Abstract: The invention relates to a rotor for a positive displacement rotary pump. The rotor comprises a hub with an aperture and a centre axis through said aperture and at least 2 lobes radially extending from said hub and in a direction essentially perpendicular to the axis of said hub. The rotor comprises a core of a first polymer material and a cover of a second polymer material, which second polymer material has a hardness which is lower than the first polymer material. The first and the second polymer materials are connected to each other. The hub or the major part of the hub is preferably provided by the core, whereas at least a part of the lobes is provided by the cover. The invention also relates to a method of providing the rotor and a pump comprising the rotor. The rotor has a high durability and provides an excellent sealing towards inner surface sections of the pumping house as well as towards an engaged rotor.

Abstract: A drive transmission mechanism for transmitting torque between two or more rotary shafts in synchronization with one another without need for lubrication thereby eliminating occurrence of oil contamination, and an oil-free fluid machine equipped with the mechanism, are provided. A magnetic drive disk 16 and a synchronization gear 18 are attached to a rotary shaft 14 connected to a drive motor 11, a magnetic drive disk 17 and a synchronization gear 19 is attached to a rotary shaft 15, torque transmission from the rotary shaft 14 to the rotary shaft 15 is carried out in two ways, via the magnetic drive disks 16, 17 and via the synchronization gears 18, 19, and at least one of the synchronization gears is made of plastic material. With the construction, torque transmit load between the rotary shafts via the synchronization gears is decreased, and a plastic gear or gears can be adopted for synchronization gears without reducing life of the gears without need for lubrication oil.

Abstract: A positive displacement, transverse flow, internally refluxing, rotary gas compressor which operates on a constant volume, variable mass, near-isothermal compression cycle. The compressor includes a pair of involutely lobed, intermeshed impellers that sweep gas from an intake port through the compressor housing to a discharge port in constant volume displacement cavities that are defined by the lobes of the impellers and the compressor housing walls. The cavities are effectively sealed against both the intake and discharge ports over upstream interior housing sidewall portions that extend from the intake port over an angle at least as great as the angle between adjacent lobes of the impellers. Downstream therefrom the interior housing sidewalls are spaced radially from the rotating impellers so as to allow limited reflux counterflow of discharge gas back into the advancing displacement cavities.

Abstract: A blending pump assembly for accurately maintaining the proper ratio of two fluid components. Flow of a first fluid is utilized to drive a fluid motor, which in turn drives a pumping mechanism to inject a proportional amount of a second fluid into the flow of the first fluid. The fluid motor and pump are sized so that a predetermined ratio between the two fluids is maintained regardless of changes in pressure and flow rate of such first fluid.

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: Pairs of rotors (R1, R2, R3, R4, R5 and R6) driven rotationally by a motor (22) are disposed in the body (21) of a main pump (20) comprising a multistage Roots dry vacuum pump. A suction opening (23) communicating with the rotor chamber of the rotor R1 is provided in the upper wall portion at the left end of the body (21). A delivery section (24) communicating with the delivery side of the rotor chamber of rotor R6 on the final stage is coupled to an exhaust pipe (25) and is provided with a silencer (26) and further coupled to a check valve (28) through a pipe (27). The check valve (28) has its forward direction toward the atmospheric side. The delivery section (24), or a delivery section (24?) at the side intermediate stage, is coupled to an auxiliary pump (30) having an exhaust capacity smaller than that of the main pump (20).

Abstract: A method of converting heat energy generated in an evaporator to mechanical energy by expanding an evaporated working fluid includes evaporating the working fluid in the evaporator and expanding the evaporated working fluid in an expansion device. The expansion is in a low-pressure expansion device which is formed as a roots blower in which the working fluid is expanded and heat energy is converted to mechanical energy.

Abstract: A compressor (20) has a housing (22) having first (52) and second (48) members. A motor (24) within the housing (22) is coupled to one or more working elements (26, 28) to drive the one or more working elements (26, 28) to compress a fluid. A number of electrical terminals (104) are each mounted in an associated aperture (132) in the second housing member (48) and electrically connected to the motor (24).

Abstract: A rotor pump assembly is disclosed which reduces noise emitted from an oil pump while preventing pumping performance and mechanical efficiency thereof from being decreased by properly forming the profiles of teeth of an inner rotor and an outer rotor which are engageable with each other. The tooth profile of an inner rotor and/or an outer rotor has curved lines obtained by dividing a cycloid curve into two segments to be separated from each other, and in which the separated segments are smoothly connected to each other using a straight line or a curve.

