Abstract: A fluid transfer pump that has a housing, a body portion movable within the housing between a first position and a second position, a gear coupled to the housing, a body cavity defined partially between the body portion and the housing, and an aperture defined in the housing that selectively provides a fluid to the body cavity. When the fluid is applied to the body cavity at or above a pilot pressure, the body portion is in the first position adjacent to the gear and when the fluid is applied to the body cavity at a fluid pressure lower than the pilot pressure, the body portion is in the second position and spaced from the gear.

Abstract: A pump includes a pump-head portion including a pump body and a magnet cup. The pump body defines an inlet and an outlet, and the pump body and the magnet cup together define a pump cavity. The pump includes a suction shoe situated on the pump body. The suction shoe includes an engaging portion. The pump includes a movable pumping member situated in the pump cavity and at least partially received within the suction shoe. The pump includes a permanent magnet coupled to the pumping member. The pump includes a pump-driver portion including a magnet driver located outside the magnet cup. The pump includes a pressure-absorbing member situated in the pump cavity. The pressure-absorbing member is configured to engage the engaging portion of the suction shoe such that the suction shoe is urged radially inwardly with respect to an outer edge portion of the surface of the pump body.

Abstract: A motor pump unit comprises an electric motor and a reversible internal gear machine. The latter has a multi-part housing in which an externally toothed pinion and an internally toothed hollow gear are arranged. A free space, in which a multi-part filler element is arranged, is configured between the gears. The filler element comprises radially movable sealing segments, between which a radial gap is configured. An axially movable sealing plate is arranged between axial faces of the gears and a housing part. This has a sealing plate control groove that is open to the faces of the gears and that can be pressurized, and which is open to the radial gap and located directly opposite thereto. The pinion segment and/or hollow gear segment has a radial sealing segment control channel that can be pressurized and extends transversely, is open to the radial gap, and ends directly in the radial gap.

Abstract: A test controller and method to operate a rotary motor of a pump are provided. The test controller includes a test speed circuit electrically coupled to, but detachable from, the pump and being configured to apply at least one signal to the pump motor to cause the pump motor to rotate at a predetermined test speed and/or for a predetermined test time. An actuator selectively activates the test speed circuit to operate the pump motor at the predetermined test speed and/or for the predetermined test time. The method includes electrically coupling the test controller to the pump and, in response to selective activation of the actuator, selectively activating the test speed circuit to apply at least one signal to the pump motor to operate the pump motor at a predetermined test speed and/or for a predetermined test time. The method further includes detaching the test controller from the pump.

Abstract: An internal gear pump includes a ring gear and a pinion configured to mesh with the ring gear. The ring gear and pinion delimit a pump chamber extending from a suction region to a pressure region. The internal gear pump also includes an axial disk arranged on front faces of the ring gear and the pinion and includes a lubricant feed from the suction region between the axial disk and the ring gear and pinion. The lubricant feed includes a lubricant channel which passes through the axial disk. A wedge gap is delimited between the axial disk and the ring gear and pinion. The wedge gap communicates with the suction region and, when the ring gear and the pinion are driven in rotation, a lubricating film forms between the axial disk and the ring gear and pinion.

Abstract: An internal gear pump for a slip-controlled hydraulic vehicle braking system includes a pinion, a ring gear, and a filler piece (sickle). The filler piece has an inner part extending in a curved manner in the peripheral direction and an outer part extending in a curved manner in the peripheral direction. The inner part and the outer part are interconnected in a hinged manner on the suction-sided ends. A leg spring is arranged between the inner and outer parts and is configured to separate the inner and outer parts and press against the tops of the teeth of the pinion and the tops of the teeth of the ring gear of the internal gear pump.

