Abstract: An improved mechanical face seal is provided which includes a pair of relatively rotatable seal rings having opposing seal faces. At least one of the seal faces includes a reverse trapezoidal face pattern having a sine wave depth profile wherein individual face features are circumferentially spaced over the seal face. The reverse trapezoidal face pattern serves to generate a hydrodynamic lift which provides a stable separation of the seal faces that permits formation of a fluid film between the seal faces. The individual trapezoidal grooves have a sinusoidal or similarly shaped depth profile wherein the trapezoid shape is arranged with the narrower edge communicating with the high pressure side of the seal, and the wider edge forms a circumferential dam region towards the low pressure side of the seal.

Abstract: A mechanical face seal and a method of using the mechanical face seal are described. The mechanical face seal includes a plurality of groove sets that are etched into a stationary seal and/or a rotating seal ring. Each of the plurality of groove sets includes feed grooves, collection grooves, distribution grooves, a collector, retention cavities and discharge grooves. The mechanical face seal can be used to reduce the friction that is generated from the stationary seal and the rotating seal ring during operation. Additionally, the groove sets work cooperatively to introduce, circulate and expel lubricant between the seal interface, thereby promoting cooling of the seal.

Abstract: An oil pump includes: a rotor chamber; an outer rotor; and an inner rotor. A partition surface between a starting end side of the intake port and a terminal end side of the discharge port is set as a first seal land. An intake groove portion that projects from the starting end side of the intake port toward the terminal end side of the discharge port and a discharge groove portion that projects from the terminal end side of the discharge port toward the starting end side of the intake port are formed in positions which are located on the first seal land. The intake groove portion and the discharge groove portion are provided in intermediate tooth height direction positions of a meshing location between the inner rotor and the outer rotor.

Abstract: Described herein is a device comprising: a chamber wall comprising outer and inner surfaces, wherein the inner surface encloses a lobed chamber with a plurality of lobes and the inner surface comprises segments of arcuate surfaces, each of the segments of arcuate surfaces being tangent with its immediate neighboring segments, and wherein the chamber wall further comprises channels connecting the outer surface and the inner surface of the chamber wall and/or channels through an end surface of the chamber wall; a lobed piston configured to translate along a circular path relative to the chamber wall, the outer surface of the piston and the inner surface of the chamber wall engaged during translation; and holes fluidly connected to the lobed chamber and configured to allow fluid discharge from the lobed chamber through the holes and to prevent fluid flow into the lobed chamber through the holes.

Abstract: A roots type fluid machine includes a case having a side wall, a pair of rotary shafts provided in the case, a pair of rotors engaged with each other and fixed to the pair of rotary shafts so as to extend axially, respectively, a suction space formed by the case and the pair of rotors for introducing fluid, a discharge space formed by the case for discharging fluid and the pair of rotors and a transfer chamber formed by the case and the rotor. The rotor has a rotor end surface. A clearance is formed between the side wall and the rotor end surface. The transfer chamber transfers gas introduced in the suction space to the discharge space in accordance with the rotation of the pair of rotors. The case has a guide groove formed in the side wall facing the rotor end surface. Gas leaked from the discharge space into the clearance is introduced to the transfer chamber through the guide groove.

Abstract: A media delivery assembly in which a defined compensating pressure is established at the backs of included axially adjustable rotors and a control valve is provided for establishing the compensating pressure at a predetermined value between a pressure on the pressure side and a pressure on the suction side.

Abstract: A housing includes a pump chamber, which rotatably receives an inner rotor and an outer rotor that define a pressure chamber therebetween. An inlet port of the housing is communicated with the pressure chamber to supply fluid into the pressure chamber. An outlet port of the housing is communicated with the pressure chamber to discharge the fluid from the pressure chamber. An axial size of an axial clearance, which is formed between an axial end surface of the pump chamber and an axial end surface of the inner rotor, differs from an axial size of an axial clearance, which is formed between the axial end surface of the pump chamber and an axial end surface of the outer rotor.

