Abstract: An adjustable axial piston machine in swashplate construction, preferably an axial piston pump, is provided in which the rocker body is supported with a semicylindrical surface by a friction bearing in a hollow semicylindrical surface and pressure pockets loaded with pressure medium are provided for hydrostatic relief of the bearing pressures in the bearing surfaces, in which case in a machine in which each of the two connections that can be loaded with feed pressure, a pressure pocket is provided on each side of the rocker body, where the pressure pocket that lies on the side on which the working pistons loaded with feed pressure also move is loaded with feed pressure.

Abstract: A control apparatus for several drive assemblies, which consist of hydrostatic drive units, is described. The hydraulic pumps of the hydrostatic drives are driven by means of a common prime mover and are controlled in terms of output. The output control device consists of an adjusting piston, which is connected with the control element of the hydraulic pumps and upon both sides of which pressure acts, and of a spool valve which controls the pressure action on both pressure chambers at the front surfaces of the adjusting piston and upon which, on one side, the working pressure of the pumps acts and upon which, on the other side, an adjustable spring acts.

Abstract: An adjustable axial piston machine of swash plate construction is provided in which the working pistons are supported against a swash plate that is formed on a rocker body 6, which in turn is supported with a semi-cylindrical support surface against a hollow-cylindrical bearing surface 4, in which case at least one pressure pocket recess 7, 57 is provided for generating a pressure cushion counteracting the bearing loads and it is connected with the high pressure line through channels in the servo piston that is capable of sliding in the operating cylinder loaded with high pressure.

Abstract: A mechanism for converting rotary motion in rectilinear to and fro comprising and hinged in the housing of a crosspiece by a prestressed rod and conical bearing. An even number of bearings stacked symmetrically on each side of the center and internal cages are fitted an intermediate bush with the interposition of spacing rings, the thicknesses of the rings being so determined that the pre-stressing force is distributed equally between the bearings and causes the complete take-up of play. The invention is particularly useful in multicylinder pump mechanisms distributed regularly around a shaft and with axial pistons.

Abstract: A hydraulic axial piston machine is provided which has a swash plate mounted on a yoke which pivots about the axis of a pair of trunnions. The back surface of the yoke is curved and is supported on the surface of a flat, rigid rotary plate which is displaced linearly as the yoke is pivoted. The rotary plate is supported on a pair of roller bearings which are mounted on a resilient damping plate.

Abstract: The invention relates to an electro-hydraulic control system for a power drive unit having a wobbler controlled variable displacement hydraulic motor wherein the electro-hydraulic control system causes the displacement of the hydraulic motor to match a load to be driven by a power drive unit output shaft coupled to the motor. The system results in the hydraulic motor displacement matching the load as a combined function of the input command signal, the actual wobbler position, as well as the velocity and position of the power drive unit output shaft.

Abstract: An electrohydraulic control arrangement for a hydrostatic machine with displacing element having a stroke determined by a control member, which has at least one pressure-actuated regulating piston arranged to adjust the control member, and a valve slider through which a pressure medium acts upon the regulating piston and which is withdrawable to a neutral position in response to adjusting the machine by a feedback signal coming from the control member in correspondence with an electrical input signal, wherein a constant pressure acts upon one side of the valve slider and a variable pressure depending upon a position of the control member acts upon the other side of the valve slider.

Abstract: The present invention is directed to an electro hydraulic control system wherein electric current output of the control is applied to an electric force motor to position a valve spool which in turn modulates fluid flow to a device to be controlled. The valve spool, either to accommodate manufacturing tolerance or to assure zero output flow, in the neutral position, has a flow dead zone which requires a substantial valve spool travel to initiate fluid flow through the valve. In the preferred device the manual control handle modulates the current output of the electric circuit which in turn proportionately modulates the position of the valve spool. The electric circuit is provided with resistance means which are selectively inserted into the circuit to assure that sufficient output current is provided to the force motor to move the valve spool that amount necessary to initiate fluid flow upon a small movement of the control handle to compensate for the fluid flow dead zone in said valve.