Abstract: In order to highly precisely adjust a gap between a bearing and a gear rotor by a simple configuration, a gear pump of the present invention includes: a casing that includes an inlet and an outlet; a pair of gear rotors each of which is formed by integrating a gear portion with a shaft portion and which is disposed so as to engage with each other inside the casing; a bearing portion that supports the shaft portion so that the gear rotor is rotatable, the bearing portion being movable in the thrust direction of the gear rotor; and a gap adjustment unit that moves the bearing portion in the thrust direction so as to adjust a gap between the gear rotor and the bearing portion.

Abstract: A gear pump includes a gear to be driven by a drive shaft, a pair of side plate members adjoining side surfaces of the gear, respectively, to restrain leakage of an operating fluid, and a tip seal member or seal block for sealing the gear tip or circumference of the gear. At least one of the side plate members and the tip seal member are integral parts of a sealing member.

Abstract: In a gear pump equipped with a pump assembly formed from a driving gear supported by a driving shaft, a driven gear supported by a driven shaft, a pair of side plates disposed at both sides in an axial direction of driving and driven shafts, and a seal block that seals tips of the gears and forms a first fluid chamber by installation onto the side plates, and a casing that houses the pump assembly and forms a second fluid chamber therein, ribs are provided for at least one member of the side plates or the seal block, and fluid tightness between the first and second fluid chambers is secured by exerting pressure between the side plates and seal block and additionally plastically deforming the ribs. By this, it is possible to provide the gear pump which is capable of achieving improvement of the seal integrity while reducing the parts count.

Abstract: A gear pump includes a gear to be driven by a drive shaft, a pair of side plate members adjoining side surfaces of the gear, respectively, to restrain leakage of an operating fluid, and a tip seal member or seal block for sealing the gear tip or circumference of the gear. At least one of the side plate members and the tip seal member are integral parts of a sealing member.

Abstract: A positive displacement gear pump including a pump housing having an inlet port, an outlet portion, and first and second pumping chambers. A first gear having helical teeth is engaged with an inner surface of the first pumping chamber. A second gear with helical teeth is engaged with an inner surface of the second pumping chamber. At least two teeth on the first and second gears are simultaneously meshed in a meshed region. A first bearing element is located at one end surface of the first and second gears. The first bearing insert includes at least a first outlet channel fluidly coupling an outlet portion of the meshed region to the outlet port.

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: An internal geared machine capable of forward and reverse operation in a closed circuit having a pinion and an internal toothed ring gear meshing with the pinion and disposed in a housing. A filling comprising two identical filler pieces fills a sickle-shaped space between the pinion and ring gear and a single stop pin mounted in the housing supports both of the filler pieces by their front ends. A pair of axial discs are seated on the pinion shaft on respective sides of the pinion and axial pressure fields and control fields provide opposing pressures against the axial discs.

Abstract: A fluid pump cowling for attachment to at least a pair of helical drivetrain gears having teeth and lands. The cowling has a pair of sidewalls adapted to extend at least partially over the lands of a first of the pair of drivetrain gears and a curved sump wall extending between the sidewalls that corresponds generally to the outermost circumference of the first gear. A sump channel is defined between the sidewalls on the sump wall adjacent a distal end of the sump wall. The sump channel has a generally frustoconical shape and leads to a fluid outlet opening defined in one of the sidewalls. The cowling is positioned such that the teeth of the pair of helical gears mesh in an area in fluid communication with the sump channel to create an area of high fluid pressure upon rotational movement of the gears with a fluid.

Abstract: A gearing, particularly for use in a gear pump which can be utilized in the power train of a motor vehicle, has a housing, a rotary internal gear in the housing, and a spur gear driven by a prime mover, mating with the internal gear and defining with the latter a crescent-shaped chamber for forcible conveying of a fluid, such as lubricant, from an inlet communicating with one end portion to an outlet communicating with the other end portion of the chamber. In order to avoid turbulent flow of fluid in the chamber, the latter is substantially filled by a composite insert. Such insert can comprise several crescent-shaped fillers with at least one seal between them, or two one-piece or composite fillers which are disposed end-to-end as seen in the circumferential direction of the internal gear and are separated from each other by an abutment which is secured to or of one piece with the housing.

