Abstract: There is disclosed a hydrostatic axial piston machine having a pulse reduction device. This device has a connection location or tap in the transition region in front of the high-pressure-side kidney-like elongate hole of a distributor plate. The connection location or tap is connected by means of one or two hydraulically passively controlled switching valves to a high-pressure store. It is used for precompression and consequently for the pulse reduction. In a development, the distributor plate also has a connection location or tap in the transition region behind the high-pressure-side kidney-like elongate hole. The connection location or tap is connected via one or two hydraulically passively controlled switching valves to a low-pressure store. This is used for the decompression and consequently also for the pulse reduction.

Abstract: The disclosure relates to a hydrostatic axial piston machine having a housing, having a drive shaft, to which a flange disc is fastened in a rotationally fixed manner, and having a swash plate, to which a rotor disc, driven by the drive shaft or the flange disc, is rotatably mounted, and having a plurality of displacement units arranged distributed between the flange disc and the rotor disc and around the axis of the drive shaft, each displacement unit comprising a cylinder sleeve and a piston which extends into the cylinder sleeve and has a ball head and a spherical joint head which extends into the cylinder sleeve, wherein during operation, the piston plunges more or less far into the cylinder sleeve.

Abstract: A pump control system and a torque control valve are disclosed. In one embodiment, the torque control valve includes a sleeve, a spool disposed in the sleeve, and a piston rod disposed through the spool. The spool has a first recess area, a second recess area, and a third recess area. The first and third recess areas each have a port extending into a central bore of the spool. The piston rod includes a groove orifice feature having a spiral groove and is configured such that a fluid flowing from the port in the first recess area to the port in the third recess area must flow through at least a portion of the spiral groove. The fluid flowing through the spiral groove operates to bias the spool in a direction towards the second axial end of the spool.

Abstract: A hydraulic actuator unit includes a first electric motor assembly formed by mounting one of a pair of electric motors to one of a pair of electric motor covers, wherein the first electric motor assembly is detachably mounted to a pump case so as to rotate a first control shaft around its axis line, and a second electric motor assembly formed by mounting the other one of the pair of electric motors to the other one of the pair of electric motor covers, wherein the second electric motor assembly is detachably mounted to the pump case so as to rotate a second control shaft around its axis line.

Abstract: The invention relates to an axial piston machine of a kind that has a plurality of pistons each reciprocating in a respective cylinder in a direction substantially parallel or at an angle less than 30 degrees to a crankshaft axis. The crankshaft axis presents a crank that is at an angle to the crankshaft axis and to which a reciprocator is mounted. The reciprocator effects the controlled movement of the pistons in their cylinders via a connection mechanism that connects each said piston with said reciprocator. The machine includes at least one pair of rotational constraint mechanisms to constrain the movement between the reciprocator and the pistons.

Abstract: A regulating device for a hydrostatic piston engine is provided. The regulating device (30) has an electronic control unit (17) for generating adjusting signals. An adjusting position of the hydrostatic piston engine scanned by a feedback element (36, 61) is detected by a sensor element (42) of the electronic control unit (17) without contact.

Abstract: A pump/compressor that utilizes a wedge at a fixed angle to operate the pump's pistons at a fixed stroke. Alternatively the wedge can be moved axially to increase or decrease the clearance volume. Variable fluid flow at any clearance volume is achieved by rotating the wedge with respect to the port plate thereby changing the timing of the pistons with respect to the fixed port plate which changes the timing of the intake and output cycles. This results in a portion of the intake charge being breathed back into the intake port and a portion of the output charge being breathed back from the outlet port. This causes the pistons to not take in a full charge from the inlet port and to not pump out a full charge into the outlet port. Thus, fluid flow is varied. The design results in a smaller pump as the wedge is supported by the pump housing rather than a mechanical linkage required of prior adjustable angle swashplate designs.

