Abstract: A fluid-operated circuit for setting the top dead center and the bottom dead center of the punch actuation cylinder in punching machines comprises a first copying distributor which distributes pressurized fluid, which has a spool at one end and can be connected in output to the upper section of the chamber in which the actuation cylinder slides and in input to a first pump for feeding low-pressure fluid and to at least one first fast-acting electric valve element; the spool can be pushed into position by contact by a corresponding setting element with continuous micrometric movement.

Abstract: An arrangement structure of a swash plate hydraulic pump which can be used in a wide range of construction equipment and industrial vehicles and is small in size, simple in structure, and inexpensive is provided. For this purpose, an arrangement structure of a swash plate hydraulic pump (1) comprises a driving source (3) and a plurality of swash plate hydraulic pumps (4, 8) which are connected to the driving source and discharge pressurized oil, and the plurality of swash plate hydraulic pumps include at least one swash plate hydraulic pump (8) of the second and subsequent swash plate hydraulic pumps which has a driving shaft (9) provided on a plane almost perpendicular to a driving shaft (6) of the first swash plate hydraulic pump (4) coupled to the driving source.

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: A symmetric pump having a symmetric end cap attached to a symmetric housing is disclosed. The end cap is attachable in a first position or a second position wherein the second position is rotated relative to the housing. A trunnion arm extends in a first direction and a system port opens in a first orientation when the housing is connected to the end cap in a first position, The end cap includes structure such that the housing may be connected in a second position so that the trunnion arm extends in a second direction while maintaining the system port opening in the first orientation. The end cap may be provided with a symmetric porting system. A control device for affecting movement of the swashplate is disclosed. Methods of locking the swashplate into a predetermined position are also taught.

Abstract: A PC board actuator that emulates a muscle fiber includes a first pressure source, a second pressure source lower than the first source, at least one expansion chamber alternately communicating with the first and second pressure sources, first and second valves mounted with the PC board that opens and closes the chamber with respect to the first and second pressure sources, and an actuator member interacting with the expansion chamber to apply a force to the object. The actuator is preferably formed using planar batch technology and the valves preferably comprise electrically controllable flap valves mounted on the PC board. Alternatively, the actuator includes antagonistically arranged expansion chambers that operatively apply reciprocating forces to the object. In other embodiments, the actuator includes plural expansion chambers arranged in series or in parallel in order to increase the overall extent of attainable displacement or to amplify the force generated by the actuator.

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: A method for operating a hydraulic drive apparatus in which flows of oil discharged from a plurality of hydraulic drive sources each using a hydraulic pump are merged in order to drive an actuator. At least in a pressure control mode, one of the hydraulic drive sources (main hydraulic drive source) is operated in a regular manner, and the other hydraulic drive source (auxiliary hydraulic drive source) is operated such that at A merge point where the oil flows merge, the pressure of oil from the auxiliary hydraulic drive source becomes lower than the pressure of oil from the main hydraulic drive by a predetermined amount. Thus, an ordinary pressure control signal is applied to the main hydraulic drive to perform an ordinary pressure control.

Abstract: A travel motor hydraulic control system for a construction machine having a plurality of hydraulic pumps which supply individually pressurized fluid for a plurality of hydraulic travel motors and a plurality of flow control valves which control the flow rate of the pressurized fluid to be supplied to the motor during an ordinary work. A controller receives a control signal representative of a travel control lever stroke sensed by a position sensor and a control signal detected by a pressure sensor, determines if the vehicle is traveling up a slope, and transmits a command signal to a solenoid operated valve to move a pilot operated shut off valve toward a valve-closing position, thereby the travel hydraulic motors are individually supplied the pressurized fluid from the hydraulic pumps.

Abstract: A backhoe loader is provided with a reversible operator's seat having a first working position facing the loader and a second working position facing the backhoe. A first hydraulic pump directs pressurized hydraulic fluid through a first supply line to loader control valves, stabilizer control valves and backhoe control valves that are mounted in series. A second hydraulic pumps directs pressurized hydraulic fluid through a second supply line to the first supply line upstream from the loader control valves. The second supply line is provided with a two-position solenoid valve. In its first position, the valve directs pressurized hydraulic fluid from the second hydraulic pump to sump. In its second position, the valve directs pressurized hydraulic fluid from the second hydraulic pump to the first supply line. The solenoid of the two-position solenoid valve is in electrical communication with a seat switch signaling the working position of the operator's seat.

