A gerotor motor of the type having an end cap (13), and a stationary valve plate (15) disposed adjacent a rearward surface of the gerotor gear set (17). Adjacent a forward surface of the gerotor star (27) is a balancing plate assembly (19) including a radially outer balance plate (73) and a radially inner balance plate (75), the balance plates defining inner (77) and outer (79) profiles, respectively, which are closely spaced apart and are radially inward from the gerotor volume chambers (29) to provide sufficient sealing land. The inner balance plate (75) is biased toward the star end surface (81) by a Belleville washer (87). The end surface (81) of the gerotor star (27) defines individual star tooth surfaces (97), each of which includes a radial fluid passage (99) receiving system pressure, and a fluid passage (101) oriented generally perpendicular to the radial passage, and having a decreasing flow volume in a direction away from the radial passage (99). The fluid flowing through the perpendicular fluid passage (101) substantially reduces the tendency for galling to occur between the end surface of the star and the adjacent surface of the balance plate (75).

The present invention relates to a scroll type fluid machinery provided with a slide type radius of revolution variable mechanism, and has an object of preventing unilateral working of a rotating bearing 23 due to tilted rotation of a drive bushing 21 and a balance weight 27 fixed thereto.

The construction of the present invention is formed in such a manner that a bolt 41 for regulating tilted rotation is projected at an inner end of a rotary shaft 7, a shaft portion 41a thereof is made to penetrate through a vain hole 42 bored in the balance weight 27, and a bearing surface 41c of a head 41b thereof is brought into slidable contact with the inner end surface of the balance weight 27. When the radius of revolution is varied at the time of revolution in a solar motion of a revolving scroll 14, an eccentric driving pin 25 slides in a slide groove 24 and the shaft portion 41a of the bolt 41 slides in the vain hole 42 at the same time. In the interim, the bearing surface 41c of the head 41 comes into slidable contact with the inner end surface of the balance weight 27, thereby to suppress tilted rotation of the balance weight 27.

A rotary fluid pressure device is provided of the type including a housing portion (13), a gerotor gear set (15), and an endcap member (17). The gerotor gear set includes an internally-toothed ring member (19) and an externally-toothed star member (23) which orbits and rotates within the ring member. The star includes an end surface (24) disposed adjacent a stationary valve member (65), and another end surface (26) disposed adjacent the shaft housing. The star (23) defines high pressure ports (93) and low-pressure ports (95) which engage in commutating fluid communication with valve passages (83) defined by the stationary valve member. The star (23) defines passages (101) and (103) which communicate with the fluid ports (93) and (95), respectively, and feed high pressure to a fluid chamber (113) having a transverse area (B). Seated against the stationary valve member (65), and disposed within the endcap (17) is a pair of O-ring seals (117) and (119) which cooperate with adjacent surfaces to define a pressurized region (121) which is in communication with whichever of the ports (37) or (39) is at higher pressure. The region (121) has a transverse area (A), the area (A) being equal to or greater than the area (B). Pressurized fluid in both the fluid chamber (113) and pressurized region (121) biases the star (23) into sealing engagement with the stationary valve plate (65) to prevent cross-port leakage, while at the same time, maintaining a sufficiently small end clearance between the end surface (26) of the star and the adjacent wear surface (111) to substantially eliminate leakage from the volume chambers to the case drain.

A fluid pressure energy translating device (10) of the sliding vane type comprising a cam ring (13) including an internal contour (30), a rotor (25) having a plurality of vanes (36) rotatable therewith and slidable relative thereto in slots in the rotor (25) with one end of each vane (36) engaging the internal contour (30). The rotor (25) and internal contour (30) cooperate to define one or more pumping chambers (31, 32) between the periphery of the rotor and the cam contour through which the vanes (36) pass carrying fluid from an inlet port (19) to an outlet port (22). At least one cheek plate (16, 17) is associated with the body (11) and rotor (25). Two pressure chambers (39, 40) are formed for each vane (36) and each vane has two piston surfaces, one in each chamber, both being effective under pressure in the respective chambers (39, 40) to urge the vanes into engagement with the cam (13). A generally annular internal feed passage (44) is formed entirely within the rotor (25) and communicates with one set (39) of the pressure chambers. A radial passage (41) is provided on each vane (36) extending from the tip of the base thereof, so that cyclically changing pressure is supplied to the other set (40) of chambers. Arcuate grooves (49a, b) are provided in the face of the cheek plate (16, 17) in the dwell zones, and a hydrostatic pressure pad (48) is associated with the opposite face of the cheek plate (16, 17) and circumscribes the arcuate grooves (49a, b). An opening (50) extends from the arcuate grooves (49a, b) through the cheek plate (16,17) to the hydrostatic area (48).

