Abstract: A drive device incorporating a hydraulic pump having a swash plate. At least two structural ribs and skirting ribs are located on and extend along the length of the swash plate. A plurality of thrust ribs may be formed on an inner housing surface and adjacent to respective contact surfaces on the swash plate, the thrust ribs being located so that at least one, but fewer than all, of the ribs can be in contact with its respective contact surface on the swash plate at a time, permitting rotation while limiting axial movement of the swash plate. A trunnion shaft includes a free end disposed so as to be accessible from outside the housing through a bore formed therein, and a control arm having a shaft portion extends into and supports the distal free end of the trunnion shaft within the bore.

Abstract: A hydraulic drive device having a pump and motor is disclosed, where the pump swash plate includes a pair of structural ribs and the housing has a pair of thrust ribs on an inner surface. Only one thrust rib is in contact with one of the structural ribs at a time, to permit arcuate rotation of the swash plate while limiting axial movement of the swash plate. The axes of rotation of the swash plate trunnion, input shaft and output shaft are in a common plane. A rotary bypass shaft for engaging transmission check plugs includes an external bypass arm. A pair of detents are externally formed on the housing, and the bypass arm includes separate pairs of openings to engage the pair of detents when the bypass arm is in different positions.

Abstract: A control device (1) for a hydrostatic steering motor comprises supply and return pump and tank connections (P, T), a slide valve arrangement in which inner and outer slide element sleeves are rotatable relative to each other to both sides of a neutral position through a limited small angle, said sleeves mutually forming controlled supply and return passages connected to said motor having supply and return throttles which are closed when said sleeves are in a neutral position, bypass throttle means (7) between said pump and tank connections (P, T) being open when said sleeves are in a neutral position, said bypass throttle means (7) having a set of at least two variable orifices connected in series. In such a device the noise should be reduced when a higher supply pressure of hydraulic fluid is used.

Abstract: A hydraulic arrangement (10) to increase a motor load is described. The hydraulic arrangement comprises a hydraulic consumer (28), a load pressure-controlled hydraulic pump (24), a hydraulic tank (26), and a hydraulic control circuit (30), connected with the hydraulic consumer (28), with which a volume flow conveyed by the hydraulic pump (24) can be changed, wherein the hydraulic control circuit (30) comprises an excess pressure valve (42) and an electronically controllable control valve (36). In order to ensure a prioritization of the hydraulic consumer with a simultaneous increase of the motor bad, a proposal is made that the hydraulic control circuit (30) comprise a load pressure-controlled pressure compensator (38) between the excess pressure valve (42) and the control valve (36).

Abstract: A hydraulic control device for moving at least one hydraulic consumer comprises at least one supply line, a discharge line or bypass line to which the hydraulic consumer is connected, and at least one pressure source and, optionally, a directional control valve. The line contains a dosing device for measuring a hydraulic medium dose by using a given compressibility of the hydraulic medium. The measured hydraulic medium dose either is supplied from the dosing device into the hydraulic consumer connected downstream or is discharged from the hydraulic consumer connected upstream into the dosing device. The dosing device comprises from upstream to downstream in series first and second blocking members which respectively can be switched into a leakage-free blocking position and into a through flow position, and a dead space between the blocking members. For dosing the hydraulic medium dose the blocking members are switched several times alternatingly.

Abstract: A hydraulic unit (1) mounted on a vehicle with an adjustable platform which is supported by two mechanically separate arms actuated by a separate hydraulic lifting device (5, 6). The hydraulic unit has the supply and return and preferably includes a balance valve (21) for controlling lowering of the platforms; a flow divider (22) enabling a division of the supply fluid into two flows having an identical flow rate, and each supplying one of the hydraulic lifting devices; and a resetting solenoid valve (23) that, when the operator controls the resetting of the hydraulic lifting devices, regardless of the operation direction and position thereof, and isolates one of the hydraulic devices (6) in order to immobilize the same while the other hydraulic lifting device (5 or 6) is adjusted.

Abstract: A fluid controller (17) controls a main fluid path (18) from a pump (11) to a primary steering cylinder (19) and a second fluid path (26) from a fluid meter (37) to a second cylinder (31). A mechanical or electrical linkage (149) couples the primary steering cylinder (19) to the second cylinder (31) such that displacement of the primary cylinder (19) results in proportional corresponding displacement of the second cylinder (31). The main fluid path (18) and the second fluid path (26) are maintained separate from each other. As such, the main fluid path (18) provides pressurized fluid from the pump to the primary steering cylinder (19) without communicating main fluid flow to the secondary cylinder (31). Due to the separate fluid paths, the present invention can be used to provide a substantial amount of fluid through a fluid controller (17) with a relatively small displacement fluid meter (37).

