Abstract: [Problem] To provide a large hydraulic excavator permitting an easy change from a machine mode corresponding to a backhoe excavator to a machine mode corresponding to a loader excavator, and vice versa. [MEANS for Solving the Problem] Arranged are a hydraulic circuit 1 provided with hydraulic pumps 11-18 and directional control valves 21-35, solenoid valves 41-43, 51-66 for controlling hydraulic pumps 11-18 and the directional control valves 21-35, and a controller 70 for controlling the solenoid valves 41-43, 51-66 in accordance with operation of control lever devices 80-83 and control pedal devices 84-87. The controller 70 performs control of the solenoid valves 41-43, 51-66 in a backhoe mode or loader mode selectively instructed by a mode instruction means 71.

Abstract: A displacement-controlled hydraulic system for installation on a multi-function machine, and multi-function machines equipped with the hydraulic system and having devices for propelling the machine, at least a first implement, and multiple actuators that perform multiple functions of the machine. The multiple actuators include first actuators that control the first implement and second actuators that control the propelling devices. The hydraulic system comprises multiple pumps for controlling the first actuators and optionally the second actuators, and valves that enable at least one of the pumps to sequentially control two of the multiple actuators and a corresponding two functions of the multiple functions performed thereby. None of the pumps sequentially controls the second actuators in combination with any of the first actuators.

Abstract: The present invention overcomes drawbacks whereby the supply of pressure oil to a hydraulic cylinder for operating a ground working device is temporarily cut, and operation of the ground working device is temporarily stopped when a control valve for the travel device is operated while a control valve for the ground working device is being operated. When control valves (V4, V5) for the travel devices are operated during operation of control valves (V6, V7, V8) for the ground working device, and a first flow channel switching valve (V12) is switched from an operating position (31) to a travel position (34), a second flow channel switching valve (V13) is switched from a non-feeding position (39) to a feeding position (40) before or at the same time as the first flow channel switching valve (V12).

Abstract: A hydraulic driver for powering the conditioner mechanism on an agricultural mower-conditioner, the hydraulic driver being powered by the same hydraulic power circuit that powers the cutting mechanism, but which includes controls for varying the speed and/or direction of rotation of the conditioner mechanism independent from the speed of the cutting mechanism.

Abstract: A hydraulic circuit for a construction machine is disclosed, which can prevent an energy loss of a hydraulic system by automatically reducing revolution of an engine when a working device such as a boom is not driven. The hydraulic circuit includes first to third hydraulic pumps, a first switching valve, a second switching valve, a third switching valve, a confluence switching valve, a first shuttle valve selecting any one of a pressure of a first signal line in which a signal pressure is formed when the third switching valve for working devices connected to the third hydraulic pump is shifted and a pressure of a second signal line in which a signal pressure is formed when a switching valve for traveling devices is shifted, and a second shuttle valve selecting any one of the pressure selected by the first shuttle valve and a pressure of a third signal line in which a signal pressure is formed when switching valves for the working devices connected to the first and second hydraulic pumps are shifted.

Abstract: In a shifting unit (1) for a vehicle transmission gearbox, the switching unit comprising valves which are connected between with one another by a pressure supply line conduit (58) and by a pressure exhaust line (60) associated with a switch chamber (10) of a switch cylinder (2). The switch chamber (10) of switch cylinder (2) has exhibits at least one opening valve (26) and at least one closing valve (28) through additional valves (62, 64, 66, 68); and the pressure supply line (58) and the pressure exhaust line (60) are separately closed, opened, blocked and/or swapped.

Abstract: The invention relates to a hydrostatic drive having one hydraulic pump unit (3) and at least one first hydraulic motor unit (14) and a second hydraulic motor unit (15). The first hydraulic motor unit (14) and the second hydraulic motor unit (15) are connected in parallel with the hydraulic pump unit (3) in a hydraulic circuit. A flow divider (80) is provided between the two hydraulic motor units (14, 15) and the hydraulic pump unit (3). The first working line (7) connecting the flow divider (80) with the hydraulic pump unit (3) is connected to a pressure control valve (23).