Abstract: An axial piston machine of the oblique-shaft type is described. The transmission of torque between the drive disc and the cylinder drum of the machine is effected by direct propulsion of the cylinder drum by way of the piston elements traveling to and fro in cylinder bores of the cylinder drum. On the side of the cylinder drum towards the drive disc, a follower plate with slot-like openings is provided. The edges of the openings are met by the piston rod areas of the piston elements to drive the cylinder drum. In order that the follower plate may be light in construction and designed for long service life, it is proposed according to the invention, that the follower plate be made, by means of a locking part, into a follower disc having openings enclosed all around for passage of the piston rod area of the piston elements.

Abstract: The invention relates to an automatic rigging arrangement for an actuation system wherein the rigging arrangement includes in combination a differential length feedback device that has a moveable inner member and an outer member, with the outer member secured at its ends respectively to a power drive unit and an actuator, the moveable inner member being controllingly coupled to a power drive control and secured to an actuator position feedback member of the actuator to thereby provide via the moveable member of an actuator position feedback input signal to a signal summing means associated with the power drive control. The feedback input signal being proportional to an actuator position and the signal summing means being responsively coupled to the power drive unit to receive as an input, a signal representative of a given position commanded.

Abstract: A control device for varying the displacement of variable volume fluid energy devices is disclosed. The control cylinder of the present invention is usable with variable volume pumps and motors having a control rod projecting from the pump housing and angular movement of the control rod varies the pump or motor displacement. The control cylinder includes a bore formed in the cylinder, a spool movable within the bore, a lever fixedly attached to the control rod for rotation therewith, a directional control valve manifold mounted to the cylinder for selectively moving the spool within the bore, and a scotch yoke for interconnecting the lever to the spool so that movement of the spool produces an angular movement of the control rod varying the pump displacement. The control device may also be directly applied to an apparatus requiring a linear input for control. A plurality of control devices may be combined to produce an analog input that is either angular or linear.

Abstract: An axial piston pump is provided for producing two output streams that can be regulated independently of each other with respect to size and pressure.

Abstract: This invention relates to hydraulic pumps. The pump includes essentially a casing (1), a barrel (3) capable of rotating on a slide face (2), the barrel comprising a plurality of pistons (16, 17) sliding in a reciprocating manner in cylinders (9, 10) provided in the casing, the pump being characterized essentially by the fact that it comprises structures (59, 54, 50, 52, 53) for sequentially applying the pressure prevailing in the cylinder on a given portion between a bearing block (26) made in the casing (1) and the part of said barrel (3) cooperating with the bearing block (26). The pump finds a particularly advantageous application in the area of those which must rotate at very high speed, for example in aeronautics.

Abstract: Axial piston pump comprising a rotatable cylinder block (16) within which at least one piston (20) is mounted slidable in a cylinder (18) and by rotation of the cylinder block is imparted a reciprocating movement by becoming inclined from a neutral or null position in which no pumping is effected, relatively a drive plate (14) in at least one direction. A distribution plate (22) adjustable jointly with the cylinder block (16) is formed with outlet and inlet slots (24,26) which by the inclination adjustment are caused to communicate with exhaust and intake ports (A,B) for the outflow and the reflux, respectively, of the pumped medium, which ports are formed in a stationary port plate (28). The port plate (28) has, in addition, at least one feed opening (32) for supply of pressure fluid to the pump.

Abstract: The invention relates to wabbler plate engine mechanisms. One such mechanism has a wabbler plate rotatably mounted on a wabbler carrier which is in turn inclinably mounted on a crankshaft in a crankcase. The wabbler plate has a plurality of arms which are coupled to pistons slidably mounted in cylinders arranged around the axis of the crankshaft. As the crankshaft rotates, each arm oscillates laterally relative to its respective piston and a stabilizer mechanism comprising ball races on the wabbler plate and a ball carrier on the crankcase, is included to prevent the oscillations from unbalancing the mechanism. This construction is quite satisfactory but is not readily adaptable to provide for variable displacement. Attempts have been made to incorporate this facility, but a successful solution has not yet been found.

Abstract: In an adjustable axial flow piston pump having a swivellable component such as a swash plate, pressure chambers for swivelling the swivellable component, a lever connected with the swivellable component and supported in the housing of the pump, a final control member mounted in and movable in the lever, a fluid passage in the lever supplying fluid pressure to the control member, a fluid passage in the pump housing connected to the pressure chamber and a fluid passage in the lever connecting the control member and the fluid passages in the housing whereby fluid pressure is delivered through the lever and control means to the pressure chamber.

