A scroll compressor of the present disclosure includes a housing; a motor provided in the housing; a rotating shaft rotated by the motor; an orbital scroll orbital moved by the rotating shaft; and a fixed scroll forming a compression chamber together with the orbital scroll, wherein the housing includes a center housing through which the rotating shaft passes; a front housing forming a motor accommodating space in which the motor is accommodated; and a rear housing having a discharge chamber accommodating a refrigerant discharged from the compression chamber, a discharge port guiding the refrigerant of the discharge chamber to an outside of the housing, an introduction port into which an intermediate pressure refrigerant is introduced from the outside of the housing, and an introduction chamber accommodating the refrigerant introduced through the introduction port, and wherein the fixed scroll comprises an injection hole guiding the refrigerant of the introduction chamber to the compression chamber. Thereby, an amount of refrigerant discharged from the compression chamber is increased, and thus the performance and efficiency of the compressor may be improved.

A pump device includes a rotating body, a pump housing including a suction port and a discharge port, and a relief valve. In the pump device, a fluid is sucked from the suction port and discharged from the discharge port by rotation of the rotating body. The relief valve includes a valve body and a biasing member. The discharge port includes an one end in a direction in which the discharge port extends. The one end is shallower than a middle portion of the discharge port. The pump housing includes a relief flow path through which the fluid flows when the relief valve opens. The relief flow path is provided so as to be open to a groove bottom surface of the one end of the discharge port.

A pumping system is provided, including a rough-vacuum pump; a Roots vacuum pump including a pumping stage having a stator inside which two Roots rotors are configured to rotate synchronously in opposite directions to drive a gas to be pumped between an inlet orifice and an outlet orifice; and a pipeline connecting the outlet orifice to an intake of the rough-vacuum pump, a shortest distance between an edge of the outlet orifice and each of the Roots rotors in the pumping stage being less than 3 cm, and the outlet orifice being situated at the end of an upstream tube of the pipeline that passes into the pumping stage.

A damping apparatus for an exhaust valve in a compressor, an exhaust valve assembly having the damping apparatus, and a compressor using the exhaust valve assembly. The damping apparatus comprises a fixed body; the fixed body comprises an exhaust hole comprises an exhaust hole through which a compression cavity and an exhaust cavity are in fluid communication with each other; the exhaust hole comprises an inlet, an outlet, and an intermediate cavity provided between the inlet and the outlet and allowing the inlet and the outlet to be in fluid communication with each other; the intermediate cavity is configured to enable the backflow of the gas from the exhaust cavity to form a vortex in the intermediate cavity. The damping apparatus has advantages of reducing the force and frequency of impacts on an exhaust valve plate, and prolonging the service life of the valve plate.

Provided is a rotary compressor excellent in energy saving performance and reliability that can suppress over-compression of a compressed refrigerant compressed in a compression chamber. A rotary compressor includes a discharge port provided on an end plate and partially located outside a cylinder inner wall and a discharge groove provided on the cylinder inner wall and communicating with a compression chamber and the discharge port, the compression chamber compressing a refrigerant by contracting as an annular piston revolves, in which the discharge port faces an end portion of a vane groove on the cylinder inner wall on the compression chamber side.

A flange for a pump comprises first and second faces and a passageway for cryogenic fluid flow extending from the first face to the second face and at least one of (1) the passageway is for a pipe and comprises a first portion of a first diameter and a second portion of a second diameter greater than the first diameter, wherein when the pipe has an outer diameter that is smaller than the second diameter a gap is formed between the pipe and the passageway where the pipe passes through the second portion; and (2) a first annular groove in one of the first face and the second face and extending around the passageway, wherein the first annular groove in cooperation with the passageway forms a bellows. The gap and bellows increase the thermal resistance between the passageway and the flange, and the bellows allows for flexure during thermal contractions of the flange reducing thermal stress on welded fluid seals.

A vane pump includes: a rotor; vanes freely slidably received in the rotor; a cam ring having a cam face with which the vanes come into sliding contact; a side member having a sliding contact surface with which side surfaces of the rotor and the vanes come into sliding contact; pump chambers; and a discharge port configured to guide working fluid discharged from the pump chambers. The side member has a guide surface that is provided on an end portion side of the opening portion, the guide surface being configured to push the end portions of the vanes upward and guide them toward the sliding contact surface of the side member as the rotor is rotated in the reverse rotation direction.

A scroll type compressor includes an orbiting scroll including an orbiting wrap and a fixed scroll including a fixed wrap, in which first and second oil channels are respectively configured to supply oil to inner and outer oil channels formed by the orbiting wrap and the fixed wrap. Thus, the scroll type compressor has an oil channel structure that allows oil feeding into to the scrolls.

An inner wall surface of a pump housing has a slide surface, which is opposite from a joint member and along which an inner rotor is slidable. This slide surface includes an external tooth slide surface and a main body slide surface. External teeth of the inner rotor are slidable along the external tooth slide surface, and a main body of the inner rotor is slidable along the main body slide surface. A surface roughness of the main body slide surface is higher than a surface roughness of the external tooth slide surface.

A variable displacement vane pump includes a notch portion which is a flow path provided to extend from an initiating end of a discharge port towards a terminating end side of a suction port. The notch portion is formed so that a sectional area of the flow path is smaller than a sectional area of the discharge port at the initiating end thereof and that a length of the flow path in a circumferential direction is 1.5 pitches or larger. The terminating end of the suction port is a point where the vane in the suction area last overlaps the suction port. The initiating end of the discharge port is a point where the vane departed from the suction area first overlaps the discharge port. One pitch is a distance defied in the circumferential direction between adjacent vanes of the plurality of vanes.