Abstract: An engine is described for operation on a fuel expanding about adiabatically in a power stroke of the engine. To aid the power stroke efficiency, the rotary engine contains one or more of a rotor configured to rotate in a stator, the rotor offset along both an x-axis and a y-axis relative to a center of the stator, a vane configured to span a distance between the rotor and the stator, where the inner wall of the stator further comprises at least one of: a first cut-out in the housing at the initiation of the power stroke, use of a build-up in the housing at the end of the power stroke, and/or use of a second cut-out in the housing at the completion of rotation of the rotor in the engine. The engine yields a cross-sectional area expanding during a portion of the power stroke at about the Fibonacci ratio.

Abstract: A hydraulic device has an inlet side and an outlet side and includes two meshing cogwheels. Each cogwheel has external oblique teeth and is arranged between an inlet side and an outlet side. At least one control groove is provided on an end side of the cogwheels. The control groove periodically produces a pressure equalizing connection during the rotation of the cogwheels.

Abstract: A hydraulic motor receives pressurized fluid from a source controlled by a human operator to convert the energy in the hydraulic fluid to a rotational output to propel a drive wheel of a machine. The hydraulic motor includes an end cover, a manifold, a drive assembly, a wear plate, a housing, and an output assembly. The drive assembly includes a rotor with external teeth and a stator with internal teeth formed by rollers having end faces. The pressurized fluid from the source flows through the manifold to the drive assembly and causes rotational and orbital movement of the rotor relative to the stator. The rotational movement of the rotor is transmitted to the drive wheel by the output assembly. A first set of anti-cogging passages and a second set of anti-cogging passages communicate fluid pressure to the end faces in timed relationship to reduce cogging or detenting of the rotational output of the motor.

Abstract: In an inner wall surface of a casing, grooves are formed that correspond to end faces of an outer rotor and an inner rotor, and seal members are disposed within the grooves, the seal members presses against the end faces of the outer rotor and the inner rotor. Inclined portions are provided in sealing portions of resin members of seal members, the sealing portions covering a closed portion. With this configuration, an internal pressure in the closed portion causes the inclined portions to separate from an outer rotor and an inner rotor when a brake fluid pressure within the closed portion increases to the point that the brake fluid is excessively compressed, releasing the brake fluid that is inside the closed portion. It is therefore possible to prevent the brake fluid pressure from increasing excessively within the closed portion.

Abstract: An embodiment of a dry screw compressor has a male rotor at a peripheral speed lower than approximately 80 m/s. The compressor includes: a casing body having an inlet for a gaseous fluid to be taken in and at least an outlet for the compressed fluid; at least a male rotor and at least a female rotor meshed together, said rotors being arranged inside said casing body whereby the ratio between the length and the external diameter of the male rotor is higher than or equal to approximately two, and the winding angle of the male rotor is smaller than or equal to approximately 300°.

Abstract: A lubricant-tight vane rotary vacuum pump, includes a pump stage (17) having a pump stage housing (10) with a gas inlet, compression chamber (11), and a gas outlet (51), a channel (50) connecting the compression chamber (11) with the gas outlet (51), and a groove (54) at least partially surrounding a mouth of the connecting channel (50) that opens into the gas outlet (51), so that lubricant, which is tossed out of the compression chamber, is collected in the groove (54) and re-entry of the lubricant back into the compression chamber (11) is prevented.

Abstract: A variable displacement vane pump that assuredly suppresses seizing of mutually contacting surfaces of a pressure plate and a rotor where the pressure plate is formed, at one side surface thereof that slidably contacts the rotor, with an annular lubricating groove. The lubricating groove is on a seal surface of the side surface at a position between arcuate back pressure grooves formed on the seal surface and a through opening which is formed in a center part of the pressure plate to receive the drive shaft. A radial width of the lubricating groove is set to a range from 10% to 25% of a radial width of the seal surface, and a distance from a center of the radial width of the lubricating groove to an inner cylindrical surface of the through opening is set to a range from 24% to 70% of the radial width of the seal surface.

Abstract: A hydraulic motor 10 receives pressurized fluid from a source 98 controlled by a human operator to convert the energy in the hydraulic fluid to a rotational output to propel a drive wheel 91 of a machine 90. The hydraulic motor 10 includes an end cover 11, a manifold 12, a drive assembly 13, a wear plate 14, a housing 15, and an output assembly 16. The drive assembly 13 includes a rotor 37 with external teeth and a stator 36 with internal teeth formed by rollers 43 having end faces 49 and 50. The pressurized fluid from the source 98 flows through the manifold 12 to the drive assembly 13 and causes rotational and orbital movement of the rotor 37 relative to the stator 36. The rotational movement of the rotor 37 is transmitted to the drive wheel 91 by the output assembly 16.

