Abstract: A sanitary design gear pump in which two gear shaft bearing blocks constitute hand removable structural end bodies of the pump. The gear shaft bearing journals extend completely through the blocks for easy cleaning and are sealed by O-rings retained by simple clamp plates. Gear cavity bore extends only the length of the largest gears, among interchangeable gear sizes. Bearing block to gear cavity seals are located at the ends of the gear bore to eliminate entrapment zones, minimal intrusion of the bearing blocks into the gear cavity allowing a large pump operating temperature range. Shaft seals of many different types can be contained in a simple hand removable cartridge. Complete pump disassembly is by one manually operated tee-handled clamp fastener. The drive and driven gear shafts are of different diameters to aid and assure correct assembly. The assembled pump slides into a pump mount with integral tie rods sealing the pump and securing it to the mount.

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: The problem of aligning the drive shaft of a pressure clamped pump with the output shaft of a drive motor in a hydraulic apparatus is solved through the use of pressure clamped pump having a housing adapted for installation into a cavity and a drive shaft coincident with the center of the housing. The hydraulic apparatus may include piloting features configured to facilitate alignment of the pump drive shaft with the output shaft of a motor used to drive the pump. The pump may include elements for retaining the drive shaft within the pump, and may also include a larger and less restricted inlet than could be achieved in prior pressure clamped pumps. The pump may include pumping means in the form of a gear pump having a single primary gear driving a single secondary gear. The pumping means may alternatively be a gear pump having a single primary gear driving two or more secondary gears.

Abstract: A rotary vane pump for delivering a fluid, having a delivery device (1) accommodated in a casing (2), with the casing (2) being closed on the one side by a casing cover (3), and on the other side by a bearing flange (4). A drive shaft (11) extends through the bearing flange (4), the delivery device (1), and optionally the casing (2), and is supported in a passageway formed in the bearing flange (4) and optionally in the casing cover (3). Also, between the delivery device (1) and the inside wall of the bearing flange (4), a side plate (16) is arranged, which supports itself on the inside wall, and centers the delivery device (1) in the casing (2). The side plate (16) is centered on the side facing the bearing flange (4) by a centering collar which extends into the passageway for the drive shaft (11).

Abstract: A chamfer is formed in bearing blocks on either side of the hydraulic fluid inlet. The chamfer allows a family of pumps with varying hydraulic inlet sizes to have similar bearing block pressure profiles. The chamfer prevents the build up of hydraulic pressure immediately adjacent to the hydraulic inlet below a given inlet size so that the bearing block pressure profile for a family of pumps with different inlet sizes more nearly matches the pressure profile of the largest opening used in a particular design family. The sealing gasket on the side of the bearing block opposite the gears is designed to accommodate this single pressure profile. The result is an improved bearing life and reduced slippage over an entire family of pumps or motors of similar design.

Abstract: A vane pump comprising a pump housing, including an inlet, an outlet, and therein a hollow space, a cam ring received in the hollow space, a rotor placed in the cam ring and defining a rotation axis. The rotor comprises plural vanes arranged in corresponding slots formed in the rotor with a slidable contact in a radial direction of the rotor. A first wall member is received in the hollow space, one side of the first wall member faces one side of the cam ring, and the first wall member comprises an intake passage provided with a groove that is formed so that a partition wall portion is defined between the intake passage and an interface between the first wall member and the cam ring. A pair of intake ports are formed on the one side of the first wall member, each intake port is connected with the inlet by the intake passage, and a pair of outlet ports are formed on the one side of the first wall member.

Abstract: A compact high efficiency vane pump is disclosed having a unique T-shaped vane and rotor slot configuration with a roller tip vane in a uniquely configured chamber. To minimize friction in chamber diameter, a pressure plate is provided which is hydraulically balanced, both in the forward and reverse pump and motor modes, having micro pressure pulses which vary multiple times per rotor rotation in order to compensate for varying hydraulic axial load on the housing.

Abstract: A vane pump includes a cylindrical rotor rotatable inside of an oval-shaped rotor chamber defined by a cam ring around the rotor. A thrust plate and a pressure plate on opposite sides of the cam ring cover the rotor chamber and are squeezed together by a pressure force attributable to fluid in a discharge chamber of the vane pump at a discharge pressure thereof. A first thrust face of the thrust plate is pressed against an end wall of a cavity of a pump housing in which the components are installed. Fluid at the discharge pressure is ported to one or more balance chambers between the thrust plate and the end wall of the housing. The balance chambers are defined by a gasket received in a groove of the first thrust face.