Abstract: A link mechanism provided between a lug plate and a cam plate in a variable displacement compressor includes a first transmitting portion for transmitting rotation of a lug plate to a cam plate and a second transmitting portion for transmitting compression reactive force from the cam plate to the lug plate, which are arranged along a rotational direction of the drive shaft. The first transmitting portion includes a first transmitting surface and a first receiving surface. The link mechanism also includes a movement restrictor arranged between the first and second transmitting portions. The movement restrictor includes a restricting surface formed in the lug plate and a restricted surface formed in the cam plate and restricts the first receiving surface to move away from the first transmitting surface in the rotational direction of the drive shaft in such a manner that the restricted surface comes into contact with the restricting surface.

Abstract: A variable displacement hydraulic/pump motor has a yoke with a pair of shafts aligned to define a yoke pivot axis and connected to a valve plate therebetween having intake and discharge apertures. A rotatable cylinder barrel has piston cylinders open at one end to receive a piston head and opening through fluid ports at another end, flush against the valve plate surface. A drive block is mounted on an input/output shaft for rotation about a central axis of rotation inclined at an angle relative to the longitudinal axis of the cylinder barrel which may be changed by a drive engaging the yoke at a point near its pivot axis. Loads on bushings supporting the yoke shafts are reduced by providing radially extending fluid ports in the shafts and in communication with the intake and discharge apertures of the valve plate.

Abstract: In the case of a control plate for an axial piston machine having at least two control openings (31, 32), by means of which cylinder bores (9) of a cylinder drum (4) rotatably mounted in a housing (2) are alternately connected, on rotation of the cylinder drum (4), to a high-pressure connection and a low-pressure connection, an outwardly extending extension surface (40) is formed on a partial region of the outer circumference of the control plate (20), the extension surface being designed for defined bearing against a holding element (52, 53) of the axial piston machine (1) in order to achieve a rotation locking for the control plate (20).

Abstract: In a swash-plate type hydrostatic piston engine, a drive unit (10) and a swash plate (17) are received by a pot-shaped housing (1b). According to the invention, the pot-shaped housing (1b) is configured such that it is able to receive drive units (10a, 10b) of at least two rated quantities of a specific product series of the hydrostatic piston engine.

Abstract: To reduce the projection of a swash plate servo mechanism in the radial direction, and to make a hydraulic continuously variable transmission compact, a swash plate plunger pump includes a pump casing provided with an input driven gear. A pump cylinder and a motor cylinder are connected to a transmission output shaft, and a motor pivot member provided with a motor swash plate member is supported to be pivotally movable. A motor servo mechanism includes a ball screw shaft, a ball nut to which an end portion of the motor pivot member is connected, and a swash plate control motor to rotate the screw shaft. A swash plate control motor, located on the side of a hydraulic pump relative to the input driven gear, is mounted to the outside surface of a transmission housing close to the center axis side of a transmission output shaft.

Abstract: A dual tandem pump apparatus having a pair of coaxially arranged pump shafts and a separate input shaft that is not coaxial with the pump shafts. The trunnion arms for the two pumps may be mounted in different locations to increase application flexibility. Charge pumps may be mounted on end caps secured to the housing or may be driven directly by the input shaft. A coupler or bevel gear arrangement is used inside the pump housing to drive the pump shafts from the input shaft.

Abstract: A pump includes a stationary pump housing having a central longitudinal axis and a housing chamber, a rotating pump shaft extending through the pump housing and into the housing chamber, a rotating barrel fixed to the pump shaft and including a plurality of pump chambers, and a plurality of rotating and reciprocating pump pistons. Each pump piston is at least partially contained within a respective pump chamber. A fluid delivery control assembly is provided to selectively vary the amount of fluid delivered by the pump. At least one pressurized fluid pool is located between a portion of the rotating barrel and a portion of the pump housing. The pressurized fluid pool may be located along an end surface of the rotating barrel and/or along a side of the rotating barrel.

Abstract: A hydraulic unit has a drive shaft (52) mounted in a manifold block (54) and coupled to a torque plate (80) on a central axis. A bent axis motive unit (60) has a yoke connected to the manifold block supported for rotation on the yoke. Hollow pistons (100) in cylinders in the cylinder block allow fluid to flow through a torque plate into and form the manifold without the necessity for passing fluid through an articulating member that pivots the cylinder block.

