A variable capacity compressor is provided, including: two cylinders and a middle plate; at least one flow channel provided in the middle plate, wherein one end of the flow channel is connected to an exhaust chamber of any one of the two cylinders, the other end is connected to a suction chamber of the other one of the two cylinders. In present disclosure, by setting a flow channel in the middle plate of the variable capacity compressor, the exhaust chamber of one cylinder is connected to the suction chamber of the other cylinder. When the flow channel is completely closed, the two cylinders operate independently; when the flow channel is opened, the refrigerant in the exhaust chamber flows into the suction chamber through the flow channel, that is, the upper cylinders and the lower cylinder are connected to each other, which can adjust the capacity of the compressor.

The disclosure relates to a compressor having a noise reduction resonator. The compressor includes: a compression part having compression space in which introduced gas is accommodated, and configured to compress and discharge the gas in the compression space; and a gas moving part having an inner wall forming a gas flow path through which the gas discharged from the compression space moves, wherein the gas moving part is provided with a first resonator configured to communicate with the gas flow path on the inner wall forming the gas flow path and having a resonance space depressed upward in a moving direction of the gas. The compressor according to the disclosure may prevent compression efficiency from decreasing and maintain a noise reduction effect for a long period of time by preventing foreign objects or liquids from being accumulated in the resonance space.

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 rotary vacuum pump includes a housing defining a pump chamber therein and a rotor extending through a first axial end panel into the pump chamber and carrying at least one vane for rotary movement of the vane within the pump chamber. The rotor comprises an annular axial end face configured to seal against a corresponding contact surface of a second axial end panel. An annular groove for reducing noise generation of the rotary vacuum pump during operation is formed at the annular axial end face of the rotor and/or the contact surface of the second axial end panel.

A vane cell pump comprises a contour ring having an inner peripheral face and a rotatable rotor which has a plurality of conveying elements displaceable radially relative to a rotation axis. The inner peripheral face includes a plurality of pump portions each constructed with an intake region and a pressure region which are passed through by the conveying elements during rotation of the rotor. A narrow location at which the conveying elements are displaced radially inward toward the rotation axis to a greatest extent, is located between a pressure region and a subsequent intake region. By applying a part-stroke, an auxiliary start contour which is arranged between the rotation axis and the inner peripheral face radially inside the conveying elements in the region of at least one pump portion displaces the conveying elements to the greatest extent radially inwardly.

A pump arrangement (1) at least comprising a pump (2) having a pressure side (3) and an intake side (4) and a drive unit (5) for the pump (2) which are arranged in a common housing (6), wherein the drive unit (5) is an axial flow electric drive which comprises a stator (7) which is connected to the housing (6) in a rotationally secure manner and a rotor (8) which is arranged so as to be able to be rotated with respect to the housing (6), wherein the rotor (8) is arranged with a first end face (9) opposite the stator (7) in an axial direction (10) and forms an outer conveying means (11) of the pump (2) and has with spacing from the first end face (9) on an inner circumferential face (12) a first conveying profile (13), wherein in a radial direction (14) inside the rotor (8) there is arranged an inner conveying means (15) of the pump (2) which has on an outer circumferential face (16) a second conveying profile (17) which cooperates with the first conveying profile (13) in order to convey a fluid (18).

A rotary compressor, including a cylinder, an inner peripheral surface of which is defined in an annular shape to define a compression space, provided with a suction port configured to communicate with the compression space to suction and provide refrigerant to the compression space; a roller rotatably provided in the compression space of the cylinder, and including with a plurality of vane slots at predetermined intervals along an outer peripheral surface, the plurality of vanes each providing a back pressure at one side thereinside; a plurality of vanes slidably inserted into the plurality of vane slots, respectively, to rotate together with the roller, front end surfaces of the plurality of vanes coming into contact with an inner periphery of the cylinder due to the back pressure to partition the compression space into a plurality of compression chambers; and a main bearing and a sub bearing provided at both ends of the cylinder, respectively.

A cam ring is capable of moving while rolling on a cam support surface. The cam ring is provided such that within a range in which the cam ring can move on the cam support surface, an eccentricity amount increasing-side angle is always greater than an eccentricity amount decreasing-side angle. On a plane perpendicular to the rotation axis of a driving shaft, the eccentricity amount increasing-side angle is an angle, in a direction opposite to a rotation direction of the driving shaft, from a first reference line, which connects a tangent point between the cam ring and the cam support surface to a rolling center of the cam ring, to a starting end of a first discharge port. The eccentricity amount decreasing-side angle is an angle, in the rotation direction of the drive shaft, from the first reference line to a terminal end of the first discharge port.

A positive displacement rotary fluid pump assembly includes a pump housing and a rotor supported within the housing for rotation about an axis offset with respect to a housing axis and including a plurality of chambers of increasing volume on an low pressure side of the pump and of decreasing volume on a high pressure side of the pump. A fluid inlet communicates with the plurality of the chambers of increasing volume for admitting fluid into the pump under a first low pressure, and a fluid outlet communicates with a plurality of the chambers of decreasing volume for selectively expelling fluid from the pump under a second higher pressure. At least one fluid control valve is operative to selectively close one or more of the chambers of decreasing volume from communication with the fluid outlet when the fluid pressure in such chambers is below the predetermined value and to open one or more other chambers of decreasing volume when the fluid pressure in such chambers is at or above the predetermined value.

An oil pump is configured to include a rotor, a drive shaft that drives the rotor to rotate, a rotor chamber in which the rotor is contained, an inlet port and an outlet port each provided in the vicinity of the rotor chamber, and a pump cover. The pump cover is made of a resin. On a portion of an outer surface side of the pump cover corresponding to an inner portion, in which oil circulates, of the pump cover, a rib that has an erecting wall shape is provided.