Abstract: An axle driving apparatus includes a first housing having a plurality of cooling fins, an axle rotatably mounted in the first housing, a hydraulic stepless speed change assembly disposed within the first housing. The axle driving apparatus also includes a second housing having a plurality of cooling fins, an axle rotatably mounted in the second housing, a hydraulic stepless speed change assembly disposed within the second housing. A connecting means, such as a bar and/or plate connects the first and second housings. The plurality of cooling fins on the first housing has a different configuration that the plurality of cooling fins on the second housing.

Abstract: A hydrostatic transmission including a main pump, two main ducts serving respectfully as feed and as discharge for first and second hydraulic motors that serve to drive disposed one after the other. A bypass valve can take up a reduced-speed position in which the feed main orifices are connected to the discharge main duct, and an increased-speed position in which one of the motors is bypassed, the feed main orifice of the motor being connected to the discharge main duct via a bypass link, while the other main orifices continue to have their respective links. The apparatus further includes a constriction suitable for being activated to restrict the flow of fluid through the bypass link.

Abstract: A machine having a hydraulic power management system. The machine includes an internal combustion engine driving first and second fixed displacement pumps to produce a combined flow of pressurized fluid. Main and auxiliary implements are operable in response to a flow of pressurized fluid, and a control valve selectively directs the combined flow to the main and auxiliary implements. A power management system is operable to stop the flow of pressurized fluid to the main implement from the second pump when the pressure of the combined flow exceeds a pressure indicative of the impending engine stall. A means for providing the combined flow to the auxiliary implement without regard to the pressure of the combined flow is also provided, and may take the form of a power management override or bypass mechanism.

Abstract: A hydraulic energy recovery and a mechanical drive system in one unit that also provides integral mounting of hydraulic pump/motors for primary drive, secondary drive, and pumps for cooling, lubrication, and low pressure systems along with a mounting position for a power take-off device.

Abstract: Hydrostatic transmission apparatus for a vehicle having a front group of drive members and a rear group of drive members, a pump, a front motor and a rear motor contributing to driving respective ones of the front and rear groups of drive members; a first one of the motors and a second one of the motors connected to the first motor via a series duct also being connected to the main orifices of the pump, thereby constituting a closed transmission circuit; at least one pressure-limiting valve being interposed between the series duct and a low-pressure circuit, and being suitable for connecting the series duct to the low-pressure circuit while being controlled as a function of the high pressure of the pump. The pressure in the series duct is thus effectively limited to a pressure representative of the pressure necessary for driving the vehicle.

Abstract: A propulsion system is for a road milling machine with a rotatable cutter drum (3). The system includes four crawler assemblies (12) movably coupled with the mainframe so as to define front and rear, and left and right, pairs of crawler assemblies. Four steering actuators (14) are each coupled with a separate crawler assembly and each angularly displaces the crawler about a vertical axis (12a). A first pump (16A) is fluidly coupled with the left pair of crawlers and a second pump (16B) is fluidly coupled with the right pair of crawlers. A control (20) is configured to selectively operate the four actuators in a plurality of different steering modes, one steering mode being a circle steer mode, and to operate the two pumps such that one of the left and right pairs of crawlers are drivable by the first pump in one direction while the other pair of crawlers are drivable in an opposing direction.

Abstract: An HST unit includes a first hydraulic motor unit for operatively driving one of a pair of driving wheels; a second hydraulic motor unit for operatively driving the other one of the pair of driving wheels; a hydraulic pump unit operatively connected to a driving power source, the hydraulic pump unit configuring a traveling hydrostatic transmission in cooperation with the first and second hydraulic motor units; and an attachment frame for supporting the first hydraulic motor unit, the second hydraulic motor unit and the hydraulic pump unit, the attachment frame being attachable to a vehicle frame.

Abstract: The present invention relates to a drive system (100) applied to the mechanism for discharging solids and regulating flows of a reactor vessel (300), reducing the degree of freedom between the components of the distributor element, increasing the definition of its movements and consequently providing more uniform and precise flow discharge. The drive system (100) comprises an actuator piston (101) affixed to a fixed support (400), a transmission rod (103) and a drive rod (106) connected to the scrapper rings (301). The transmission (103) and drive (106) rods are connected by a vertical joint (105).

