Abstract: A hydrostatic axial piston pump has adjustable swept volume and is configured for fluidic connection to a hydraulic motor of a hydrostatic propulsion drive in a hydraulic circuit. The hydrostatic axial piston pump includes an adjusting unit configured to adjust the swept volume. The adjusting unit has an actuating cylinder with a first actuating pressure chamber, in which a first actuating pressure can be set via a first pressure reducing valve. The first actuating pressure is dependent on a first current at a first electromagnet of the first pressure reducing valve. An electronic control device is configured to store a model of the first current in a manner which is dependent on a requested speed.

Abstract: The present invention relates, in particular, to a forging hammer comprising a striker and a hydraulic linear drive that is coupled to the striker and is designed to drive the striker, which drive comprises a hydraulic circuit having a servo-motor hydro pump, a hydraulic cylinder, in particular a differential cylinder, which is fluidically connected downstream of the hydro pump via a directional valve module, and a servo-motor hydro generator, which is fluidically connected downstream of the hydraulic cylinder via the directional valve module, and comprising in addition a control unit configured at least for the simultaneous control of the hydro pump, the hydro generator and the directional valve module.

Abstract: The present invention relates to devices and methods for controlled motion of a tool. In one embodiment, the device can support a tool needed to perform an activity requiring a highly-precise, stable motion, while also accommodating a person's hand for the purposes of moving the tool. In another embodiment, the device of the present invention allows for rotational motion of a tool independently of the directive motion of the tool. In yet another embodiment, the present invention relates to the design of a force transducer useful in a cooperative robot. The device and methods of the present invention are particularly useful for microsurgery or other tasks that are typically performed using cooperative robotics.

Abstract: The present invention relates to a hydraulic-assistance system for motor vehicles, comprising a primary motor (M) and two hydraulic machines (140; 240, 250) connected by a hydraulic circuit such that when a first hydraulic machine (140) operates as a pump, the second hydraulic machine (240, 250) operates as a motor.

Abstract: A cell stack comprising an electrochemical cell, or a plurality of axially arranged electrochemical cells, with an end plate at each end of the stack, each cell comprising an active area surrounded by a peripheral area, wherein the active area comprises the membrane electrode assembly, and the peripheral area includes one or more channels for reactants, and wherein the stack comprises means for applying pressure axially to the active area to contact the membrane and electrodes, and separate means for applying pressure axially to the peripheral area. Further, a method of performing an electrochemical reaction in a cell comprising an active area surrounded by a peripheral area, comprises applying pressure to the active area, and varying the pressure during operation of the cell, wherein the active area includes the membrane electrode assembly and is the area where the cell reaction occurs.

Abstract: A method of manufacturing an absorbent article includes feeding a first web of material in a machine direction, feeding a second web of material in the machine direction, the second web being spaced from the first web by a gap, attaching an absorbent assembly to the first web and the second web such that the absorbent assembly spans the gap between the first and second webs, forming a partial cut line through the second web, folding the first web into face-to-face relationship with the second web after forming the partial cut line, and cutting the first and second webs after folding the first web into face-to-face relationship with the second web to separate the absorbent article from the first and second webs. The partial cut line defines at least one finger tab on the absorbent article.

Abstract: The present invention relates to devices and methods for controlled motion of a tool. In one embodiment, the device can support a tool needed to perform an activity requiring a highly-precise, stable motion, while also accommodating a person's hand for the purposes of moving the tool. In another embodiment, the device of the present invention allows for rotational motion of a tool independently of the directive motion of the tool. In yet another embodiment, the present invention relates to the design of a force transducer useful in a cooperative robot. The device and methods of the present invention are particularly useful for microsurgery or other tasks that are typically performed using cooperative robotics.

Abstract: According to one embodiment, a radial fluid device comprises a cylinder block, a first plurality of pistons, a second plurality of pistons, a first cam, a second cam, and a cam rotation device. Each of the first plurality of pistons are slidably received within a different one of a first plurality of radially extending cylinders. Each of the second plurality of pistons are slidably received within a different one of a second plurality of radially extending cylinders. The first cam is disposed about the first plurality of radially extending cylinders. The second cam is disposed about the second plurality of radially extending cylinders. The cam rotation device is coupled to the first cam and the second cam. The cam rotation device is operable to rotate the first cam in a first direction and the second cam in a second direction.