Abstract: The invention relates to a hydraulic control arrangement for actuating at least two consumers (2, 4) which can be supplied with pressure medium by means of a pump (6) with an adjustable delivery rate. Provided in the pressure medium flow path between the pump (6) and at least one of the consumers (2, 4) is an input pressure balance (60), by means of which a connection to a tank can be opened in a controlled manner. A power beyond connection (72) for connecting a power beyond consumer (74) branches off from a pressure medium flow path between the pump (6) and the input pressure balance (60). The adjustment of the input pressure balance takes place as a function of one of the load pressures of the consumer or of a power beyond consumer. Said hydraulic control arrangement permits a prioritized supply to the power beyond consumer and an increase in the regulating pressure difference when supplying power beyond consumers.

Abstract: A hydraulic system is provided for an air cart towed by a tow vehicle across a field. The hydraulic system includes a first selector valve configured to selectively communicate a first flow rate regulated by a first control valve to drive a hydraulic-driven auger mechanism at the air cart. The hydraulic system also includes a second selector valve control configured to selectively communicate a second flow rate regulated by a second control valve to drive a hydraulic-driven pressure source at the air cart. The first and second selector valves and first and second control valves are located at the tow vehicle, and are connected via a common hydraulic line to a main selector valve located at the air cart. The main selector valve is connected to selectively communicate the first hydraulic fluid flow rate to a pressure source and the second hydraulic fluid flow rate to the hydraulic-driven auger mechanism.

Abstract: According to one embodiment of the invention, a gerotor apparatus includes an outer gerotor having an outer gerotor chamber, an inner gerotor, at least a portion of which is disposed within the outer gerotor chamber, and a synchronizing apparatus operable to control the rotation of the inner gerotor relative to the outer gerotor. The inner gerotor includes one or more entrance passages operable to communicate a lubricant into the outer gerotor chamber.

Abstract: An improved diagnostic system for a hydrostatic apparatus such as a hydrostatic transmission or transaxle is disclosed. A fastener having a port formed therein is used to connect a hydraulic component such as a center section to a housing. A diagnostic system may be located external to the housing and connected to the hydraulic circuit at least partially through the fastener port. A relief valve may also be located in the fastener and connected to the fastener port, or in a different fastener having a separate fastener port, to permit the fluid in the hydraulic circuit to be discharged to a sump.

Abstract: A neutral start switch for preventing vehicle users from starting or activating a vehicle engine under certain circumstances and for use in connection with a control arm mechanism, which may be attached to a casing of a hydraulic pump.

Abstract: A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.

Abstract: A full fluid-linked steering system includes a fluid pump (11), a fluid controller (19), a steering actuator (17), an electro-hydraulic compensation valve (21), and a vehicle microprocessor (23). Downstream of the fluid pump (11) is a load sensing priority flow control valve (15) having both a controlled flow outlet port (CF) and an excess flow outlet port (EF). The excess flow outlet port (EF) communicates with an inlet port (35) of the fluid controller (19), while the controlled flow outlet port (CF) communicates with a fluid inlet (63) of the compensation valve (21). As a result, when the steering actuator (17) is at the end of its travel, pressure will be communicated only through the compensation valve (21), and the operator will be unable to turn the steering wheel further in the same direction.

Abstract: A hydraulic steering system for a tractor is provided which can be operated in a conventional steering mode or in a fast steering mode. In conventional steering mode, a conventional steering wheel and steering motor direct pressurized oil to the steerable wheels for selecting the turning direction, the turning angle, and the speed with which the turning angle is achieved. In fast steering mode, a fast-turning valve is controlled by the operator to direct oil directly to the steerable wheels, thereby by-passing the steering motor. The conventional steering wheel and steering motor continue however to control the steering operation.

Abstract: The invention relates to a hydraulic steering arrangement (1) with a housing (4), in which an inner control slide (7) and an outer control slide (6) are arranged to be mutually rotational, forming together a variable flow path device between a supply connection device (P, T) and a working connection device (L,R), at least one pressure chamber (17) being arranged between two working slides (15, 16), connected with both control slides (6, 7), the volume change of said pressure chamber (17) causing the relative displacement, and with a measuring motor (10). In such steering arrangements a simple an inexpensive way of realizing a remote control principle is desired. For this purpose, an intermediary plate (14) is arranged between the measuring motor (10) and the control slides (6, 7), in which plate at least one fluid channel (18, 19) is arranged to form at least one part of a connection from the pressure chamber (17) to the outside.

