Abstract: A compression mechanism of a scroll compressor has a back-pressure chamber defined on a back face of an end plate of a movable scroll. The compression mechanism has an annular space defined at an outer periphery of the end plate of the movable scroll. The movable scroll has a movable-side passage through which a compression chamber intermittently communicates with the back-pressure chamber in accordance with eccentric rotation of the movable scroll. The end plate of the movable scroll has a communication space through which the movable-side passage communicates with the annular space. The communication space includes first and second communication portions located forward and rearward of the movable-side passage in a direction of eccentric rotation, respectively. A first circumferential width of a first opening in the first communication portion is larger than a second circumferential width of a second opening in the second communication portion.

Abstract: A screw compressor and a compressor body thereof, in which the compressor body includes a housing provided with a suction inlet and a discharge end face, the housing is internally provided with a rotor chamber and a spool chamber, the housing is provided with a cooling chamber around the rotor chamber, the cooling chamber communicates with the suction inlet, and the cooling chamber is provided with an air inlet communicating with the rotor chamber.

Abstract: According to the present invention, a rotary blower or supercharger includes a recirculation loop for readmitting pressurized outlet gas back into the rotor chambers, and cooling means for cooling the pressurized outlet gas before it is readmitted into the rotor chambers, thereby providing a supercharger having a lower operating temperature and a higher operating pressure capability. In the preferred embodiment of the present invention, a supercharger includes a housing assembly defining first and second transversely overlapping cylindrical chambers. The housing defines an inlet port for the inflow of an inlet gas, and an outlet port for the outflow of the outlet gas. The supercharger further has first and second meshed, lobed rotors respectively disposed in the chambers for counter rotation about axes substantially coincident with the chamber axes.

Abstract: A compressor (10) is provided and may include a shell (12), a main bearing housing (18) disposed within the shell (12), a driveshaft (16), a non-orbiting scroll member (24), and an orbiting scroll member (22). The driveshaft (16) may be supported by the main bearing housing (18). The non-orbiting scroll member (24) may be coupled to the main bearing housing (18) and may include a first lubricant supply path in fluid communication with a lubricant source. The orbiting scroll member (22) may be rotatably coupled to the driveshaft (16) and may be meshingly engaged with the non-orbiting scroll member (24). The orbiting scroll member (22) may include a recess (96) that is moved between a first position in fluid communication with the first lubricant supply path and a second position fluidly isolated from the first lubricant supply path.

Abstract: A vane fluid pump for a vehicle component is provided with an inner rotor supported within a cam. The inner rotor has an outer wall extending between first and second end faces, the outer wall defining a series of slots spaced apart about the outer wall to provide a series of outer wall sections. One of the wall sections defines a groove. Another of the wall sections is independent of grooves or is ungrooved. The pump has vanes positioned within respective slots of the inner rotor and extending outwardly to contact the continuous inner wall of the cam. The groove on the inner rotor is configured fluidly couple with a notch on the housing to provide fluid flow to the discharge port from an upstream pumping chamber to disrupt harmonics during operation to reduce pressure ripples and associated tonal noise.

Abstract: A gerotor pump has a pump housing defining a chamber and having a fluid inlet and a fluid outlet. An outer gear member is supported for rotation within the chamber about a first axis, the outer gear member having a series of internal teeth. An inner gear member or inner rotor is rotatably supported within the outer gear member about a second axis spaced apart from the first axis. The inner gear member defining a series of external teeth interposed with a series of external pockets. The inner gear member defines a fluid passage therethrough to fluidly connect two nonadjacent pockets, with another pocket independent of fluid passages. The fluid passage is configured to disrupt harmonics during operation to reduce pressure ripples and associated tonal noise.

Abstract: A compressor and an air conditioner including the same having an improved structure capable of decreasing a discharge temperature of the compressor. The compressor which compresses and discharges refrigerant includes a casing defining an external appearance thereof, at least one cylinder including an inner space, a rolling piston which eccentrically turns in the inner space, a vane which radially abuts the rolling piston and divides the inner space into a suction chamber and a compression chamber, and a vane chamber recessed outward of the inner space such that the vane advances and retreats, a plurality of plates disposed above and below the at least one cylinder so as to define the inner space, an injection line provided in one of the at least one cylinder and the plural plates, and a check valve installed on the injection line.

