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 fluid machine includes a housing, an electric motor, a drive circuit that includes a heat-generating component and drives the electric motor, a cover that defines an accommodation chamber, which accommodates the drive circuit, with the housing, and a fastener that fastens the cover to the housing. The cover is configured to press the heat-generating component or a heat transfer member, to which heat of the heat-generating component is transferred, against the housing in a fastening direction of the fastener when fastened by the fastener. The fluid machine further includes a seal that is held between the first opposing surface of the housing and the second opposing surface of the cover in the direction intersecting the fastening direction of the fastener.

A fluid machine includes a housing, an electric motor, a drive circuit that includes a heat-generating component and drives the electric motor, a cover that defines an accommodation chamber, which accommodates the drive circuit, with the housing, and a fastener that fastens the cover to the housing. The cover is configured to press the heat-generating component or a heat transfer member, to which heat of the heat-generating component is transferred, against the housing in a fastening direction of the fastener when fastened by the fastener. The fluid machine further includes a seal that is held between the first opposing surface of the housing and the second opposing surface of the cover in the direction intersecting the fastening direction of the fastener.

A motor-driven compressor is installed in a fuel cell vehicle to supply air to a fuel cell. The motor driven compressor includes a rotation shaft, an electric motor, a compression unit that compresses air, a housing that includes a motor chamber and a compression chamber, and a seal member that restricts a flow of a fluid between the motor chamber and the compression chamber. The housing includes an inlet and an outlet. The inlet draws, into the motor chamber, the air-conditioning refrigerant that has passed through the evaporator but has not reached the air-conditioning compressor as a low-temperature refrigerant. The outlet discharges the low-temperature refrigerant, which is drawn from the inlet into the motor chamber, out of the motor chamber.

A positive displacement pump has a casing with a central body and two closing lids, the central body being provided with two cylindrical communicating chambers, one suction pipe and one discharge pipe, and two rotors revolvingly mounted in the chambers of the central body and supported by shafts revolvingly mounted in the closing lids. The two rotors include a male rotor having only protuberances, not cavities, and a female rotor having only cavities, not teeth or protuberances.

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.

This scroll compressor includes a scroll compression unit including a first fixed scroll including a first fixed base plate and a first fixed spiral wrap, an orbiting scroll arrangement (7) including a first orbiting spiral wrap (14), the first fixed spiral wrap and the first orbiting spiral wrap (14) forming a plurality of first compression chambers. The scroll compressor further includes a refrigerant suction part suitable for supplying the scroll compression unit with refrigerant to be compressed. The orbiting scroll arrangement (7) further includes a first orbiting guiding portion (21) extending from an outer end portion of the first orbiting spiral wrap (14) and configured to guide, in use, at least a part of the refrigerant supplied to the scroll compression unit towards the first compression chambers.

A scroll compressor is provided in which a center of a back pressure chamber is eccentrically disposed relative to a center of a fixed scroll. For example, the center of the back pressure chamber may be moved towards a center of an orbiting scroll at a time of discharge, thereby preventing displacement of the fixed scroll and ensuring stability in orbital movement of the orbiting scroll.

A multi-stage vacuum pump may include a sealing arrangement for sealing between the stator components of the pump. The end seals of the arrangement comprise an annular portion for sealing between end stator components and shell components and axial portions which extend from the annular portion and together with separate axial seals seal between the shell components.