Abstract: The invention relates to an internal gear machine for reversed operation in a closed circuit comprising an outer-toothed pinion, an inner-toothed ring gear meshing with the pinion; a housing; a filing that fills the sickle-shaped space between the pinion and the ring gear; the filling comprises two identical filler pieces; a stop pin is provided that is mounted in the housing and against which the filler pieces are supported by their front faces; the housing has two pressure lines and a drain outlet; the filler pieces are symmetrically disposed relative to a plane (symmetrical plane) extending through the center points of the pinion and the ring gear; the two pressure lines are located on both sides of the symmetrical plane viewed in axial direction.

Abstract: A gearing, particularly for use in a gear pump which can be utilized in the power train of a motor vehicle, has a housing, a rotary internal gear in the housing, and a spur gear driven by a prime mover, mating with the internal gear and defining with the latter a crescent-shaped chamber for forcible conveying of a fluid, such as lubricant, from an inlet communicating with one end portion to an outlet communicating with the other end portion of the chamber. In order to avoid turbulent flow of fluid in the chamber, the latter is substantially filled by a composite insert. Such insert can comprise several crescent-shaped fillers with at least one seal between them, or two one-piece or composite fillers which are disposed end-to-end as seen in the circumferential direction of the internal gear and are separated from each other by an abutment which is secured to or of one piece with the housing.

Abstract: A crescent pump including a housing having an inlet port and a discharge port, a driving gear, and a driven gear meshing with driving gear in a gap between the inlet and the discharge ports. External and internal troughs on the driving and the driven gears define pump chambers. A stationary crescent-body has a pair of arc-shaped walls which cooperate with the tips of the external and the internal gear teeth thereon in defining fluid seals. The edges of an inlet ramp at an upstream end of the crescent body and the edges of a discharge ramp at a downstream end of the crescent body define inner and outer upstream and downstream metering orifices which close and open in complementary fashion to maintain constant the rate of fluid leakage from the discharge port toward the inlet port. A pair of shaped metering grooves in the pump housing cooperate in defining a flow path between the discharge port and the inlet port through a succession of trapped volumes between the driving and the driven gears.

Abstract: An internal-gear machine comprises a casing with an internally toothed annular gear rotatable therein, an externally toothed pinion engaged with the annular gear and a filling member between the annular gear and the pinion. The filling member is subdivided into two portions by a substantially circumferentially extending separating surface. The filling member portions have respectively mutually oppositely disposed recesses which extend from the separating surface and which each have an inclined surface parallel to the axis of the machine. The inclined surfaces are in a wedge-shaped relationship with each other and a sealing roller is arranged in the wedge-shaped space. The sealing roller is pressed against the inclined surfaces by a hairpin spring operatively disposed between the sealing surface and a support surface. The spring limbs bear against the sealing roller and the support surface while the bent end of the spring projects into a free space in the casing.

Abstract: Described is an internal-gear machine (10) comprising a casing (12, 80) in which there are provided an internally toothed annular gear (20), an externally toothed pinion (24) in engagement therewith, and a filling portion (28) which is divided into two in the space (14) between the annular gear (20) and the pinion (24). The filling portion parts (32, 34) are provided with openings (56, 58) which start from the common separation surface (30) and which are each provided with an inclined surface (60, 62) that is parallel to the axis, in such a way that the two inclined surfaces (60, 62) which face towards each other form with each other wedge surfaces which include a wedge angle. Bearing against the wedge surfaces is a respectively associated sealing roller (64) which is pressed against the associated wedge surfaces by means of a spring element (88).

Abstract: Internal gear pump with an internal gear, a thrust plate arranged on each side of the internal gear, a powered external pinion arranged eccentrically relative to the internal gear and meshing with it, and a sickle-shaped, floating filler part split in peripheral direction and bearing with its blunt end on an axial support pin. The first segment of the filler part that faces the teeth of the pinion has a greater radial thickness than its second segment facing the teeth of the internal gear. The first segment features in the parting interface at least one axially extending groove for accommodation of a sealing element. The first segment features at least one stop for restricting wear on the surface facing the teeth of the pinion.