Abstract: A scavenge gear pump and its method of operation is described. The scavenge gear pump includes a pump housing defining a pump chamber, an inlet passage, an outlet passage, and a fluid injection passage in fluid communication with the pump chamber. The inlet passage receives an admixed fluid at low pressure and the outlet passage the admixed fluid at high pressure from a downstream region of said pump chamber. The fluid injection passage receives a third fluid at an injection pressure for input into the pump chamber. A pair of driveable gears is disposed in the pump chamber. The third fluid is injected directly into the gear meshing area of the pump chamber through the fluid injection passage so that the third fluid fills voids at least between said intermeshing teeth of the driveable gears and so that the second fluid does not occupy the gear meshing area.

Abstract: A compressor including a housing defining a suction pressure region and a discharge pressure region includes first and second scroll members forming compression pockets. A first chamber located on the first end plate of the first scroll member includes first and second passages and a first aperture extending therethrough and in communication with the first chamber. The first aperture provides communication between a compression pocket and the first chamber. A modulation assembly is located in the first chamber and includes a heater and a thermal valve. The valve is displaceable from a first position that isolates the first passage from the second passage and a second position that permits communication between the first and second passages. The valve is displaced as a result of a temperature change provided by the heater.

Abstract: The scroll refrigeration compressor includes a stationary volute and a moving volute provided with spiral wraps defining variable-volume compression chambers, a separating member sealably mounted on a plate of the stationary volute so as to allow a relative movement between the separating member and the stationary volute, a delivery chamber at least partially defined by the separating member and the sealed casing. The compressor further includes a bypass passage arranged to communicate the delivery chamber with an intermediate compression chamber, and a anti-return device comprising a closing member movable between closing and opening positions for closing and opening the bypass passage, and an enclosure, positioned between the separating member and the plate of the stationary volute, including a first portion sealably mounted in a housing defined by the separating member and oriented substantially parallel to the longitudinal axis of the compressor.

Abstract: A scroll compressor is provided, in which at least one bypass hole that bypass a portion of a refrigerant before the refrigerant is discharged through a discharge hole is formed at a position where a bypass section that bypasses the refrigerant through the at least one bypass hole overlaps a discharge section that discharges the refrigerant through the discharge hole. The at least one bypass hole is formed at a position where a wrap volume ratio (Vs/Vd), which is a ratio of a suction volume (Vs) with respect to a discharge volume (Vd) in a compression chamber, is within the range of about 1.8˜2.2. With this configuration, over-compression of refrigerant may be prevented in a low speed driving mode, and efficiency of the compressor may be enhanced in the low speed driving mode and under a low load condition.

Abstract: A scroll compressor includes an orbiting scroll member, a drive mechanism accommodation space, a rotary shaft, a drive bushing, an upstream space, a downstream space, a first communication passage and a second communication passage. The upstream space and the downstream space are formed in the drive mechanism accommodation space by a plain bearing, the drive bushing and an eccentric pin of the rotary shaft. The second communication passage passes through at least the drive bushing and allows the upstream space and the downstream space to communicate with each other. A control valve is disposed in the second communication passage. Centrifugal force of the control valve developed when the rotary shaft is rotated at a predetermined speed or higher causes the control valve to move in a direction in which the second communication passage is opened, thereby to allow the upstream space and the downstream space to communicate with each other.

Abstract: A machine having two volute casings describing an orbital relative movement, one of the volute casings being fitted with at least one scroll and the other volute casing being equipped with at least two scrolls, the various scrolls delimiting a first series of variable-volume chambers belonging to a first compression or expansion stage, and a second series of variable-volume chambers belonging to a second compression or expansion stage, each stage having a high-pressure fluid passage and low-pressure fluid passage. A portion of the low-pressure fluid passage of the second stage is designed to open into one of the chambers of the second stage and is further away from the zone of convergence of the scrolls delimiting the variable-volume chambers of the second stage than a portion of the high-pressure fluid passage of the first stage that is designed to open into one of the chambers of the first stage.

Abstract: A mounting adapter is disclosed for use with a gear pump. The mounting adapter may have a generally plate-like base member, and inlet and outlet ports both formed in the base member. The mounting adapter may also have a first bearing bore formed in the base member between the inlet port and the outlet port and configured to receive a first gear shaft, and a first bleed groove formed in the base member adjacent the outlet port. The first bleed groove may be generally concentric with the first bearing bore. The mounting adapter may further have a second bearing bore formed in the base member between the inlet port and the outlet port and configured to receive a second gear shaft, and a second bleed groove formed in the base member adjacent the outlet port. The second bleed groove may be generally concentric with the second bearing bore.