Abstract: An axial piston machine having an inclined axis construction, including a cylinder drum pivotally arranged within a housing, and a swivel carriage located opposite to the cylinder drum and which is supported in a sliding guide, which contains the control surface as well as the reniform control recesses on the pressure and suction sides and connects these with, respectively, a pressure or suction passageway communicating in one of the sliding guide surfaces. Included is an adjusting arrangement for setting the angular position of the cylinder drum, consisting of a displaceable setting element arranged on the housing generally in parallel with the drive shaft and of an angle lever supported in the housing so as to be pivotable about the swivel axis of the cylinder drum, whose first lever arm is articulated on the setting element and whose second lever arm engages on the swivel carriage.

Abstract: Two fluid passages are connected through flow restrictors to a fluid supply. Downstream of the restrictors the fluid supply has a drooping pressure-load characteristic. Venting means for the fluid passages comprises vent openings therein downstream of the restrictors and variable position obstructor means cooperating with vent openings to vary venting and thereby vary fluid pressures in the fluid passages.Fluid conduits connect these pressure outputs to a double acting piston moving in a cylinder whose opposite ends are connected to the fluid conduits. The piston and cylinder form the responder of the system.A receiver is formed by a piston and cylinder or other fluidic motor remotely fluidically connected to the responder, the motor driving a load.A feedback means controlled by the position of the responder piston and/or the load varies pressure in the fluid conduits by variably venting same.Both rotary and linear types of transmitters and load feedback means and receivers may be used.

Abstract: A displacement control for a pump or motor having a swash plate for setting displacement includes a control device operatively connected to the swash plate and a control valve having connections to a source of pressure and drain for operating said control cylinder. The control valve has a neutral position wherein the swash plate is at or near a minimum displacement position. The control valve is operable to other positions for setting the displacement of the pump or motor and, additionally, is movable to a control position other than the neutral position or normal displacement-setting positions in response to an operative failure of the control valve positioning system which enables the swash plate to move to a position which minimizes any adverse effects from the occurrence of said operative failure. In a pump, the swash plate moves to a zero displacement position upon the occurrence of a failure while, in a motor, the swash plate moves to a maximum displacement position.

Abstract: A reciprocating-to-rotating motion conversion and power control device for a Stirling engine includes a hub mounted on an offset portion of the output shaft for rotation relative to the shaft and for sliding motion therealong which causes the hub to tilt relative to the axis of rotation of the shaft. This changes the angle of inclination of the hub relative to the shaft axis and changes the axial stroke of a set of arms connected to the hub and nutating therewith. A hydraulic actuating mechanism is connected to the hub for moving its axial position along the shaft. A balancing wheel is linked to the hub and changes its angle of inclination as the angle of inclination of the hub changes to maintain the mechanism in perfect balance throughout its range of motion.

Abstract: A regulating device for a hydrostatic drive unit such as a hydropiston pump is provided with an adjusting piston designed as a differential piston, connected with the final control element of the drive unit and/or the pump and under pressure from both sides, and with a control valve controlling the pressure exerted on the adjusting piston in the pressure spaces in front of the end faces and with a control pressure gauge piston arranged in a sliding manner in the housing and on which the working pressure of the drive unit and/or feed pressure of the pump is exerted, and which lies against a lever, which is connected through a flexible coupling with the adjusting piston and is supported on this latter and is forced against it by a spring and actuates the control valve, in which case the control valve is located in the adjusting piston crosswise to its longitudinal axis, characterized in that the lever is designed as an angle lever and that the spring is located in the adjusting piston and lies against the secti

Abstract: A fluid power apparatus for converting steam to hydraulic energy having one or more pairs of linear steam and linear hydraulic cylinders arranged symmetrically and with their axis parallel about a steam generator. The rod ends of the cylinders are connected to a wobble plate. Valving directs steam in and out of the steam cylinders and as the steam cylinders reciprocate, the corresponding hydraulic cylinders will be reciprocated generating hydraulic fluid pressure. Valving is accomplished by valving plates rotated by the wobble plate or by means of a slide valve positioned by a wobble plate actuated linkage.