Abstract: A hydraulic positive displacement machine has rotating conveying elements whose end faces are sealed by pressure plate. This pressure plate is loaded by a control valve with hydraulic pressure in order to adjust the size of the sealing gap. The control valve has a hollow piston in which a metering orifice is located. A return connector, a connector communicating with a consumer, and a hydraulic control connector connected to the pressure plate can be controlled by the hollow piston with its metering orifice.

Abstract: A pump comprises a housing and a pump unit arranged therein. The pump unit comprises a first and a second thrust plate and a ring arranged therebetween and having a through opening. The ring rests on the two thrust plates at least at an outer peripheral region thereof, and a pressure chamber is formed between the second thrust plate and the housing. A spacer supports the first thrust plate at a distance from the housing, and the spacer is associated at least in part with a radially inner surface area of the first thrust plate opposite the through opening. This allows deformation of the first thrust plate under operational pressure so as to hinder formation of a gap between the thrust plate and the pump insert.

Abstract: Rotary pump apparatus includes a pump housing having a drive gear and a driven gear positioned in the interior of the housing. A fluid-flow passageway provides fluid to a volumetrically changing space located between meshing gear teeth to prevent the pressure in the space from dropping below the vapor pressure of the fluid.

Abstract: A pump assembly comprises a hydraulic fluid pump having a housing assembled from a plurality of housing components that are pinned together rather than being clamped together by bolts. The pump is disposed in a cavity in a valve block so that the outlet fluid pressure from the pump is applied axially to the housing components to create a greater external axial force on the pump components than the internal axial force and thereby maintain the housing components in tight, sealing relation without the need for clamping bolts or other clamping means.

Abstract: The invention relates to a vane pump with a rotor which receives vanes, with two pressure plates (17) which bear sealingly on the rotor and of which one is arranged on a delivery side of the vane pump and one on the opposite side, and with a contour ring surrounding the vanes and forming two suction and discharge regions, at least one of the two pressure plates being provided with inlet and outlet orifices (53, 59, 63a, b) which make a fluid connection between a discharge region and an undervane region. The invention is distinguished in that the pressure plate (17.2) located opposite the delivery side has an orifice, which makes a fluid connection between a discharge region and a pressure space (61) partially delimited by this pressure plate (17.2), and seals off the pressure space (61) relative to the other discharge region.

Abstract: A gear pump has a housing, a pump shaft supported in a housing wall by a bearing, and a pumping gear supported on the pump shaft which is operable to pump newtonian and non-newtonian liquid of different densities. A relief collection zone is arranged on a low-pressure side of the bearing for collecting leakage liquid passing through the bearing along the shaft. At least two return ducts or bores are provided which connect the collection or relief zone with a suction side of the pump in order to return the collected leakage liquid.

Abstract: A vane pump is proposed which has a rotor which accommodates a number of vanes that can move in the radial direction, has a cam ring which surrounds the rotor and forms at least one suction region and one pressure region, and has at least one pressure plate, which forms a lateral boundary surface of the suction and pressure regions and, when the vane pump is operating, is loaded by pressure on its side facing away from the suction and pressure regions, the pump being defined in that that surface (17; 19) of the pressure plate (13; 15) which faces the rotor (5) is designed to be concave--when there is no pressure in the vane pump (1).

Abstract: The invention provides a rotary-vane machine having a stationary shell including a casing member (2), a camming ring (4) having an internal, noncircular camming surface (6), and a flange member (8); a rotor (10) including at least two first vanes (12) fixedly attached to, or integral with, the rotor (10), a first cover plate (14) fixedly attachable to the rotor (10); a second cover plate (16) fixedly attachable to the rotor and integral with a first shaft (22) supported on its free end by bearing (26) mounted in the casing (2), and being provided with at least four ports (a) for access or egress of a working medium; a second shaft (23) supported by a first bearing (28) accommodated in the first cover plate (14) and by a second bearing (30) accommodated in the second cover plate (16); at least two second vanes (38) fixedly attached to the second shaft (23) and oscillatably accommodated within the rotor (10), and defining, together with the rotor (10), the first vanes (12) and the first and second cover plates

Abstract: A filling member-less internal-gear unit has a casing with a bearing ring which is accommodated movably in a bore in the casing transversely with respect to its axis but non-rotatably. An internally toothed annular gear is rotatably mounted in the bearing ring and meshes with a pinion rotatably mounted in the casing. The bearing ring is pivotable relative to the bore in the casing about a pivot axis parallel to its axis. The pivot axis is so disposed that the ring portion of the bearing ring, which is associated with the engagement-free annular gear region, is moved at least approximately radially towards the pinion axis by the hydraulic pressure forces acting on the annular gear in the pressure chamber.

