A rotary compressor is provided that may include a cylinder having an inner peripheral surface defining a compression space; a roller rotatably provided in the compression space, and including a plurality of vane slots at a predetermined interval along an outer peripheral surface, each providing a back pressure; and a plurality of vanes slidably inserted into the plurality of vane slots to rotate together with the roller, front end surfaces of which come into contact with the inner peripheral surface of the cylinder due to the back pressure to partition the compression space into a plurality of compression chambers. The cylinder may further include a suction flow path for refrigerant that may include a suction port that communicates with the compression space to suction the refrigerant in a lateral direction, and a suction passage disposed in a direction that crosses the suction port to provide communication between the compression space and the suction port.

A fluid working system such as a pump for displacing a working fluid such as hydraulic fluid or a motor using a working fluid is provided. The system may have a positive displacement machine which includes one or more working chamber with displacement means such as a cylinder with a reciprocating piston. There are also two or more fluid ports to allow the working fluid to flow into and out of the working chamber. The working fluid flows from one fluid port means to another either being forced to do so when pumped or moving the piston when functioning as an engine. The fluid working system has associated therewith a non-dead compliance volume of a material such as syntactic foam. This compliance volume acts to smooth any pressure fluctuations within the working fluid system.

A compressor according to embodiments of the present invention may comprise: a first fluid channel provided to communicate with an oil supply fluid channel so as to allow oil to flow therethrough; a second fluid channel provided to extend from the first fluid channel so as to allow the oil to flow to the outside of a case; a third fluid channel extending from the second fluid channel and provided outside the case; and a main fluid channel extending from the third fluid channel and provided through a fixed scroll or a main frame. Accordingly, the oil is supplied to a compression part by passing along the outside of the case, so that oil can be effectively supplied when a high-pressure operation is performed. Moreover, the present invention may not have a facility such as a pressure reduction pin, so that oil can be effectively supplied when a low-pressure operation is performed.

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 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 compressor according to embodiments of the present disclosure comprises a discharge valve which is provided so as to be coupled to a fixed scroll and open/close a discharge hole. The discharge valve includes a coupling portion which is coupled to one surface of the fixed scroll, the surface facing a muffler, and a head portion extending from the coupling portion and opening/closing the discharge hole. The head portion may be provided with a communicating hole for allowing the discharge hole and the muffler to be in communication with each other. Accordingly, a backflow of a compressed refrigerant is prevented during the operation of the compressor, and thus over-compression of the refrigerant can be prevented. Also, when the compressor stops operating, only a certain amount of the discharged refrigerant is allowed to flow backward to prevent a reverse rotation of an orbiting scroll and a decrease in the oil level of the oil stored in a case.

The invention relates to a vacuum pump for a motor vehicle, comprising a pump housing surface, on which a noise reduction hood delimiting a sound damping volume is mounted. The invention is characterized in that a multi-functional decoupling element is located between the pump housing surface and the noise reduction hood, said element carrying out a sealing function and a valve function in addition to a sound decoupling function.

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.

First closing plate and second closing plate close opening portions at both ends of cylindrical member in an axial direction. Base is housed in a space formed by cylindrical member, first closing plate, and second closing plate, and rotates around an axis in the same direction as the axial direction of cylindrical member. Resin layers are formed on thrust surfaces of base. Groove C is a plurality of concentric circular grooves or a spiral groove formed on each resin layer, and the center of circles of the circular grooves or the center of a spiral of the spiral groove is different from the rotation center of base.

A scroll compressor according to the present invention includes a casing, an orbiting member provided within the casing and performing an orbiting motion, a non-orbiting member forming a compression chamber together with the orbiting member, the compression chamber having a suction chamber, an intermediate pressure chamber and a discharge chamber, a communication passage configured to bypass a refrigerant of the compression chamber into the casing, an opening/closing valve assembly configured to open and close the communication passage, and a switching valve assembly configured to operate the opening/closing valve assembly, the switching valve assembly being provided outside the casing and connected to the opening/closing valve assembly, whereby an installation of the bypass hole can result in prevention of over-compression and an installation of a control valve for varying a capacity outside the casing can result in reduction of costs for the control valve.