A scroll-type fluid displacement apparatus, in particular, a compressor unit is disclosed. The unit includes a housing with a fluid inlet port and a fluid outlet port. A fixed scroll (28) with first end plate (281) and first spiral element (282) is fixedly disposed in the housing. An orbiting scroll (30) with a second end plate (301) and a second spiral element (302) is disposed for orbiting motion in the housing. The first and second spiral elements interfitwith one another at an angular offsetto make a plurality of line contacts to define at least one pair of sealed off fluid pockets. A drive pin (154) is eccentrically disposed at an inner end of a drive shaft. The orbiting scroll member has a boss (303) which rotatably supports a bushing (33). An eccentric hole is formed in the bushing and the drive pin is received within this hole. The center of the drive pin is located on an opposite side to the center of the drive shaft with regard to a straight line, which passes through the center of the bushing and is perpendicular to a connecting line passing through the centre of the drive shaft and the center of the bushing. The center of the drive pin also is beyond the connecting line in the direction of rotation of the drive shaft. The bushing has a balance weight (331) for cancelling a centrifugal force which arises because of the orbiting motion of the scroll member and bushing. Perfect dynamic balance is accomplished by the use of a pair of balance weights (35, 36) affixed to the drive shaft for generating a moment of some amount, but opposite in direction, to the moment generated by a force couple due to centrifugal force of the orbiting parts and the balance weight.

The present invention relates to a compressor configured to allow lubrication of a thrust surface through an oil groove formed in a thrust surface of a fixed scroll. Also, a scroll compressor according to one embodiment of the present invention allows oil to be smoothly supplied to a thrust surface of a fixed scroll by including a fixed scroll having an oil groove formed in a thrust surface of a fixed scroll sidewall, and allows an injection pressure acting on an orbiting scroll in an upward direction to be added by supplying the oil guided to the oil groove to the thrust surface of the fixed scroll such that an overturn moment generated in the orbiting scroll can be offset.

In order to adapt a balance piston unit of a compressor to a high speed, and to extend a service life of the compressor, a screw compressor according to the present invention includes a screw rotor including a rotor shaft, a radial bearing, a thrust plate, a balance mechanism, which is a slide bearing, a lubrication oil supply flow passage for supplying a lubrication oil, and a working fluid supply flow passage for supplying a working fluid for pressing the balance mechanism toward the thrust plate so that a reverse thrust load acts on the thrust plate.

A vane air motor is disclosed which is configured to prevent grease in a radial bearing from leaking into a rotor chamber. The vane air motor has a motor housing (20) having a rotor chamber, a rotor (22) with vanes (24) disposed in the rotor chamber, a first end wall (16) of the motor housing equipped with a radial bearing (50) rotatably supporting a support shaft portion (28) of the rotor, and a casing contiguously joined to the motor housing to form a compressed air supply chamber (44) together with the first end wall to supply compressed air into the rotor chamber through an air supply hole (46) formed in the first end wall. The first end wall has communication means (16-5, 16-6 and 16-7) for supplying compressed air from the compressed air supply chamber to the side of the first radial bearing closer to the rotor.

In a scroll fluid machine, an orbiting scroll is eccentrically revolved with respect to a stationary scroll so that fluid in a sealed chamber between the stationary and orbiting scrolls may be compressed toward a center. A first magnet is mounted on the stationary scroll and a second magnet is mounted on the orbiting scroll so that the same poles of the first and second scrolls may be opposite to each other thereby preventing the orbiting scroll from pressing the stationary scroll excessively.