Abstract: An arrangement for a hydraulic eccentric adjustment for setting a predetermined displacement volume in a hydrostatic motor and, in particular a radial piston motor (1). The arrangement has an adjustment device which, to position an eccentric element (2), can be acted upon with pressure medium via a shuttle valve (5) such that at least one actuating piston (19), of an adjustment cylinder (3) that can be acted upon on both opposed sides is provided, as the adjustment device. A first pressure chamber (7) of the cylinder is connected to a first supply line (9), for setting a smaller displacement volume while a second opposed pressure chamber (8) is connected to a second supply line (10), for setting a larger displacement volume. The two supply lines (9, 10) are connected to one another by a connecting line (11).

Abstract: A control device for controlling a speed of a hydraulic motor includes a housing defining a first void. A speed valve is disposed within the first void and is moveable between a first speed valve position and a second speed valve position. The first void includes a speed valve pressure chamber disposed at one end of the speed valve. A speed valve spring is disposed at another end of the speed valve. The housing further defines a speed change port and a speed change passage interconnecting the speed change port and the speed change pressure chamber for directing a pressurized fluid directly into the speed valve pressure chamber to exert a pressure force on the speed valve and bias against the speed valve spring to move the speed valve between the first speed valve position and the second speed valve position.

Abstract: The present invention provides a hydraulic pump for use in driving a load with a control modulation system which modulates a primary control signal in order to accommodate variations in secondary changeable parameters which require control at a higher frequency or have a lower latency.

Abstract: A radial cylinder hydraulic motor having continuously variable displacement capabilities includes: oscillating hydraulic cylinders which are driven to oscillate through an eccentric crankpin formed on the motor shaft and carrying a radially movable ring adapted to be shifted along the radial direction of the crankpin by actuation of opposed counteracting hydraulic cylinders housed within the crankpin; a hydraulic control circuit for controlling and adjusting the positions of said counteracting hydraulic cylinders in a continuous manner; an electronic control circuit adapted to control the hydraulic control circuit and process signals from at least one position sensor arranged to detect the positions of said oscillating cylinders; a rotary joint for hydraulic conduits through which said counteracting hydraulic cylinders are controlled and adjusted.

Abstract: The present invention is directed to a rotary engine power transmission system for use in vehicular as well as other applications. The power system includes a rotary engine or pump, which may be pneumatic or hydraulic in configuration. The power system includes components whose purpose is to convert rotational force into pneumatic or hydraulic pressure where that same fluid pressure can be reconverted back into rotational force. This conversion can be from a source to a driven component, or from the driven component back to the same source for use, for example, in vehicular applications for use. One purpose in a vehicular specific application is to convert rotational source energy into rotational power at the vehicles wheels, for acceleration, and to reverse this process to recapture deceleration losses.

Abstract: A radial cylinder hydraulic motor having continuously variable displacement capabilities comprises: oscillating hydraulic cylinders (1) which are driven to oscillate through an eccentric crankpin (2) formed on the motor shaft (3) and carrying a radially movable ring (14) adapted to be shifted along the radial direction of the crankpin by actuation of opposed counteracting hydraulic cylinders (5, 6, 7) housed within the crankpin; a hydraulic control circuit for controlling and adjusting the positions of said counteracting hydraulic cylinders in a continuous manner; an electronic control circuit adapted to control the hydraulic control circuit and process signals from at least one position sensor arranged to detect the positions of said oscillating cylinders; a rotary joint (8) for hydraulic conduits (9, 10) through which said counteracting hydraulic cylinders are controlled and adjusted; wherein the sensor (45) is an angular position sensor placed close to the oscillation axis (C) of at least one oscillating c

Abstract: The invention relates to a radial piston hydraulic motor (100) and to a method in the control of a radial piston hydraulic motor. The radial piston hydraulic motor (100) includes a free rotation valve (50) which is built inside it and includes a spindle (19). The spindle (19) is disposed in a spindle cavity (20) and it is movable in the spindle cavity (20) such that, in a free rotation situation, shoulders of the spindle (19) block the inlet and outlet passages of working pressure. In a free rotation situation, springs (U1, U2 . . . ) press pistons (13a1, 13a2 . . . ) and press rollers (14a1, 14a2 . . . ) associated therewith to a bottom position and out of contact with a cam ring (11).