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: A material eject system includes an ejector mounted to a bed of a vehicle which is movable between a rear end and a forward end of the bed for ejecting material from the bed. The ejector is powered by a cylinder having different fluid volumes depending on the direction of motion of the cylinder. Two pumps having flow rates matching the different fluid volumes of the cylinder are used to power the cylinder in the different directions.

Abstract: A hydraulic circuit includes first and second pumps, a first discharge passage receiving hydraulic fluid discharged from the first pump and communicating with a main gallery, a second discharge passage receiving hydraulic fluid discharged from the second pump and communicating with an actuator, a communication passage ensuring communication between the first and second discharge passages, and a relief valve arranged with the communication passage to be opened at a predetermined pressure for the second discharge passage.

Abstract: A travel motor hydraulic control system for a construction machine having a plurality of hydraulic pumps which supply individually pressurized fluid for a plurality of hydraulic travel motors and a plurality of flow control valves which control the flow rate of the pressurized fluid to be supplied to the motor during an ordinary work. A controller receives a control signal representative of a travel control lever stroke sensed by a position sensor and a control signal detected by a pressure sensor, determines if the vehicle is traveling up a slope, and transmits a command signal to a solenoid operated valve to move a pilot operated shut off valve toward a valve-closing position, thereby the travel hydraulic motors are individually supplied the pressurized fluid from the hydraulic pumps.

Abstract: When simultaneous operation of rotating and arm pulling is detected by a detector, a switching controller recognizes that both signals are output simultaneously, and switches a switching valve to a second position, so that oil flows discharged from a plurality of hydraulic pumps are united and supplied to a rotating motor and an arm cylinder. A meter-in flow controller restricts a quantity of oil supplied to the arm cylinder. Thereby, even where rotating and arm pulling are operated simultaneously, each of operations can be done quickly, and the delay of the rotating operation is overcome, to enable proper rotating and arm pulling operations.

Abstract: A hydraulic circuit which, when applied to a turning excavator having hydraulic actuators for the working arms and the turning excavator body supplied with pressure oil from three pumps, can increase the operation speed of the booms and arms without providing a separate hydraulic pump to improve the work efficiency. During the individual driving, the boom cylinder (CY1) is supplied with a pressure oil from the first and third pumps (P1, P3), the arm cylinder (CY2) from the second and third pumps (P2, P3), the bucket cylinder (CY3) from the first pump (P1), and the turning motor (M) from the third pump (P3). During the simultaneous driving of the boom and arm cylinders (CY1, CY2), the arm is supplied with an operation speed increasing pressure oil from the third pump (P3). When the boom cylinder (CY1) and the turning motor (M) are simultaneously operated, a part of the pressure oil to the turning motor (M) from the third pump (P3) is supplied to the boom cylinder (CY2).

Abstract: This invention relates to a hydraulic circuit for a forklift, and intends to lift a fork for lifting in high speed, or to inch the fork little by little, as occasion demands. In this hydraulic circuit, a first electric motor for driving a first electric motor disposed on a first route extending from a tank to a lift cylinder is on-off controlled. A check valve disposed on the first route downstream of the first hydraulic pump allows only an oil-flow from the oil tank to the lift cylinder. A second motor for driving a second electric motor disposed on a second route extending from a tank to a lift cylinder is PMW-controlled. A flow controlling valve is disposed on the second route downstream of the second hydraulic pump and including an electro-magnetic valve operated associating with the PMW-controlling of said second electric motor. A separating element hydraulically separates the check valve and the electro-magnetic valve of the flow controlling valve.

Abstract: An improved pressure fluid supply and delivery apparatus is disclosed that has a pressure compensating function and yet a reduced loss in pressure. The apparatus includes a variable displacement hydraulic pump unit(10; 60, 61) having a plurality of fluid discharge ports(10a, 10b; 60a, 61a) independent each other and a common drive shaft. A plurality of fluid circuits (11, 12) are connected to the plural discharge ports (10a, 10b; 60a, 61a), respectively, and a plurality of fluid operated actuators (14, 16; 14, 14′, 16, 16′) are connected via respective operating valves (13, 15; 13, 13′, 15, 15′) to the plural fluid circuits (11, 12), respectively. Also included in the apparatus is a displacement control means (19, 20; 64, 64) operable in response to discharge pressures in the fluid discharge ports (10a, 10b; 60a. 61a) and load pressures in the actuators (14, 16; 14, 14′, 16, 16′) for controlling discharge fluid pressure of the variable displacement pump unit (10; 60, 61).

