A rotary pump, preferably a vacuum pump, featuring: a delivery space including an inlet on a low-pressure side and an outlet on a high-pressure side of the pump; a rotor which is arranged in the delivery space and delivers a fluid from the inlet into the delivery space to the outlet from the delivery space; at least one housing part which delineates the delivery space at least axially; and a drive shaft which is connected in drive terms to the rotor; including at least one sealing element which is connected, secured against shifting and/or rotating, to the drive shaft and/or rotor and forms a radial sealing gap with the housing part.

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 fluid machine includes a first rotor having a first rotor first working portion and a first rotor second working portion, a second rotor having a second rotor first working portion configured to mesh with the first rotor first working portion and a second rotor second working portion configured to mesh with the first rotor second working portion and rotate independently from the second rotor first working portion.

A scroll compressor includes a scroll compression element including a movable scroll, a drive shaft configured to allow the movable scroll to rotate, a boss portion, and a sliding bearing. The boss portion is connected to a back surface of the movable scroll. The boss portion is configured to rotatably support an upper end portion of the drive shaft. The upper end of the drive shaft is configured as an eccentric shaft portion. The sliding bearing is provided between the boss portion and the eccentric shaft portion. An axially central portion of the boss portion is more rigid than a connection portion of the boss portion connected to the movable scroll. The boss portion is shaped so that the central portion projects outward.

A rotary positive displacement pump comprising a pair of forwardly-positioned sealing arrangements and a pair of forwardly-positioned sleeves are received within a cavity providing for easy maintenance of the pump when the seals need to serviced. Each of the sealing arrangement includes a dynamic seal and a static seal. The dynamic seal abuts a corresponding sleeve and hub while a static seal is established between the corresponding sleeve and rotor.

A screw compressor includes a casing, a motor provided in the casing, a screw rotor inserted into a cylinder in the casing, a bearing holder, a drive shaft, a first bearing, and a second bearing. The cylinder is formed on a lateral side of the motor. The bearing holder is disposed on an opposite side of the screw rotor from the motor and adjacent to the screw rotor. The drive shaft is connected to the motor and the screw rotor. The first bearing is disposed adjacent to the screw rotor. The second bearing is disposed adjacent to the motor in an axial direction of the drive shaft. At least a portion of the first bearing is disposed inside the screw rotor.

A braking system for a hose or cable reel including a housing configured to fit inside a drum of the reel and to rotate with the drum during use, and a gerotor including inner and outer gears disposed inside the housing, wherein the inner gear is attachable to a shaft of the reel and the outer gear is configured to rotate relative to the inner gear with the housing during use thereby causing hydraulic fluid to be pumped through the gerotor and impede rotation of the drum.

A rotation shaft of a scroll compressor that includes an oil flow path formed therein, an upper frame support portion which is inserted into an upper frame, a boss insertion portion which is recessed from an upper surface of the upper frame support portion for insertion of the boss portion, and an oil residual groove which is recessed at a predetermined depth from a bottom portion of the boss insertion portion.

A fluid displacement apparatus includes a stator section with a rotor therein. The stator section includes a cylindrical casing, a helically-convoluted chamber section within the cylindrical casing, and a rigid sleeve within the cylindrical casing and separate from the helically-convoluted chamber section. The rigid sleeve includes a circular internal bore. The rotor is rotatably disposed within the cylindrical casing. The rotor includes a helically-lobed section disposed within the helically-convoluted chamber section, and a circular cylinder section disposed within the rigid sleeve. The circular cylinder section provides a fluid passageway between the rigid sleeve and the circular cylinder section. Side loads from the rotor are distributed along a contact line at any point of rotation of the circular cylinder section within the rigid sleeve.

A compressor may include a non-orbiting scroll, an orbiting scroll, a driveshaft and a bushing. The non-orbiting scroll includes a first end plate having a first spiral wrap extending therefrom. The orbiting scroll includes a second end plate having a first side and a second side. The first side has a second spiral wrap extending therefrom and meshingly engaged with the spiral wrap of the non-orbiting scroll. The second side has a hub extending therefrom. The driveshaft drivingly engaged to the orbiting scroll. The bushing supporting the driveshaft and is disposed within the hub of the orbiting scroll. One of the hub of the orbiting scroll and the bushing includes a convex portion.