Abstract: The invention concerns a radial piston hydraulic engine (10), which includes a rotated box section (11), with which box section (11) a cam ring (12) is connected. The radial piston hydraulic engine (10) includes a fixed non-rotary shaft (14), with which a cylinder body (15) in a fixed position is connected. The radial piston hydraulic engine includes a distributor (13), which is connected with the box section (11) and rotates together with it, whereby through channels located in the distributor a pressurised medium is conducted to pistons (16a1, 16a2 . . . ) of cylinders (P1, P2 . . . ) controlled by the distributing valve, that is, by distributor (13), and that at least some cylinders (P1, P2 . . . ) include in connection with themselves a shut-off valve (70a1, 70a2 . . . ), which is used to make some pistons (16a1, 16a2 . . . ) inoperative.

Abstract: The present invention relates to a pump, more particularly a radial piston pump, including at least two pump pistons (10) with an associated working chamber (13) each, wherein the working chambers (13) are connected to suction lines (4) by way of suction valve devices (8) and to a joint pressure line (5) by way of pressure valve devices (9), wherein at least one of the suction valve devices (8) opens during the pressure stroke in dependence on the pressure in one of the associated lines (4, 5), and wherein at least one of the suction valve devices (8) opens during the pressure stroke in dependence on the pressure in the pressure line (5).

Abstract: An adjustable rotor and/or a radial piston machine which may utilize an adjustable rotor. The rotor has a primary eccentric rotatable around an axis and a secondary eccentric adjustable in position relative to the primary eccentric. The radial piston machine includes a plurality of piston cartridges arranged radially around the axis and both high pressure and low pressure fluid distribution systems. Multiple units may be axially coupled. A single unit may handle a variety of fluids in various combinations.

Abstract: A cooperating rotor device having a first rotor supported for rotation about a first rotation axis (R1) and a second rotor supported for rotation about a second rotation axis (R2). A cylinder rotor (32), supporting a plurality of radially aligned cylinders (33) spaced apart and supported for collective rotation about one rotation axis (R1). Each cylinder (33) having a piston (39) slidable within. A piston rotor (61) has a number of piston rollers (64) corresponding to the number of cylinders (33), each radially supporting a piston (39), with each piston roller (64) independently rotatably supported and all piston rollers (64) collectively rotatable about the other rotation axis (R2). Members including the piston rollers (64), pistons (39), cylinders (33), and cylinder ports (34), all sharing a common plane of rotation about diametrically opposed non-rotating valve ports (74a) and (74b).

Abstract: A radial piston hydrostatic machine having an outer housing structure and defining an internal chamber, a drive-shaft supported in the housing and operatively connected to the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons bear on the track-ring, the track-ring eccentrically position within the internal chamber by means of fixed abutment means in the housing, the abutment means disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and thereby suppressing vibration emanating from the track-ring.

Abstract: A neutral by-pass for hydraulic fluid in a hydrostatic transmission is provided by an essentially closed conduit comprising a pair of bores and a channel communicating the pair of bores, all formed in the cam ring of the transmission. When the neutral point is attained, the bores will be communicated with oil dampening pistons in communication with the hydraulic fluid supply passages and the fluid pressure between the passages will be equalized. This will operate from either the forward or reverse direction. As the cam ring is angularly moved, essentially closed conduit is moved away from the dampening pistons, so there can be no fluid flow therethrough. When this occurs, all fluid flow goes to the motor rotor, causing output rotation.

Abstract: A hydrostatic radial piston machine 10 is proposed, whose adjustable reciprocating ring 18 has integrated means for detecting the eccentricity 20 between the reciprocating ring 18 and the rotor 14. In combination with the rotating rotor 14 and the binding of the sliding blocks 17 to this reciprocating ring 18, the eccentric location of the reciprocating ring 18 leads to a reciprocating motion of the work pistons 16 in a radial direction. Together with the kinematic conditions in the radial piston machine 10, this leads to a change in the spacing between two successive sliding blocks 17. This change in spacing varies in proportion to the eccentricity 20 of the reciprocating ring 18 and is therefore detected by a measuring instrument. To that end, this measuring instrument has a measured value pickup 27, which is integrated in the reciprocating ring 18 and outputs an increased voltage signal as long as sliding blocks 17, which act as measured value transducers, move past it.