Abstract: A hydrostatic vehicle drive (1) comprises a first hydropump (2) and a second hydropump (3) as well as a first hydromotor (7) and a second hydromotor (12). The hydromotors (7, 12) each drive separate drive lines. During straight-ahead travel operation, the hydropumps (2, 3) and the hydromotors (7, 12) are coupled to one another in a single, closed hydraulic circuit without crossed connections in such a manner that an input connection (6) of the first hydromotor (7) is connected to an output connection (5) of the first hydropump (2) and an input connection (9) of the second hydropump (3) is connected to an output connection (8) of the first hydromotor (7). An input connection (11) of the second hydromotor (12) is connected to an output connection (10) of the second hydropump (3), whilst an input connection (14) of the first hydropump (2) is connected to an output connection (13) of the second hydromotor (12).

Abstract: Earthmoving machines are often provided with quick coupling devices that allow them to change work implements in a relatively rapid fashion when compared to changing conventionally mounted implements. A locking system between the machine linkage and the implement is positioned between the components and includes a hydraulic system which continually applies pressurized fluid to the locking system.

Abstract: A hydraulic circuit for a loader vehicle includes: a working machine hydraulic circuit (10); a steering hydraulic circuit (20); a variable displacement auxiliary hydraulic pump (50A), in which the displacement volume (Vs) becomes smaller as the operating oil pressure becomes higher, when the operating oil pressure exceeds a predetermined oil pressure by receiving the operating oil pressure of the working machine hydraulic circuit (10); a flow dividing valve (60), for switching and supplying oil discharge (Qs) from the auxiliary hydraulic pump to either one of the hydraulic circuits (10, 20), with a priority being given to the steering hydraulic circuit (20). One pump capacity control device includes a working machine hydraulic actuator (201); a working machine hydraulic pump (202); a working machine pump capacity control means (205); a working machine load detecting means (206a); and an engine speed detecting means (207).

Abstract: The present invention has an object to enable to supply a discharged pressurized fluid of a hydraulic pump without any energy loss with an arbitrary flow rate distribution ratio to a plurality of actuators. A discharged pressurized fluid of the hydraulic pump 11 is supplied to the first and second actuators 15 and 16 via the first and second variable displacement type hydraulic pump/motors 13 and 14. The first variable displacement type hydraulic pump/motor 13 and the second variable displacement type hydraulic pump/motor 14 are mechanically connected to rotate at the same revolution speed. By this, the pressurized fluid is supplied to the first and second actuators 15 and 16 depending upon displacements of the first and second variable displacement type hydraulic pump/motors.

Abstract: A fluid control system including a valve arrangement operable for selectively, controllably supplying pressurized fluid to a work element of the system from at least two pressurized fluid sources depending on load conditions on the pressurized fluid sources. The valve arrangement is operable for directing pressurized fluid from the first pressurized fluid source to the work element when a first or low load condition is present on the first pressurized fluid source and directing pressurized fluid from the second pressurized fluid source to the work element when a second or high load condition greater than the first load condition is present on the first pressurized fluid source and a low load condition is present on the second pressurized fluid source, such that operability of the work element and other work elements supplied by the pressurized fluid sources is maintained.

Abstract: A hydraulic circuit having a boost pump in series with a primary (tractor) hydraulic source provides additional fluid power to operate an aircart fan in an air seeding system for which a tractor hydraulic system does not have enough fluid power capacity. The boost pump raises the pressure of the flow delivered to the fan motor up from that pressure delivered from the tractor to a higher pressure. Tractor pressure is supplied to the boost pump inlet, the boost pump is driven by ground engaging wheels of the aircart, and the resulting flow to the aircart fan motor is increased in pressure by the boost pump.

Abstract: A hydraulic drive system includes a variable displacement pump unit having a rotor rotatably supported within a housing on a main rotor axis, and an input shaft coupled to the rotor by mating bevel reduction gears. A main pump includes a plurality of main hydraulic cylinders fixedly supported relative to the housing; a ring member supported by a journal at variable eccentricity; a plurality of pistons sealingly slidable in corresponding ones of the cylinders that are coupled by respective followers to the shaft input by the ring member for reciprocating movement; and inlet and exhaust one-way check valves fluid coupled to each of the cylinders. A hydraulic actuator of the pump unit moves the journal in response to fluid pressure.