Abstract: A compressor includes a housing, a first scroll member, a second scroll member and a valve assembly. The first scroll member is positioned within the housing and includes a first end plate portion and a second end plate portion coupled to the first end plate portion and having a first spiral wrap extending therefrom. The first end plate portion and the second end plate portion define a discharge passage. The second scroll member is positioned within the housing and includes a second spiral wrap meshingly engaged with the first spiral wrap. The valve assembly is supported by at least one of the first end plate portion and the second end plate portion at a location radially outward from the discharge passage.

Abstract: In a gear pump according to the present invention, a wall surface portion of a casing (2) includes a drive side partition surface (41) on which tooth crests (11) of a drive gear (10) slide, a driven side partition surface (42) on which tooth crests (21) of a driven gear (20) slide, a suction side inner peripheral surface (43) that connects the drive side partition surface (41) and the driven side partition surface (42) on a suction chamber (3) side, and a discharge side inner peripheral surface (44) that connects the drive side partition surface (41) and the driven side partition surface (42) on a discharge chamber (4) side.

Abstract: In a scroll compressor, a pass hole is formed at a position overlapping with a discharge sector of a discharge hole, where a sector for passing a refrigerant through the pass hole is overlapped with a sector for discharging the refrigerant through a discharge hole. This may prevent over-compression of a refrigerant when the scroll compressor is driven at a low speed. This may enhance efficiency of the scroll compressor in a low speed driving mode and under a low load condition.

Abstract: A system is provided for controlling the balance piston pressure in a screw compressor. The system can use the slide valve of the compressor as a valve to control the flow of fluid from a fluid source to the balance piston. When the slide valve prevents direct flow between the fluid source and the balance piston, an alternate path is used to provide fluid at a reduced pressure to the balance piston. The reduced pressure fluid is obtained by passing the fluid from the fluid source through an orifice to lower the fluid pressure.

Abstract: A compressor includes a housing, a first scroll member, a second scroll member and a modulation assembly. The first scroll member includes a first end plate having a discharge passage, a first spiral wrap, and a first aperture extending through the first end plate. The second scroll member includes a second end plate having a second spiral wrap extending therefrom and meshingly engaged with the first spiral wrap to form a series of pockets. The first aperture is in communication with a first of the pockets. The modulation assembly is in communication with the first aperture and is operable in a full capacity mode where the first aperture is isolated from a suction pressure region providing full capacity operation and in a reduced capacity mode where the first aperture is in communication with the suction pressure region providing approximately zero capacity operation.

Abstract: A screw compressor includes a pair of rotors housed in a rotor chamber. A gas sucked from an intake channel is compressed by the screw rotors and discharged from a discharge channel. A columnar space having a functional end face with an opening into an intermediate pressure section, which is an empty space in the rotor chamber and isolatable from both the intake channel and the discharge channel by the screw rotors. The functional end face has an opening into a bypass channel in communication with the discharge channel. A piston, inserted in the columnar space and brought into contact with the functional end face, separates the intermediate pressure section from the bypass channel when the piston contacts the functional end face. A pressure detection channel allows an area located on an opposite side of the functional end face in the columnar space to communicate with the discharge channel.

Abstract: A scroll compressor has a housing enclosing a compressor pump unit which includes an orbiting scroll member and a non-orbiting scroll member. Each of the orbiting and non-orbiting scroll members include a base and a generally spiral wrap extending from the base. The wraps interfit to define compression chambers, with a central-most discharge pressure chamber, and circumferentially spaced intermediate pressure chambers being defined. The base of the non-orbiting scroll includes ports associated with the intermediate pressure chambers. At least one port is associated with the discharge pressure chamber. Valves are associated with each of the ports. A discharge plenum is defined downstream of the ports and valves within the housing. A back pressure chamber is defined behind the base of one of the orbiting and non-orbiting scroll members, and taps a refrigerant from the discharge pressure chamber.