Abstract: A three-gear type gear pump or double gear pump wherein the first driven gear and the second driven gear are opposed to one another with the driving gear disposed between them, wherein the number of teeth of the driving gear is greater than the number of teeth of each of the first driven gear and the second driven gear.

Abstract: A casing with housing space for retaining a first gear and a second gear in a condition where the tooth tips and both side surfaces slide, comprises a main casing which retains the first gear in a manner which allows rotation but restricts movement in the axial direction, and a gear holder which can move in the rotating shaft direction in the main casing and which rotatably retains the second gear. The main casing contains a biasing member which applies a biasing force to bias the gear holder to one side in the rotating shaft direction, and a piston which is acted on by hydraulic pressure and presses the gear holder on the other end side in the rotating shaft direction to counteract the biasing force. The gear holder is acted on by the hydraulic force from the piston to counteract the bias from the biasing member and moves in the rotating shaft direction according to the hydraulic force so that the engagement width between the first gear and the second gear which is retained by the gear holder is changed.

Abstract: A roots type fluid machine includes a housing, a pair of parallel rotary shafts and two-lobe rotors. Each rotor includes two lobe portions and two well portions. Each lobe portion has a profile of convex arc with a radius R and each well portion has a profile of concave arc which is an envelope of the convex arc of the lobe portion. The rotor has a configuration defined by a curve which includes the convex arc, the concave arc and further an involute curve with a base radius r between the convex and concave arcs. The base radius r is set in a range L/(2?{square root over ( )}2)<r<0.3(?{square root over ( )}2)L where distance between axes of the rotary shafts is L, and the radius R is set in a range {(?{square root over ( )}2)/16}?L<R<{(27?5?{square root over ( )}2)/56}L.

Abstract: A roots compressor has a housing, a rotary shaft, a rotor and a layer. The housing defines a pump chamber, a suction port and a discharge port. The suction port and the discharge port adjoin to the pump chamber. The rotary shaft is rotatably supported by the housing. The rotor is connected to the rotary shaft and contained in the pump chamber. Fluid introduced into the pump chamber through the suction port is discharged to the outside of the pump chamber through the discharge port by rotation of the rotor which is driven through the rotary shaft. The layer is formed on an inner peripheral surface of the housing, which defines the pump chamber. The layer is thinner from a side adjacent to the suction port toward a side adjacent to the discharge port in circumferential direction of the housing.

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 pump e.g. a screw pump, includes a main pumping element and a generally parallel auxiliary pumping element, and a pump housing, the main and auxiliary pumping elements interacting with each other and with an internal wall of an elongate pumping chamber of the housing as they relatively rotate to pump fluid from a first axial inlet end of the elongate chamber towards a second axial outlet end of the elongate chamber, and wherein the internal wall of the elongate pumping chamber includes at least one recess which extends along at least a substantial portion of the axial extent of the chamber between the inlet and outlet ends of the chamber, an adjacent pumping element being contactable with the chamber wall at discrete contact edges either side of the recess.

Abstract: A gas-compression module for use in a fuel cell system includes an air compressor, a motor and an intercooler. The air compressor has a pump chamber for compressing gas. The motor has a drive shaft for driving the air compressor. The intercooler cools the compressed gas exhausted from the air compressor. The air compressor includes a first rotor and a main rotary shaft connected to the drive shaft of the motor for driving the first rotor. The air compressor also includes a second rotor and a driven rotary shaft driven by power transmitted from the main rotary shaft for driving the second rotor. The motor and the intercooler exist in an imaginary plane passing through an axis of the main rotary shaft and an axis of the driven rotary shaft. The center of gravity of the intercooler is located closer to the driven rotary shaft than that of the motor.

Abstract: A rotary positive displacement hydraulic machine includes a housing defining two mutually intersecting parallel working chambers having a low pressure inlet side and a high pressure outlet side. Two meshing rotors are mounted for rotation in the two chambers, respectively. Bearing supports at opposite ends of the chambers, support bearings in which the rotors are journalled for rotation. At least one end of the housing is closed by an end cover. The end cover and adjacent housing end have at least one elongate recess on each side of the working chambers. The end cover recesses are alignable with the housing recesses. There is at least one keying element in each pair of aligned recesses so that the open end of the housing is supported against relative movement by differential fluid pressure in the chambers in a direction transverse to a plane containing the axes of rotation of the meshing rotors.