Abstract: A hydraulic system for an aircart having a fan cooperable with an air seeder system to distribute material to the ground utilizes two or more fluid power sources combined in parallel. Total fluid capacity is increased so that one source may have reserve capacity for serving other loads. Flow controls for the system are set so that one source maintains at least a minimum flow to a load when the flow provided by the other source diminishes. Specifically, an aircart fan is operated by fluid power combined from a tractor source and a ground driven pump source with controls being provided to control the fin speed and proportions of flow from each source. The ground driven source (boost pump) boosts available fluid power volume to meet demands of the aircart fan. The boost pump is located near the aircart fan and connected with short lines to minimize power loss in the lines.

Abstract: A drive system for a mobile operating device. The drive system includes a drive motor driving a first variable-delivery hydraulic pump which is in fluid engagement with a first hydraulic motor, the first hydraulic motor being part of a hydraulic travelling drive. A second hydraulic motor drives at least one second variable-delivery hydraulic pump which is in fluid engagement with an operating hydraulic system for implementing device-specific functions.

Abstract: The present invention relates to a method of operating a winch, in which a rope which is wound onto a driven reel is supplied to at least one capstan head and wound around said capstan head, with a capstan drive rotating the capstan head and producing a rope advance due to the rope friction existing between rope and capstan head. Moreover, the present invention relates to a corresponding device. As an improvement of the method and the device, the invention suggests a reel drive which is adjusted separately next to the capstan drive.

Abstract: The present invention is a multiple pump transmission jack for use with removing and repairing transmissions. The jack has two hydraulic pumps mounted on a base which are connected with interrelated oil passages or conduits formed within the base, which is operated by a pedal connected with the two pumps for drawing hydraulic oil from a reservoir and into an oil pressure cylinder to easily and quickly raise a piston rod within the oil pressure cylinder saving the operator's effort and increasing the efficiency of operation. The jack also includes an overload system that prevents the operator from placing a load on the jack which is greater than its rated load, thus preventing danger.

Abstract: A tandem pump apparatus having a first hydraulic pump for supplying operating fluid to a first actuator and a second hydraulic pump for supplying operating fluid to a second actuator in cooperation with each other is disclosed. Each hydraulic pump is provided with a flow rate control valve for refluxing a surplus of flow discharged from the pump to a suction side of the pump through a relief passage. A connecting passage connects the first relief passage downstream from the first flow rate control valve and the second relief passage downstream from the second flow rate control valve. A check valve is provided in the connecting passage for allowing operating fluid to flow from one of the relief passages that has a relatively great reflux flow rate to the other relief passage having a relatively small reflux flow rate, thereby ensuring sufficient supercharge into the two pump to achieve sufficient restraint of cavitation.

Abstract: A hydraulic system for a motor vehicle having a first flow circuit for steering power assist and a second flow circuit for a radiator cooling fan. The first flow circuit includes a reservoir, a power steering pump connected to the reservoir through a first inlet conduit and a first return conduit, a steering assist fluid motor, and a first flow control valve. The second flow circuit includes the aforesaid reservoir, a second pump connected to the reservoir through a second inlet conduit and a second return conduit, a second fluid motor for the radiator cooling fan in the second return conduit, and a second flow control valve. Fluid in the first return conduit is conducted into the reservoir substantially without turbulence. Fluid in the second return conduit is conducted into the reservoir as a jet stream aimed at a submerged passage in a venturi tube. The submerged passage communicates with a feeder conduit between the reservoir and each of the first and the second inlet conduits.

Abstract: In a hydraulic cylinder actuation system for a crane having a conventionally charged main hydraulic pump, a supplemental pump or "charge boost" pump is provided. To efficiently achieve fast actuation speeds of the cylinder, the charge boost pump provides supplemental charge flow in response to a need in the system. The charge boost pump is driven independently from the main pump or may be driven by the main pump if the main pump is equipped with drive thru capability to provide a variable output and preferably includes a load sensing means for controlling the output.

Abstract: A hydrostatic transmission has a pair of overcenter variable displacement pumps, each having a flow control element controlled by a double acting actuator to control direction and flow rate of the pump. Fluid pressure in first and second chambers of each actuator are equal at a neutral position of the transmission. A forward control valve controllably communicates the first chambers of both actuators to a tank through a first orifice to reduce the pressure in the first chambers to simultaneously move the flow control elements in a first direction for forward travel. A reverse control valve controllably communicates the second chambers of both actuators to the tank through a second orifice to reduce the pressure in the second chambers to simultaneously move the flow control elements in a second direction for reverse travel.