Abstract: A stirling engine with variable stroke can change output power in the same rotating speed. By an adjuster, it changes the contact position of the piston connecting rods and the swash plate to cause the connecting rods have different track on the swash plate. Then there will produce different distance to change the stroke of the piston of the engine. It changes the torque to control the output power.

Abstract: A hydrostatic axial piston machine has a drum-like cylinder block which is supported in a manner fixed against rotation on a driving or output shaft and is provided concentrically and parallel to its center line with cylinder boreholes in which axially displaccable pistons are arranged which are supported via spherical heads on a slanting disk which is fixed to the housing and preferably adjustable in its slanting angle. The cylinder openings opposite the slanting disk sweep over roughly kidney-shaped low pressure and high pressure control openings of a control body, between which reversing regions with additional boreholes are located. To control the additional boreholes, which influence the pressure increase or the pressure drop on the passing of the cylinder openings over the reversing regions, in dependence on the operating states, a borehole opens at least in a reversing region of the control body which is connected to the high pressure side or the high pressure control opening by a line.

Abstract: A variable displacement compressor has a control valve for controlling the displacement of the compressor. When the pressure in a discharge chamber of the compressor (discharge pressure) is equal to or higher than a first threshold value, a controller executes a limiting control for limiting the discharge pressure. During the limiting control, the controller gradually decreases a duty ratio, which is sent to the control valve, such that the displacement of the compressor is gradually decreased. When the duty ratio is decreased to a reference duty ratio, the controller sets the duty ratio to zero %. As a result, the compressor displacement is minimized and the discharge pressure is lowered. Therefore, the pipes of an external refrigerant circuit does not receive excessive load based on high discharge pressure.

Abstract: A non-feedback proportional system is provided to achieve desired operating characteristics which will allow the control of a hydrostatic transmission to closely approximate the control performance of a displacement feedback control system by establishing certain parameters relating to (1) the servo spring rate; (2) the valve plate index; (3) valve plate crossport/trap; (4) valve plate porting geometry; (5) swashplate offset; and (6) piston bore volume.

Abstract: An inclined-axis variable displacement unit comprises an output shaft (1), mounted in a housing (4), and a cylinder block (10), the cylinder block (10) being connected to the output shaft (1) via a synchronizing articulation (18), and via working pistons (11) which can be displaced in the cylinder block (10), the cylinder block (10) being mounted in a pivoting body (5) which can be pivoted in relation to the axis of the output shaft (1) by an adjusting means, it being the case that the adjusting means is arranged on that side of the pivoting body (5) on which the output shaft is located.

Abstract: An electronic bore pressure optimization mechanism for dynamically varying the cylinder block piston bore pressure profile in a multiple piston hydraulic unit includes a valve means having a variable orifice disposed in the end cap for metering fluid between leading and trailing pistons in a transition region or between a piston in a transition region and a high or low pressure source; and means for generating a control error signal to the valve means so as to adjust the size of the variable orifice based upon the control signal.

Abstract: A variable displacement hydraulic power unit has a housing and a rotating piston block with a rotatable axis and a servo piston bore having a reciprocal piston therein with the bore extending in a direction parallel to the rotatable axis of the rotating piston block. The housing and servo piston each have adjacent open ends. A single integral cover is attached to the housing to cover close and close the open ends of both the housing and the piston bore.

Abstract: An axial piston compressor produces air supplied to an air system of a vehicle, typically a heavy duty truck through a plurality of pistons held within a stationary block, and the movement of the pistons is predicated through the control of a pivotal swash plate. The pistons are idle in a neutral position of the swash plate, wherein a pressure above the pistons in the cylinder block counterbalances a thrust generated by an actuator upon the plate positioned in a plane extending perpendicular to a drive shaft. The plate oscillates in response to a pressure drop above the pistons causing the actuator to expand toward the plate and exert a thrust exceeding the lowered pressure above the pistons and enabling the swash plate to provide the pistons with reciprocal motion.