Abstract: A radial piston hydrostatic machine having an outer housing structure comprising at least two housing elements connectable together along a parting-plane arranged perpendicular to the rotational axis of said drive-shaft to define an internal chamber, a drive-shaft supported in the housing to drive the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons can bear on the track-ring, fixed abutment means in the housing and disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and suppressing vibration emanating from the track-ring.

Abstract: A radial piston hydrostatic machine contained within a housing and comprising a cylinder-barrel mounted to rotate on a pintle-valve fixed to said housing. Two hydraulic-rams operatively acting on a track-ring to provide eccentric displacement relative to the pintle-valve to change the rate of fluid output from the machine. The hydraulic-rams being of unequal size and subjected to the same level of machine discharge pressure during periods when the level of discharge pressure is insufficient to cause an internally disposed pressure relief-valve to "open". A throttle-valve disposed in a fluid channel linking the cylinders of said hydraulic-rams and arranged to introduce a pressure differential across two said two cylinders during periods when the machine discharge pressure is sufficiently high to cause said pressure-relief-valve to "open".

Abstract: A hydrostatic displacement machine has in a revolving cylinder block several displacement elements movable in a guideway and having a radial position during the rotation of the cylinder block determined by a nonrotating displacement ring. The displacement elements, viewed axially, are retained on the displacement ring by two retaining rings. The retaining rings feature relative to the displacement ring a radial seal. The axial seal of the retaining rings is effected in standstill, relative to the housing or housing lid, by way of spring elements, and during the pumping operation, by a contact force which is indirectly dependent on the operating pressure.

Abstract: A variable-stroke crank mechanism has a crankshaft rotatably supported in a casing for relative rotation about an axis with a crankpin displaced out of alignment with the axis. An eccentric collar is rotatably mounted on the crankpin for revolving around the axis in response to the relative rotation of the crankshaft with respect to the casing to reciprocally move an actuator relative to the casing. A stroke adjusting mechanism for adjusting angular displacement of the eccentric collar on the crankpin comprises an internal ring gear integral with the eccentric collar concentrically with the crankpin, a planetary pinion rotatably mounted on the crankshaft and meshing with the internal ring gear, a sun gear meshing with the planetary pinion, and a stroke adjusting shaft rotatably disposed axially in a portion of the crankshaft and coupled to the sun gear, whereby the stroke adjusting shaft is adjustable in angular displacement to adjust a stroke of reciprocating movement of the actuator.

Abstract: A variable displacement radial ball pump (11) is disclosed of the type in which the balls (59) are restrained by a cam ring (25), which is pivotable about a cam pivot pin (27) to vary the displacement of the pump. In accordance with the invention, in order to return the pump to absolute zero displacement, the pump is provided with a detent mechanism (65;83). The cam ring 25 has a neutral region (73) and a ramp surface (77), and a detent member (69;89) is biased into engagement with the neutral region when the cam ring is in neutral (FIGS. 2 and 3). When the cam ring is displaced from neutral, the detent member engages the ramp surface, against the bias force of a spring (71;91), which exerts a force tending to return the cam ring to neutral in the absence of an input to the control assembly (33).

Abstract: A rotary reciprocating engine has a rotating center shaft and a rotating outer rim with a rotational eccentricity in relation to the center shaft. The engine has a synchronization mechanism including a synchronizing hub, a guide rail, one cam member fitted to the center shaft, and another cam member fitted to the outer rim. The synchronization mechanism has the same rotational eccentricity in relation to the center shaft as the outer rim, but the rotational axes of the synchronization mechanism and the outer rim are on opposite sides of the rotational axis of the center shaft. The synchronization mechanism restrictively guides rotation of the center shaft and the outer rim, and transfers and balances the forces and moments generated by the pressure medium in the engine, leading to the pistons and cylinders being subjected to axially directed forces only and not moment transferring cross head forces.