Abstract: There is disclosed a rotary compressor which delays a pressure rise on a high pressure chamber side in a cylinder of a rotary compression element to decrease a high pressure load applied to a roller and a rotary shaft, thereby improving performance. In the rotary compressor including a sealed container in which an electromotive element (a driving element) and first and second rotary compression elements driven by a rotary shaft of the electromotive element are included, each of the rotary compression elements being constituted of a cylinder, a roller fitted into an eccentric portion formed on the rotary shaft to eccentrically rotate in the cylinder, and a vane which abuts on the roller to partition the inside of the cylinder into a low pressure chamber side and a high pressure chamber side, the inner diameter of a suction passage formed in each cylinder is 59% or more and 70% or less of the thickness of the cylinder.

Abstract: A fuel pump includes an impeller and a cover. The impeller includes a ring portion, which is annular and is placed radially outward of blades. The cover has an arcuate pump flow passage. An enlarged space is formed in a cover side slide surface of the cover. The enlarged space is communicated with the pump flow passage and has an axial gap size, which is axially measured between an axial bottom surface of the enlarged space and an axial end surface of the ring portion and is larger than that of an axial slide gap between the slide surface and the axial end surface of the ring portion.

Abstract: [Task] To provide a variable displacement vane pump that assuredly suppresses seizing of mutually contacting surfaces of a pressure plate and a rotor. [Means for Achieving the Task] In this variable displacement vane pump, pump elements, such as a drive shaft 7, a rotor 8 and a pressure plate 11 are installed in a receiving space 2a of a front body 2, and an open side of the receiving space 2a is closed by a rear body 3. The pressure plate is formed, at one side surface thereof that slidably contacts the rotor, with an annular lubricating groove 44, the lubricating groove 44 being provided on a seal surface 43 of the side surface at a position between each of arcuate back pressure grooves 41 and 42 which are formed on the seal surface 43 and a through opening 26 which is formed in a center part of the pressure plate to receive the drive shaft.

Abstract: A pump, preferably a vane cell pump for supplying a transmission with oil, includes a pump housing and a rotating group which is disposed inside the pump housing. The rotating group includes a side plate that may be mounted inside the pump housing in such a manner as to produce, at least temporarily, an axial gap between the side plate and the pump housing. A shaft is mounted inside the pump housing and a radial packing ring is located in a recess around the shaft. The packing ring seals off the rotating group towards the exterior radially on the pump housing and radially on the shaft using a sealing lip.

Abstract: A screw pump includes a housing and a pair of intermeshing screw rotors. An end face of the rotor adjacent to an inlet port of the housing is provided with an inlet opening. Each rotor has a first portion whose lead angle changes. The first portions and the housing cooperate to form an inlet space. During rotation of the rotors, communication between the inlet space and the inlet port is blocked by the first portions and the housing thereby to form a closed pump space adjacent to the inlet space. Volume of the pump space is set smaller than the maximum volume of the inlet space. A closure member is provided which covers at least a part of the inlet openings. The closure member closes the inlet space when the volume of the inlet space exceeds that of the pump space.

Abstract: The invention relates to a vane pump comprising a rotor which is arranged therein, rotatably driven by a drive shaft. The rotor is provided with several grooves which are distributed through the circumference thereof and which extend substantially radially with respect to the axis of rotation of the rotor. In each groove a blade-shaped conveying element is slidingly guided. The end walls of the pump housing are adjacent to the rotor in the direction of the axis of rotation thereof. At least one ring-shaped groove surrounding the axis of rotation of the rotor is embodied in at least one front side of the rotor. The ring-shaped groove is connected to lower areas restricted by the blades in the grooves of the rotor, and to pressure areas. In a preferred embodiment, the ring-shaped groove is formed in the rotor by shaping.