Abstract: A compressor is provided in which the arrangement and the position of a spring chamber, in which a coil spring biasing a main shaft is accommodated, are designed and the various designs of the compressor is possible.

Abstract: An electronic bore pressure optimization mechanism for dynamically varying the cylinder block piston bore pressure profile in a multiple piston hydraulic unit includes a valve means having a variable orifice disposed in the end cap for metering fluid between leading and trailing pistons in a transition region or between a piston in a transition region and a high or low pressure source; and means for generating a control error signal to the valve means so as to adjust the size of the variable orifice based upon the control signal.

Abstract: A swashplate assist mechanism for dynamically varying swashplate moments in a multiple piston hydraulic unit includes a valve means disposed in the swashplate and defining a variable orifice for metering fluid from at least one of the pistons; and means for generating a control error signal to the valve means so as to adjust the size of the variable orifice based upon the control error signal. When fluid is metered from a leading piston to a trailing piston near one or more of the pressure transition zones, or when fluid is metered from a trailing piston to a leading piston near the opposite transition zones, the swashplate moments can be reduced.

Abstract: A hydraulic rotating axial piston engine has a housing enclosing a rotatable cylinder barrel. The barrel has a number of axial cylinders with a number of reciprocating pistons. The pistons reciprocate between two defined end positions, and cooperate with an angled plate in order to obtain the reciprocating movement. The cylinder barrel is rotatable relative to a first axis, which is inclined relative to a second axis of an input/output shaft. The housing has two parts, one part of the housing positions the input/out shaft and a second part includes inlet and outlet channels. The rotation of the cylinder barrel and the input/output shaft is synchronized by means of synchronizing means. A central support pin extends along the first axis between the angled plate and the cylinder barrel. The support pin is at one end axially connected with the angled plate, and at the other end axially connected to the cylinder barrel. The support pin limits axial movement at the cylinder barrel relative to the angled plate.

Abstract: In an axial piston pump having an oblique disk, the axial piston pump includes a piston drum with pistons disposed therein that are displaceable by way of a holder that runs along the oblique disk. The angle of engagement of the oblique disk can be increased. On the outer side of a spherical adjustment surface provided on a component of a shaft, there are at least two glide blocks that are rotatable about a rotational mount and that exhibit an axial extent with respect to the drive shaft axis. For the purpose of transmitting torque from the drive shaft to a holder, the glide blocks are engaged with grooves that are provided in the holder, and in particular in the wall of the holder that circumscribes a receiving bore of the holder.

Abstract: A device for varying the displacement of a variable displacement bent axis unit includes a one-piece yoke having a bucket portion adapted to carry a cylinder block kit of the bent axis unit, a trunnion bearing portion for swing control on one side of the bucket portion, and a trunnion portion for fluid porting on the other side of the bucket portion. The bucket portion has a bottom wall, a continuous side wall, and an open top. Inside the yoke is a pair of fluid passages intersecting the interior of the bucket portion and extending separately and entirely within the bottom wall and the side wall before opening onto the trunnion portion for fluid porting.

Abstract: The fluid expander includes a housing, a drive shaft mounted for rotation within the housing, a piston-cylinder assembly including a cylinder and a piston disposed within the cylinder for converting energy from a working fluid to rotational energy output via a drive shaft. Various adjustment assemblies are provided for adjusting speed, torque, stroke length, and thermodynamic cycles of the device. The fluid expander assembly can be used with external combustion systems, with solar or geothermal energy systems, or with internal combustion systems.

Abstract: A compressor (1) with at least one piston (9) movable in a cylinder (10), a drive shaft (2) and a wobble plate arrangement (4, 5) between piston (9) and drive shaft (2), having an inclined plate (4) with variable inclination angle, and with a spring arrangement (17; 41 to 43), acting on the wobble plate arrangement in the direction of a minimum displacement. Such a compressor should also be able to operate at higher pressures without increasing its size, e.g. to enable the use of CO.sub.2 as refrigerant. For this purpose the spring arrangement (17; 41 to 43) acts on the wobble plate arrangement (4, 5) in the area of the radial edge.

