A compressor includes a fixed scroll, a movable scroll and a cover body. The cover body has an injection hole. The compressor has a compression chamber which is at least partially located between the fixed scroll and the movable scroll. The compressor includes a communication tube which defines a communication channel in communication with the enthalpy increasing channel. One end of the communication tube is at least partially located in the enthalpy increasing channel. A circumferential side wall of the one end of the communication tube is directly or indirectly in contact with an inner wall of the enthalpy increasing channel. Another end of the communication tube is at least partially located within the injection hole. A circumferential side wall of the another end of the communication tube is directly or indirectly in contact with an inner wall of the injection hole.

Pressure changing devices and methods of making and using the same are disclosed. One pressure changing device includes an elliptic cylinder and a piston that has an external surface with a trochoid cross-section. Another pressure changing device includes a piston and a rotating cylinder that has an internal surface with a trochoid cross-section. Another pressure changing device includes two fixed axes, one for rotation of one component and another for orbiting or oscillation of the other component. The devices and methods include stacked pressure changing devices with one or more common shafts. The pressure changing device may be easier and less expensive to manufacture and repair than prior pressure changing devices of the same or similar functionality, and can provide efficient gap sealing in a high-pressure expansion part of a compression or expansion cycle.

A compressor includes: a casing with an inner wall defining a compression chamber, an inlet leading into the compression chamber, and an outlet leading out of the compression chamber; a rotor rotatably coupled to the casing for rotation relative to the casing; and a gate coupled to the casing for movement relative to the casing. The gate may be pivotally, or translationally coupled to the casing. A hydrostatic bearing may be disposed between the gate and casing. A plurality of compressors may be mechanically linked together such that their compression cycles are out of phase.

The invention relates to a suction/compression assembly for aspirating/compressing gases from/in a system to/from an external environment. The assembly comprises an operating machine, a four-way valve, an intake pipe and an exhaust pipe connecting an intake section and an exhaust section of the operating machine to said four-way valve, respectively. The assembly is characterized in that it comprises a first body, which defines, in one piece, a chamber of the operating machine, a first portion of the intake pipe and a first portion of said exhaust pipe. The assembly further comprises a second body, which defines, in one piece, a seat of the four-way valve, a second portion of the intake pipe and a second portion of the exhaust pipe. Moreover, the assembly according to the invention comprises a one-way valve arranged within the intake pipe in a position adjacent to the seat of the four-way valve.

Provided is a scroll fluid machine that makes it possible to attenuate the bending stress applied to the base of a wall body having an inclined section. The scroll fluid machine is provided with a wall body inclined section in which the distance between the facing surfaces of an end plate of a fixed scroll and an end plate of a rotating scroll that face each other continuously decreases from the outer circumferential side toward the inner circumferential side. A mesh clearance that is a gap between wall bodies formed when the wall bodies mesh with each other is larger on the outer circumferential side of the inclined section than on the inner circumferential side of the inclined section. The mesh clearance is made larger by drawing the wall surface of a wall body further back toward the central side of the wall body in the thickness direction than the original wall surface profile thereof.

A vane pump including: a housing having a pump chamber; a rotor having a cylindrical peripheral wall portion accommodated in the pump chamber and having a pair of vane holding grooves facing each other in a diameter direction, and an oil chamber defined inside the peripheral wall portion to store lubricating oil; and a vane that is held in the pair of vane holding grooves and moves across the oil chamber in the diameter direction, is provided. At least one of an inner surface of the housing and an end face of the peripheral wall portion, which together with the inner surface defines a sliding interface, has an oil groove for the lubricating oil.

A rotary compressor is provided that may include a casing, a cylinder having an inner circumferential surface in an annular shape, a roller rotatably disposed in a compression space of the cylinder, a rotational shaft coupled to an inner circumference of the roller, main and sub bearings defining surfaces of the compression space, and a sub bearing cover coupled to the sub bearing to cover one end of the sub bearing and defining a discharge chamber with the sub bearing to communicate with the compression space so as to accommodate compressed refrigerant to be discharged. The sub bearing or the sub bearing cover may include a first barrier rib that protrudes from a surface thereof located inside of the discharge chamber. The first barrier rib may be spaced apart from a surface opposite to the surface within the discharge chamber by a predetermined distance.

A first rotor configured to rotate adjacent to a second rotor is disclosed. The second rotor includes a circular main body with a first axis of rotation and a vane extending radially from the main body. The first rotor includes a first curved surface that corresponds to a curve swept at a constant radius about a second axis of rotation, a second curved surface that corresponds to a curve swept by a leading edge of the vane when the second rotor is simultaneously rotated about the first axis of rotation and the second axis of rotation, a third curved surface that corresponds to a curve swept by a trailing edge of the vane when the second rotor is simultaneously rotated about the first axis of rotation and the second axis of rotation, and a vane-receiving groove disposed between the second curved surface and the third curved surface.

A positive displacement device includes a first cylinder, a second cylinder disposed within the first cylinder, and a third cylinder disposed around the first cylinder. An interior surface of the first cylinder and an exterior surface of the second cylinder define an inner cavity. An exterior surface of the first cylinder and an interior surface of the third cylinder define an outer cavity. A partition between the interior surface of the first cylinder and the exterior surface of the second cylinder divides the inner cavity into inner regions, and another partition between the exterior surface of the first cylinder and the interior surface of the third cylinder divides the outer cavity into outer regions. The second cylinder and the third cylinder orbit with respect to the first cylinder to create alternating regions of high pressure and low pressure in the inner regions and the outer regions.

A compressor may include first and second scrolls and a seal. The first scroll includes a first end plate and a first spiral wrap extending from the first end plate. The first end plate may define a discharge passage and an annular recess surrounding the discharge passage. The second scroll includes a second end plate and a second spiral wrap extending from the second end plate. The first and second spiral wraps cooperate to define a plurality of fluid pockets. The seal may be at least partially received in the annular recess and may cooperate with the first scroll to define a biasing chamber receiving fluid at an intermediate pressure. The seal may include inner and outer diametrical surfaces. The inner diametrical surface may include a plurality of first annular grooves. The outer diametrical surface may include a plurality of second annular grooves.