Abstract: A crescent internal gear pump achieves greatly improved sealing against cter flow of fluid and greatly reduced noise by increase of the number of teeth of each of the ring and pinion gears which form discrete volumes of pumped fluid against a crescent-shaped member or insert. Reduction of the size of the teeth on the ring and pinion gears allows an increase in the angular extent of the crescent-shaped insert in order to increase the number of discrete volumes to be increased to a minimum of nineteen for each of the ring and pinion gears. The reduction in noise is accompanied by an increase in the fundamental frequency of the remaining noise, which can be more readily attenuated by acoustic filtering and isolation. Perfecting features of the invention include shaping of the crescent-shaped member to equalize the number of discrete volumes formed by each of the ring and pinion gears and shaping the teeth of the pinion gear to equalize the volumes of the discrete volumes formed by each gear.

Abstract: Filler piece (8) of a gear pump or a gearmotor, mounted in an interspace (4), formed from an internal gear (2) and a pinion (3), exhibits a sickle-shaped seal (7), with which laterally projecting pivot pins (6) are connected, and filler piece (8) is designed in one-piece and/or in two parts by a separating gap (14) extending from high-pressure area (13) into low-pressure space (11).

Abstract: For improving the gap sealing between the circumferential surfaces of rot of a rotary piston machine and circular cylindrical inner surfaces (9) of the surrounding casing, rib-like protuberances (11) are displaced from the casing inner surfaces by cold working. On running in the rotary piston machine the external cross-sectional area of the protuberances (11) is removed by wear, so that between the protruberance (11) and the inner surface (9) a minimum sealing gap is obtained without corresponding manufacturing costs being involved in the formation thereof.

Abstract: A gear pump which includes a housing having an internally toothed gear and a pinion meshing with the internally toothed gear disposed therein. The housing has a sickle-shaped space between the two gears and has therein a filler piece. In order to avoid a fluttering of the filler piece and the noises connected therewith, structure is provided for urging the filler piece, due to pressurized oil being guided from the pressure chamber and one side of the filler piece into a bore extending through the filler piece to the opposite side of the filler piece, against the pump housing. The filler piece can also be locked in the direction of rotation by a pressure piece also loaded by the pressurized oil.

Abstract: An internal-gear machine such as a pump comprises a casing with an internally toothed annular gear mounted therein. An externally toothed pinion meshes with the internal teeth of the annular gear over a portion thereof, and an arcuate filling member is disposed between the annular gear and the pinion. The filling member has a first end of substantial thickness in the radial direction of the assembly and tapers almost to a point at the second end, and is mounted in the casing by means of at least one mounting pin. The pin is arranged at a spacing from the first end of the filling member, which is towards the intake chamber defined between the annular gear and the pinion, and the pin has a mounting portion engaging into a groove in a side surface of the filling member. The filling member is thus rotatable about the axis of the pin and displaceable by virtue of displacement of the mounting portion in the groove in the filling member.

Abstract: Hydraulic gear-driven rotary machine (pump or motor) in which the gears are free-floating with no supporting shaft or bearings. Their internal ducts rotate, providing a commutation with the stator ducts. This maintains the hydraulic equilibrium of the gears. A hydrostatic compensating device on the faces of the gears and on their toothing assures internal tightness. The hydraulic gear-driven rotary machine is suitable for operation at very high pressure with hydraulic equilibrium and internal tightness.