Abstract: The curvature of a circular arc constituted by a side of a suction groove is made larger than that of a circular arc constituted by a side of a discharge groove. Thus, when the suction groove and the discharge groove are viewed in the axial direction of a drive shaft, the distance between the suction groove and the discharge groove in the radial direction of a rotary portion is short in a region intersecting with a line W perpendicular to a centerline, and increases in accordance with a decrease in distance from containment portions. It is therefore possible to ensure a sufficient distance between the discharge and suction grooves and enhance a total fluid pressure generated therebetween, and the contact surface pressure that is necessitated by a second side plate to obtain a press-back force when being in contact with an outer rotor and an inner rotor is reduced.

Abstract: A scroll compressor is provided with spaced grooves in a base of one of the two scroll members. A recess is formed in a wrap tip of the other scroll member. The recess in the wrap tip bridges a space between the grooves of the other scroll member. This bridging equalizes pressure between two parallel intermediate compression chambers. Pressure equalization between the chambers improves compressor efficiency.

Abstract: A multi-stage vacuum pump includes a plurality of casings connected in series and each casing defining a respective compression chamber, a plurality of partition plates each set in between each two casings. When compressed by rotors at shafts in one compression chamber, compressed air passes through the air path formed in the corresponding partition plate to the next compression chamber for further compression, and finally compressed air passes to the last compression chamber through the air path formed in the last partition plate. Because the invention is designed to let compressed air directly pass through the air path in each partition plate, the outer diameter and volume of the multi-stage vacuum pump can be minimized to reduce the weight and the manufacturing cost.

Abstract: A positive-displacement pump, in particular for use in machines or dispensing fluids, including two elements that are with respect to one another and which mesh with one another (20, 30), each of them being rotatably mounted in the pump with centered coupling without interference with a corresponding centering body (18, 11a). At least one of the two above-mentioned ratable elements has a plurality of undercut regions (26, 34, 35)) at the location of the centering walls. The undercut regions (26, 34, 35) comprise a wall portion which is spaced with respect to the facing wall of the respective centering body.

Abstract: A surface of a fixed scroll which is opposed to a end plate of an orbiting scroll existing outside of a lap of the fixed scroll is formed with: a substantially annular seal portion which extends such as to have an outer wall surface of the fixed scroll outwardly extending from an inner wall surface of outermost periphery of the lap substantially along the inner wall surface, and which comes into slide contact with the end plate of the orbiting scroll; a substantially annular recess located outside of the substantially annular seal portion; and a recess which is brought into communication with an intake port of the fixed scroll independently from the substantially annular recess. With this, back pressure of the orbiting scroll is increased, and turning-over phenomenon of the orbiting scroll can be suppressed.

Abstract: A scroll compressor enabling decrease of a flow path loss in a communication groove extending from a suction port toward a suction chamber to decrease a loss of suction power is disclosed. In the scroll compressor, a movable scroll is provided so as to perform a swivel motion relative to a fixed scroll, a fixed scroll lap and a movable scroll lap are engaged with each other to form a suction chamber and compression chambers, a suction port communicating with the suction chamber is formed in the fixed scroll, and a communication groove extending from the suction port toward the suction chamber is formed in the fixed scroll. The communication groove has a shape such that the bottom thereof is inclined so as to become shallower from the suction port side to the suction chamber side.

Abstract: A fluid delivery device, such as a geared machine or a gear pump, with a housing having at least one supply chamber and a displacement unit arranged within the supply chamber. The displacement unit serves to supply a medium to at least one pressure chamber provided within the housing. A pressure plate is arranged between the pressure chamber and the housing, and the pressure plate is uncoupled from the housing by at least one spacer element that is arranged between the pressure plate and the housing to provide a fluid delivery device that operates more quietly than conventional fluid delivery devices.

Abstract: A positive-displacement pump, in particular for use in machines or dispensing fluids, including two elements that are with respect to one another and which mesh with one another (20, 30), each of them being rotatably mounted in the pump with centered coupling without interference with a corresponding centering body (18, 11a). At least one of the two above-mentioned ratable elements has a plurality of undercut regions (26, 34, 35) at the location of the centering walls. The undercut regions (26, 34, 35) comprise a wall portion which is spaced with respect to the facing wall of the respective centering body.