Abstract: A rotary pump has a simple construction by omitting a transmission shaft on the side of a motor and whereby makes a cost of the rotary pump as low as possible, with maintaining feature that assembling and disassembling is facilitated. The rotary pump has a main casing, a casing cover cooperated with the main casing for defining a pumping chamber therebetween, a pair of rotors received within the pumping chamber with mutually meshing pumping segments for synchronous revolution in mutually opposite directions, a space being defined in one portion of the casing cover, a cover piston being disposed within the space for movement back and forth with respect to an end surface of the rotor, and an air cylinder being mounted on the casing cover and having a piston rod, to which the cover piston is connected.

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 seal assembly for the protection of a static seal device for use in a vacuum pump. The seal assembly comprising at least two components which are sealingly connected together, an o-ring seal, which is engaged between the two components to prevent transfer of fluid to and from the pump between these two components and a fluid channel. The fluid channel being in the plane of the o-ring and located between the o-ring seal and a process gas flow path. The fluid channel provides a path for a barrier gas to be routed when the apparatus is in use. The channel being connectable to an external source of barrier fluid and having an outlet in fluid communication with the pump swept volume.

Abstract: A variable capacity pump/motor has a meshing internal and external gear set disposed between an upper mandrel and a lower mandrel, each including a flange extending towards the gears to divide a pump/motor chamber into suction and discharge chambers. The outer gear is fixed and the internal gear is axially moveable with respect thereto. The inner gear and the upper mandrel move in response to changing pressures in the casing, allowing the motor to vary displacement and the pump to vary its output based on supplied fluid pressure or based on the speed of the prime mover. An external configuration includes a pair of meshing gears mounted on separate shafts in a casing. One gear is fixed and the other is axially moveable with respect thereto and moves in response to changing pressures in the casing. Each of the gears is sealed by a seal/bushing on a free end thereof.

Abstract: A gear•rear shaft containing main body of a bottomed type is penetrated with a bearing hole and a rear face of the gear•rear shaft containing main body is coupled with a closing plate to form an airtight seal from an outside environment. Shafts extended from two gears to a side of the rear face are set to be shorter than a length of the bearing hole in an axis core direction. Bushes are also set to a length that is the same as that of the shafts. The gear•rear shaft containing main body is formed with a recess portion at the rear face and the bearing hole is penetrated to open to the recess portion. The gear•rear shaft containing main body is bored to penetrate with a low pressure port communicating with a low pressure region in an axis core direction.

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: An engine pump is provided which operates with an internal combustion engine or as a supplemental pump or as used in a stand alone device, and includes an internal vent for improved pump and motor durability. The pump is operably and sealably connected to a motor and adapted for connection with a source of fluid and a discharge means. An internal vent is positioned in between an armature shaft of bore along an inlet port thereby decreasing the pressure in the area of the seal. Alternatively, a valve is positioned between the inlet and outlet ports to selectively permit fluid pumped between the inlet and outlet ports to pass through when the outlet port is flow restricted.

Abstract: In a gear pump with variable throughput volume, with two meshed gears with external toothing which are rotatably held in the working chamber of a pump housing, at least one of the two gears is driven from a drive shaft and one of the gears, preferably the driven gear, is shiftable in the direction of its axis. In order to realize a control mechanism in a simple manner a gap width defined as the distance measured in axial direction between an essentially plane first interior side wall of the working chamber of the pump housing and a first front face of the shiftable gear, is designed to be variable.

Abstract: A blending pump assembly for accurately maintaining the proper ratio of two fluid components. Flow of a first fluid is utilized to drive a fluid motor, which in turn drives a pumping mechanism to inject a proportional amount of a second fluid into the flow of the first fluid. The fluid motor and pump are sized so that a predetermined ratio between the two fluids is maintained regardless of changes in pressure and flow rate of such first fluid.

Abstract: The compressor machine has two rotors rotating in opposite directions, which are fitted to two parallel, spaced apart shafts mounted in a housing. One of the shafts is driven directly and the other by intermeshing toothed gears mounted on the shafts. The housing has two radial walls which are configured in one piece with each other and with a peripheral wall and in which the shafts are mounted. The toothed gears are arranged between these radial walls. A side wall of the housing has an opening sealed by a removable cover. With the cover removed, the toothed gears can be fitted to the shafts through these openings. The bearing bores for the shafts can be produced and machined in the one-piece housing in a single set-up, so that, with a minimum number of parts, any causes of alignment errors are avoided.