Abstract: The invention relates to a mechanism comprising: a cam; cylinders; pistons; two main enclosures containing feed fluid and exhaust fluid; a fluid distributor; and balancing enclosures communicating with distribution ducts included in the distributor. According to the invention, the distributor includes a face facing a reaction face secured to the cam or to the cylinder block, the balancing enclosures being constituted by chambers that open out into said end face and by a sealing device received inside the chamber and bearing against the reaction face. One application lies in providing a range of compact motors.

Abstract: A hydrostatic pump and motor combination is disclosed including a rotor having radially disposed cylinders containing reciprocatably disposed spherical balls therein. A free outer race is eccentrically disposed about the rotor to define either a pump or motor. The cylinders are tilted relative to the center of the rotor to reduce side torque thrust loads on the cylinders. Also disclosed are a hydrostatic pump and motor including matching spherical slipper shoes and spherical free outer race. Hydrostatic thrust cups are disposed within the cylinders to reduce frictional losses, wear, and leakage. The thrust cups include hydrostatic means for supporting the balls in the cylinders, thereby self adjusting in response to fluid pressure and centrifugal loads.

Abstract: A fluid pressure independent, mechanically controlled dampener for a hydrostatic transmission pump track ring is shown. In one embodiment, two opposing wedge-shaped blocks are biased against each other by a spring-loaded bolt. A pad, axially adjacent the track ring on one side and axially adjacent and held together with one block by a Z-bracket on the other side, is biased against the track ring by pressure exerted through the spring-loaded bolt and wedging action of the opposing wedges. In another embodiment, a spring-loaded piston disposed within a spring housing, exerts pressure against a first pad axially adjacent the track ring to hold the track ring against another pad axially adjacent and opposite the first pad.

Abstract: A neutral centering spring mechanism (71) is provided for a variable displacement hydrostatic pump (25) of the type of which control of the displacement occurs in response to rotation of a control shaft (101;101'). Disposed about the control shaft is a pair of preferably identical actuator members (111,113), each of which is in engagement with a pin (115) such that clockwise rotation of the control shaft rotates one actuator member (111) while counter-clockwise rotation of the control shaft rotates the other actuator member (113). Each actuator member defines a movable stop surface (131,137), which are in engagement with fixed stop surfaces (133,139). A single torsion spring member (121) surrounds the actuator members, biasing both actuator members toward the neutral position.

Abstract: The improved hydrodynamic variator of velocity comprises a pump (3) having radial pistons and a hydromotor (4) also having radial pistons. At least the pump is arranged with a variable eccentricity and there is provided a central body (56) the latter having frontal distributors (30 and 31) which are placed in communication with the radial cylindrical cavities respectively of the pump and the hydromotor by means of the openings of the conduits (32 and 33). By varying the eccentricity of the pump, the rate of flow of the liquid in the pump is varied, thus causing a variation in the number of turns of the hydromotor.

Abstract: A hydrostatic transaxle has a hydrostatic transmission, including a pump in fluid communication with a motor, the pump including a track ring for eccentrically varying radially displaceable pistons. A control mechanism for the pump is disposed adjacent to the axle assembly on the inboard side of the transmission. The pump track ring pivots about a pin disposed through one end of the pump track ring so as to be eccentrically adjustable about the pintle. The pin is located on the outboard side of the transmission or remote from the axle assembly, and is clampingly held between the portions of the transmission housing having casing bolts extending on either end therethrough.

Abstract: A drive comprising a first group of cylinders of a radial hydraulic pump, rotating in relation to the drive frame about a first axis, and torsionally integral with the input shaft of the drive and with a housing inside which the first group of cylinders rotates; a second group of cylinders of a radial hydraulic motor, rotating in relation to the frame about a second axis; an output shaft, the axis of which is located between the aforementioned axes, and which is integral with a gear meshing with a gear integral with the housing in which the first group of cylinders rotates, and with another gear integral with the second group of cylinders; a mechanism for varying displacement of the first and second group of cylinders; and a distributing mechanism for alternately connecting the cylinders in the first group with those of the second group.