Abstract: A module for use in connection with a dual pump apparatus, where each pump is hydraulically connected to a separate hydraulic motor. The module may include motors and/or an engine for ease of installation in a vehicle, providing flexibility for different applications. Various brackets, stabilizers and other elements are provided to assist in securing the module to the vehicle.

Abstract: A hydraulic power transmission device in a work vehicle transmits motive power from two hydraulic motors disposed in parallel to each other. The hydraulic power transmission device includes: a case; a first motor shaft and a second motor shaft respectively disposed in a right-side area and in a left-side area inside the case, each linked to one of the two hydraulic motors; a counter shaft disposed in an area ranging between the first motor shaft and the second motor shaft in the case; an output shaft; a first transmission mechanism that transmits motive power from the first motor shaft to the output shaft via the counter shaft; a second transmission mechanism that transmits motive power from the second motor shaft to the output shaft; and a hydraulic clutch device disposed at the counter shaft, that transmits the motive power from the first motor shaft to the output shaft or cuts off transmission of the motive power.

Abstract: A dual pump apparatus for use on a vehicle or industrial application having a housing in which a pair of hydraulic pumps are mounted and driven by a prime mover. The prime mover is drivingly coupled to a main input shaft, which drives the hydraulic pumps. An auxiliary pump may be drivingly coupled to the main drive shaft and a power take off unit may also be connected thereto. The power take off unit may be driven by a power take off unit output drive shaft, on which a cooling fan may be attached.

Abstract: A hydraulic circuit that enables smooth absorption of the energy of a return fluid from a hydraulic actuator by means of an energy recovery motor. A return fluid passage to which the fluid discharged from a boom cylinder is branched is provided at the tank passage side of a solenoid valve of a boom control circuit. The return fluid passage comprises two return passages, which are provided with a flow rate ratio control valve for controlling a ratio of fluid that branches off into the return passages. The flow rate ratio control valve is comprised of a solenoid valve disposed in the return passage, which is provided with an energy recovery motor, and a solenoid valve disposed in the return passage, which branches off the upstream side of the solenoid valve.

Abstract: A hybrid system for a machine is disclosed. The system has a pump configured to generate fluid flow within a hydraulic system and a first actuator actuated by fluid pressurized by the pump. The system also has a first motor configured to be selectively actuated by pressurized fluid directed from the first actuator by an external load and directed to the first motor by a first control valve. The system further has a first generator configured to be actuated by the first motor and a power source configured to actuate the pump. The system also has a powertrain including a first driveshaft and at least one traction device, the powertrain configured to transfer kinetic energy from the traction device to the first driveshaft during deceleration of the machine. The system further has a second generator configured to be selectively actuated by the kinetic energy transferred by the powertrain.

Abstract: A hydraulic four-wheel-drive working vehicle includes a front/rear differential-lock switch valve. The front/rear differential-lock switch valve fluidly connects forward-movement high-pressure lines of the pair of main operation fluid lines, which are fluidly connected to a main hydraulic motor, and the pair of sub operation fluid lines, which are fluidly connected to a sub hydraulic motor, and also fluidly connects the forward-movement low-pressure lines of the pair of main operation fluid lines and the pair of sub operation fluid lines. The front/rear differential-lock switch valve is capable of taking a throttling fluid-connection state of fluidly connecting the corresponding lines in a state where a throttle is interposed therebetween and a full fluid-connection state of fluidly connecting the corresponding lines in a state where the throttle is not interposed therebetween.

Abstract: A straight traveling hydraulic circuit is disclosed, which, in the case of performing a combined operation in which working and traveling devices are simultaneously driven, can prevent a declination of equipment due to an overload of the working devices. A straight traveling valve is shifted to supply the hydraulic fluid from the first hydraulic pump to the left and right traveling motors and to supply the hydraulic fluid from the second hydraulic pump to the first and second working devices. A control valve connects inlet and outlet parts of the straight traveling valve, and is shifted, when the combined operation is performed, to intercept a supply of the hydraulic fluid from the second hydraulic pump to the traveling motor.