Abstract: A dual-inlet gear pump includes a drive gear and a driven gear. The invention utilizes the discovery that the drive gear will typically move a higher flow volume than does the driven gear, particularly when the fluid being moved is an air/oil mixture. The present invention takes advantage of this discovery to communicate a first higher expected flow source to the drive gear, and to separately communicate a second, relatively lower expected flow rate to the driven gear. A particular application is in a scavenging pump for a jet engine.

Abstract: A pump (12) for generating pressure and/or negative pressure comprises a pump chamber having a high-pressure port (16) and a low-pressure port (14), and two at least two-blade rotors which are mounted in the pump chamber on two parallel shafts offset in relation to each other. The rotors roll off onto each other free of contact during rotation while forming cells with an internal compression. Provision is made for a supply of a cooling agent (21) into the pump chamber, the supply being closed-loop controlled depending on the temperature on the side of the high-pressure port (16).

Abstract: In a screw type vacuum pump which includes a housing provided with a rotor chamber, a pair of screw rotors in mesh with each other rotably provided in the rotor chamber, a transfer chamber of gas formed between an inner wall of the housing and flutes of the aforesaid pair of screw rotors, and a suction port and an exhaust port communicated to the transfer chamber, the gas being sucked from the suction port into the transfer chamber and exhausted from the exhaust port, by providing the aforesaid exhaust port in a side face of the housing, it is possible to form a larger exhaust port, and a time until the port is blocked with deposits can be prolonged.

Abstract: An improved high pressure intermeshing gear pump that achieves high efficiency and a low cost by forming the pumping cavity such that no fillets exist at the corners permitting closed fits without utilizing bearing end plates. In addition an improved coupling between the gears and their supporting shafts is disclosed as is a simplified machining method that eliminates burrs that may be formed during the drilling operations.

Abstract: An engine including a housing formed with a pair of side-by-side intersecting substantially cylindrical cavities, and a pair of counter-rotating power rotors rotatably mounted within the cavities. The pair of power rotors include intermeshing lobes that each define open ended combustion chambers.

Abstract: A novel bi-rotational pump adapted to pump fluid in either of two directions by reason of construction inclusive of passageways and an array of check valves and pilot pistons which cooperate in one direction and in another way in the other direction.

Abstract: External gear pump, comprising: a casing (3a, 3b) with a gear chamber (4), comprising an inlet (5) for a fluid on a low pressure side and an outlet (6) on a high pressure side and comprising axial and radial sealing stays (7, 8); toothed wheels (1, 2) being in toothed mesh, wherein the external toothings of the wheels (1, 2) form delivery cells (10) for the fluid which are axially sealed off by the axial sealing stays (7) and radially sealed off by the radial sealing stays (8); and at least one pressure fluid supply (15, 16) through which pressure fluid may be supplied to the low pressure side, wherein the at least one pressure fluid supply (15, 16) opens on the low pressure side into a delivery cell (10) which is radially opposed by one of the radial sealing stays (8).

Abstract: A hydraulic motor comprising a housing having a fluid inlet. A fluid outlet and a cavity there between, a pair of intermeshing gear elements rotatable in the housing about mutually parallel axes. Each of the gear elements having a set of gear teeth disposed about the periphery of the element and a support shaft extending from oppositely directed end faces of the set of gear teeth. A bearing assembly located on opposite sides of the cavity in said housing to support the shafts for rotation about respective ones of the axes. Each of the bearing assemblies having a sealing face overlying the end faces and biased into engage with the end faced by a pressure compensating seal located between the bearing and the housing. The sealing face having a channel extending partially about the spindle and in fluid communication with the inlet to introduce fluid under pressure between the faces.

Abstract: The invention concerns a metering gear pump comprising a set of gears supported and guided solely by the inner peripheral surface of the lobe of the chamber wherein they are housed. They do not comprise any shaft to act as support or guide, thereby enabling to reduce significantly useless spaced difficult to rinse when changing the product to be pumped. For the same purpose, the driving shaft is flexibly connected to the driving gear. Such arrangement provides the advantage of requiring only one single packing seal. Such a pump, connected to a drive motor and an encoder delivering a signal proportional to the number of pump cycles, enables to provide an accurate metering pump for numerous uses.