Abstract: A compressor hub assembly may include a hub member, a valve retainer and a valve member. The hub member may include first and second portions. The first portion may define an annular hub wall for a compressor and may have a first inner diameter. The second portion may have a second inner diameter greater than the first inner diameter and may define a stepped region between the first and second portions. The valve retainer may be fixed to the hub member at an end of the second portion opposite the stepped region and may define a third inner diameter. The valve member may be located between the valve retainer in the stepped region and may have an outer diameter less than the second inner diameter and greater than the first and third inner diameters.

Abstract: A Roots vacuum pump stator is arranged to house a pair of intermeshing rotors, said stator being characterized in that it comprises a director or deflector arranged to direct solid material entrained in a gas pumped through the pump towards the outlet. In other words, the stator according to the present invention has a means for directing or deflecting powder or solid material entrained in a gas being pumped directly towards an outlet of the pump or out of the pump. The directing means can comprise a channel disposed between the arcuate surface and the outlet, said channel comprising a portion that engages the arcuate surface prior to the bottom-dead-centre position and which extends away from the rotor's axis of rotation towards the pump outlet.

Abstract: The invention relates to a gear pump in which the amplitudes of the pressure impulses in a pressure chamber can be significantly reduced by a suitable embodiment of a first groove and/or a second groove. The circumferential walls of a pump chamber containing the pressure chamber, in an angular range extending toward the pressure chamber, each have a respective groove communicating with the pressure chamber, by which grooves a radial spacing between the outer circumference of two gear wheels disposed in the pump chamber and the circumferential walls is increased.

Abstract: A compressor including a housing defining a suction pressure region and a discharge pressure region includes first and second scroll members forming compression pockets. A first chamber located on the first end plate of the first scroll member includes first and second passages and a first aperture extending therethrough and in communication with the first chamber. The first aperture provides communication between a compression pocket and the first chamber. A piston in the first chamber is axially displaceable to isolate the first passage from communication with the second passage when in first and second positions, prevent communication between the first aperture and the first passage when in the first position, and provide communication between the first aperture and the first passage when in the second position.

Abstract: A vane liner for use in a vane pump has a vane liner body defining an inner bore for providing a cam surface in a vane pump. The cam surface has a suction opening formed through the body at one circumferential extent, and a discharge opening through the body at a distinct circumferential extent. A pre-pressurization opening extends through the body at a location upstream of an upstream end of the discharge opening, but spaced by at least 90 degrees from a downstream end of the suction opening. A vane pump incorporating the above-discussed liner is also claimed. Further, a vane pump is also disclosed and claimed having the spacing from the downstream end of the suction opening at least X degrees wherein X equals 360 divided by N, N being the number of vanes in the vane pump.

Abstract: A rotary blood pump includes a casing defining a pumping chamber. The pumping chamber has a blood inlet and a tangential blood outlet. One or more motor stators are provided outside of the pumping chamber. A rotatable impeller is within the pumping chamber and is adapted to cause blood entering the pumping chamber to move to the blood outlet. The impeller has one or more magnetic regions. The impeller is radially constrained in rotation by magnetic coupling to one or more motor stators and is axially constrained in rotation by one or more hydrodynamic thrust bearing surfaces on the impeller.

Abstract: According to an aspect of the present invention, an electric pump includes: a housing; an outer rotor; an inner rotor; a base member facing one side surface of the outer rotor and one side surface of the inner rotor; a side plate member, having a facing surface facing the other side surface of the outer rotor and the other side surface of the inner rotor and a non-facing surface opposed to the facing surface; a shaft; a suction port; a discharge port; a negative pressure applied region; a positive pressure applied region; and a relief valve, discharging the fluid from the positive pressure applied region to a non-facing surface side of the side plate member when a pressure applied at the positive pressure applied region exceeds a predetermined value.

Abstract: A compressor may include a shell assembly defining suction and discharge pressure regions, first and second scroll members disposed within the shell assembly, and a capacity modulation assembly. The first scroll member may include a first end plate defining a discharge passage, a biasing passage, a modulation port, a first spiral wrap extending from a first side of the first end plate, and an annular hub extending from a second side of the first end plate. The second scroll member may include a second spiral wrap meshingly engaged with the first spiral wrap forming a suction pocket in communication with the suction pressure region, intermediate compression pockets, and a discharge pocket in communication with the discharge passage. A first intermediate compression pocket may be in communication with the biasing passage and a second intermediate compression pocket may be in communication with the modulation port.