Abstract: A vane pump including a cylindrical rotor rotatable inside of an oval-shaped rotor chamber defined by a cam ring around the rotor. A thrust plate and a pressure plate on opposite sides of the cam ring cover the rotor chamber and are squeezed together by a pressure force attributable to fluid in a discharge chamber of the vane pump at a discharge pressure thereof. Fluid at the discharge pressure of the pump is ported to an annular first longitudinal balance chamber between the pressure plate and an end of the rotor facing the pressure plate and to an annular second longitudinal balance chamber between the thrust plate and an opposite end of the rotor facing the thrust plate. A pressure force on the pressure plate attributable to fluid in the first balance chamber balances a fraction of the pressure force on the pressure plate attributable to fluid in the discharge chamber to reduce flexure of the pressure plate into the rotor chamber.

Abstract: A gear pump has a pair of gears a seal member for sealing up teeth of the gross engaging with each other in a sealed-up gear case, which seal member is provided at a place occupied by plurality of teeth in the vicinity of a working area of the teeth in a low pressure side of the gear case and is not connected to the gear case, the seal member having a low pressure fuel the flow of hole for flowing a low pressure fuel, wherein a tooth sealing angle for the plurality of teeth is set substantially to a value within a range of 35.degree..+-.5.degree. for gears having of 14 to 18 teeth, and a high pressure fuel flowing passage for the flow of a high pressure fuel, formed in a space other than the working area of the teeth and the area of and the sealing member, in the gear case.

Abstract: A bearing for a gear pump including a bearing dam which has a surface, an inlet face relief located on the bearing dam, and a discharge face relief located on the bearing dam. A bearing dam wall is located between the inlet face relief and the discharge face relief and a bleed hole arrangement. The bleed hole arrangement includes a blind passage located on the discharge face relief, and a second passage positioned perpendicular to and connected to the blind passage. The second passage extends to the surface of the bearing dam. In an alternative embodiment, the second passage is of a stepped configuration. The bleed hole arrangement reduces cavitation on the bearing and gear surfaces by pulsing fuel into an inter-tooth volume formed between the gear teeth during gear rotation.

Abstract: A hydraulic motor having hydraulic pressure compensating annuli for compensating for different hydraulic forces exerted on seal plates that seal both ends of a rotor and a stator.

Abstract: A hydraulic gear machine, in particular an internal gear machine having two gear wheels which mesh with each other in a chamber of a multipart housing, a sealing plate arranged on the side of the two gear wheels axially between them and a housing part, and a pressure field which is present in the housing part on the high-pressure side, is open towards the sealing plate, and is adapted to be acted on by high pressure. The order to provide embodiments of the gear machine which differ in their direction of rotation with the use of many of the same parts, a second pressure field is present in the housing part and the first pressure field is present only on the one side and the second pressure field only on the other side of a center plane which is defined by the axes of rotation of the two gear wheels so that a piece of the housing part is still present between the two pressure fields.

Abstract: A moderately high pressure, sliding vane pump is fabricated from low modulus plastic by routing high pressure fluid away from the central pump perimeter and into a bearing gland chamber for discharge porting. Port fittings are push socket connections that are sealed by O-rings and held in place against fluid pressure ejection by a saddle plate that cross-pins to the port boss.

Abstract: A fluid pressure operated device including a gerotor (17) including an orbiting and rotating star (27). A balancing plate (19) is biased into engagement by means of pressurized fluid in a space (102), with an adjacent end surface (28) of the star (27). Adjacent the balancing plate (19) is a housing member (21) defining a seal chamber (83), in which is disposed a seal assembly (89), including a support member (91) and a seal member (93) disposed radially inward from the support member. The outer periphery (92) of the support member (91) is disposed radially outward of a tangent circle (TC) of the bolts (11), thereby moving the pivot point (PP) of the balancing plate (19) further outward radially. This results in an improved ability of the balancing plate to follow the end surface of the gerotor star, whether the height of the star is more or less than that of the gerotor ring (23). As a result, volumetric efficiency is improved, even while the manufacturing cost of the gerotor gear set (17) may be reduced.

