The invention relates to a vacuum pump for a motor vehicle, comprising a pump housing surface, on which a noise reduction hood delimiting a sound damping volume is mounted. The invention is characterized in that a multi-functional decoupling element is located between the pump housing surface and the noise reduction hood, said element carrying out a sealing function and a valve function in addition to a sound decoupling function.

A sealing joint for a compressor casing, such as a compressor casing for a centrifugal compressor of a chiller, is provided. The sealing joint may be configured to have a first cover and a second cover. A first mating surface of the first cover may have an inner annular portion surrounding an inner cavity of the sealing joint, and an outer annular portion. The inner annular portion may be positioned between the inner cavity of the compressor casing and the outer annular portion. A sealant may be applied to the sealing joint, and a depth of the sealant on the inner annular portion may be deeper than a depth of the sealant on the outer annular portion. The depth of the sealant on the inner annular portion may help the sealing joint tolerate more elongation range without a sealant failure than a regular casing.

A cylindrical rotor inside of the cylindrical stator, wherein the cylindrical rotor has a screw thread with an opposite direction relating to the stator screw thread, wherein the rotor has a curvilinear external surface shape and a stator having an internal semicircular surface shape wherein rotor external surface shape and the stator has an internal surface shape having rounded shapes without rectangular edges to obtain high speed performance with reduced vortices, wherein a gap between the internal surface of the stator and the external surface of the rotor is 0.1-0.2 millimeters and an unloading thrust bearing attached to the rotor shaft positioned between intake thrust bearing and the intake end of the rotor and a cavity in the unloading thrust bearing configured to receive production fluid from the discharge end of the rotor.

A scroll compressor is provided that may include a motor; an orbiting scroll; a fixed scroll coupled to the orbiting scroll, and forming a compression chamber together with the orbiting scroll; a frame coupled to the fixed scroll, and configured to support the orbiting scroll; a sealing member mounting groove having a ring shape, and formed on a first surface of the frame contacting the orbiting scroll, or a second surface of the orbiting scroll contacting the frame; and a sealing member including a first sealing portion formed in a ring shape, inserted into the sealing member mounting groove so as to be moveable in an axial direction, and configured to perform a sealing operation between the frame and the orbiting scroll in the axial direction and including a second sealing portion extending from the first sealing portion in the axial direction, and configured to perform a sealing operation between the frame and the orbiting scroll in a radial direction by contacting an outer side wall surface of the sealing member mounting groove A thickness of the second sealing portion in the radial direction may be smaller than a thickness of the first sealing portion in the axial direction.

A scroll compressor is provided that may include a first scroll, a second scroll that defines a plurality of compression chambers together with the first scroll, the second scroll having a discharge hole that communicates with a compression chamber among the plurality of compression chambers, a back pressure plate that defines a back pressure chamber to accommodate a refrigerant discharged from the discharge hole, a floating plate to define the back pressure chamber, and a sealing member to prevent the refrigerant from flowing between a first surface, which may be a sliding surface of the floating plate, and a second surface, which may face the first surface, of the back pressure plate. The sealing member may include a seal cover that contacts the other one of the first and second surfaces, and a seal, a portion of which may be accommodated in the seal cover. The seal cover may have a friction coefficient less than a friction coefficient of the seal.

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

A compressor according to the present invention includes an oil separation mechanism and an oil supply mechanism. The oil separation mechanism includes an oil separation chamber and an oil drain path. The oil supply mechanism includes an oil supply port. The oil drain path includes a first flow path formed by penetrating a second partition of a housing and configured to open toward a first partition of a housing from the oil separation chamber, and a second flow path recessed in at least one of the first partition and the second partition and formed by the cooperation of the first partition and the second partition so as to get communicated with the first flow path. An outlet of the second flow path is located at a higher level in a vertical direction than an inlet of the second flow path while avoiding a direction facing the oil supply port.

A main bearing is disposed on one surface of a first cylinder, an intermediate plate is disposed on another surface of the first cylinder, the intermediate plate is disposed on one surface of a second cylinder, and an auxiliary bearing is disposed on another surface of the second cylinder. A shaft is constituted by a main shaft portion, a first eccentric portion, a second eccentric portion, and an auxiliary shaft portion. A first eccentric portion center position (H1/2) which is the center position of the first eccentric portion in height (H1) is located at a position closer to the main bearing than a first piston center position (P1/2) which is the center position of a first piston in height (P1). A second eccentric portion center position (H2/2) which is the center position of the second eccentric portion in height (H2) is located at a position closer to the auxiliary bearing than a second piston center position (P2/2) which is the center position of a second piston in height (P2).

In the two-cylinder hermetic compressor, a main bearing is disposed on one surface of a first cylinder, an intermediate plate is disposed on another surface of the first cylinder, the intermediate plate is disposed on one surface of a second cylinder, and an auxiliary bearing is disposed on another surface of the second cylinder. A shaft is constituted by a main shaft portion which has a rotor attached thereto and is supported by the main bearing, a first eccentric portion having a first piston attached thereto, a second eccentric portion having a second piston attached thereto, and an auxiliary shaft portion supported by the auxiliary bearing. A thrust receiving portion is provided on a side of the second eccentric portion facing the auxiliary shaft portion, and the auxiliary bearing is provided with a thrust surface on which the end face of the thrust receiving portion slides while contacting therewith. The thrust surface is provided with a ring groove.

A scroll compressor is provided. The scroll compressor may include a casing, a discharge cover to partition an inside of the casing into suction and discharge spaces, a first scroll, a second scroll that defines compression chambers together with the first scroll and includes an intermediate pressure discharge hole that communicates with a compression chamber having an intermediate pressure of the compression chambers, a back pressure plate that defines a back pressure chamber that accommodates a refrigerant discharged from the intermediate pressure discharge hole, a floating plate that defines the back pressure chamber together with the back pressure plate, and a gasket disposed between the back pressure plate and the second scroll and having an intermediate pressure communication hole that allows the intermediate pressure discharge hole to communicate with the intermediate pressure suction hole. The gasket may block communication between the back pressure chamber and the suction and discharge spaces.