Abstract: A drive comprising a rotatably journalled shaft on which a plate is mounted so that the plate cannot rotate with respect to the shaft during operation. The plate can, however, be adjusted around a pin which extends transverse to the rotatably journalled shaft, so that the angle enclosed by the plate and the shaft can be varied. The pin is journalled in a bearing block which is adjustable in the shaft direction. Each of the pistons has a piston rod with a piston rod head whose side which faces the plate is provided with a spherical surface which cooperates with a sliding body which bears against the contact surface of the plate. The side of the plate which is remote from the piston rod comprises a spherical cam which has the same center of curvature as the spherical surface of the drive rod head. The cam is supported by a surface which forms part of a structural member which is rigidly coupled to the shaft.

Abstract: An axial piston machine having relatively swingable oblique disc and cylinder block components, a yoke lever spring urged against stationary stops on the housing when the components are in a zero stroke position and swinging around one of the stops when the swingable component is moved from its neutral position by a setting mechanism separate from the biasing spring for the yoke lever.

Abstract: A control device for an axial piston machine in which the rocker controlling the angular orientation of the cylinder drum is shifted by a differential-action setting piston having a pin which engages in the rocker. The opposite end of this pin bears via a pressure body on one arm of a bell crank lever which can have a curved camming surface, the pressure body including a roller and being urged by a first spring against the bell crank lever. The other arm of the bell crank lever is engaged on one side by a control piston subjected to the pump pressure while the valve member which controls the pressure to the large-diameter side of the setting piston engages the opposite side of the bell crank lever and is urged against this opposite side by a second spring.

Abstract: A variable angle wobble plate drive for varying piston displacement has constant velocity coupling from the wobble plate to the frame which permits all axis-dynamic balancing. The coupling uses an idler element rotating on a tilted axis portion of the shaft, and conical gear sets connecting the idler member to the machine frame and the idler member to the wobble plate. The sum of the acute angles from the tilted axis to the shaft, and to the driving axis, is made greater than the maximum driving angle thereby permitting low reaction torque on a driving angle control mechanism without reversal of control torque.

Abstract: A multicylinder hydraulic machine of the split-shaft kind comprises a rotatable shaft and a drive plate fixed on the shaft and linked to piston and rod units received in the cylinders of the drum. Liquid flow is through orifices in a distribution plate non-rotatably positioned around the shaft, through ducts in the drive plate and through the piston and rod units which are hollow. The shaft is rotatably mounted and axially located by conical bearings. The distribution plate is mounted in an axially floating manner and a hydraulic abutment is developed between the distribution plate and the drive plate during operation of the machine so as to reduce the force on the shaft bearings.

Abstract: Mechanical feedback through an articulated mechanism is provided between the swashplate of a variable displacement hydraulic device and the output stage of an electrohydraulic servovalve for controlling such swashplate.

Abstract: A fluid repeater system may be balanced so that displacement of the load has a desired correspondence to displacement of the transmitter. This may be done by making the fluid resistance offerd to fluid flowing along a path from the source to the reservoir and through the feedback controlled directly by the load, exclusive of the resistance offered by such load feedback, approximately equal to that offered to fluid flowing along a path from the source to the reservoir and through the transmitter, exclusive of the resistance offered by such transmitter.

Abstract: The instant invention relates to an electrically operated control which operates the displacement setting mechanism of a variable displacement pump and allows the displacement mechanism to be manually operated when the electrically operated control is disabled.

Abstract: A hydrostatic transmission includes a reversible, variable displacement pump having a swashplate actuator controlled by a pilot-operated displacement control valve. A manually operated displacement control lever is manipulated to opposite sides of a neutral position to effect command signals for causing pilot operation of the displacement control valve to control movement of the swashplate in accordance with the command. A neutral control valve is coupled to the displacement control lever and is operated thereby to a neutral position, wherein it connects the swashplate actuator to sump, when the lever is moved to its neutral position.

Abstract: A power drive unit for operation of structure in opposite directions, such as aircraft structure and, particularly, thrust reverser structure of an aircraft engine operable between stow and deploy positions, including, a bi-directional hydraulic motor having a variably positionable wobbler for controlling displacement of the motor. Control structure includes a valve for causing fluid flow through the motor in either of two directions, a control cylinder and piston connected to the wobbler for setting the motor at either minimum or maximum displacement conditions. In one embodiment, there is an intermediate displacement position. The displacement condition is established by valve structure responsive to the particular cycle of operation.