Abstract: A pump/motor control mechanism comprising a first actuator for actuating forward a forward/backward member when a fluid pressure is introduced into a first cylinder chamber located in the forward/backward member, a second actuator for actuating backward the forward/backward member when a fluid pressure is introduced into a second cylinder chamber located in the forward/backward member at a position oppositely facing the first actuator, a spool holding hole which is provided in the forward/backward member and has an axis center parallel to the forward/backward direction, a spool which is slidable fitted in the spool holding hole and has on its outer periphery a high-pressure groove connected to a high-pressure fluid source and a low-pressure groove opened to a low-pressure zone, input means for driving forward or backward the spool, a first pressure introducing path whose one end is connected to the first cylinder chamber and whose other end is opened to an area which is on the inner periphery of the spool hol

Abstract: In a radial piston hydraulic motor of the "star-shaped" type the variation of the cylinder capacity is achieved by the fact that the motor crankshaft is provided with a mechanism which varies the eccentricity, this mechanism being powered by hydraulic actuators carried by the shaft and controlled by a circuit external to the frame of the motor, comprising a rotating coupling and stop valves, while stability of the cylinder capacity may be obtained by means of locking mechanisms carried on the shaft.

Abstract: In a radial piston hydraulic motor of the "star-shaped" type the variation of the cylinder capacity is achieved by the fact that the motor crankshaft is provided with a mechanism which varies the eccentricity, this mechanism being powered by hydraulic actuators carried by the shaft and controlled by a circuit external to the frame of the motor, comprising a rotating coupling and stop valves, while stability of the cylinder capacity may be obtained by means of locking mechanisms carried on the shaft.

Abstract: In an apparatus for controlling the operation of hydraulic motors having infinitely adjustable eccentricity, wherein a flow-control valve between a pump and a hydraulic motor supplied with pressure medium and a control valve for adjusting the eccentricity of the hydraulic motor as a function of the operating pressure required by the hydraulic motor are provided, in connection with pressure optimization for keeping constant the torque of the hydraulic motor, the hydraulic motor is provided with a regulating device (7,10) which is mechanically connected to the eccentric (3) and transmits an eccentric adjustment outward, wherein this mechanical regulating device (7,10) acts on the flow-control valve (17) in such a way that, as a function of the change in the eccentricity, the flow-control valve (17) controls the pressure-medium quantity supplied to the hydraulic motor in such a way that the speed of the hydraulic motor is kept constant.

Abstract: A hydrostatic displacement engine having pistons which slide on the inside of a stroke ring. The eccentricity of the stroke ring, relative to the cylinder block, is variable. The interior of the housing is divided in two areas which are separated from each other preferably by a seal, namely in the area located radially outside the stroke ring and the area located radially within the stroke ring. The inner and outer areas serve as a leakage oil collection space and connects through a leakage oil line with a pressureless liquid container. Emptying in the area situated radially outside the stroke ring is a connection line which is supplied by a pressure supply. A pressure valve maintains the pressure in the outer area at a value of several bars.

Abstract: Radial piston machine as a fluid pump or fluid motor comprising an inner valving trunnion, an outer cam ring and at least a cylinder block arranged therebetween and having reciprocating pistons, which tilt when the cylinder block rotates. The pistons have spherical heads and crowned piston rings along the biggest diameter or equator in order to create each an oblique sealing plane when the respective piston is tilted. Pressure in each chamber limited by said oblique sealing plane will give rise to a direct transformation of torque and fluid pressure. The valving trunnion has enlarged sealing fields to get a precompression of the fluid between high and low pressure fluid areas in order to avoid excitation of noise. The machine design can be for constant or variable displacement. In case of variable displacement, the sinusoidal curve of piston travel is adjusted for a variable preceeding angle (.epsilon.) by adding a constant eccentricity (c) so that the angle of the separation (.tau.

Abstract: A variable-stroke crank mechanism includes a crankshaft rotatably mounted in a casing and having an eccentric crankpin, and a plurality of fluid pressure actuators disposed substantially radially with respect to the crankshaft, for pressing the eccentric crankpin to rotate the main shaft and the casing relatively to each other. The fluid pressure actuators are selectively supplied with a working fluid. An eccentric collar is rotatably mounted on the crankpin and operatively coupled to the fluid pressure actuators. The eccentric collar having an axis which is eccentrically displaced with respect to the axis of the crankpin. The crankpin and the eccentric collar are arrested in their respective angular positions by intermeshing internal and external gears. The crank mechanism may be incorporated in a plunger-type hydraulic unit, which may also be incorporated in a hydromechanical continuously variable transmission.