Abstract: A variable displacement axial piston hydraulic unit includes first and second control pockets individually disposed between first and second arcuate shaped fluid passages, a first electrohydraulic valve for controlling fluid flow between the first control pocket and the first fluid passage and a second electrohydraulic valve for controlling fluid flow between the second passage and the second control pocket. A controller outputs first and second control signals to the first and second electrohydraulic valves in response to receiving a command signal so that the tilt angle of a swashplate is controlled to obtain a desired operating parameter. An angle detector, a pressure detector, and a speed detector provide feedback signals to the controller for determining when the desired operating parameter has been obtained.

Abstract: A pair of axles and a hydrostatic transmission which drives them are housed in a common housing. The hydrostatic transmission comprises a hydraulic pump, with a movable swash plate, which drives a hydraulic motor with pressurized oil. Adjusting the angle and direction of slant of the movable swash plate controls the volume and direction of flow of the pressurized oil. The angle and direction of slant of the movable swash plate are controlled by a rotating member and a shaft housed within the common housing. The rotating member has a contact portion which abuts against an abutting member when transmission is operating in reverse. When the abutting member abuts against the contact portion, a detector operates a switching unit, allowing an alarm to be sounded or the operating device of the vehicle to be disengaged automatically when the vehicle is running in reverse.

Abstract: The present invention has for its object to provide a swash plate type piston pump/motor which is simple in construction and small in size and which enables a swash plate to be tilted surely. The swash type piston pump/motor is arranged such that a swash plate receiving surface (1) formed in a housing (1) is inclined by a predetermined angle relative to the axis (2) of a rotating shaft (2) so that even when the angle of tilting of the swash plate is increased the distance from the axis of the rotation shaft to the center (12) of a ball (12) which serves as the center of swing of the swash plate can be reduced.

Abstract: Described is a bent axis type variable displacement hydraulic machine which is provided with a hydrostatic radial bearing 23 and/or a hydrostatic thrust bearing 28 to support hydraulic reaction forces exerted on a cylinder block 8. The hydraulic machine is arranged to draw out a high oil pressure corresponding to the tilt angle of the cylinder block 8 through a variable throttle means 34, 37, 51 or 54 or through a control valve 77 or 78, and to supply the pressure to the hydrostatic radial or thrust bearing 23 or 28 thereby imparting to a hydrostatic supporting capacity commensurate with the tilt angle of the cylinder block 8 to support a rotational shaft stably while holding oil leaks to a minimum.

Abstract: A novel planetary roller type flow control valve, which can precisely control a flow rate and has a small friction, is provided.

Abstract: A bent axis type variable displacement hydraulic machine employing hydrostatic radial bearings for supporting hydraulic reaction forces exerted on the cylinder block. In a hydraulic machine of this sort, the number of pistons which are located in the high pressure are varies with the rotation of the cylinder block, and the resultant force of hydraulic reaction forces has an acting point at a position off the axis of the rotational shaft. Therefore, the hydrostatic radial bearings are located in such positions as to balance the moment loads which occur about the rotational shaft in relation with the acting point of the resultant force of radial hydraulic reaction forces on the drive disc of the rotational shaft. As a result, it becomes possible to lead to suppression of oil leaks from the sliding surfaces to a minimal rate and to prevent abnormal abrasive wear of each of the sliding surfaces.

Abstract: Described herein is a variable displacement bent axis type hydraulic machine having a center shaft within a casing in a tilted state along with a valve plate and a cylinder block, and provided with a tilt angle sensor mechanism for detecting the tilt angle of the valve plate. For the purpose of improving the resolution in angle detection, the tilt angle sensor mechanism is constituted by a support shaft rotatably supported on a side wall of the casing at a position deviated toward the valve plate from the pivoting point of the center shaft, a rocking lever having one end thereof securely fixed to the support shaft and the other end pivotally supported at one side of the valve plate, and an angle sensor adapted to detect the rotational angle of the support shaft resulting from rocking movement of the rocking lever. This arrangement permits a wider rotational angle for the support shaft to guarantee higher resolution in the tilt angle detection.