Abstract: A system and method for substantially simultaneously shifting the speed of a plurality of multiple-speed motors that have shifting valves. The system and method includes substantially simultaneously applying an equal shifting force to all shifting valves, resisting shifting of all shifting valves with an equal biasing force arising from deflection of springs contained in springs chambers, and fluidly communicating all spring chambers with a common receptacle to equalize the pressure in all spring chambers.

Abstract: A dual pump apparatus for use on a vehicle or industrial application and having a pair of hydraulic pumps that are disposed in separate chambers within a housing. A pair of input shafts are disposed within the housing to drive the respective hydraulic pumps and one of the input shafts engages a prime mover. A charge pump may be mounted on an end cap, and trunnion arms for controlling the hydraulic pumps may extend out of opposite sides of the housing. An auxiliary pump may also be mounted on one of the input shafts and may be located either at the input end thereof or on the opposite side of the housing.

Abstract: A swing control circuit is provided separately from a hydraulic actuator control circuit. The swing control circuit includes a swing pump motor connected to closed circuits of a swing motor through a solenoid valve that serves as a directional control valve. A swing motor generator is connected to the swing pump motor. The swing motor generator is connected to an electric power storage device of a hybrid type drive system. An exterior-connecting passage for feeding hydraulic fluid to hydraulic actuators of a lower structure and a work equipment is drawn from a pipeline between the swing pump motor and the solenoid valve. A connecting passage solenoid valve is disposed in the exterior-connecting passage. The invention enables hydraulic energy generated in the swing system to be directly fed to the outside of the swing system.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, a pump operating at a range of pump speeds for converting between mechanical energy and hydraulic energy, and a motor operating at a range of motor speeds for converting between hydraulic energy and mechanical energy. The pump and motor are both fluidly connected to the high and low pressure storage devices. The hydraulic drive system further includes a control valve fluidly connected to the high pressure storage device, the pump and the motor, the control valve being operable to selectively distribute high pressure fluid between the pump, motor and high pressure storage device.

Abstract: A ground engaging vehicle including a movable member, a hydraulically driven actuator, a hydraulic pump, a plurality of valves and at least one hydraulic conduit. The hydraulically driven actuator is coupled to the movable member and the actuator has a first chamber and a second chamber. The plurality of non-proportional valves include a first valve, a second valve, a third valve and a fourth valve. The at least one hydraulic conduit couples the pump with the first valve and the second valve. The first valve is in direct fluid communication with the first chamber. The second valve is in direct fluid communication with the second chamber. The third valve is in direct fluid communication with the first chamber and the fourth valve is in direct fluid communication with the second chamber. The first valve and the second valve each include an open position and a closed position.

Abstract: A smart flow sharing system, useful in hydraulic systems having more than one hydraulically demanding equipment function wherein more than one of the hydraulically demanding functions are sometimes activated at the same time, has modified hydraulic passages and at least two fixed displacement pumps. The system automatically prioritizes hydraulic fluid flow so that when only one of two hydraulically demanding functions is activated by an operator, it receives the hydraulic fluid flow from both fixed displacement pumps, but when both hydraulically demanding functions are activated, one of the functions receives hydraulic fluid flow from the first fixed displacement pump, and the other function separately receives hydraulic fluid flow from the second fixed displacement pump. The smart flow sharing system accomplishes the foregoing without resorting to complex hydraulics or expensive additional components.

Abstract: A variable capacity pump and two variable capacity motors are connected in a closed circuit. First to fourth drive gears are fitted to motor shafts of the variable capacity motors via clutches. A first driven gear, which meshes with the first and third drive gears, and a second driven gear which meshes with the second and fourth drive gears are fitted to an output shaft. Equivalent capacities of the variable capacity motors are made different. Control is exerted such that the capacities are decreased to zero in order of equivalent capacities. To decrease the capacity of each variable capacity motor, the gear change ratio of the variable capacity motor the capacity of which has decreased to zero is changed to decrease the equivalent capacity and, at the same time, the capacity is increased to maximum. This increases the gear change ratio for the continuously variable transmission and controls acceleration.