Abstract: A rotary fluid pressure device having a housing member, a manifold assembly, an internally generated rotor type gerotor set, an end plate, and a rotatably journaled torque transfer shaft interconnected with the gerotor set and extending within the housing member and manifold assembly. The gerotor set having at least an internally toothed stator member and a rotating rotor member disposed within the stator member. The rotor member having a first and second axial end surface and external teeth which interengage with the internal teeth of the stator to define a plurality of expanding and contracting volume chambers. The rotor member also having a plurality of circumferentially spaced laterally directed fluid paths fluidly connecting the manifold assembly with a plurality of circumferentially spaced radiating fluid paths which directly connect with the volume chambers. The fluid pressure device further including a plurality of coupling members for interconnecting the components.

Abstract: In a rotary pump for a braking apparatus, a discharge trench is formed on an axial direction end surface of a second side plate that forms a mechanical seal. As a result, rotors are pressed back toward a side of a first side plate by a discharge pressure of brake fluid channeled to the discharge trench. Accordingly, a force pressing the rotors toward the second side plate is reduced and frictional resistance is reduced.

Abstract: A bottom portion of an intake port is provided with a sloped bottom surface formed of a plane such that sloped bottom surface approaches the side surfaces of external teeth and internal teeth from an upstream side to a downstream side in rotational direction of two rotors. Fluid that flows in the intake port is regulated by the sloped bottom surface and smoothly guided into individual inter-teeth chambers that are expanding. Since the sloped bottom surface on the bottom portion of the intake port is formed of a plane without spiral or twisting, design and manufacturing of a gear pump is extremely easy.

Abstract: The invention relates to a pump with a pump chamber with a rotary-driven pump element mounted, at least one suction and at least one pressure connection opening into the pump chamber and with circulating pumping cells whose volume can be changed, which are connected with the suction or pressure connection depending on the rotary position of the pump element. A hydraulic intermediate capacity is provided that can be stressed with the pumping medium pressure present at the pressure connection by way of its first connection and that, by way of its second connection, can be stressed with the pumping medium pressure present at the pressure connection depending on the rotary position of the pump element or it can be connected with a pumping cell that has no direct connection to the pressure connection.

Abstract: A gerotor pump for pressurizing gasoline fuel is capable of developing pressures up to 2.0 MPa with good mechanical and volumetric efficiency and satisfying the durability requirements for an automotive fuel pump. The pump has been designed with optimized clearances and by including features that promote the formation of lubricating films of pressurized fuel. Features of the improved pump include the use of a shadow port in the side plate opposite the outlet port to promote balancing of high fuel pressures on the opposite sides of the rotors. Inner and outer rotors have predetermined side clearances with the clearances of the outer rotor being greater than those of the inner rotor in order to promote fuel pressure balance on the sides of the outer rotor. Support of the inner rotor and a drive shaft on a single bushing with bearing sleeves maintains concentricity. Additional features are disclosed.

Abstract: Two-inner gears are overlapped with each other through a partition wall and are eccentrically arranged at an inner peripheral side of an outer gear, and eccentric directions of both the inner gears are shifted from each other by 180° to the opposite side. By this, loads in an outer diameter direction due to a rise in fuel pressure affect one outer gear from the two inner gears oppositely to each other by 180°, so that an eccentric load is not generated, and sliding resistance of the outer gear to a cylindrical casing becomes small. Further, the number of teeth of the outer gear is made odd, and the number of teeth of the inner gears is made even.

Abstract: A vacuum pump of the rotary vane type, comprises a casing (50) having a cylindrical inner wall surface (52), a first (54; 54′) and a second (56; 56′) end wall at opposite sides of said casing defining a fluid cavity therein, fluid inlet (60) and outlet (62) ports in open communication with said fluid cavity, and a rotor (64; 64′) extending between said end walls carried by a drive shaft (70) for rotation about an axis eccentric to said casing inner wall surface, said rotor being provided with a plurality of longitudinally extending radial slots (66) about the periphery thereof. Further, there are provided a plurality of vanes (68), each being radially slidably carried within a respective of said slots.

Abstract: An oil pump apparatus includes an oil pump housing having a first suction port, a second suction port and a discharge port in the circumferential direction thereof. A shape of the end portion in the anti-rotational direction at the second suction port is formed to be along a shape of the end portion on the rotational direction side of one pump chamber which is sealed momentarily between the two suction ports, and a shape of the inner circumferential end portion of the first suction port is formed to be along the rotational trace of the end portion on the anti-rotational direction side of the pump chamber. A plural first pockets are formed on the driven rotor, and a second pocket is formed on the pump housing to communicate between the pump chamber and one of the first pockets when the pump chamber is communicated to the first suction port.