Abstract: The dynamic performance of hydraulic apparatus including a fluid-operated actuator controlled by a servo-controller, is improved by providing phase lead compensation to the controller in response to movement of the movable element of the actuator so that the low frequency response of the apparatus is raised.

Abstract: A power drive unit for operation of structure in opposite directions, such as aircraft structure and, particularly, thrust reverser structure of an aircraft engine operable between stow and deploy positions, including, a bi-directional hydraulic motor having a variably positionable wobbler for controlling displacement of the motor. Control structure includes a valve for causing fluid flow through the motor in either of two directions, a control cylinder and piston connected to the wobbler for setting the motor at either minimum or maximum displacement conditions or at any condition therebetween, a servo valve operable for setting the position of the piston in the control cylinder, and a differential area piston operatively connected to the servo valve for positioning thereof and responsive to the pressure drop across the motor in either direction of operation thereof to set the motor displacement at the least value possible for the load condition on the motor.

Abstract: A fluid driven mechanism in the form of a fluid motor or fluid pump which is transmissionless, wherein speed and power are selectively varied by the operator through corresponding adjustment in the orientation of angularly disposed power transmitting structure. A large capacity unrestricted rotating fluid distributor vortically and cyclically directs ingress fluid successively to a series of pistons which is power-related to the power transmitting structure. The fluid distributor is uniquely caused to float during its rotation by oppositely imposed fluid under pressure within aligned eccentric chambers, each chamber being formed partly in the rotating distributor and partly in adjacent stationary structure.

Abstract: An axially oriented variable displacemnt pistoned device adaptable for use as motor and having a pivoted swash plate angularly positionable for establishing displacement of the device is fitted with externally mounted low pressure hydraulic actuators operably connected with the swash plate for operation thereof. Adjustable stops are provided in the device body to limit travel of the swash plate under urging of the low pressure hydraulic actuators.

Abstract: A variable displacement axial piston hydraulic pump or motor having a rotatable cylinder barrel with working pistons suitably connected for thrust engagement with the thrust face of a cradle supported for pivoted movement in one plane within a housing for the pump or motor to effect reciprocal movement of the working pistons in accordance with the tilt of the thrust face. The cradle has a rigid lever arm extending rearwardly of the face. A coupling pin is journalled in the lever arm; and a free end of the coupling pin has two flat sides fitted in an annular groove of a displacement control piston; whereby linear movement of the control piston transmitted through the coupling pin as the free end of the coupling pin slides laterally within the annular groove of the control piston to accommodate the angular movement of the cradle. And stops within the housing abut either side of the coupling pin intermediate the ends thereof to limit maximum displacement.

Abstract: A spring compensation mechanism for a swashplate drive having a variable swashplate angle, particularly suited for use with ahot gas engine. A compensating rod has one end connected for movement in one direction in response to tilting of the swashplate while the other end is connected to move in a perpendicular direction against the force of a spring.

Abstract: An axial-piston machine of the type in which a prismatic housing, usually of rectangular or square cross section, receives a rotatable cylinder drum, the pistons of which bear against an inclinable control surface. The control surface is formed on a rocker or tilting box which can be tilted about an axis perpendicular to the axis of rotation of the drum. The rocker-setting elements are disposed between the housing bottom and the reaction surface of the rocker (against which the pistons bear), at the corners of a rectangle which closely circumscribes the orbit of the pistons. Consequently, the presence of the rocker-displacing means does not increase the dimensions of the machine over those necessary for a fixed control surface machine.

Abstract: A bent axis pump having a port in the housing thereof which port is movable to vary the displacement of the pump and including leak-proof transfer sleeves extending between the port and the housing to effect flow of fluid between the pump housing and the port.

Abstract: An axial piston machine with a variable or adjustable stroke comprises a rotatable cylinder drum provided with annularly spaced cylinder bores each of which receives a piston reciprocal in its bore parallel to the axis of rotation of the drum and with a stroke determined by the extent of tilt of a guide surface about an axis perpendicular to the axis of rotation of the drum. The piston stroke is controlled by a rocker carrying the control surface and hydraulically displaceable in the machine housing by application of hydraulic fluid pressure directly to the rocker.

