A vacuuming device comprises a main body, a rotary shaft, a vacuum pump rotor, a motor stator and a motor rotor. An air inlet, an air outlet, an oil storage chamber and a motor chamber are disposed in the main body. The oil storage chamber communicates with the air outlet. The rotary shaft is rotationally connected to the main body. The vacuum pump rotor is fixedly mounted to the rotary shaft and cooperatively forms a stator cavity of the vacuum pump with the inner-wall of the main body. The air inlet and the oil storage chamber communicate with the stator cavity of the vacuum pump respectively. The vacuuming device reduces the cost of manufacturing, optimizes the spatial structure and downsizes the device.

A screw rotor is made out of polymer. The screw rotor includes a shaft with a rotor body on it. The polymer of the shaft is reinforced with fibers. The shaft features elements that engage the rotor body or corresponding elements on the rotor body, such that the elements prevent an axial and/or rotational movement of the shaft with respect to the rotor body.

A scroll compressor having a casing, a drive motor which is held in place within the casing and has an internal flow passage and an external flow passage to pass through, a rotation shaft which is combined with the drive motor for rotation, a frame that is provided under the drive motor and through which the rotation shaft passes for support, a first scroll which is provided under the frame and on whose one flank surface a first wrap is formed, a second scroll which is provided between the frame and the first scroll, on which a second wrap that is engaged with the first wrap is formed, with which the rotation shaft is eccentrically combined and which forms a compression chamber, and a flow passage separation unit which separates a space between the drive motor and the frame into an internal space and an external space is provided.

A scroll compressor is disclosed. The scroll compressor includes a rotating shaft coupling portion axially extending from a central portion of an orbiting end plate to radially overlap an orbiting wrap, such that an eccentric portion of a rotating shaft is coupled thereto, and a portion of the orbiting wrap may extend from an end surface of the rotating shaft coupling portion facing a fixed end plate. With the configuration, a distance between bearing reaction force and gas reaction force acting on the orbiting scroll can be reduced, to stabilize a behavior of the orbiting scroll and thus reduce back pressure, thereby decreasing friction loss between scrolls. Simultaneously, compression chambers can be formed even in a central portion of the orbiting scroll, which can increase a compression ratio and improve volumetric efficiency.

The invention provides a crank sleeve for a scroll pump. The crank sleeve has a longitudinal axis and is configured to provide a radially extending crank offset for imparting an orbital path on an orbital scroll of the scroll pump. The crank sleeve further comprises an integrally formed counterbalance for reducing pump vibration extending radially in a direction substantially opposite to the crank offset.

A multi-stage dry Roots vacuum pump, including a pump body, multi-stage Roots working units and a plurality of drive components. The pump body is provided with a plurality of independent working chambers, and airflow channels communicating the various working chambers; the airflow channels are communicated with outside; the Roots working units of each stage include driving Roots rotors and driven Roots rotors; the driving Roots rotors and driven Roots rotors are positioned in the working chambers; and the various drive components are respectively used for driving the driving Roots rotors and driven Roots rotors positioned in the various working chambers to rotate towards opposite directions at the same rotating speed. The Roots working units of various stages may be randomly distributed at various positions of the pump body on premise of ensuring that the airflow channels can communicate the working chambers of each stage.

A scroll compressor having a casing, a drive motor which is held in place within the casing and has an internal flow passage and an external flow passage to pass through, a rotation shaft which is combined with the drive motor for rotation, a frame that is provided under the drive motor and through which the rotation shaft passes for support, a first scroll which is provided under the frame and on which one flank surface a first wrap is formed, a second scroll which is provided between the frame and the first scroll, on which a second wrap that is engaged with the first wrap is formed, with which the rotation shaft is eccentrically combined and which forms a compression chamber, and a flow passage separation unit which separates a space between the drive motor and the frame into an internal space and an external space is provided.

A compressor includes a motor, a compression mechanism portion driven by the motor, and a rotation shaft connecting the motor and the compression mechanism portion. At least a part of the rotation shaft is composed of a material having a higher Young's modulus than that of cast iron, and having a higher thermal conductivity than that of cast iron.

Technologies are generally described for clearance adjustments in twin-screw pump assemblies. A twin-screw pump assembly may include a conically shaped portion of a drive shaft enveloped by a bushing. For clearance adjustment, both clamping nuts of the drive shaft, which provide pretention to the bushing and secure an axial position of a threaded screw to the drive shaft, may be removed on the flow side of the pump assembly and the bushing loosened to adjust the angularity between bushing and drive shaft. The bushing may then be pushed over the conically shaped portion and both clamping nuts re-assembled. In some examples, a clamping nut of the driven shaft may be designed and used as removal/loosening tool for the drive shaft bushing.

A single-screw compressor includes a screw rotor with helical grooves, a gate rotor assembly including first and second gate rotors, and a casing housing the screw rotor and the gate rotor assembly. A rotor support member is attached to the first and second gate rotor rotors, and is rotatably supported by the casing. Each of the helical grooves of the screw rotor has a front sidewall surface and a rear sidewall surface. Each of the gates of the first gate rotor slides only on the front sidewall surface of the helical groove in which the gate has entered. Each of the gates of the second gate rotor slides only on the rear sidewall surface of the helical groove in which the gate has entered. The first and second gate rotors of the gate rotor assembly are coaxially arranged and relatively displaceable in a circumferential direction.