Abstract: A drive apparatus for a zero turn vehicle or similar application comprising a pair of pumps mounted in a common housing and having coaxial input shafts and an input shaft mounted in the common housing perpendicular to the two pump shafts. A pair of center sections or end caps including hydraulic porting are mounted to opposite ends of the common housing, and each center section has a hydraulic motor mounted thereon external to the common housing.

Abstract: An apparatus for increasing an operation speed of a boom on excavators is disclosed, which enables an unskilled operator to conveniently manipulate a working device by decreasing a rotation speed and increasing a lifting speed relatively when the excavator performs combined operation of boom lift and swing drive to improve its working efficiency. The apparatus includes first and second hydraulic pumps, a first actuator, a pair of second actuators, first to third control valves, a block valve installed in a flow path between the selected second actuator and the second control valve, supplying the hydraulic fluid from a second hydraulic pump to the selected actuator only when the second actuators are driven to be switched according to a control signal of boom lift at combined operation in which the first and second actuators are simultaneously driven, to replenish the first actuator with the hydraulic fluid to be supplied to the second actuator.

Abstract: The present invention relates to a hydraulic drive system for driving an apparatus, with a drive unit, a first and a second hydraulic displacement machine, with which the drive unit is connectable or connected for transmitting mechanical energy, and a third and a fourth hydraulic displacement machine, which are connectable or connected with the apparatus for transmitting mechanical energy, wherein the first hydraulic displacement machine is hydraulically connected or connectable with the third hydraulic displacement machine, and wherein a high-pressure accumulator is provided, which is hydraulically connected or connectable with the second and the fourth hydraulic displacement machine.

Abstract: The invention relates to an excavator or to a machine for material transfer comprising an element movable via at least one hydraulic cylinder. In accordance with the invention, one or more hydraulic cylinders are additionally hinged to the element, with the additional hydraulic cylinder(s) being connected to one or more hydraulic accumulators.

Abstract: An axle driving apparatus for being mounted on the body frame of a vehicle and for independently rotating drive wheel members. The axle driving apparatus includes a first axle driving unit (18L) having a housing (40) and a single axle (20L), the single axle (20L) defining a proximal end portion rotatably mounted in the housing (40) and a distal end portion extending outwardly from a first side of tile housing (40). An enlarged region is defined by the housing (40), with the enlarged region extending substantially perpendicular to the longitudinal axis of the single axle (20L). A hydraulic stepless speed change assembly (22) is disposed within the enlarged region. The speed change assembly (22) includes a hydraulic pump (52) having an input shaft (21) projecting from the enlarged region aid includes a hydraulic motor (55) including an output shaft (74) drivingly connected to the single axle (20L).

Abstract: A hydraulic drive system comprises directional flow control valves (10a-f) for selectively supplying a hydraulic fluid from a first hydraulic pump (1a, 1b), inflow control valves (201-203) disposed respectively in branch lines (150A-C) branched from a supply line (100) for supplying a hydraulic fluid delivered from a second hydraulic pump (3a, 3b) to rod pushing-side chambers (5aA, 5bA, 6A, 7A) of hydraulic cylinders, a bypass flow control valve (204) disposed in a line (104) connecting the supply line (100) and a reservoir (2), and a controller (31) for computing control variables corresponding to operation command signals from control levers (32, 33) and controlling the inflow control valves (201-203) and the bypass flow control valve (204) in accordance with the computed control variables. Thus, the number of flow control valves and the length of piping required for their connection can be reduced, and a total pressure loss can be further reduced.

Abstract: The objective of the present invention is to provide a device that accurately communicates a subtle variation of an operation side to an action side. Specifically, in the present invention, an operating device is provided to perform a lock release operation of an extension device. The operating device feeds oil to a valve chamber by pressing a piston. When the flow rate of the fed oil is excessive, the valve is pressed to an opening resisting a biasing force of a compressed spring, thereby a rapid increase in the oil supplied to the action section is suppressed. Further, the supplied oil is suppressed to a very small amount by the throttle section, thereby an increase in the operation amount on the action section side is suppressed while maintaining the supply of the oil.

