A geared volumetric machine including: a first and a second door; the second door operating at a greater pressure than the first door; one from between the first and second door being an inlet door of a fluid into the volumetric machine and the other door being an outlet door; a first cogged wheel in turn including a first and a second lateral flank; a second cogged wheel enmeshing with the first cogged wheel; a first and a second abutment between which the first cogged wheel is interposed and that respectively face the first and the second lateral flank of the first cogged wheel; a first grooved pathway which at least in a first angular position of the first cogged wheel connects a first and a second zone, the first zone including at least one of the compartments which is in communication with the second door.

A scroll compressor includes a first scroll member, a second scroll member, and an aerostatic thrust bearing. The aerostatic thrust bearing forms a layer of gas between the second scroll member and a fixed supporting member to support the second scroll member as the second scroll member rotates and/or orbits. Also disclosed is a method of supporting a rotating/orbiting scroll member in a scroll compressor. The method including supplying pressurized gas to an aerostatic thrust bearing such that a layer of gas is formed between the rotating/orbiting scroll member and a fixed supporting member.

A vacuum scroll pump having an inlet portion having a pump inlet, and an exhaust portion having a pump outlet; a frame; a stationary scroll plate fixed to the frame and comprising a stationary plate comprising at least one stationary scroll blade; an orbiting scroll plate comprising an orbiting plate comprising at least one orbiting scroll blade projecting axially from a front side of the orbiting plate toward the stationary plate; a drive mechanism supported by the frame and operatively connected to the orbiting scroll plate so as to cause the orbiting scroll plate to orbit about a longitudinal axis of the vacuum scroll pump and thereby pump a process gas; a double-sided thrust bearing supporting the orbiting scroll plate; and a bellows which isolates the process gas from the drive mechanism.

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 pump device includes: a drive shaft; a pump element; a pump housing including; a pump element receiving space, first and second bearing receiving spaces, a suction passage, a discharge passage, a return passage, and a seal receiving space, a first bearing including a first lubrication groove, received within the first bearing receiving space, and supporting the drive shaft; a second bearing which includes a second lubrication groove having a sectional area that is perpendicular to the rotation axis, and that is greater than a sectional area of the first bearing that is perpendicular to the rotation axis, which is received within the second bearing receiving space, and which supports the drive shaft; and a seal member provided within the seal receiving space, and arranged to seal between the drive shaft and the pump housing.

A fluid machine includes a rotary shaft, an operation body configured to discharge fluid by rotation of the rotary shaft, a housing accommodating the rotary shaft and the operation body, and a foil bearing disposed in the housing rotatably supporting the rotary shaft. The foil bearing includes a cylindrical bearing housing, a top foil between the bearing housing and the rotary shaft, and a bump foil between the bearing housing and the top foil and elastically supporting the top foil. The bearing housing has a protrusion protruding inwardly in a radial direction from the bearing housing. The protrusion includes an abutment surface configured to restrict deformation of the bump foil to an elastic range not to reach a plastic range by abutting against the top foil or the bump foil when the top foil is displaced outwardly in the radial direction of the bearing housing.

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 gear pump is provided with: a casing including a suction port configured to suck fluid, and a discharge port configured to expel the pressurized fluid; a gear including a wheel portion with gear teeth and an axially elongated shaft portion, the gear being so housed in the casing as to transport the fluid from the suction port to the discharge port; and a floating bearing rotatably supporting the shaft portion and being movable axially, the floating bearing including a sealing face in contact with the wheel portion, a receiver face axially opposed to the sealing face; and a communication path having an opening on the sealing face and communicating the opening with a third pressurization chamber defined by a third receiver face of the receiver face and the casing.

A geared volumetric machine comprising: a first and a second door (91, 92); the second door (92) operating at a greater pressure than the first door (91); one from between the first and second door (91, 92) being an inlet door of a fluid into the volumetric machine (1) and the other door being an outlet door of the fluid from the volumetric machine (1); a first cogged wheel (11) in turn comprising a first and a second lateral flank (111, 112); a second cogged wheel (12) enmeshing with the first cogged wheel (11); the first wheel (11) comprising a plurality of teeth defining between them a plurality of compartments (9) suitable to house teeth of the second wheel (12); a first and the second abutment (3, 4) between which the first cogged wheel (11) is interposed and that respectively face the first and the second lateral flank (111, 112) of the first cogged wheel (11). a first grooved pathway (31) which at least in a first angular position of the first cogged wheel connects a first and a second zone (51, 52), the first zone (51) comprising at least one of the compartments (9) which is in communication with the second door (92), the second zone (52) being a locus of points interposed between the first abutment (3) and the first flank (111). The first grooved pathway (31) comprises at least one stretch having a passage section having a surface smaller than 1 mm.sup.2.

A refrigeration apparatus includes a compressor connected to a refrigerant circuit, and a bearing monitor. The compressor includes a compression mechanism, an electric motor, a drive shaft, and a plain bearing that supports a journal portion of the drive shaft. The bearing monitor performs an abnormal-state operation to cope with poor lubrication on the plain bearing if an abnormal state condition is satisfied. The abnormal state condition is a condition indicating that a rate of change of current exceeds a first reference value. The rate of change of current is an amount of change in a driving current usable to drive the compressor per unit time. The journal portion of the drive shaft has a surface roughness of at least 0.05 μm.