Provided are a pump body assembly and an assembly method therefor. The pump body assembly includes a first cylinder assembly (10), a second cylinder assembly (20) and a third cylinder assembly (30) sequentially arranged in a vertical direction. At least one of the first cylinder assembly (10), the second cylinder assembly (20) and the third cylinder assembly (30) is provided with a positioning detection portion (40).

A pump having an adjustable delivery volume, including: a pump housing featuring a delivery chamber which includes a delivery chamber inlet for a fluid and a delivery chamber outlet for the fluid; a delivery member, which can be rotated within the delivery chamber, for delivering the fluid; an adjusting device featuring a setting structure, which is mounted such that it can move back and forth within the pump housing in order to adjust the delivery volume of the pump, and a helical spring for applying a spring force, which acts in a setting direction, to the setting structure, wherein the windings of the helical spring are enclosed by an envelope lying on the outside of the helical spring wherein the cross-sectional area of the envelope as measured transversely with respect to the longitudinal direction of the spring changes progressively in the longitudinal direction of the spring.

A crankshaft assembly, a compressor and a refrigeration device are provided. The crankshaft assembly has an eccentric shaft component, a spindle component and a main screw oil pump. The eccentric shaft component has an eccentric cavity, and the spindle component has a first cavity communicated with the eccentric cavity. A first through-hole and a second through-hole in a first spindle are each communicated with the first cavity. An outer surface of the first spindle is provided with a first spiral oil groove connecting the first through-hole and the second through-hole. An outer surface of the main screw oil pump is provided with a second spiral oil groove along its length direction, and a spiral direction of the second spiral oil groove is opposite that of the first spiral oil groove.

A pump technology that provides for more effective and efficient transfer of liquids, such as petroleum products and components, to and through pipelines. Such a technology can comprise a type of external gear pump that creates higher flow, resulting in higher pressures in the pipeline, to move the liquids, while providing for longer pump life, simpler and less maintenance, and fewer undesired conditions, with a smaller footprint, in a cost-effective system. Further, one or more portions of the pump can be configured to be easily replaceable to provide for maintenance in place, and provide for longer pump life. Additionally, one or more portions of the pump can be constructed with or coated with abrasive resistant material that extends the life of the external gear pump. Such material can also reduce the friction between surfaces and improve the life of the external gear pump under poor feeding conditions.

A compressor may include first and second scrolls, an axial biasing chamber, and a modulation control valve. The second scroll includes an outer port and an inner port. The outer and inner ports may be open to respective intermediate-pressure compression pockets. The modulation control valve may be in fluid communication with the inner port, the outer port, and the axial biasing chamber. Movement of the modulation control valve into a first position switches the compressor into a reduced-capacity mode and allows fluid communication between the inner port and the axial biasing chamber while preventing fluid communication between the outer port and the axial biasing chamber. Movement of the modulation control valve into a second position switches the compressor into a full-capacity mode and allows fluid communication between the outer port and the axial biasing chamber while preventing fluid communication between the inner port and the axial biasing chamber.

A structure comprising a rotor body, the rotor body including a rotor shaft arranged on one end face of the rotor body, a sub-shaft cavity opened in the rotor shaft, and locating keyways symmetrically opened on both sides inside the sub-shaft cavity; a sub-shaft arranged on the other end face of the rotor body, and sub-shaft locating keyways symmetrically opened on both sides of the sub-shaft.

A multistage compressor system with intercooler can include a sealed housing with first and second compressor stages, where the first compressor stage is for receiving refrigerant from outside of the sealed housing, and the second compressor stage is for receiving refrigerant from within the sealed housing. The compressor system can also include a crank for mechanically driving the first compressor stage and/or the second compressor stage, and a heat exchanger outside of the sealed housing for receiving refrigerant from the first compressor stage and exchanging heat with the refrigerant. The compressor system can further include an oil reservoir contained by the sealed housing, where the oil reservoir includes oil for lubricating the crank, receives the refrigerant from the heat exchanger, and exchanges heat with the refrigerant to cool the oil in the oil reservoir, and where the refrigerant can be supplied to the second compressor stage.

A rotary fluid device including an outer housing assembly and an inner rotating arrangement adapted to rotate relative to the outer housing assembly, the outer housing assembly including a rotor housing and the inner rotating arrangement including a rotor dimensioned to rotatably fit within the rotor housing. One of the rotor and the rotor housing include lobes extending in a radial direction relative to respective inner and outer circumferential surfaces and the other of the rotor and the rotor housing includes followers and follower recesses in which the followers are moveably located. Three pressure zones may be defined between the followers and follower recesses the three pressure zones including an intermediate pressure zone and two laterally pressure zones on opposing circumferentially lateral sides of the intermediate pressure zone.

There is disclosed a scroll compressor according to the present disclosure in which a discharge port is formed at a central portion thereof, and a pair of two compression chambers continuously moving toward the discharge port are formed, and a plurality of bypass portions are formed at each interval along a movement path of each compression chamber in the both compression chambers, and compression gradients of the both compression chambers are formed to be different from each other, wherein when an interval between a bypass portion closest to the discharge port and another bypass portion adjacent to the bypass portion among the bypass portions of each compression chamber is defined as a first interval, respectively, a first interval of a second bypass portion belonging to a compression chamber having a relatively larger compression gradient is formed to be smaller than that of a first bypass portion belonging to the other compression chamber between the both compressor chambers.

A compressor may include a shell, first and second scrolls, a seal assembly, a modulation control chamber, and a modulation control valve. The first scroll may include a first end plate having a biasing passage extending therethrough. The seal assembly may isolate a discharge pressure region from a suction pressure region. The seal assembly and the first scroll may define an axial biasing chamber therebetween that communicates with the axial biasing chamber and a first pocket between the first and second scrolls. The modulation control chamber may be fluidly coupled with the biasing chamber by a first passage. The modulation control valve may be fluidly coupled with the modulation control chamber by a second passage and movable between a first position allowing communication between the second passage and the suction pressure region and a second position restricting communication between the second passage and the suction pressure region.