Abstract: A hydraulic transaxle has an axle casing and a pair of hydraulic motors disposed in the axle casing. The hydraulic motors have respective motor shafts and respective moveable swash plates. An axis of tilt of each moveable swash plate is offset with respect to a longitudinal axis of the respective motor shaft, and the moveable swash plates are operatively engaged to a steering operation device.

Abstract: An axle driving apparatus for being mounted on the body frame of a vehicle and for independently rotating drive wheel members. The axle driving apparatus includes a first axle driving unit (18L) having a housing (40) and a single axle (20L), the single axle (20L) defining a proximal end portion rotatably mounted in the housing (40) and a distal end portion extending outwardly from a first side of the housing (40). An enlarged region is defined by the housing (40), with the enlarged region extending substantially perpendicular to the longitudinal axis of the single axle (20L). A hydraulic stepless speed change assembly (22) is disposed within the enlarged region. The speed change assembly (22) includes a hydraulic pump (52) having an input shaft (21) projecting from the enlarged region and includes a hydraulic motor (55) including an output shaft (74) drivingly connected to the single axle (20L).

Abstract: An actuation system for a servo-assisted transmission; the actuation system is provided with: a hydraulic circuit comprising a reservoir containing a control fluid, a hydraulic accumulator containing the pressurized control fluid, and a pump which draws from the reservoir and feeds the hydraulic accumulator; at least a hydraulic actuator comprising at least one actuation chamber and a mobile piston which slides within the actuation chamber; a solenoid valve for connecting the actuation chamber of the hydraulic actuator to the hydraulic accumulator and to the reservoir; and a recirculation circuit, which departs from at least one environment bordering with the actuation chamber of the hydraulic actuator and ends in the reservoir.

Abstract: The invention relates to an axial piston machine having a first group of pistons (34.1) for delivering into a first hydraulic circuit and a second group of pistons (34.2) for delivering into a second hydraulic circuit. The pistons (34.1) of the first group and the pistons (34.2) of the second group are supported on a common slanted swash plate (37?) and the slanted swash plate (37?) can be slanted to a first swivel axis (55) in order to regulate a first delivery volume of the first group of pistons (34.1) in the first hydraulic circuit (55) and to a second swivel axis (56) in order to regulate a second delivery volume of the second group of pistons (34.2) in the second hydraulic circuit.

Abstract: A hydraulic distributor 10 assembles in a single body an assembly of hydraulic components that assure the supply of actuators for controlling the movements of the moving elements of an airplane landing gear, for which the movements of the landing-gear legs and of the trap-doors are assured by hydraulic actuators. The airplane includes two or more landing-gear systems, each including a distributor 10 with a single body. The body of each single-body distributor is advantageously created by removing unused parts from a body that can satisfy the needs of all of the landing-gear systems of an airplane, or by addition of extensions onto a minimal body that can satisfy the needs common to all of the landing-gear systems of the airplane.

Abstract: An axle driving apparatus for being mounted on the body frame of a vehicle and for independently rotating drive wheel members. The axle driving apparatus includes a first axle driving unit (18L) leaving a housing (40) and a single axle (20L), the single axle (20L) defining a proximal end portion rotatably mounted in the housing (40) and a distal end portion extending outwardly from a first side of the housing (40). An enlarged region is defined by the housing (40), with the enlarged region extending substantially perpendicular to the longitudinal axis of the single axle (20L). A hydraulic stepless speed change assembly (22) is disposed within the enlarged region. The speed change assembly (22) includes a hydraulic pump (52) having an input shaft (21) projecting from the enlarged region and includes a hydraulic motor (55) including an output shaft (74) drivingly connected to the single axle (20L).

Abstract: A hydraulic system for synchronized movement of multiple cylinders in a horizontal plane includes a bidirectional pump, a shuttle valve cross-connected between pump outlets, flow-control check valves, and control valves which combine to reduce the number of valves in the hydraulic circuit and to reduce total cost of components for the system. The shuttle valve of the hydraulic system provides fluid for resynchronizing extension and retraction of multiple cylinder assemblies without disconnection of lines, provides air removal without disconnection of lines, allows easy addition/refill of hydraulic fluid, and allows excellent control of the extendable cylinder assemblies.