Abstract: A gear.rear shaft containing main body of a bottomed type is penetrated with a bearing hole and a rear face of the gear.rear shaft containing main body is coupled with a closing plate to seal in airtight from outside. Shafts extended from two gears to a side of the rear face are set to be more less shorter than a length of the bearing hole in an axis core direction. Bushes are also set to a length the same as that of the shafts. The gear.rear shaft containing main body is formed with a recess portion at the rear face and the bearing hole is penetrated to open to the recess portion. The gear.rear shaft containing main body is bored to penetrate with a low pressure port communicating with a low pressure region in an axis core direction.

Abstract: A conjugate pair of intermeshing rotors having helical lobes having helical crests and intervening grooves and adapted for rotation about parallel axes within a working space of a screw rotor machine. Each rotor has a tip circle, a pitch circle, and a root circle, one rotor of each pair being a female rotor such that the major portion of each lobe of said female rotor is located inside the pitch circle of the female rotor. The other rotor is a male rotor formed such that the major portion of each lobe of said male rotor is located outside said pitch circle of the male rotor. The lobes of one rotor follow the grooves of the other rotor to form a continuous sealing line between said pair of rotors, each of the lobes having a primary and secondary flank portion, wherein the primary flank portion of said lobes of the female rotor have a profile formed from at least one ellipse and the primary flank portion of the lobes of the male rotor have a profile formed from at least one ellipses.

Abstract: External gear pump, comprising: a casing (3a, 3b) with a gear chamber (4), comprising an inlet (5) for a fluid on a low pressure side and an outlet (6) on a high pressure side and comprising axial and radial sealing stays (7, 8); toothed wheels (1, 2) being in toothed mesh, wherein the external toothings of the wheels (1, 2) form delivery cells (10) for the fluid which are axially sealed off by the axial sealing stays (7) and radially sealed off by the radial sealing stays (8); and at least one pressure fluid supply (15, 16) through which pressure fluid may be supplied to the low pressure side, wherein the at least one pressure fluid supply (15, 16) opens on the low pressure side into a delivery cell (10) which is radially opposed by one of the radial sealing stays (8).

Abstract: There is provided a rotary internal combustion engine (20) comprising a plurality of rotors (21) each having a plurality of lobes (22) for intermeshing with lobes of other rotors to form successive combustion chambers. Axial seal elements (60, 61) are provided at the rotor tips and trailing tips of the rotors respectively. Circumferential axial edge seals (59) are also provided to interconnect the axial seals. The seals engage sealing plates (30) on each axial side of an engine housing (29) so as to effect the combustion chambers. Fuel inlets and ignition means are provided at suitable locations, as are exhaust means.

Abstract: In a gear pump with variable throughput volume, with two meshed gears with external toothing which are rotatably held in the working chamber of a pump housing, at least one of the two gears is driven from a drive shaft and one of the gears, preferably the driven gear, is shiftable in the direction of its axis. In order to realize a control mechanism in a simple manner a gap width defined as the distance measured in axial direction between an essentially plane first interior side wall of the working chamber of the pump housing and a first font face of the shiftable gear, is designed to be variable.

Abstract: A rotary lobe pump includes two geared-together, counter-rotating shafts, to which are affixed rotors with interdigital lobes. Adjustment of the angular relationship of the rotors uses a clamping device within each rotor. The clamping device consists of a tapered, slotted bushing that is forced between a mating taper on the rotor and a locking device on the shaft by means of a flanged fastener mated to each pump shaft's threads.

Abstract: The invention relates to a gear pump in particular for rubber mixes, comprising an enclosure in which rotates a set of gear wheels comprising a central gear wheel which cooperates with two other peripheral gear wheels, said pump comprising at least one feed chamber in which acts at least one feed means for delivering the material to said enclosure via at least one passage orifice, each of the gear wheels being driven directly by a driving torque and prestressing means between the teeth ensuring hermetic contact of the meshing zone of the central wheel with each of the two peripheral wheels.

