A positive displacement device includes a first cylinder, a second cylinder disposed within the first cylinder, and a third cylinder disposed around the first cylinder. An interior surface of the first cylinder and an exterior surface of the second cylinder define an inner cavity. An exterior surface of the first cylinder and an interior surface of the third cylinder define an outer cavity. A partition between the interior surface of the first cylinder and the exterior surface of the second cylinder divides the inner cavity into inner regions, and another partition between the exterior surface of the first cylinder and the interior surface of the third cylinder divides the outer cavity into outer regions. The second cylinder and the third cylinder orbit with respect to the first cylinder to create alternating regions of high pressure and low pressure in the inner regions and the outer regions.

A negative pressure pump includes an electrically insulative casing an electrically conductive rotary shaft and an electrically conductive vane. The casing is formed in a tubular shape, an axial direction one end of which is closed off by a cap body. The rotary shaft is disposed in the casing, is mechanically and electrically connected to an earthed power source, and is rotated by power being transmitted from the power source. The vane is disposed in the casing, is supported at the rotary shaft to freely reciprocate in a direction orthogonal to the rotary shaft, and is electrically connected to the power source via the rotary shaft. The vane rotates integrally with the rotary shaft, and end portions of the vane slide over an inner wall face of the casing. The vane divides the interior of the casing into a plurality of spaces and generates negative pressure.

In the vane pump comprising the housing, the vane, and the cap, the sliding surface of the cap is configured as arc shape in the view from the rotational axis direction and the width toward the sliding direction of the cap is configured to be smaller than the width at the sliding angle field which is virtual area for contacting the inner surface of the pump room among the circumference including the arc shape of the sliding surface of the cap and to be bigger than the width at the high loading area where the load added to the sliding surface which is bigger than the predetermined value among the sliding angle field.

A compressor according to the present invention includes an oil separation mechanism and an oil supply mechanism. The oil separation mechanism includes an oil separation chamber and an oil drain path. The oil supply mechanism includes an oil supply port. The oil drain path includes a first flow path formed by penetrating a second partition of a housing and configured to open toward a first partition of a housing from the oil separation chamber, and a second flow path recessed in at least one of the first partition and the second partition and formed by the cooperation of the first partition and the second partition so as to get communicated with the first flow path. An outlet of the second flow path is located at a higher level in a vertical direction than an inlet of the second flow path while avoiding a direction facing the oil supply port.

The present disclosure provides a pumping assembly, a compressor and air conditioning equipment. The pumping assembly includes a first structural body, a rolling bearing assembly, a second structural body, a third structural body and a main shaft passing through the first structural body, the rolling bearing assembly, the second structural body and the third structural body. The pumping assembly includes: a first lubricating oil path passing through a second structural part, the sliding sheet backpressure cavity, a third structural part, a second structural part and a rolling body of the rolling bearing assembly; a second lubricating oil path passing through the sliding sheet backpressure cavity and a first pressure relieving groove of the first structural body; and a third lubricating oil path passing through the sliding sheet backpressure cavity, the first structural part and the rolling body of the rolling bearing assembly.

A vane pump includes: a casing forming a pump chamber therein; a rotor arranged inside the casing to rotate eccentrically with respect to the casing; and a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing. At least one of Formula (1): l≤(b/a)×k and Formula (2): l≤(c/a)×j is satisfied, where “a” represents a height of the pump chamber, “b” represents a height of the rotor, “c” represents a height of the vane in a rotation axis direction of the rotor, and where “l” represents a linear expansion coefficient of the casing in the rotation axis direction, “k” represents a linear expansion coefficient of the rotor in the rotation axis direction, and “j” represents a linear expansion coefficient of the vane in the rotation axis direction.

A pump body assembly and a compressor are provided. The pump body includes: a spindle, wherein the spindle has a sliding vane chute, a back pressure oil cavity being at least a part of an oil passage is located at a tail end of the sliding vane chute, an oil outlet of the back pressure oil cavity is located at the top of the back pressure oil cavity, and a position of the oil inlet of the back pressure oil cavity is lower than that of an oil outlet of the back pressure oil cavity such that a lubrication medium enters the back pressure oil cavity through the oil inlet of the back pressure oil cavity and fills up the back pressure oil cavity and flows out from the top of the back pressure oil cavity.

A vacuum pump for a vehicle includes: a pump housing having an internal cylindrical space, an inlet for receiving oil to be supplied to the space, and an outlet for discharging the oil from the space; a rotor eccentrically rotating in the internal cylindrical space of the pump housing; a vane rotating along the inner side of the internal cylindrical space of the pump housing; and a valve maintaining a pressure in the internal cylindrical space of the pump housing at less than a predetermined level.

A gas compressor includes at least two first and second discharge ports (45a, 45b) which are provided at an upstream side in a rotation direction of a rotor (50) along a peripheral direction of an inner peripheral surface 40a of a cylinder (40) with respect to a closest area (proximity part (48)) where the inner peripheral surface (40a) of the cylinder (40) and an outer peripheral surface (50a) of the rotor (50) are closest in a range of one revolution of a rotation shaft (51) and configured to discharge the refrigerant gas compressed in compression chambers (43). Of the first and second discharge ports (45a, 45b), on only the first discharge port (45a) closest to the proximity part (48), a cutout groove portion (47) is provided at a downstream-side edge portion of the first discharge port (45a) in the rotation direction of the rotor (50).

A vane compressor for a surgical gas delivery system is disclosed, which includes a compressor head having an outlet port for delivering pressurized gas to a gaseous sealing manifold communicating with a gas sealed trocar and an inlet port for receiving spent gas from the gaseous sealing manifold by way of the gas sealed trocar, wherein the compressor head is coupled to and driven by a motor.