Abstract: A drivetrain for use in a mobile vehicle is disclosed. The drivetrain may have a housing, a first hydraulic pump connected to the housing, and a second hydraulic pump connected to the housing. The second hydraulic pump may be in axial alignment with the first hydraulic pump. The drivetrain may also have a first motor fluidly connected to the first hydraulic pump, and a second motor fluidly connected to the second hydraulic pump. The first and second motors may have an axial direction substantially perpendicular to the axial alignment of the first and second hydraulic pumps.

Abstract: A hydrostatic transmission assembly includes a first gerotor motor, a pump housing, a first variable displacement pump, a second gerotor motor, and a second variable displacement pump. The first gerotor motor includes a first output shaft aligned along a first axis. The pump housing connects to and contacts the first gerotor motor. The first variable displacement pump includes a first driven shaft mounted to the pump housing and aligned along a second axis, the second axis being generally perpendicular to the first axis (the first output shaft axis). The first variable displacement pump is in fluid communication with the first gerotor motor via passages in the pump housing. The second gerotor motor includes a second output shaft generally aligned along or generally parallel to the first axis. The second gerotor motor is connected to the pump housing on an opposite side of the pump housing as the first gerotor motor.

Abstract: Disclosed are a control arrangement and a method for the pressure medium supply of at least two hydraulic consumers that are supplied with pressure medium through the intermediary of a variable displacement pump. In the pressure medium flow path between the consumers and the variable displacement pump a respective meter-in orifice is provided. An adjustment of the variable displacement pump and of the meter-in orifices takes place electronically through the intermediary of a control means in dependence on the target values input by an operator. In accordance with the invention, the meter-in orifice associated with the consumer having the highest load pressure is controlled to open completely, so that the pressure loss across this meter-in orifice is minimum.

Abstract: The present invention provides a pump unit including at least one hydraulic pump with inlet and outlet ports, a pump case for accommodating the hydraulic pump having an opening through which the hydraulic pump is insertable, and a lid, called a center section, closing the pump case. The center section forms a pair of inlet/outlet passages communicating an end with the inlet and outlet ports of the hydraulic pump and an end opening through a pump case abutting surface of the center section, and a first charging passage by which hydraulic fluid is fed through the pump case abutting surface of the center section. At least one of the pump case and the center section communicates the first charging passage with the pair of inlet/outlet passages via a first hydraulic fluid feeding valve preventing the reverse flow into said first charging passage.

Abstract: The present invention provides a tandem pump unit that includes: a first hydraulic pump and a second hydraulic pump respectively having a first pump shaft and a second pump shaft respectively having adjacent ends connected together so that the first and second pump shafts are coaxially aligned and non-rotatably connected in tandem; a common housing for accommodating the first hydraulic pump and the second hydraulic pump; and a first center section and a second center section that respectively support the first and second hydraulic pumps.

Abstract: Control device 1 having a changeover valve 5, a pump 4 delivering operating medium, in particular a motor-operated pump or a hand pump, connection devices for connecting the control device 1 to at least two tools, in particular a first lifting cylinder 2 and a second lifting cylinder 3 or the like, the changeover valve 5 being operable in particular by hand; wherein a) the changeover valve 5, when the operator lets go of it, can be brought automatically into a basic position in which no pressure build-up in the region of the tools is possible, b) a control valve 7 is provided between the changeover valve 5 and the tools, and c) the control valve 7 can likewise be operated by hand by an operator.

Abstract: The present invention provides a pump unit including at least one hydraulic pump with inlet and outlet ports, a pump case for accommodating the hydraulic pump having an opening through which the hydraulic pump is insertable, and a lid, called a center section, closing the pump case. The center section forms a pair of inlet/outlet passages communicating an end with the inlet and outlet ports of the hydraulic pump and an end opening through a pump case abutting surface of the center section, and a first charging passage by which hydraulic fluid is fed through the pump case abutting surface of the center section. At least one of the pump case and the center section communicates the first charging passage with the pair of inlet/outlet passages via a first hydraulic fluid feeding valve preventing the reverse flow into said first charging passage.