Abstract: A compressor may include a housing and first and second scroll members supported within the housing, each having an end plate with a spiral wrap extending therefrom and meshingly engaged with the other to form a series of compression pockets operating at an intermediate fluid pressure between a suction pressure and a discharge pressure. A first passage in communication with one of the compression pockets extends from a first side of the first end plate to a second side of the first end plate generally opposite the first side. A modulation plate overlies the second side of the first scroll member for radial displacement between first and second positions. The modulation plate isolates the first passage from communication with a suction pressure region of the compressor when in the first position and provides communication between the first passage and the suction pressure region when in the second position.

Abstract: A compressor may include a housing, orbiting and non-orbiting scroll members, a first porting, and a second porting. The first and second porting may each extend through the end plate of the non-orbiting scroll member and may each have an angular extent of at least twenty degrees. An ending point of the first porting may be rotationally spaced from a starting point of the first porting by the angular extent in a rotational direction of a drive shaft of the compressor. An ending point of the second porting may be rotationally spaced from a starting point of the second porting by the angular extent in a rotational direction opposite the rotational direction of the drive shaft. The ending point of the second porting may be rotationally spaced from the starting point of the first porting by less than one hundred and eighty degrees in the rotational direction of the drive shaft.

Abstract: A compressor includes a housing, a first scroll member supported within the housing and having a first end plate with a discharge passage, and a second scroll member supported within the housing and having a second end plate with a second spiral wrap extending therefrom and meshingly engaged with the first spiral wrap to form a series of pockets. A first aperture extends through the first end plate and is in communication with a first product of the series of pockets. A modulation assembly axially biases the first scroll member into engagement with the second scroll member when the first aperture is in communication with a suction pressure region of the compressor.

Abstract: The invention relates to a device for branching a fluidic partial flow off a main flow by means of a hydraulic pump (10), said device comprising individual main chambers (12,14,16,18,20) which are sealed from each other and divided into functional groups, and operate according to the displacement principle. Said chambers enable fluid from at least one main flow inlet (22) to be transported from an inlet or suction side to an outlet or pressure side of the hydraulic pump (10) and then via at least one main flow outlet. At least one independent partial chamber (26) is provided for the transport of the partial flow, in addition to the main chambers (12,14,16,18,20), said partial chamber forming part of the pressure side of the hydraulic pump (10) and being connected to an independent partial current outlet (42) separate from the respective main flow inlet (22) and the respective main flow outlet (24).

Abstract: A compressor may include a housing, first and second scroll members, and a compressor output adjustment assembly. The first scroll member may define a first chamber having first and second passages in communication therewith, a second chamber having third and fourth passages in communication therewith, and first and second apertures. The first and third passages may be in communication with a first pressure source and the second and fourth passages may be selectively in communication with a second pressure source. The compressor output adjustment assembly may include a first piston located in the first chamber and displaceable between first and second positions and a second piston located in the second chamber and displaceable between first and second positions. The first piston may isolate the first aperture from the first passage and the second piston may isolate the second aperture from the third passage when in their respective second positions.

Abstract: A compressor (20) has an unloading slide valve (100). The valve has a valve element (102) having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition. A piston (124) is in a cylinder (128) and mechanically coupled to the valve element. A control valve (40; 42) is coupled to a headspace (138) of the cylinder to selectively expose the headspace to a fluid source (144), pressure of fluid in the headspace producing a force on the piston and valve element in a direction from the second condition toward the first condition. The compressor includes means (190, 192; 210; 220) for relieving excess pressure in the headspace.

Abstract: A compressor apparatus (20) has a housing (22) having first (53) and second (58) ports along a flow path. One or more working elements (26; 28) cooperate with the housing (22) to define a compression path between suction (60) and discharge (62) locations along the flow path. An unloading valve (100) has a valve element (102) having a range between a first condition and a second condition, the second condition being unloaded relative to the first condition. Means (120, 160) bias the valve element toward a third condition intermediate the first and second conditions.

Abstract: A pneumatic vane motor with a stator cylinder having an air inlet opening and an air outlet opening, a rotor eccentrically journalled in the cylinder and carrying a number of sliding vanes which divide the cylinder into moving cells, wherein the cylinder comprises a by-pass passage located between the air inlet opening and the air outlet opening and arranged to leak air from a pressurized working cell into a preceding cell before the working cell reaches the outlet opening, thereby using a preceding cell as an expansion volume for sound attenuation.