Abstract: A steering system having a first auxiliary branch line (23, 24) connecting a main line (6) to a return port (12); with a load line (22) connecting the first auxiliary branch line to a load port (13) and dividing the first auxiliary branch line into first (24) and second (23) flow paths. The main line includes an adjustable input throttle (20). The first flow path (24) includes an adjustable load throttle (27) and a second throttle (26) in series. The adjustable input throttle and the adjustable load throttle act in a same direction. The purpose of this control circuit is to raise the load port pressure level, so as to prevent relatively high power losses.

Abstract: The steering system of a motor vehicle includes a two chamber steering motor having the application of pressurized fluid applied thereto through change over valves in one position by the way of a by pass valve and alternately in a second position by the way of a steering unit. The change over valves are operated from their first position to their second position upon activation of the steering unit which results in control valve moving from a position applying pressurized fluid from a pump to the by pass valve to a position applying pressurized fluid from the pump to the steering unit.

Abstract: Hydrostatic auxiliary power steering devices transmit the steering power to the steered wheels via oil pressure. Such devices utilize a metering pump 5 and a steering valve 2 combined into a single unit. The metering pump distributes oil flow produced by a power steering pump 1 to a pressure operated steering power cylinder 8 under control of a steering valve 2 responsive to drive rotation of the vehicle steering wheel. The oil flow synchronizes the angle of rotation of the steering wheel with the angle of the lock of the wheels being steered. In hydrostatic systems there is a tendency to pressure oscillations. In the present invention these oscillations are minimized without occurring excessive pressure loss. The arrangement provides an inlet conduit 4 for steering, a damping valve 11 having a damping piston 12 centered by springs 13, 14 and closing off a branch conduit 6 which stops flow to the metering pump 5.

Abstract: A hydrostatic steering device is provided with a pump connected with a reservoir, a steering valve, a controlled-volume pump that is capable of being activated by a steering wheel and with a steering cylinder. The steering mechanism has a variable working flow and a constant pilot flow, with the pilot stream flowing through a constant throttle and the pressure drop through the constant throttle serving as a control signal for the conveying flow in a pressure delivery line. The controlled-volume pump is coupled mechanically with an adjustment throttle through which the pilot flows. Between the constant throttle and the adjustment throttle lies a pressure compensator that is controlled by the adjustment throttle's differential pressure. To receive the load signal, a control line branches off between the constant throttle and the pressure compensator and leads to the pump or, in the case of a fixed displacement pump with a rear-position flow-dividing valve, to the flow-dividing valve.

Abstract: A vehicle steering system having more than one set of steerable wheels includes a hydrostatic steering unit connected in fluid communication with actuatable hydraulic steering motors operatively coupled with one set of wheels. The hydraulic steering motors are actuated when hydraulic fluid is applied thereto. Steering movement of the one set of wheels is effected in response to actuation of the hydraulic steering motors. The hydrostatic steering unit has an input shaft drivingly connected with an output shaft of an electric motor. The speed and direction of rotation of the output shaft of the electric motor, and hence the speed and direction of rotation of the input shaft of the hydrostatic steering unit, is controlled in response to a control output signal from a microcomputer. The control output signal from the microcomputer is generated in response to the magnitude and direction of steering torque applied to the steering wheel, the vehicle speed, and the positions of the sets of steerable wheels.

Abstract: A hydraulic system having multiple actuators is provided with positive pressure flow equalization for both advancing and retracting movements of the system by means of first and second flow divider elements for each actuator. The flow divider elements are cross-coupled between the actuators, a controllable source of pressurized fluid and a reservoir. The flow divider elements are positive-displacement gear or vane pump units that are connected by a common shaft for coordinating fluid flow to the various actuators. Two or more of the actuators can be connected for lifting a load such as an automobile, the system being provided with safety latches at each actuator, the flow dividers not only coordinating the actuator movements during normal raising and lowering operation, but also preventing loss of synchronization of the actuators in case of engagement of a subset only of the latches.