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: In an hydraulic generator-receiver for power transmission, with an improved hydraulic balancing, balancing of the axial force of the driving gear is effected by varying the value of the surface of the permanent high pressure zone, so that this variation causes an application of the high pressure on a surface of one of the side plates, either greater, or lower, while the value of the permanent high pressure zone has no influence on the other side plate. In addition, the inter-sector zone is incorporated in the sectors of the envelope to balance the tangential force of the driving gear.

Abstract: A floating bearing having an oval body located in a cavity along with a fixed bearing retains a pair of intermeshing gear members in the cavity in a housing of a pump. A spacer member engages an axial rib on the oval body to form a control chamber between the spacer member and the oval body. A resilient member provides an initial force which urges the floating bearing into engagement with the pair of intermeshing gears and forms a gap between the spacer and the oval body. Entrance fluid pressure from an entrance chamber is communicated to the control chamber while discharge fluid pressure from a discharge chamber is communicated to the gap. The entrance and discharge fluid pressures act on the floating bearing to provides a secondary force which urges the floating bearing into engagement with the pair of intermeshing gears to seal the entrance chamber from the discharge chamber.

Abstract: In a tandem type gear pump, the housing body has an inner middle partition wall portion integral with the body and having bearing means. The housing body is formed at the opposite axial end faces thereof with a pair of recesses each shaped like a pair of glasses, with a pair of covers being fixed to the axial end faces of the body to close the recesses. A pair of gear pump units are set in the recesses so as to be rotatable by the bearing means in synchronism with each other. The housing is provided with inlet and outlet port means in communication with the gear pump units.

Abstract: The invention relates to a sickleless internal gear pump with an internal ring gear and a pinion meshing with the ring gear. The ring gear and pinion are rotatably mounted in a common housing part having an axial expanse corresponding to the width of the teeth of the ring gear and the pinion. The housing features a suction port and a pressure port. The ring gear features radial ports for the fluid medium to be pumped. Disposed in the pressure side region of the housing, opposite the rotating gearing parts of the ring gear and the pinion, is an axially movable axial disk exerting a force on the rotating gearing parts dependent on an axial pressure derived from the working pressure. The axially movable disk provides axial sealing by compensating for the gap between it and the fixed housing.

Abstract: A gerotor motor (11) of the valve-in in-star type is provided wherein a stationary valve member (17) is disposed immediately adjacent the gerotor gear set (19). The stationary valve member defines a shuttle bore (81) and disposed therein is a shuttle member (107) which moves between two operating positions (FIGS. 6 and 7) under the influence of system pressure. The shuttle valve member (107) communicates system pressure from whichever of the ports (39 or 41) is at high pressure to a pressure balancing recess (63). At the same time, the shuttle valve (107) provides fluid communication between whichever of the ports is at low pressure and a low pressure passage (83) which may be in communication with a lubrication circuit (95), or may be in communication with a case drain port, to divert a small amount of fluid to a heat exchanger.

Abstract: A rotary positive displacement hydraulic machine such as a gear pump or motor, comprises a housing defining two mutually intersecting parallel working chambers, two meshing rotors mounted for rotation in the two chambers, respectively, and two bearing supports at opposite ends of the parallel chambers and each supporting bearings in which the two rotors are journalled for rotation. The housing is open at one or both ends. The or each open end of the housing has a hollow, non-circular spigot which is received in a recess of matching non-circular shape defined by a continuous flange projecting from a peripheral region of a respective bearing support in a direction parallel to the axes of rotation of the meshing rotors and which is surrounded by a shoulder extending from the spigot to the peripheral edge of the housing, so that the or each open end of the housing is supported by its bearing support against outwards movement in a plane transverse to the axes of rotation of the meshing rotors.

Abstract: A rotary hydraulic device that includes a housing with support plates mounted against rotation. A pair of pressure plates are mounted on the support plates and cooperate with a surrounding cam ring to form a rotor cavity. A rotor is disposed for rotation with the rotor cavity, and has vanes that radially engage the surrounding surface of the cam ring. A circumferentially continuous hydrostatic pressure pool is formed between each pressure plate and its adjacent support plate for balancing and/or slightly exceeding the forces in the pump cavities that tend to separate the pressure plates. An isolated area within each hydrostatic pressure pool intermittently communicates with the pumping chambers through timing passages in the rotor. Fluid flowing to this isolated area may be employed to form a supplemental hydrostatic pressure pool for enhanced axial balance on the pressure plates, and/or for directing discharged flow through multistaged orifices to precompress the fluid volume to be displaced.