Abstract: A compressor includes a compression mechanism having two opposed end plates, a fixed member disposed between the two end plates, a movable member disposed between the two end plates, a bypass passage, and an opener/closer. The movable member is arranged to eccentrically move about a predetermined rotational axis to compress refrigerant in a compression chamber formed between the fixed member and the movable member. The bypass passageway has an upstream end opened to the compression chamber through which refrigerant is partially ejected from the compression chamber so as to be returned to a suction side of the compression mechanism. The cross section of the upstream end of the bypass passage is preferably elongated circumferentially about the rotational axis. The compression mechanism may include a plurality of bypass passages and a plurality of openers/closers.

Abstract: An oil pump includes a pump cover covering a recess in a side face of a pump body to form a gear compartment therebetween. A drive gear and a rotatably driven gear are meshed and mounted in the gear compartment. Working spaces R are formed by the engagement of the meshed gear teeth. Discharge ports are formed in both the pump body and the pump cover in communication with the gear compartment. A notch is formed in the pump body at the bottom of the gear compartment and extends from the front end of the discharge port in the pump body to the rear end of a discharge area for the working spaces. Another notch is formed in the inner side face of the pump cover, and extends from the front end of the discharge port in the cover to the rear end of the discharge area.

Abstract: A scroll type compressor is disclosed. The scroll type compressor includes a housing, a frame, a compartment, a separator, a scroll pairs, a slider, a plurality of compartments, at least a pressure-regulating mechanism, and a guiding element. The compartment in the housing is separated into a high-pressure compartment, a low-pressure compartment, and a middle-pressure compartment. The separator is disposed between the high-pressure compartment and the low-pressure compartment. The separator includes an outlet at the center thereof, and at least a passage through the separator. When the pressure in the high-pressure compartment is less than that in low-pressure compartment, the pressure-regulating mechanism is opened to exhaust pressure from the middle-pressure compartment to the high-pressure compartment.

Abstract: A power steering pump having a plate disposed between a first surface and an intake chamber, wherein an intake flow channel defined by the first surface is in fluid communication with the intake chamber through an opening extending through the plate, the plate opening having opposed terminal ends. The intake flow channel defined by the first surface is configured to direct fluid flow through the plate opening into the intake chamber at a location through the plate opening that is intermediate and spaced from the two terminal ends of the plate opening. Also, a power steering pump having a plate disposed between a first surface and a pair of intake chambers, wherein a pair of intake flow channels defined by the first surface are in fluid communication with the intake chambers through a corresponding pair of openings extending through the plate.

Abstract: The rotary piston machine has a bypass channel, which is formed through two openings (15, 16) provided in a sidewall (6) of its delivery housing (4) and a channel (17) extending into this sidewall (6) in such a way that the bypass channel (17) is restricted on one side by a wall area of the sidewall (6) and on the opposite side by a channel cover (19) embedded in this sidewall (6). The housing (25) of a pressure relief valve (14) is formed cup-shaped in the channel cover (19) in whose cylindrical inner surface (27) a closing member (2) is operated piston-like. The machine which is designed from few individual parts is suitable especially for the space-saving and direct coupling in the engine space of a motor vehicle, in which its pressure relief valve (14) provided in the bypass channel overcomes the disadvantages of the rotational speed-dependent pressure difference between suction and pressure sides.

Abstract: A bypass apparatus for a scroll compressor includes multiple bypass holes located at a plurality of locations along a path traced by the compression chambers of the compressor. A dimple portion having a large cross sectional area may be formed at an outlet of the bypass holes to increase the surface area of the compressed gas pushing against the bypass valves. Angled openings of the dimple portions, or angled openings of the bypass holes would also act to further increase the area of the compressed gas pushing on the bypass valves. The increased surface area of the gas pressing on the bypass, by virtue of its greater overall force, enhances an opening speed of the bypass valve. Accordingly, the over-compression of the refrigerant gas is prevented.

Abstract: A cylinder to a vane motor is designed to include cylindrically shaped inlet and outlet holes, an axial passage that includes a blocked upstream portion that bypasses the upstream inlet holes, spaced circumferentially slots for leading a portion of the pressurized air into the inlet holes, discharging the portion of pressurized air from the axial passage into an annular cavity to bathe the bearing in the cooler pressurized air, and recirculating the portion of pressurized air through another axial passageway to flow into all of the inlet holes. The discharge holes are judiciously oriented in a particular pattern to assure that the edge of the vanes wear uniformly. The inlet holes are spaced from the pinch point of the spindle to cylinder to permit an increased volume of pressurized air to enter the vane motor and the outlet holes are spaced to maximize the power stroke of the vane motor.