Abstract: A multi-vane hydraulic motor for accessory drive in which the vanes of a hydraulically balanced rotor are primarily urged into operative engagement with a surrounding cam by forces of the hydraulic fluid in undervane passage produced by an associated hydraulic pump to eliminate requirement for biasing springs and spring attachment of prior art motor. A high pressure chamber provided between the motor housing and a pressure plate mounted therein is hydraulically connected to the vane chambers of the rotor of the motor for the hydraulic drive thereof. An end cap closing the motor housing has the hydraulic input and output lines operatively connected thereto.

Abstract: A gear pump has a gear wheel with teeth on an outer circumference and a second gear ring with teeth on the inside surface. The gear ring is guided in a circular-cylindrical recess of a housing and together with the gear wheel, each rotates about their own axis which are offset from one another. The gear pump is equipped with an intake opening and a crescent-shaped pressure opening in a first side wall of the housing that defines the recess. A countersunk feature is also provided, embodied as a hollow cone, in a second wall of the housing opposite the pressure opening. The hollow cone, which is in fluid communication with the pressure opening, promotes the buildup of a fluid film between the gear ring and the housing, which improves the wear resistance of the gear pump.

Abstract: The present invention relates to a hermetic rotary compressor. More particularly, since the conventional rotary compressor has problems that the effect of a surge recess for reducing noises due to pressure pulsation is insufficient, and it is impossible to obtain the maximum compression efficiency, the present invention is constructed such that noises due to pressure pulsation can be reduced to the maximum and at the same time the compressive driving force required for compressing gaseous refrigerant is decreased to thereby improve the compression efficiency.

Abstract: A scroll compressor is provided with a pressure equalization groove in the base of one of the scroll members. The pressure equalization groove communicates between the compression chambers at an intermediate pressure. Thus, should one of the two compression chambers be at higher pressure than the other, pressure is equalized. The invention eliminates mixing losses which would otherwise occur when two chambers of differing pressures communicate with each other or at discharge. Vibration and noise are also reduced.

Abstract: A metering pump includes a set of externally-toothed gears, with a first of the gears, the drive gear, having a central opening to receive a drive shaft. The gears are supported within a housing defined between first and second housing plates. The first and second housing plates each have central openings aligned with the central opening in the drive gear, and inner wall surfaces adjacent opposite side surfaces of the gears. The first and second gears are rotatably supported within the housing such that the rotational axis of the gears are parallel to one another, and certain of the gear teeth intermesh together when the gears rotate. A first port in the housing provides an inlet fluid flow to an inlet side of the meshing gear teeth, while a second port provides an outlet fluid flow from an outlet side of the meshing teeth. An annular resilient, face-type lip seal is disposed against each side surface of the drive gear, surrounding the central opening in the gear.

Abstract: A rotor-type pump comprises a housing having a trochoidal curved surface and an intake port and a discharge port. A drive shaft is mounted rotatably about a first axis in the housing. A rotor having a second axis eccentric to the first axis is rotatably mounted to the drive shaft. The rotor cooperates with the trochoidal curved surface. A plurality of working-fluid chambers are defined by the trochoidal curved surface and an outer peripheral surface of the rotor and variable in volume as the rotor rotates. The intake port is open into one chamber of the chambers and the discharge port is open into another chamber thereof. A communication passage fluidly interconnects at least adjacent two of the chambers. A rotor control mechanism is provided for controlling the rotor to move along the trochoidal curved surface with a predetermined clearance therebetween upon rotation of the rotor.

Abstract: A roller gerotor device is disclosed including an outer rotor (39) and an inner rotor (31), and a plurality of rollers (37) serving as teeth. The device includes a housing means (11,45,47) defining a first wear surface (67) disposed axially adjacent first axial end surfaces (55,63) of the rotors. The first wear surface cooperates with one of the rotors to define an annular fluid passage (83) and a plurality of fluid grooves communicating with the passage (83) and extending radially outward. At least a terminal portion of each of the grooves (87) is adjacent an axial end surface (59) of each roller member (37) as the rotors rotate. Each of the terminal portions (95) becomes progressively shallower in the direction of rotation of the rotors, thus building up fluid pressure in the fluid groove (87) to prevent gouging or galling of the roller end surface against the adjacent wear surface (67).