Abstract: In order to entirely eliminate pressure drop sensors in a variable displacement hydraulic motor (10), and to change the wobbler angle mechanically rather than hydraulically, the hydraulic motor (10) includes a motor housing (26) having a plurality of hydraulic cylinders (32) and a plurality of hydraulic pistons (34) radially disposed about an axis (36) thereof. A servovalve (40) is provided for controlling the rate and direction of flow of hydraulic fluid to and from the hydraulic cylinders (32), and the wobbler (22) is operatively associated with the hydraulic pistons (34) in a variably angularly positionable manner for varying displacement of the hydraulic motor (10). With this arrangement, the hydraulic motor (10) includes a cam system (22a, 30) for automatically varying the angular positioning of the wobbler (22) relative to the axis (36) of the hydraulic motor (10) responsive to a load-related torque at an output shaft (12) thereof.

Abstract: An axial piston machine having a longitudinally movable rotary cylindrical drum with cylindrical bores arranged concentrically to the axis of rotation of the drum. A longitudinally sliding piston located in each bore and lying against a control surface in contact with the drum. The pistons have an end in contact with a control surface that can be positioned diagonally to the axis of rotation of the drum and said cylindrical bores are provided with openings connecting to control channels in the control surface. Additional piston surfaces are provided in a cavity formed in the cylindrical drum for controlling the pressing force of the cylindrical drum on the control surface.

Abstract: A torque transmission apparatus has a hydraulic assembly with a variable speed control, and comprises first and second rotors at a power side of the transmission apparatus, the rotors being coaxially rotatable with respect to each other. The first rotor has a swash plate facing the second rotor. The second rotor has a plurality of cylindrical bores which have open ends facing the swash plate and other ends which are communicated with through bores arranged in communication with ports. Plunger members are provided for sliding in the cylindrical bores, the plunger members being guided by the swash plate. A control rotor and a stator are provided at a control side of the transmission apparatus. The stator has a swash plate, and the control rotor has cylindrical bores having open ends facing the swash plate of the stator and communicating with through bores in the stator. Plungers are provided which slide in the cylindrical bores of the control rotor, guided by the variable swash plate of the stator.

Abstract: An axial piston type motor for a hydrostatic transmission, wherein the motor is arranged to generate an output torque at the drive flange uses a Rzeppa joint (32) to couple the drive flange (10) with the cylinder barrel (16). The center of the Rzeppa joint (32) is located in the tilting point (60) between the axes of the drive flange (10) and of the cylinder barrel (16). The number of balls (42) of the Rzeppa joint (32) is equal to the number of pistons (24). The outer joint member of the Rzeppa joint (32) is formed by the drive flange (10). The balls (42) and grooves (40) of the Rzeppa joint (32) are angularly offset with respect to the ball-and-socket joints (28,30) of the pistons (24) by half the angular spacing of the ball-and-socket joints and extend up to the space between the ball-and-socket joints.

Abstract: A swashplate type hydraulic axial piston machine whose swashplate is arranged on a rocker mounted to pivot in a segmental rolling contact bearing has a tracking device for the cage of the pivot bearing which comprises a rod-like guide element which is connected to said rocker in a first bearing in the rocker so that it can pivot parallel to the pivot plane (SE), is connected to said cage in a second bearing so that it can pivot parallel to the pivot plane (SE) and so that it can be displaced longitudinally, and is mounted to pivot parallel to the pivot plane (SE) in a third bearing. To make tracking by the cage possible without mounting the guide element on the housing, a rocker adjustment member is provided mounted so that it can be displaced transverse to the middle axis of the axial piston machine, and the third bearing is arranged on a guide member movably connected to the adjustment member and the rocker.

Abstract: A bearing comprising a body of polymeric material and a reinforcing member embedded in the body and having a plurality of perforations throughout which are affixed in the reinforcing member. The polymeric material extends through the perforations. The bearing may have various configurations. The reinforcing member may comprise a thin metal sheet having perforations therein, a woven metal body defining the perforations, or adjacent woven metal bodies each having perforations. In one form, a backing member is adhered to on one side of said reinforcing member. Where a thin metal sheet is used, it has a roughened surface finish at the interface with the plastic body.