Abstract: A pump including at least three rotors each being provided with a generally helical screw thread, the rotors being mounted for rotation in a housing such that the screw threads of the rotors mesh and rotation of one rotor causes rotation of the other rotor, wherein the pitch of the threads is less than 1.6 times the outer diameter of the rotors or where one of the rotors has a larger outer diameter than the other rotors the outer diameter of the larger diameter rotor.

Abstract: In a Roots vacuum pump, an inlet port is located at a position n spaced by a positive displacement angle of 120° in one direction from a center of each rotational axis relative to an imaginary line m connecting rotor axes. An outlet port is located at a position o opposite to the inlet port relative to the line. An air feed port is formed at a position t on a casing wall obtained by returning by 90° from the position o to the inlet port side so that two closed spaces are defined by adjacent rotor lobes and a casing inner wall at both port sides immediately after air suction respectively. The casing has discharge grooves in an area of the inner wall so as to communicate with the outlet port. The area ranges from the position o to a position u obtained by returning by 45° from the position o to the inlet port side. The discharge grooves have a total volume ranging from 2% to 5% of a volume of one of the closed spaces.

Abstract: A scroll compressor with a backflow-proof mechanism. The scroll compressor comprises a slider disposed on a scroll couple, forming several enclosed spaces. The slider is raised by the working fluid in the spaces, preventing liquid leakage from a high-pressure chamber to a low-pressure chamber, when the scroll compressor starts. The slider descends when the compression ratio of the scroll compressor is exceeded. Thus, the pressure is released, and the performance of the scroll compressor is improved. The slider of the invention further comprises a floating element to prevent reversal of pressurized fluid and damage to the scroll couple.

Abstract: It is an object of the present invention to provide a trochoid type oil pump in which erosion of the rotor surfaces caused by cavitation is minimized, vibration and noise are reduced, and the structure is greatly simplified. The trochoid type oil pump of the present invention comprises a rotor chamber which has an intake port and a discharge port, an outer rotor, an inner rotor, and shallow grooves which are formed on the side of the initial end portion of the discharge port on the circular circumference of the track of the positions of the bottom portions of the teeth created by the rotation of the outer rotor. In a state in which the sealed spaces formed by the outer rotor, the inner rotor and a partition part between the final end portion of the intake port and the initial end portion of the discharge port are reduced in volume from the maximum volume, the sealed spaces Sa are caused to communicate with the shallow grooves.

Abstract: The invention concerns a gear pump comprising a pump body (2) closed with a cover (3) forming a cavity wherein is provided a drive pinion (4) capable of being driven in rotation by a drive shaft (1) whereto it is fixed, a driven pinion (5) whereof the teeth co-operate with the drive pinion (4) teeth so as to be driven in rotation thereby and two end shields (8) arranged on either side of the driven pinion (5) penetrating into a cavity (10) provided therefor in the pump body (2) and the cover (3) respectively, means being provided for exerting pressure on the outer surface of the end shields. In order to prevent the cover from being deformed under the effect of the pressure thereby creating a leakage zone between the delivery zone and the suction zone, the end shields each consist of a disc (8) integral with one end of the driven pinion (5), the discs (8) and the driven pinion (5) being concentric, the discs (8) covering the teeth of the driven pinion (5).

Abstract: A roots pump has a housing, a plurality of rotary shafts, a rotor, a confluent passage and a closed space. The housing forms therein a pump chamber. The rotary shafts are supported on the housing in parallel relation to each other. The rotor is mounted on each of the rotary shafts, and the rotors on any adjacent rotary shafts are in engagement with each other. A set of the engaged rotors is accommodated in the pump chamber. The confluent passage is formed along one crossing line of paired imaginary swept peripheral surfaces in one-to-one correspondence with the paired and engaged rotors. The closed space is formed in one-to-one correspondence with each of the paired rotors between the paired rotors and paired peripheral wall surfaces which form the pump chamber. The closed space initially joins the confluent passage from a terminal end thereof with rotation of the paired rotors.