A sliding component has an annular shape with a fluid facing inside and outside of the sliding component and has a sliding surface relatively sliding with eccentric rotation, in which the sliding surface includes a land and a plurality of dynamic pressure generation mechanisms arranged in a circumferential direction, the dynamic pressure generation mechanism includes a shallow groove portion and a deep groove portion, the shallow groove portion communicates with the deep groove portion, and a communication passage providing a communication between the deep groove portion and either an inside space or an outside space of the sliding component is formed in the sliding component.

A scroll type compressor includes a housing, a fixed scroll cooperating with the housing to define a discharge chamber, a movable scroll cooperating with the fixed scroll to define a compression chamber, and a shaft support member cooperating with the movable scroll to define a back pressure chamber. Fluid in the compression chamber is supplied to the back pressure chamber. The back pressure chamber and the discharge chamber communicate with each chamber through a relief passage. A check valve is disposed in the relief passage, and the check valve allows the fluid to flow from the back pressure chamber to the discharge chamber, when back pressure of the back pressure chamber is higher than discharge pressure of the discharge chamber.

The present application provides a screw compressor that comprises a first male rotor and a second male rotor, each of the first male rotor and the second male rotor having convex-helical teeth, the first male rotor and the second male rotor being rigidly connected together; a first female rotor and a second female rotor, each of the first female rotor and the second female rotor having concave-helical teeth, the first female rotor being arranged separately from and opposite to each other; wherein the convex-helical teeth of the first male rotor are engaged with the concave-helical teeth of the first female rotor, and the convex-helical teeth of the second male rotor are engaged with the concave-helical teeth of the second female rotor. The male rotors in the screw compressor are symmetrically so that the axial force exerted on the first male rotor counteract with the axial force exerted on the second male rotor.

According to one embodiment, a horizontal compressor comprises a container accommodating a compression mechanism unit and an electric motor unit, a first leg fixed to the container near the motor unit, a second leg fixed to an end of the container on the compression mechanism unit side, an accumulator between the legs, and a joint port in the container. The second leg includes a first support portion supporting the container in a horizontal attitude, and a second support portion supporting the container standing in a vertical attitude. The first support portion extends in a direction away from the joint port relative to the second support portion.

Disclosed herein is a scroll compressor capable of optimizing a position where a load is applied from a support member to an orbiting scroll. The scroll compressor includes a fixed scroll fixed to an inside of a body, an orbiting scroll configured to orbit in engagement with the fixed scroll, a rotary shaft configured to allow the orbiting scroll to orbit, a holding member configured to hold the fixed scroll from a side opposite to the orbiting scroll, and a support member arranged between the rotary shaft and the holding member to support the orbiting scroll by a load applied to a position away from a center of the orbiting scroll.

In order to improve a machine for depressurizing or compressing substantially gaseous media, comprising a machine casing and at least one screw rotor, which is arranged in a screw rotor bore in the machine casing, extends between a low-pressure side and a high-pressure side of the screw rotor bore, cooperates with the substantially gaseous medium and is mounted on both sides in the machine casing by means of a respective bearing set, and a motor/generator unit that is coupled or couplable to the at least one screw rotor, it is proposed that the at least one screw rotor should be provided with at least one axial support bearing that axially supports the at least one screw rotor such that a high-pressure end face of the at least one screw rotor is guided, without making contact, to an end wall, which faces this end face, of the machine casing that receives the at least one screw rotor.

A back pressure chamber forming portion forms a back pressure chamber configured to accumulate a high pressure refrigerant discharged from a working chamber and thereby generate a refrigerant pressure, which urges a movable scroll against a stationary scroll. A balancer is placed at an inside of the back pressure chamber and is configured to be rotated by a rotatable shaft. The back pressure chamber forming portion has a discharge hole that communicates between a radially outer side of the back pressure chamber, which is located radially outward in a radial direction of an axis of the rotatable shaft, and a suction chamber to discharge a liquid phase refrigerant from the back pressure chamber into the suction chamber when the liquid phase refrigerant flows from the working chamber into the back pressure chamber.

A pressure balancing system for a pump. In one example, the pressure balancing system has: a housing; a first rotor a first shaft, a first face surface; a second rotor, a second face surface adjacent the first face surface of the first rotor; the face of the first rotor, the face of the second rotor, and an inner surface of the housing forming at least one working fluid chamber; an annular ring fitted around a shaft, adjacent a first pressure chamber having a fluid connection through the housing; the annular ring configured to bias the first rotor toward the second rotor when fluid is supplied under pressure to the first pressure chamber; a fluid conduit is configured to convey fluid to a pressure chamber between the housing and the annular ring to bias the annular ring thus biasing the first rotor toward the second rotor.

A scroll compressor includes a housing, a rotary shaft, a movable scroll, an eccentric shaft, an opposed wall, a looped elastic plate, a looped support portion, an annular protrusion, a back pressure chamber, and a back pressure supplying groove. The distance in the radial direction of the rotary shaft from the rotation axis of the rotary shaft to then outer end of the back pressure supplying groove in the radial direction of the rotary shaft is shorter than or equal to the distance obtained by subtracting the distance in the radial direction of the rotary shaft between the rotation axis of the rotary shaft and the axis of the eccentric shaft from the distance in the radial direction of the rotary shaft from the axis of the eccentric shaft to the part of the protrusion that contacts the elastic plate.

A balancing mechanism for a positive displacement machine, in particular a scroll compressor, wherein the balancing mechanism includes a drive shaft, a first balancing element and a second balancing element. The first balancing element includes a cylindrical hub section and a first force transmission section and is rotatably in contact with the drive shaft via a first axis of rotation. The second balancing element is rotatably in contact with the drive shaft via a second axis of rotation. A center axis S of the drive shaft and a center axis C of the cylindrical hub section are arranged on a first reference line CS, and a center of gravity J of the first balancing element and a center of gravity K of the second balancing element are arranged on a different side of the first reference line CS than a center axis P of the first axis of rotation.