Abstract: A rotary blower (26) of the Roots type, used as an engine supercharger, comprising a housing (50,52) including a forward wall portion (52F) defining an inlet port (30) disposed toward the upper portion of the housing. Typically, the housing defines an outlet port (34) on the underside (54) of the blower. Disposed within the housing is a pair of meshed, lobed rotors (28,29), with one of the rotors being driven by an input shaft (62). The blower includes a pair of timing gears (58,60) disposed adjacent the rearward end (52R) of the housing. The housing includes an inlet duct (32) disposed above the input shaft (62) and extending forwardly and transversely (FIG. 2) from the housing, and having a duct opening (70) in open communication with the inlet port (30). The arrangement of the invention provides substantially improved air flow efficiency through the blower, which corresponds to improved horsepower output of the engine on which the rotary blower is being used.

Abstract: An automatic colorant dispenser having a compact modular design incorporating simply installed, precision stepper-motor driven, colorant pump modules, specifically designed to provide maximum abrasion resistance using advanced aerospace technologies plus exceptional operational life utilizing high quality, high precision and high reliability mechanical and electrical components. By employing advanced performance materials and space saving, compact geometric and ergonomic design methodology in the fully modular automatic colorant dispenser, up to sixteen space saving, two gallon colorant canister modules are efficiently grouped and directly connected to their respective energy-saving colorant pump modules. All component modules have been ergonomically located behind large open access panels to ultimately maintain the system with maximum convenience and simplicity.

Abstract: A hydraulic pump assembly includes a pump housing having a chamber defined therein, wherein the chamber includes a pair of cylindrically shaped portions each defining at least one end wall. The hydraulic pump assembly also includes a pair of rotary pump elements disposed for rotation within the cylindrically shaped portions of the chamber, and which cooperate to create a hydraulic pressure. The hydraulic pump assembly further includes a pair of cylindrically shaped shafts each having at least one end wall, and disposed within the pair of cylindrically shaped portions of the chamber and within the pair of pump elements. The shafts are fixed for rotation and are axially shiftable with respect to the pump elements. A hydraulic fluid within the chamber stabilizes at least one of the axially shiftable shafts such that the end face of the shaft is spaced from the end wall of the cylindrically shaped portion of the chamber when the hydraulic pump is in use.

Abstract: A rotary displacement machine has a housing and at least two annular displacement gears arranged in the housing and supported rotatably on a stationary axle, receptively. The at least two annular displacement gears have external teeth for conveying a fluid. At least two supply channels are provided in the housing and have a supply mouth, respectively, opening toward the annular displacement gears for supplying a fluid to the annular displacement gears. The supply mouth is configured such that, upon operation of the rotary, displacement machine, a fluid exiting from the supply mouth reaches either only the teeth of a single one of the annular displacement gears or only the teeth of the annular displacement gears rotating in the same direction.

Abstract: A hydraulic pump assembly includes a pump housing having a chamber defined therein, wherein the chamber includes a pair of cylindrically shaped portions each defining at least one end wall. The hydraulic pump assembly also includes a pair of rotary pump elements disposed for rotation within the cylindrically shaped portions of the chamber, and which cooperate to create a hydraulic pressure. The hydraulic pump assembly further includes a pair of cylindrically shaped shafts each having at least one end wall, and disposed within the pair of cylindrically shaped portions of the chamber and within the pair of pump elements. The shafts are fixed for rotation and are axially shiftable with respect to the pump elements. A hydraulic fluid within the chamber stabilizes at least one of the axially shiftable shafts such that the end face of the shaft is spaced from the end wall of the cylindrically shaped portion of the chamber when the hydraulic pump is in use.

Abstract: A spherical gear pump that comprises two rotors, or geared spheres, with the teeth arranged around them in a circular band at right angles to their axis of rotation: the pump spheres are covered by close-fitting spherical cases or housings except at the central or most internal part of the connection between the gears on the two spheres, the fluid contained in the cavity created between the most external gears and the case or housing is moved during rotation from the intake to the outlet, one sphere is driven by its shaft and the other is dragged by the gearing between the two.

Abstract: A subject of the present invention is to provide a water based hydraulic fluid and a hydraulic pressure device able to prevent burning and wearing in a sliding portion of a member constructed by an iron-based material as much as possible. Therefore, the water based hydraulic fluid relative to the invention contains copper ions for forming a film on addendum surfaces of a drive gear and a driven gear constructed by the iron-based material. A gear pump as the hydraulic pressure device relative to the invention uses the water based hydraulic fluid containing metallic ions for forming the film on the addendum surfaces of the drive gear and the driven gear constructed by the iron-based material.