Abstract: An internal-gear machine such as a pump comprises a casing with an internally toothed annular gear rotatably mounted therein. An externally toothed pinion meshes with the internal teeth of the annular gear, and a generally sickle-shaped filling member which is split approximately in a circumferential direction is disposed in the clearance between the pinion and the annular gear. The end faces of the filling member portions which are towards the intake side of the machine may be of a convexly curved configuration and bear against a support element fixedly connected only to one wall of the casing so as to be radially slidable thereagainst and also pivotable about a pivot axis parallel to the axis of the pinion. Alternatively the end faces of the filling member portions may be flat and bear radially slidably against an intermediate element pivotally supported on an at least part-cylindrical peg fixed to only one wall of the casing.

Abstract: An internal-gear machine such as pump comprises a casing with an internally toothed annular gear rotatably mounted therein. An externally toothed pinion meshes with the internal teeth of the annular gear, and a generally sickle-shaped filling member which is split approximately in a circumferential direction is disposed in the clearance between the pinion and the annular gear. The end faces of the filling member portions which are towards the intake side of the machine may be of a convexly curved configuration and bear against a support element fixedly connected only to one wall of the casing so as to be radially slidable thereagainst and also pivotable about a pivot axis parallel to the axis of the pinion. Alternatively the end faces of the filling member portions may be flat and bear radially slidably against an intermediate element pivotally supported on an at least part-cylindrical peg fixed to only one wall of the casing.

Abstract: A gear pump or motor comprises a pair of gears intermeshing with each other, a case body accommodating the pair of gears, and a hard layer formed on an inner surface of the case body. The hard layer is made of a material to be as hard as not to be cut by tooth tips of the pair of gears. The hard layer may be a ceramic coating or a composite coating layer which performs a grinding like operation on the tooth tips.

Abstract: An internal-gear pump with a partition plate, comprising: an arcuate chamfer formed at an inner edge of an end face of the partition plate rotationally opposing an inner gear of the pump and having a curvature at least greater than that of tooth tip edges of the inner gear.

Abstract: The drive and driven gears of a pump are formed with grooves extending inward from the tips of the teeth to inside the root diameter. Thus each gear is divided into a first portion which serves solely as a drive or driven gear and a second portion which serves the two functions of a conventional pump gear, mainly to perform the pumping function and part of the drive function. Fitting within the grooves of both gears is a suction shoe which also overlies the inlet duct of the pump block and the mesh points of the first portions of the gears plus about two teeth to either side of the mesh point. The shoe separates the large portion of the pump chamber from the inlet duct.

Abstract: In an internal gear pump comprising a ring gear and a pinion in mesh therewith to define a lunate cavity therebetween, a segmented part-lunate filler inserted in said cavity has supporting faces contacting a pin which extends axially through the cavity and is rotatable about its longitudinal axis. In operation, the resulting forces acting on the filler segments are transmitted to the pin by said supporting faces and produce a torque about the longitudinal pin axis.

Abstract: An internal gear pump motor having a housing, a pinion and an internal gear rotatably supported in the housing and meshing with each other, and filler piece means located in a space defined between the pinion and internal gear for dividing the space into two regions providing a low pressure region and a high pressure region during operation. The filler piece means includes at least one filler piece floatingly mounted within the space and having portions capable of coming into sliding engagement with tooth crests of the pinion and internal gear respectively in a portion of the space where the distance between the tooth crests of the pinion and internal gear is reduced toward the low pressure region. A stopper pin is secured to the housing operative to engage one end of the filler piece on the side of the low pressure region for restricting the circumferential movement of the filler piece toward the low pressure region.

Abstract: The disclosure relates to improvements in pumps and motors of the gear type. The gear elements are arranged within the pump or motor housing so that the ends or the tips of the teeth are spaced out of fluid sealing relationship and not pressed into the surrounding chamber wall on the low pressure side of the housing. Rigid sealing members of limited circumferential extent having a curved sealing surface and planar support and side wall surfaces are seated in a recess in the housing at the high pressure side of the gears for the purpose of providing a fluid seal between the tips of the teeth in a limited region adjacent the opening in the housing which is at higher pressure. The sealing members are positioned in a recess in the housing and are configured to be resistant to bending and movement. The sole support for the shoes is provided by planar surfaces on the side pressure plates.