Abstract: A hydraulic pump/motor in which working piston elements are arranged for radial reciprocation. A cam is arranged eccentrically to a rotor which carries the pistons. Fluid cavities are provided in feet on the pistons, in the faces of a polygon to which the feet are attached, and in bearing pads in the outer ends of the cylinders to provide hydrostatic balancing. The pistons are hollow and are equipped with check valves to prevent centrifugal force from expelling fluid from the polygon and foot cavities. The cam includes mating spherical surfaces which compensate for bending forces applied to the cam. An improved mechanism for adjusting the cam position uses inherent forces to eliminate the need for a power assist device for cam adjustment. Port plates on opposite sides of the rotor provide inlet to the unit near the axis of the unit and outlet near the outer edge to alleviate stresses and increase efficiency.

Abstract: The present invention is a neutral shifting mechanism for a hydrostatic transmission. A motor track ring has a groove and cam slot for receiving a control rod of the transmission, with the control rod having a cam portion for engaging the cam slot to lock the track ring in a position concentric with the pintle of the hydraulic motor, i.e. a neutral position. In the normal position, the cam portion positions the track ring eccentrically, allowing a speed control shaft to shift the hydrostatic transmission by pivoting the pump track ring about the control rod.

Abstract: In a radial piston hydraulic motor of the "star-shaped" type the variation of the cylinder capacity is achieved by the fact that the motor crankshaft is provided with a mechanism which varies the eccentricity, this mechanism being powered by hydraulic actuators carried by the shaft and controlled by a circuit external to the frame of the motor, comprising a rotating coupling and stop valves, while stability of the cylinder capacity may be obtained by means of locking mechanisms carried on the shaft.

Abstract: The present invention is an expander band for use in hydraulic pumps, motors, and hydrostatic transmissions. The band has a plurality of elongated slots located circumferentially which receive slippers attached to pistons. One reduced dimension slot fixes the position of a slipper relative to the expander band while the other slippers move within the elongated slots. The fixed slipper limits the range of movement of the other slippers relative to the band, and thus the slippers avoid abutting the side ends of the elongated slots.

Abstract: A variable displacement, rotary fluid pressure pump (11) is disclosed of the type having a cam ring member (25) which is movable, in response to rotation of a control shaft (35), between a neutral position (FIG. 5) and a displaced position (FIG. 4). The pump housing (13, 15) includes a support member (25), and they cooperate to define a high-pressure fluid passage (51). In communication with the passage (51) is a recess (71), in which is disposed a dampening shoe (73). The dampening shoe is biased by high-pressure fluid in the passage (51) into engagement with an adjacent surface (77) of the cam ring (25). The surface (77) defines a neutral fluid passage (79), and the dampening shoe (73) defines a restricted opening (85).

Abstract: A radial piston hydraulic motor includes an in-board computer which permits monitoring and control of various operating parameters. A position code disc is associated with the shaft of the motor by means of which the position of the drive cam on the shaft, relative to the individual piston can be sensed and fed to the computer. The motor is of high versatility and performance.

Abstract: A neutral centering mechanism (15) is disclosed of the type which may be used with a variable pump (11) of the type including a control shaft (33) rotatable about its axis of rotation (35) from a neutral position to first and second operating positions (FIGS. 12 and 13). A control handle (61) is rotatably fixed to the control shaft. The centering mechanism includes a stop plate (41) defining a fixed stop surface (43) and a spring plate (49) which is rotatable about the axis of rotation and defines a movable stop surface (79) in engagement with the handle (61) in the neutral position. The stop plate includes an adjustment screw (45) which adjusts the rotational position of the spring plate to a position in which the movable stop surface is disposed for neutral centering of the control handle and control shaft. A spring (59) biases the handle toward the movable stop surface, when the handle is rotated away from neutral to a first operating position.

Abstract: A radial piston pump for the automotive brake system has a rotor, a couple of pistons reciprocated within a respective cylinder formed within the rotor and a bearing. The top end of the piston abuts directly to the inner surface so that no show is existed therebetween. The relationship within a starting point and a finishing point of a suction groove, a starting point and a finishing point of a disharge groove and an opening port the cylinder is designed in such a manner that at least one of a couple of cylinders connects to the suction groove during a whole rotation of the rotor.