Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. 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 structural and/or operational advantages in the rotary machine.

An apparatus for a submersible screw pump includes a cylindrical rotor located inside of a cylindrical stator. The rotor has a screw thread formed in an opposite direction in relation to screw threads of the stator. The external surface of the rotor has a curvilinear shape and the internal surface of the stator has semicircular shapes without rectangular edges. These surface features of the rotor and stator obtain high speed performance for the apparatus with reduced vortices. A gap between the internal surface of the stator and the external surface of the rotor is 0.1-0.2 millimeters. A unloading thrust bearing is attached to a rotor shaft positioned between an intake thrust bearing and the intake end of the rotor. A cavity in the unloading thrust bearing is configured to receive production fluid from the discharge end of the rotor.

An electric compressor includes a cylindrical motor housing, an inverter case, and a conductive member. The inverter case is joined to an end portion of the motor housing. The inverter case includes a cylindrical case peripheral wall surrounding the end portion. The end portion has an end face that extends in a radial direction of the motor housing and a peripheral surface that extends in an axial direction of the motor housing and is connected to the end face. A ring-shaped sealing member is disposed between the peripheral surface and the case peripheral wall. An accommodation groove for accommodating the sealing member is recessed in the peripheral surface. The sealing member is held by the peripheral surface and the case peripheral wall in a radial direction of the sealing member to seal a space in which the conductive member is disposed.

A motor-operated compressor is provided and includes an orbiting scroll and a rear housing supporting a rear surface of the orbiting scroll. The rear housing includes a discharge space communicating with a discharge port of the orbiting scroll formed at a central portion of a surface facing the orbiting scroll, an oil separation space formed at one side of the discharge space to communicate with the discharge space, and an oil storage space formed at an edge portion of the surface facing the orbiting scroll. An oil return passage is provided between the oil separation space and the oil storage space, so as to guide oil separated in the oil separation space to the oil storage space. Accordingly, a space for storing oil separated from a discharged refrigerant is sufficiently secured while allowing the rear housing defining the oil storage space to be easily fabricated.

Disclosed is a scroll type compressor having an Oldham's ring having an asymmetrical structure with respect to a long or minor axis thereof.

An electric compressor includes a compression portion, an electric motor portion, a motor drive circuit portion, and a housing in which the compression portion, the electric motor portion, and the motor drive circuit portion are arranged in this order in an axial direction. The electric compressor further includes a partition wall, a refrigerant inlet, and a conductive member. The refrigerant inlet is disposed at a position in the housing closer to a partition wall than to the compression portion. The conductive member electrically connects the motor drive circuit portion and the electric motor portion. The electric compressor includes a shield member configured to block flow of refrigerant taken in through the refrigerant inlet and flowing toward the conductive member. The shield member is disposed in the electric motor portion so as to be located between the refrigerant inlet and the conductive member.

A scroll compressor is provided and includes a motor housing having a support surface, a fixed scroll fixedly disposable on the motor housing, an orbiting scroll which is operably disposable for fluid-compressive orbital movement relative to the fixed scroll and a removable hydropad removably disposable on the support surface between the orbiting scroll and the support surface.

A motor operated compressor includes an orbiting scroll that defines a compression chamber together with a fixed scroll. The compressor includes a main frame disposed around and supporting the orbiting scroll. The main frame defines a back-pressure chamber together with the orbiting scroll. The compressor includes a groove disposed in one of the orbiting scroll and the main frame. A first sealing member is inserted into the groove. A second sealing member is inserted into the groove to elastically press the first sealing member into close contact with the orbiting scroll or the main frame. A radial distance (a) between an outer wall of the groove and the first sealing member is 6 to 8% (0.06a/W0.08) of a difference (W) between an outer radius (OR) and an inner radius (IR) of the first sealing member (W=ORIR).

A scroll compressor is provided which includes: a revolving scroll, a fixed scroll, an autorotation preventing mechanism, a frame, a crank shaft provided with an eccentric pin portion which is eccentric with respect to an axis, the crank shaft being provided with a flange portion at a lower portion of the eccentric pin portion, the flange portion being larger than the diameter of the eccentric pin portion, a balance weight mounted on the flange portion, a sealing member performing sealing between the revolving scroll and the flange portion, and a thrust bearing arranged between the frame and the flange portion. The scroll compressor reduces the amount of oil flowing into a back pressure chamber, thereby improving the performance of the scroll compressor.

A co-rotating scroll compressor is provided in which pressure differences between inner and outer portions of a suction chamber are maintained, back pressures are applied to rear surfaces of end plates of a drive scroll and a driven scroll in directions in which the two scrolls are moved toward each other to prevent compression leakage of a fluid, and a lubricant oil is easily supplied to the two scrolls using the back pressures. The co-rotating scroll compressor may include pressure seals between the rear surfaces of the end plates of the drive scroll and the driven scroll and an inner wall of the suction chamber such that the two scrolls are pressed in directions to be moved toward each other by the back pressures, and the oil is supplied to rotary supports and close contact portions of the two scrolls using the back pressures.