Abstract: A fluid operated engine having a pair of spaced apart disc-like plate members respectively fixedly secured to a pair of drive shaft sections having adjacent ends interconnected by a universal joint, a plurality of pressurized fluid actuated axially expansile and retractile devices extending between and being connected to corresponding circumferentially spaced points of said members, a valve mechanism for sequentially controlling the flow of actuating fluid to and from said devices, said shaft sections being rotatably supported in tiltable bearing supports selectively adjustable to vary the angular relation of the interconnected shaft sections and selectively position the connected plate members respectively in different angular nutating relationships to cause shaft rotations in opposite directions at varied speeds, and in a parallel non-nutating relationship in which the shaft remains stationary.

Abstract: A fluid energy translating device in which nul displacement is effected by a valve element operated by an abnormal temperature or an abnormal pressure.

Abstract: Two fluid passages are connected through flow restrictors to a fluid supply. Downstream of the restrictors the fluid supply has a drooping pressure-load characteristic. Venting means for the fluid passages comprises vent openings therein downstream of the restrictors and variable position obstructor means cooperating with vent openings to vary venting and thereby vary fluid pressures in the fluid passages. This forms a mechanical to fluidic translator. Pressures at the translator's outputs are a function of the obstructor's position. This translator forms the transmitter of a servo or remote control or indicator system.Fluid conduits connect these pressure outputs to a fluid to mechanical translator comprising a double acting piston moving in a cylinder whose opposite ends are connected to the fluid conduits. The piston and cylinder form the responder of the system, which may be adjacent the mechanical to fluidic translator and form part of the transmitter.

Abstract: A pump is provided with a regulating device which includes a valve and a motor. The motor operates on the pump to vary the capacity thereof. Movement of the motor is controlled by the valve which has a spool and a body. A feedback link is provided between the motor and the body so that movement of the motor due to a displacement of the spool moves the body to return the valve to neutral. Hunting of the transmission is thus reduced.

Abstract: A fluid pressure device comprising a pump or motor having a rotating internal assembly comprising linear pistons and cylinders operated through a "swash" plate to actuate the pistons to provide output pressure. The swash plate is mounted to the drive shaft through a universal connection and the cylinder and piston assemblies are coupled to their component parts through universal swiveling ball and socket connections. Special spring washers are provided for insuring a sliding seal between the internal cylinders and a valving plate, and the valve ports are designed for noise minimization.

Abstract: A transmission having a variable capacity pump and motor is provided with an override device which ensures that the motor is at a maximum capacity, and hence maximum torque capability, prior to operation of other protection devices.

Abstract: A device comprising at least three reciprocable piston-shaped bodies, each of which is provided with a drive rod which cooperates, via a drive rod head accommodating sliding bodies, with a plate which is mounted on a rotatable shaft and which can be tilted about a tilting axis which is transverse to the center line of the shaft. The means for tilting the plate are formed by piston-shaped bodies which can rotate with the shaft and which can be adjusted in the direction of the shaft, the first of the said bodies being coupled to the plate on the one side of the tilting axis, the other body being coupled to the plate on the other side of the tilting axis. Each of the said piston-shaped bodies bounds a space whereto pressurized liquid can be applied, the masses of the said piston-shaped bodies also serving for balancing the unbalancing forces occurring during operation.

Abstract: In combination with a pump having a variable rate of flow, a device for varying such rate of flow is governed by the pressure generated by the pumps through a variable transmission mechanism the ratio of which depends on the said rate of flow, whereby the power output of the pump can be maintained at a predeterminate value. The device can be used with two pumps for limiting the total power output of both pumps, as being governed by the average of the two pressures.

Abstract: A hydrostatic pump unit is located within a housing which serves also as a hydraulic fluid sump. A displacement control valve for controlling actuators for adjusting the angular position of a swashplate of the pump unit is mounted on the exterior of the housing. Disposed along the axis about which the swashplate is adjustable and joining the swashplate to a shiftable sleeve of the control valve is a feedback shaft which acts to return the valve to a null condition when the swashplate arrives at a commanded new displacement effecting position. The feedback shaft has a passage extending therethrough which acts as a drain connection between the valve and the sump defined by the housing. A check valve is located in the passage for preventing fluid from draining from the housing when the valve is disconnected from the feedback shaft for service.