Abstract: A pump having a pair of intermeshing gear members retained in first and second bushings located in a cavity for pressuring a fluid from an entrance pressure to a desired exit pressure. The first bushing has a passage located therein which communicates a selected pressure less than the exit pressure which acts on an outer face of the first bushing to develop a clamping force which urges an inner face on the first bushing into engagement with the intermeshing gear members and the intermeshing gear member into engagement with an inner face on said second bushing to seal the entrance chamber from the exit chamber.

Abstract: The machine includes at least one set of two cooperating pinions rotating between two mobile bearing flanges which are mobile in translation in cavities provided in a median casing closed on the two opposite sides thereof by anterior and posterior covers. Each of these two bearing flanges is substantially pressure equilibrated by a suitable sealing system arranged between this bearing flange and the adjacent cover. The bearing flanges supporting the pinions are floatingly mounted inside the median casing, and pressure means are provided to press the bearing flanges against the median casing and cause a differential pressure pressing the bearing flanges against side faces of the pinions.

Abstract: A seal device for a gear pump, whose gear case (1), rotatably containing a pair of gears (2), (3) meshing with each other therein, is closed by side plates (4) at both sides thereof interposing seals (5) therebetween, wherein the seal (5) is formed of a plurality of annular parts (5.sub.1), (5.sub.2), projections 5a) formed on the annular parts (5.sub.1), (5.sub.2), a connecting part (5c) for connecting the annular parts (5.sub.1), (5.sub.2), and a notch (5d) formed on at least one side of said connecting part (5c). Thanks to a structure as above, even when a tensile force acts on the connecting part during the use of the device, cracks concentratedly develop at the notch (5d) and are prevented from developing at the other parts, whereby oil leakage can be prevented.

Abstract: A liquid dispensing system utilizes a microprocessor based electronic control and a positive displacement gear pump to accurately meter predetermined batches of liquid pumped from a supply tank. The gear pump is driven by a reversible motor through a gear reducer, and is operative to pump a predetermined fixed volume of liquid for each revolution or fraction of revolution of the pump drive shaft. A passive magnetic sensor is positioned adjacent the toothed periphery of a target wheel, which is mounted on the motor shaft, and generates a signal representative of the amount of rotation of the pump drive shaft. The electronic control is responsive to this signal for calculating the total volume of liquid dispaced by the pump. The electronic control includes a keyboard which enables a user to preprogram the precise amount of liquid to be dispensed.

Abstract: In a generator-receiver for power transmission, side plates are molded on an insert with a good coefficient of friction whose outer face is flush with the inner face of each side plate and which comprises two circular parts joined by a bi-concave joint, the insert comprising grooves in each of which the plastic material constituting the side plates penetrates to form a bead in which each cavity is formed.

Abstract: A gear pump having improved low-temperature operation includes a housing with a cavity wherein is rotatably received a pair of meshed pinion gears. A pair of bushing members matched in external shape to a projection of the pair of gears and complementary to the housing cavity alone journal the pair of gears. The bushings and gears are freely movable relative to the housing at all operating temperatures for the pump, and the bushings are urged by fluid pressure forces into sealing cooperation with the gears and with the housing. The pump achieves an improved pumping volume by directing a trapped intermesh volume to the outlet port of the pump.

Abstract: A gear motor comprises two meshing gears and a pressure plate pressed against respective lateral surfaces of the gears by pressure in two substantially concentric separate pressure areas arranged on a side of the pressure plate remote from the gears. A control valve controls pressure in one of the pressure areas to adjust a contact pressure of the pressure plate on the gear in such a manner as to increase the contact pressure with an increase in working pressure.

Abstract: Hydraulic generator-receiver with needle bearings (123) on the driving gear (9) and providing for play compensation between the end plates (21, 22) and the envelope (36), a leak return and a better supply of the pressure zone (34).