Abstract: An internal gear pump includes a casing, a cover mounted to the casing, a pump chamber defined between the casing and the cover, an internal gear slidably arranged within the pump chamber, an external gear rotatably arranged within the pump chamber and rotatingly driven from the outside to engage with and drive the internal gear, a fixed filler for regulating sliding movements of the internal and external gears and for preventing oil leakage from a high-pressure side to a lower-pressure side within the pump chamber, a suction port formed in the cover and extended circumferentially within the angular range of about 90 degrees, an oil pocket device formed in respective sliding surfaces of the casing and cover, on which the opposite side surfaces of the internal gear slide, the oil pocket device having a plurality of taper lands extended within the radial width of from the root of tooth of the internal gear to the outer peripheral surface of the internal gear between the peripheral wall of the pump chamber and t

Abstract: A rotary compressor includes a top clearance volume formed between a cylinder chamber and at least one delivery valve. Another top clearance volume, in communication with the cylinder chamber, produces a reverse flow of compressed fluid which generates pulsations adapted to offset a high frequency component of pulsations generated in the cylinder chamber by compressed fluid reversely flowing from the first top clearance volume to the cylinder chamber. Thereby the high frequency component of pulsations generated in the cylinder chamber is eliminated, and a low-noise rotary compressor is provided.

Abstract: In the displacement machine for compressible media described in the specification, a stationary housing has two spiral displacement chambers and a spiral displacement body is engaged in each displacement chamber. The displacement body extends essentially perpendicularly to a disc-shaped rotor which can be driven eccentrically relative to the housing. In order to avoid butting of the displacement bodies against the walls of the displacement chambers resulting from different heat expansions of the rotor and the housing while maintaining a relatively small clearance between the peripheral contours of the displacement bodies and the peripheral walls of the displacement chambers, the radially outer peripheral walls of the displacement chambers have recesses in their upper edges which extend in the peripheral direction. The height of the recesses is approximately one quarter of the chamber height and the maximum depth of the recesses is approximately 0.15 mm.

Abstract: A rotary compressor for helium gas has a cylinder defining a closed space therein, a rotor disposed in the closed space for eccentric rotary motion while making a sliding contact with the inner peripheral surface of the cylinder, and a blade slidably mounted on the cylinder and resiliently projected into the closed space for sliding contact with the rotor so as to divide the closed space into a suction chamber and a discharge chamber. The compressor further has an oil relief passage which is arranged to allow the discharge chamber to communicate with a space outside the discharge chamber in the final stage of the discharging stroke before the crank angle of the compressor reaches an angle corresponding to the position of a discharge port.

Abstract: A gerotor device wherein a body (10) includes high pressure ports (20) that communicate with an inlet (12) and low pressure ports (22) that communicate with an outlet (14). An inner member (42) and an outer member (40) cooperate to define pressure chambers (52) that increase and decrease in volume as the member (42) orbits and rotates. A rotary valve (62) selectively connects pressure chambers (52) to pressure ports (20) and (22) to convert between mechanical torque and fluid pressure. Cavities (75) and (77) are provided adjacent rotary valve (62) to hydraulically balance the valve.

Abstract: An improved supercharger or blower (10) of the Roots-type with reduced airborne noise and improved efficiency. The blower includes a housing (12) defining generally cylindrical chambers (32, 34) containing meshed lobed rotors (14, 16) having the lobes (14a, 14b, 14c, 16a, 16b, 16c) thereon formed with an end-to-end helical twist according to the relation 360.degree./2n, where n equals the number of lobes per rotor. The chambers include cylindrical wall surfaces 20a, 20b and end wall surfaces 20c, 24a which sealing cooperate with the rotor lobes and ends. Blower housing (12) also defines inlet and outlet ports (36, 38). The inlet port includes a longitudinal extent defined by housing wall surfaces (20f, 20f) and a transverse extent defined by housing wall surfaces 20g, 20i. Transverse wall surfaces (20g, 20i) are disposed substantially parallel to the associated rotor lobes.