Abstract: A device for biasing a cylinder drum in a variable-displacement axial piston machine against an associated slide valve member comprises a compression spring means, the axial piston machine having between the cylinder drum and the drive disk a synchronizing shaft which at each of its ends has a universal joint of the so-called tripoid type for angularly rigid but pivotable connection with the drum and disk, respectively, the synchronizing shaft furthermore being supported at each end approximately axially from the cylinder drum and drive disk, respectively, by a link pin.

Abstract: A thrust hydrostatic bearing device for use in an axial piston machine includes a bearing sleeve fitted into a housing cover for rotatably supporting a drive shaft through a bearing and having a plurality of hydrostatic pads. The hydrostatic pads are disposed at locations which are symmetrical with respect to an axis lying in a cross-section taken perpendicular to the drive shaft, and these pads increase the performance and durability of the thrust hydrostatic bearing device for use in an axial piston machine.

Abstract: Driving device of a rotating cylinder block (8) of a pump or hydraulic motor whose axis is inclined along an angle that is fixed or that can be adjusted in relation to the axis of rotation XX' of the drive shaft (1) and in which the transmission of the rotation torque from the drive shaft (1) to the cylinder block (8) (pump) and from the cylinder block (8) to the drive shaft (1) (motor) is performed by pistons (5) mounted by connecting ball joints (6) to a pulse plate (4) fixed in rotation with the drive shaft (1). The face (8a) of the cylinder block (8) turned toward the pulse plate (4) carries pairs of diametrically opposed projections (10) located at the entrance of the bores (7) of the cylinder block in which the pistons (5) move, which projections exhibit a concave surface (11) in contact with a surface of the ball joints (6) for connecting the pistons with the pulse plate (4). Applications is to motors and pumps having rotating cylinder blocks.

Abstract: An axial piston-type transmission in which a group of axially displaced pump pistons, that move in a cylinder block rotated by an input shaft, slidably engage one surface of a swash plate that rotates an output shaft. A group of axially displaced motor pistons, that move in a stationary cylinder block, slidably engage an opposite surface of the swash plate so that the plate is squeezed between the two groups of pistons. The swash plate is pivotally attached to the output shaft so that the angles between the two surfaces and the axis of rotation of the swash plate can be adjusted. The pump pistons and motor pistons are hydraulically connected in pairs. A rotary valve driven by the output shaft connects half the pump cylinders together hydraulically to form an output port and the other half together to form an input port.

Abstract: A pair of bearing support members (48, 50) are located within opposite end portions (12, 14) of an elongated housing (10). Piston drive rings (58, 68) are mounted for rotation on oblique inner end portions of the bearing support members (48, 50). A cylinder block (44) is mounted for rotation within the housing (10) between the bearing support members (48, 50). The cylinder block (44) includes a plurality of axial bores (46). A pair of pistons (70, 72) reciprocate within each bore (46). Each piston (70, 72) is connected to the piston drive ring (58, 68) at its end of the housing (10) by means of a connector rod (74, 76). An inlet scroll (206 or 208) and an outlet scroll (206 or 208) communicate with center regions of the cylinder bores (46).

Abstract: A variable displacement hydraulic motor/pump apparatus 10 of the axial piston type is described that is more efficient over a wider range of speeds than previous devices. The apparatus 10 includes a main shaft 17 having a piston rod carrier 30 extending radially outward from the shaft for supporting a plurality of radially and angularly spaced piston rods 37. The piston rods 37 are double ended and held axially stationary with respect to the main shaft. Pistons 51 and 52 are mounted at the ends of the piston rods 37. Annular cylindrical barrels 60, 61 are supported by barrel carrier assemblies 84, 85 respectively circumferentially about the main shaft. Torque is transmitted between annular cylinder barrels 60, 61 and the main shaft 17 by the carrier 30. The barrels have piston cavities 65 formed therein for receiving corresponding pistons 51, 52.