A fluid pump includes a pump head and a motor coupled by a drive shaft. The pump head includes a pump inlet, a pump outlet, and a pumping stage in which a movable pump element is driven by the drive shaft. The motor includes a motor rotor and a motor stator. A connector couples the motor rotor and the drive shaft. The connector includes a plate rotatable with the drive shaft, fan blades attached to the plate for establishing a flow of air for cooling the motor, and one or more counterweights attached to the plate for reducing or eliminating imbalance created by certain forces generated by the pump during operation.

In a screw compressor (20), a male rotor suction end bearing (96) and discharge end bearing (90 1, 90 2, 90 3) mount the male rotor suction end shaft portion (39) and discharge end shaft portion (40). A female rotor suction end bearing (98) and discharge end bearing (92 1, 92 2) mount the female rotor suction end shaft portion (41) and discharge end shaft portion (42). At least one valve (182; 282; 382 1,382 2,382 3; 82; 582-1,582-2; 682-1,682-2; 782-1,782-2) is along a lubricant flowpath and has an energized condition and a de-energized condition. At least one restriction (184; 84-1,84-2; 84-1, 84-2,84-3; 484 1,484-2,84-3; 84 1,84 2,584; 84-1,84-2,684; 84-1,84-2,784) is along the lubricant flowpath. The at least one valve and the at least one restriction are positioned to create a lubricant pressure difference biasing the rotors away from a discharge end of the case.

Disclosed herein is a rotary compressor capable of maintaining the overall dynamic balance and providing low vibration and low noise even at high speed operation and capable of improving efficiency by providing a communication passage to communicate operation chambers, which are provided inside each of the plurality of cylinders for compressing a refrigerant, to each other. The rotary-type compressor includes a housing, a drive motor provided inside the housing to generate power and having a stator and a rotor, and a compression unit that receives power from the drive motor and compresses the refrigerant. The compression unit includes a plurality of cylinders in which an operation chamber to compress the refrigerant is provided. The operation chambers provided in each of the plurality of cylinders are provided to have different volumes, and a balancer provided to maintain dynamic balance is provided only in the lower side of the rotor.

The present invention provides an improved vacuum pump assembly for a motor vehicle comprising of a housing, a rotor, modified vane, a sealing ring, a cover, wherein, the modified vane containing a vane slider is having at least one oil vent or relief hole or slot, for the reduction of the exit port oil peak pressure, by channelizing oil supplies to the vane top and bottom face, thereby improving the seal-ability between the moving and stationary part of the pump; and the modified vane further having an oil vent control at the exit port, for maintaining oil pressure and reducing the exit port hydraulic pressure, leading to reduction in the opposite end vane slider tip load causing low friction between the pump housing, the vane and vane slider, and further channelizing the excess amount of oil to the vane top face which creates additional sealing between the vane and the housing, reducing the air leakage between the low pressure chamber and high pressure chamber inside the pump.

A compressor may include a shell, a bearing housing, an orbiting scroll, and a non-orbiting scroll. The bearing housing is supported within the shell and includes a central body and a plurality of arms. Each arm extends radially outwardly from the central body and has a first aperture. The orbiting scroll is supported on the bearing housing. The non-orbiting scroll is meshingly engaged with the orbiting scroll and includes a plurality of second apertures. Each second aperture receives a plurality of bushings and a fastener. The fastener extends through the bushings and into a corresponding one of the first apertures in the bearing housing to rotatably secure the non-orbiting scroll relative to the bearing housing while allowing relative axial movement between the non-orbiting scroll and the bearing housing.

A rotor has at its two axis end portions an upper large-diameter inner circumferential portion and a lower large-diameter inner circumferential portion that have inner diameters larger than the inner diameter of the axially middle portion of the rotor and are offset in the radial direction. A crankshaft has a passageway, which is formed in the crankshaft and allows refrigerant to flow therethrough, and a gas venting hole, which provides communication between the passageway and at least one discharge opening formed in the outer circumferential surface of the crankshaft. The at least one discharge opening is formed at a position facing the inner circumferential surface of the lower large-diameter inner circumferential portion 5b on the compression unit side.

Scroll compressor includes a shaft rotatably supported to a casing; an eccentric bush having a recess part into which one end portion of the shaft is inserted, an eccentric part eccentric to the shaft, and a balance weight disposed at the opposite side of the eccentric part with respect to the recess part; an orbiting scroll for performing the orbiting motion in interlock with the eccentric part; and a fixed scroll for forming a compression chamber together with the orbiting scroll. The casing has an orbiting groove in which the eccentric bush performs the orbiting motion, a buffer member is interposed between the orbiting groove and the balance weight. Rotation clearance is formed between the recess part and the shaft. The buffer member is compressed between the balance weight and the orbiting groove before the recess part and the shaft contact each other by the rotation clearance.

A scroll compressor includes a compressing mechanism unit including a fixed scroll that is fixedly provided in a shell and an orbiting scroll that moves around the fixed scroll, the compressing mechanism unit compressing fluid; a main shaft including an eccentric shaft portion at one end thereof that transmits a rotational driving force to the orbiting scroll; a slider having a slide groove in which the eccentric shaft portion is slidably fitted; and an orbital bearing provided to the orbiting scroll that rotatably supports the slider. The slider is provided on the inner peripheral side of the orbital bearing when seen in a direction of a center axis of the slider. The center axis of the slider is eccentric in one direction from an axis of rotation of the main shaft and a center of gravity of the slider is eccentric in an opposite direction.

Disclosed herein is a scroll compressor having a shaft balancer capable of attenuating vibration while preventing deformation of the rotary shaft during operation at a high speed.

Disclosed is a compressor having a torque load reducing unit for moving a center of weight to which a gas force is applied. As the torque load reducing unit is formed at an oval-shaped roller, a distance between a rotation center of the roller and an operation point to which a gas force is applied becomes short. This can reduce a torque load to the roller, and can enhance compression efficiency.