Abstract: The disclosure relates to improvements in pumps and motors of the gear type. The gear elements are arranged within the pump or motor housing so that the ends or the tips of the teeth are spaced out of fluid sealing relationship and not pressed into the surrounding chamber wall on the low pressure side of the housing. According to the disclosure, sealing members of limited circumferential extent are provided in the housing at the high pressure side of the gears for the purpose of providing a fluid seal between the tips of the teeth in a limited region adjacent the opening in the housing which is at higher pressure. The sealing members disclosed are a pair of separate shoes located adjacent the high pressure opening. The sole support for the shoes is provided by the side pressure plates.

Abstract: A gear pump for use particularly with the new type water hydraulic fluids. A gear track insert is located in the gear housing pressure-generating zone to protect the gear housing from abrasion and high pressure wear. The gear track insert is replaceable, when required, thereby saving the more expensive cost of replacing the gear housing. Isolation seals are of a new design to eliminate high pressure from leaking into the low pressure zone of the pump. These seals also control the pressure plate to gear face load to minimize wear and leakage.

Abstract: A high pressure internal gear pump has an inner rotor with outer gear-type teeth inside of an outer rotor with inner gear type teeth. The outer rotor is eccentrically revolving relatively to the inner rotor, whereby the gear-teeth are meeting each other as known from the former art. A half-moon like part is provided between the inner and outer rotor as usual in such pumps. The invention provides slots for the reception of pressure in the part between the teeth or in the housing surrounding the outer rotor. The pressure in said slot or slots presses the neighboring portions against the inner- and/or outer rotor for more perfect seal at high pressure. In addition an axially adjusting thrust body may be provided to seal the ends of the rotors. The mentioned slots may have enlargements on suitable locations in order to make the adjacent sealing parts more flexible for suitable sealing engagement with the respective portions of the rotors.

Abstract: In an internal gear pump or motor the insert control member between the inner and the outer gear is provided with balancing pockets, which receive fluid under pressure to counter-balance the pressure forces exerted onto the inner and outer gear of the device. Thereby it is obtained, that the radial forces of fluid onto the inner and outer gear are balancing each other by diametrically located oppositional directed fields of force of pressure in fluid. The inner and outer rotors such float freely between radial forces of fluid. Radial rest loads are prevented and the life of the rotors is extended. There may be a single insert or a plurality of inserts and there may be one or a plurality of suction chambers in the device. Additional outer guide means or pressure fields of fluid under pressure may be provided. The loading of the balancing pockets with pressure fluid may be done through respective passages from areas under pressure to said balancing pockets.

Abstract: A module pump comprises a manifold having intake and outlet connections; a plate to which gears and a "shoe" (which function to define pump chambers for a pair of gears) or, in a pump having three gears two "shoes;" a drive for the gears, which in a preferred embodiment is a magnetic drive; and a barrier between the drive and the plate. Each of the modules is subject to variations in design depending upon end use and hence wide versatility is achieved without great increases in manufacturing cost since only one of the modules need be altered. Use of three gears doubles the capacity of the pump; if three gears are not needed the mounting holes for the third gear may be plugged. A unique bypass is installed in the manifold to permit flow back to the intake when the pressure exceeds an adjustable amount.

Abstract: An internal-gear fluid-displacement machine, such as a fluid-displacing pump or a fluid-displaced motor includes an internal gear and a spur gear which meshes with the internal gear at a meshing region. A separating body fills a separating region between the gears which narrows toward the meshing region and separates the same from the remainder of the interspace between the gears. An actuating lever is mounted on the housing for pivoting and extends through the interspace, and a piston subjected to the pressure prevailing at the meshing region abuts against a free end of the actuating lever, pressing the same into abutment with that end of the separating body which faces into the remainder of the interspace. A strap connects the separating body to the actuating lever. The axial sides of the separating body have depressions therein which are bounded by narrow sealing projections which converge toward the meshing region.