Abstract: An impact power tool for delicate hand working operations is provided which is especially adapted for detailed engraving, carving, and delicate stone setting applications. The power tool preferably includes a hand-held impact device, a piston received within the body of the device and shiftable therein for delivering impact energy to the device, conduit for delivering and venting motive fluid from and to the hand-held device for shifting of the piston, and a valve coupling the directing and venting conduits to the device in alternative fashion at rapid, variable, cyclical rate. The impact tool may be operated by connection to a standard source of pressurized air. The tool is capable of providing a greater range of impact strokes per second than conventional hand-held controlled impact tools, and thereby provides expanded capability for extremely delicate and fine engraving, carving and stone setting work.

Abstract: This invention relates to integrated electro-hydraulic actuators for use aboard aircraft or elsewhere. A balanced, double-acting hydraulic ram or motor (12) is connected between a support (16) and a member to be moved relative to the support. The ram includes first and second changeable volume hydraulic chambers (30, 32). A reversible hydraulic pump (38) is connected by a pair of conduits (44, 46) to the ram chambers (30, 32). The pump (38) displaces hydraulic fluid from one chamber to another for the purpose of causing a pressure differential between them. A hydraulic accumulator (60) provides leakage makeup fluid to the actuator, and further provides a quiescent pressure to the actuator when it is in a substantially nonoperative condition. A conduit (62) may connect the accumulator (60) to the ram (12). A laminar leakage flow path within the actuator permits hydraulic connection of the accumulator (60) to the ram (12) without use of valves.

Abstract: The invention in a preferred embodiment contemplates a dual-lift hydraulic arrangement in which each of two hydraulic-lift systems employs a power integrator in the connection between a charged hydraulic accumulator and a hydraulic actuator for cable suspension of a load. The accumulator may be a single device serving the respective hydraulic systems, each of which terminates in a traction cylinder for operating a cable lift for its end of the load suspension. A single prime mover serves both power integrators, and the pressurized charge of the accumulator is advisedly set to accommodate (counterbalance) a predetermined average of the combined load on the two actuators. The arrangement lends itself to single-handed control of both hydraulic systems and to the corrective tilt orientation of a load which may be relatively heavy at one end and relatively light at the other end.

Abstract: A piston sealed by a rolling membrane is arranged in a cylindrical housing comprising two components and this piston translates against the force of a return spring. A vibrating armature pump driven via two wires by a variable alternating voltage serves for operating the positioning drive. The vibrating armature pump draws hydraulic fluid from a reservoir chamber through an inlet opening and transports the hydraulic fluid through a return valve and through a first orifice into a pressure chamber. The piston is displaced downwardly conjointly with a piston rod. The pressure generated by the vibrating armature pump is dependent upon the applied voltage. A state of equilibrium between this pressure and the counterpressure of the spring arises such that the positioning drive is suitable for continuous control or regulation operations.

Abstract: In a hydrostatic auxiliary power steering apparatus, a short-circuit passage of a control valve establishes a restricted flow path from a pump pressure line to a reservoir return line in the neutral position of the control valve wherein all other flow paths are blocked. A fixed flow restrictor in the pump pressure line conducts a continuous flow from one of two pumps connected to the pressure line for regulation of the fluid power steering circuit by the pressure drop across the flow restrictor. If one of the pumps is of the variable volume type, the pressure downstream of the flow restrictor is utilized to regulate pump flow adjustment. If fluid under operating pressure is supplied to both the fluid power steering circuit and another fluid operating circuit, a flow dividing valve controlled by the pressure differential across the flow restrictor distributes pressurized fluid between the two fluid circuits.

Abstract: A pumping unit for a well pump has a surface main cylinder with a main piston reciprocable therein, the piston having a connection to a standard well pump. In a flow cylinder of a relatively large diameter, a flow piston reciprocates within and divides the flow cylinder into a first flow chamber and a second flow chamber. The first flow chamber is in communication with the main cylinder. Air under pressure substantially to counterbalance the load on the well pump connection is supplied to the second flow chamber. There is a drive cylinder divided into a first drive chamber and a second drive chamber by a drive piston connected to but substantially smaller in diameter than the flow piston.

Abstract: In a mineral mining installation employing a series of shifting rams for advancing a scraper-chain conveyor provided with a guide for a mining machine a control system with a central control station for transmitting control signals. The control signals serve to actuate local control valves, possibly in time dependence, to cause a selected one or group of metering devices to transfer a pre-determined volume of pressure fluid to one or more of the rams to effect said advancement. This volume of pressure fluid is some fraction of the total capacity of the ram or rams in question so that by repeatedly transmitting control signals the device or devices can perform successive cycles of operation to thereby cause the ram or rams associated therewith to extend in defined increments.