Provided is a scroll compressor capable of expanding a compression space and accordingly increasing a design volume ratio. The scroll compressor includes: a main body; a fixed scroll fixed inside the main body; an orbiting scroll orbiting the fixed scroll; and a plurality of compressing portions respectively provided in the fixed scroll and the orbiting scroll, wherein each compressing portion includes a circular arc portion of which a curvature is constant, a curved portion positioned in an inside of the circular arc portion and spaced a preset distance from the circular arc portion, and a connection portion connecting the circular arc portion to the curved portion, wherein a curvature of the connection portion changes from the first circular arc portion to the second circular arc portion.

A scroll compressor includes a fixed scroll including a first end plate having an injection passage through which refrigerant is supplied to a refrigerant suction chamber. The injection passage includes an outlet passage section that opens into the refrigerant suction chamber and extends linearly. A refrigerant compression chamber is disposed on an extension of the outlet passage section.

A spiral compressor may include a stationary first spiral member and an orbiting second spiral member intermeshing with the first spiral member. The spiral compressor may include a pendulum slide mechanism that may have an inner ring and a stationary outer ring connected to the inner ring via a plurality of pendulums. The pendulum slide mechanism may include an eccentric member disposed on a radial inside of the inner ring with respect to a central access of the inner ring. The inner ring on an inner circumferential side may be drivingly connected to the eccentric member and on an outer circumferential side may be rigidly connected to the second spiral member. The second spiral member may transmit an orbiting motion in relation to the first spiral member via the pendulum slide mechanism when the eccentric member is driven.

A rotor for a multi-stage vacuum pump, a multi-stage vacuum pump and a method. The rotor comprises: a plurality of rotary vanes, the plurality of rotary vanes being axially displaced and coaxially aligned; a pair of end shafts, each end shaft extending from opposing axial ends of the plurality of rotary vanes; and an inter-vane shaft extending between adjacent rotary vanes of the plurality of rotary vanes, the inter-vane shaft having a diameter which is greater than that of the end shafts. In this way, the inter-vane shaft provided between each rotary vane may have an increased diameter, which improves the stiffness of the shaft and changes the modal frequency of the rotor. Such a change in the modal frequency is typically sufficient to improve its operation.

An oil lubrication system for a multi-stage compressor separates oil from a refrigerant at an intermediate pressure following the first stage of compression and then routes the separated oil at the intermediate pressure to the compressor suction cavity bearings at the intermediate pressure, thus avoiding further compression of oil in subsequent stages of compression. The efficiency of the multi-stage compressor can be increased by not raising the pressure of the oil through the subsequent stages of compression.

A scroll compressor is provided capable of supplying oil stored in an oil storage chamber upward through a rotary shaft to supply the oil to a compression device and to lubricate a bearing portion. The scroll compressor may include a casing, a drive motor, a rotary shaft, a main frame, a fixed scroll, and an orbiting scroll. A medium pressure chamber may be formed in or at a middle of the main frame, the fixed scroll, and the orbiting scroll. A pocket groove configured to guide oil discharged through the oil hole to the medium pressure chamber may be formed in an upper surface of the orbiting scroll, and a differential pressure path configured to guide the oil guided to the medium pressure chamber to the compression chamber may be provided in the fixed scroll.

A scroll compressor is provided that may prevent an oil-feeding hole from being blocked due to a high pressure refrigerant, which is compressed in compression chambers and introduced into the oil-feeding hole through an oil-feeding slit, by blocking one of both end portions of the oil-feeding slit, adjacent to the compression chambers, when the oil-feeding hole is formed through an outer circumferential surface of a bearing and the oil-feeding slit, which communicates with the oil-feeding hole, is formed on the outer circumferential surface. This may allow for smooth oil supply onto the outer circumferential surface of the bearing through the oil-feeding hole, thereby enhancing a bearing performance. Also, the oil-feeding hole or slit may be formed at a closest position to an oil feeding-required section, not within the section. This may allow for quick oil supply into the oil feeding-required section, resulting in further enhanced bearing performance.

A compressor includes a shell assembly and a compression mechanism disposed within the shell assembly. The shell assembly includes first and second end caps. A suction chamber is disposed within the shell assembly between the first end cap and the second end cap. A discharge chamber and oil sump may be disposed within the shell assembly. The shell assembly includes at least one suction opening into the suction chamber. A distributor is in communication with one of the suction openings. Plugs may sealingly engage another one of the suction openings. The distributor includes an inlet path and first and second outlet paths. A suction line is coupled to the inlet path. The suction line includes at least first and second portions. A first plane bisecting the second portion along a length of the second portion is perpendicular to a second plane that bisects the first and second outlet paths.

In a scroll compressor, a first flow passage is formed in a fixed base plate and a frame to supply oil separated by an oil separating mechanism provided in a sealed container to an oil sump at the bottom of the sealed container. In the fixed base plate, a second flow passage is formed to supply the oil separated by the oil separating mechanism into a compression mechanism.

A rotary positive displacement pump for fluids, in particular for the lubrication oil of a motor vehicle engine (60), has a displacement that can be regulated by means of the rotation of a stator ring (12) having an eccentric cavity (13) in which the rotor (15) of the pump (1) rotates. The stator ring (12) is configured as a multistage rotary piston for displacement regulation and is arranged to be directly driven by a fluid under pressure, in particular oil taken from a delivery side (19) of the pump or from a point of the lubrication circuit located downstream the oil filter (62). The invention also concerns a method of regulating the displacement of the pump (1) and a lubrication system for a motor vehicle engine in which the pump (1) is used.