Abstract: A seal arrangement for a gear machine includes a thrust plate for reducing the cross face leakage of fluid from a high pressure side to a low pressure side of a gear machine. A first groove and a second groove are formed in the thrust plate for receiving a first seal assembly and a second seal assembly, respectively. The first groove generally defines the numeral "8" with lateral sides spaced from one another and includes a top segment and a bottom segment. Each of the segments has an extension at each of its ends. The second groove generally defines a geometric form located between the lateral sides of the first groove and has its center spaced generally equidistant between the top and bottom segments. The first groove and the first seal assembly are arranged to form four chambers. Three of these chambers confine pressurized fluid therein for each direction of rotation of the machine, thereby urging the plate toward localized sealing engagement with the gears of the machine.

Abstract: A gear machine includes a machine casing closed by two covers and within which two gear wheels provided on respective shafts supported by bushes are in mutual engagement. A compensation area for the axial thrusts to which a bush is subjected is defined between an elastic diaphragm installed between the bush and a cover, so that because of the clearance between the gear wheels and bushes rapid starting is possible even under load, whereas as pressure increases a corresponding flexure of the diaphragm towards the bushes occurs, so as to gradually narrow clearance while at the same time partially balancing the axial thrusts.

Abstract: A gear pump comprises two gears arranged in engagement with one another, a sealing plate arranged at one side of the gears and insignificantly movable relative to the latter, two pressure fields including a low pressure field and a high pressure field, and forming a narrowing at the side of the high pressure field such that pressure difference at the narrowing act on the sealing plate so as to lift the sealing plate from side surfaces of the gears starting from a predetermined number of revolutions of the gears which is determined by the narrowing.

Abstract: The gear machine comprises a housing in which two gears mounted on shaft journals mesh. The shaft journals are supported in bushing or eyeglass-shaped bearing members. Located between the latter and the lateral surfaces of the gears are sealing plates which are brought into sealing contact with the lateral surfaces of the gears by axially-acting pressure fields. Relief grooves are formed circumferentially in the outer circumference of the bearing members and are spaced from and adjacent to the sealing plates. These relief grooves communicate with the low-pressure sdide of the gear machine and attain an optimal sealing action.

Abstract: A thrust plate for a gear pump or motor which permits the use of high pressure fluid from the outlet side thereof to lubricate the trunnions and bushings therein. The thrust plates include two small bores which pass therethrough the which are in fluidic communication with the inlet side of the pump via the surface of the thrust plate that confronts the gears within the pump. The foregoing bores are also in fluidic communication with the bushings by means of associated slots in the opposite side of the thrust plate. The opposite ends of the bushings are in fluidic communication with fluid at atmospheric pressure. By minimizing the size of the foregoing bores and by allowing the passage of fluid through same to the inlet side of the pump via the gear tooth confronting surface of the thrust plate, pressure gradients are created across the trunnions and their associated bushings.

Abstract: An external gear pump and/or motor of floating-shaft type comprising a front cover, a back cover and a housing forming a cavity in which a pair of meshed gears are mounted, characterized in that the gear shafts are brought toward the high-pressure side by means of a sleeve which can float radially under the pressure of the hydraulic oil and meanwhile said sleeves are pushed against the ends of the gears under the pressure of the hydraulic oil so that radial floating is achieved without any additional floating means in an external gear pump and/or motor. Therefore, the size of high-pressure zone and thereby, the inherent radial force are reduced in the gear pump and/or motor according to the present invention. Furthermore, its structure is simplified and reliable and its production cost is reduced.

Abstract: A gear pump or motor comprises a pair of rotary gears which are in external meshing engagement with each other. A thrust plate is pressed against the side faces of the gears by means of a plurality of pressure areas which are produced by means of a sealing and compensating unit. The unit is urged piston-like by virtue of fluid pressure chambers against the back of the thrust plate to engage it against the gears. Depending on the direction of rotation of the gears of the machine the pressure areas define the general configuration of a 3 or a .epsilon..

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: In a volumetric blade pump for fluid-hydraulic actuation, provided with a blade-bearing rotor and with a stator of annular shape mounted around the rotor, for the closure of the stator, on at least one side of the stator, a couple of plates are provided, of which one, stationary, rigidly constrained at the outside of the stator side, and the other, movable, positioned inside the stator between the stationary plate and the rotor; on both faces of the movable plate the delivery pressure of the pump is active.

Abstract: A hydraulic fluid seal, a pressure plate and gear pump are provided in which two spaced adjacent surfaces are sealed, one surface having a groove opening toward the other surface, a sealing member adapted to fit in said groove and a plastically deformable interference member in the sealing member having a section such that it will plastically deform before the seal surface of the sealing member.