Abstract: A high pressure hydraulic gear pump or motor of the internally geared type with a radially movable sealing plate arranged on one side of the filler member so as to form a seal against one gear, while the filler member forms a seal against the other gear, the sealing plate being arranged in a floating mode, with a sealing batten underneath it and springs biasing the plate and the batten radially outwardly. Pressure space delimiting control edges and tooth prefill passages are arranged on the sealing plate and on the filler member.

Abstract: A pump has a block and a cup-like member having a rim engaging the block to define a pump cavity. Recessed into the block and opening or extending into the cavity are an inlet and an outlet duct and three parallel pins. The drive and driven gears are mounted on two of the pins, one face of each gear being tight against the block, and the two ducts are on opposite sides of the mesh point of the gears. A shoe is mounted on the third pin and overlies the inlet duct and the mesh point of the gears plus about two teeth to either side of the mesh point. A spring biases the shoe into contact with portions of the gears and the block to define a pump chamber. After a differential between the inlet and outlet duct pressures is established, this differential supplements the spring. One means of driving the drive gear comprises a motor driven annular magnet on the outside of the cup-like member and a smaller magnet within the cup-like member drivingly connected to the drive gear.

Abstract: A rotary gas compressor or expansion motor with a housing having circumferentially spaced inlet and outlet ports. An outer cage or sleeve rotor has alternate slots and teeth. An inner lobe rotor has lobes which mesh with the slots of the cage rotor as the two rotate. The space between the two rotors is filled with a crescent-shaped housing member. The slots, teeth and lobes of the rotors are helical.

Abstract: A magnetically driven, sealed gear pump has hard metal gears and a pair of relatively soft gear tip seals near the pump inlet chamber that compensate for wear of its parts.

Abstract: A gear pump having a drive gear provided with trunions mounted for rotation in the housing of the pump and a driven gear meshing with the drive gear and guided in the housing only on side faces and a portion of the inner peripheral surface of the housing and pressed by fluid pressure against the driven gear. A first sealing member at the outlet of the housing presses the driven gear against a sealing zone of the housing adjacent the inlet thereof and a second sealing member subjected to fluid pressure presses the driven gear against the drive gear. A low pressure zone is arranged at the inner peripheral surface of the housing between the two sealing members, whereas a high pressure zone is arranged between the second sealing member and the sealing zone.

Abstract: An external gear pump wherein the gears are installed in an eight-shaped compartment of a central housing section which is flanked by two covers. The outlet port of the housing communicates with two arcuate recesses for metallic inserts which are biased against the adjacent gears by fluid pressure in the outlet port whereby the inserts urge the gears against those portions of the internal surface of the central housing section which are located opposite the recesses. Such portions of the internal surface are formed with narrow first cutouts which communicate with the outlet port. The internal surface is further formed with relatively wide additional cutouts which are located between the first cutouts and the recesses and communicate with the inlet port. The force which is produced by fluid in the cutouts opposes the force which urges the gears against the internal surface of the central housing section to thus reduce the force with which the stubs of the gear shafts are urged against the housing.

Abstract: In a fluid motor or pump, a combinaton is disclosed having an internal ring gear operably secured within a housing meshing with a pinion gear and having a wedge with a shape conforming to the outer peripheries of the ring and pinion gears to provide a sealing effect and pressure or suction chamber where the wedge has a piston end and porting in the tip thereof to create a hydrostatic pressure in an operable direction to overcome pressure from the chamber and means for supporting the pinion gearing and carrying the wedge in slidable relatonship where the mechanism receives fluid under pressure from a source to the pressure chamber and includes means for returning fluid to the source.

Abstract: A gear pump and motor having a plurality of pumps and motors, each of which have at least three gears interengaged with one another, seal members disposed adjacent to the gears, and control means for selectively controlling the movement of the seal members toward or away from the gears of the pump and motors so as to selectively actuate the pumps and motors so as to attain a desired output.