Provided is a multi-stage screw compressor with which an intermediate shaft section of a rotor can be made shorter. A two-stage screw compressor includes a front-stage compressing mechanism 1 which has a front-stage male rotor 11A and a front-stage female rotor 11B, and which compresses air, and a rear-stage compressing mechanism 2 which has a rear-stage male rotor 12A and a rear-stage female rotor 12B, and which further compresses the air compressed by the front-stage compressing mechanism 1. The front-stage male rotor 11A and the rear-stage male rotor 12A are configured to be coaxial, and the front-stage female rotor 11B and the rear-stage female rotor 12B are configured to be coaxial. An axial delivery pocket 34 of the front-stage compressing mechanism 1 and an axial intake pocket 39 of the rear-stage compressing mechanism 2 are arranged in a positional relation of partly overlapping with each other in the axial direction of the rotor, and are separated from each other by a separating wall 41.

Provided is a feed screw assembly for a fluid dispense pump, comprising a feed screw; a feed screw shaft extending from the feed screw; a spanner nut about the feed screw shaft; a bearing assembly about the feed screw shaft between the spanner nut and the feed screw The bearing assembly includes an outer ring that directly abuts the spanner nut; and an inner ring that rotates inside and relative to the outer ring, wherein the inner ring is coupled to the feed screw shaft for rotating the feed screw, and wherein the inner ring is separated from the spanner nut by a gap.

Provided is a feed screw assembly for a fluid dispense pump, comprising a feed screw; a feed screw shaft extending from the feed screw; a spanner nut about the feed screw shaft; a bearing assembly about the feed screw shaft between the spanner nut and the feed screw The bearing assembly includes an outer ring that directly abuts the spanner nut; and an inner ring that rotates inside and relative to the outer ring, wherein the inner ring is coupled to the feed screw shaft for rotating the feed screw, and wherein the inner ring is separated from the spanner nut by a gap.

Disclosed are a hydrostatic pressure support and a spherical pump having the same. The hydrostatic pressure support is arranged between each of two parallel sides of a slipper and a sliding groove, and includes a first liquid flow channel, a second liquid flow channel, and a pressure-bearing groove. An inlet of the first liquid flow channel is communicated with one of two working chambers of the spherical pump, and an inlet of the second liquid flow channel is communicated with the other of the two working chambers. An outlet of the first liquid flow channel and an outlet the second liquid flow channel are respectively communicated with the pressure-bearing grooves provided on the two parallel sides of the slipper.

A compressor includes a driving motor, a centrifugation space, a discharge pipe, a rotary shaft, a compression portion, a pump assembly, and an oil pickup. The centrifugation space is defined inside a case by a downstream side of the driving motor and the case, and enables centrifugation of a compressed refrigerant and a lubricant oil. The discharge pipe can discharge the refrigerant from the centrifugation space outside the case. The rotary shaft is coupled to a rotor of the driving motor and defines an oil supply path. The compression portion is provided at an upstream side of the driving motor and can compress the refrigerant as the rotary shaft rotates. The pump assembly is provided below the rotary shaft and can pump oil as rotated with the rotary shaft. The oil pickup defines an oil supply path between the pump assembly and a low oil space formed inside the case.

A screw compressor element may have a housing; a cylinder bearing including an inner ring, an outer ring, a raceway, and a cylindrical rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof; and a ball bearing including an inner ring, an outer ring, a raceway, and a ball shaped rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof, wherein a rotor is rotatably arranged by way of the cylinder bearing and the ball bearing.

The scroll compressor (1) includes a fixed scroll (7); an orbiting scroll (8); a support arrangement (5) including a thrust bearing surface (9) on which is slidably mounted the orbiting scroll (8); a rotation preventing device configured to prevent rotation of the orbiting scroll (8) with respect to the fixed scroll (7), the rotation preventing device including a plurality of orbital discs (28) respectively rotatably mounted in circular receiving cavities (29) provided on the support arrangement (5), each orbital disc (28) being provided with an outer circumferential bearing surface (31) configured to cooperate with an inner circumferential bearing surface (32) provided on the respective circular receiving cavity (29); and a lubrication system configured to lubricate the inner and outer circumferential bearing surfaces (32, 31) with oil supplied from an oil sump (36), the lubrication system including a plurality of oil reservoirs (43) each arranged in a bottom surface of a respective circular receiving cavity, and a plurality of oil stirring arrangements each configured to stir oil contained in a respective oil reservoir (43).

The invention provides a scroll pump comprising an orbiting scroll and a fixed scroll, wherein the orbital axis of the orbiting scroll is movable in a radial direction relative to the fixed scroll while the orbiting scroll is orbiting about its orbital axis, or wherein the fixed scroll is movable relative to the orbiting scroll in a radial direction while the orbiting scroll is orbiting about its orbital axis.

The invention provides a scroll pump comprising an orbiting scroll and a fixed scroll, wherein the orbital axis of the orbiting scroll is movable in a radial direction relative to the fixed scroll while the orbiting scroll is orbiting about its orbital axis, or wherein the fixed scroll is movable relative to the orbiting scroll in a radial direction while the orbiting scroll is orbiting about its orbital axis.

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.