Abstract: In addition to a first oil pump directly connected to an engine, a second oil pump is provided which is driven by an electric motor. Accordingly, a start clutch engaging pressure is applied through first and second solenoid-operated valves. The electric motor-driven pump is of the constant pressure type, and therefore its start, at the start of the automobile, can be achieved with a simple control program. After the start of the automobile, the solenoid-operated valve is switched over to the other one, so that the oil pressure is applied from the first oil pump directly connected to the engine, whereby the battery power consumption is minimized. This oil circuit is applied to various kinds of friction engagement clutches.

Abstract: A hydraulic axial piston machine, such as a high-pressure water discharge pump, may include a first subassembly having a plurality of cylinder-piston units arranged at a distance from, and either parallel to or at an acute angle to, a central axis. The cylinder-piston units may be circumferentially offset, relative to each other, around the central axis by a predetermined angle. The hydraulic axial discharge pump may also include a second subassembly which may be coaxially positioned and arranged for rotation around the central axis on a drive shaft and which may have a force-transmitting connection with the cylinder-piston units to receive oscillating drive forces of the cylinder-piston units. The drive shaft, which may include at least two rotationally coupled longitudinal sections, may extend coaxially to the central axis from its drive input end through at least one of a corresponding central opening of the first subassembly and of the housing to a head-subassembly.

Abstract: A hydrostatic transmission. The hydrostatic transmission generally comprises a sump containing hydraulic fluid, a charge pump in flow communication with the sump for creating high pressure hydraulic fluid from the hydraulic fluid, a center section having hydraulic porting formed therein, a hydraulic pump, a hydraulic motor drivingly connected to the hydraulic pump through the hydraulic porting, and a manifold defining a gallery for storing the high pressure fluid. The gallery is in flow communication with the charge pump and the hydraulic porting.

Abstract: The present invention relates generally to a hydraulic power unit for supplying hydraulic fluid under pressure to industrial equipment, and more particularly to an auxiliary hydraulic power unit that is adapted to mount to a vehicle and supply auxiliary hydraulic power to auxiliary equipment associated with the vehicle during operation in the field.

Abstract: Disclosed is a mobile hydraulic system with a hydraulic pump, which is powered by a battery powered motor and fed from a hydraulic reservoir, whereby the pump, the battery, the motor and the hydraulic reservoir are a compact, portable hydraulic unit, to which a working tool, which is separated from the portable hydraulic unit and is exchangeable, can be connected via a hydraulic connecting line of the hydraulic pump.

Abstract: A hydraulic control system is provided for use in a forklift truck having an engine, a steering cylinder, a lift cylinder, a tilt cylinder, a steering pump rotatably driven by the engine for producing a steering fluid under pressure to actuate the steering cylinder and a main pump for generating a working fluid under pressure to actuate the lift and tilt cylinders.

Abstract: A hydraulic circuit has a first PV pump connected to a valve group for powering a plurality of hydraulic mechanisms connected to the group, and a second PF pump connected in the circuit. In the improvement, a hydraulic line extends between the second pump and the valve group and there is a conductor sensing a mechanism load pressure. A valve network directs flow from the second pump to the valve group when the difference between the pressure in the hydraulic line and the load pressure declines below a predetermined value. Such decline "signals" that the mechanisms require more fluid than is available from the first pump alone. A new method for supplementing the flow of a first pump with that of a second pump is also disclosed.

Abstract: Means for connecting auxiliary pumps and charge pumps to an axle driving apparatus to transfer power from a light duty vehicle engine to an output axle, wherein the charge and/or auxiliary pumps are mounted to the external housing for an integrated hydrostatic transmission or to the external housing for a hydrostatic transmission which is connected to separate axle mechanisms.

Abstract: A bypass pressure regulator valve, having first and second regulator ports connected to a sump and each port supplied from the output side of a first and second pump, regulates the magnitude of line pressure in response to a control pressure produced by a variable force solenoid. A high pump feed select valve alternately connects the output of the first pump and the sump to the inlet of the second pump. Output from the first pump is directed through a torque converter clutch pressure regulator valve and a converter charge pressure regulator valve to a first inlet of the torque converter causing the torque converter to open and to a second inlet causing the torque converter to close. Hydraulic fluid is directed to lubrication circuits and through a transmission oil cooler.

Abstract: A valve range is suggested suitable for use in connection with the control of fluid operated equipment. It possesses a fluid manifold, which is able to be fitted with pneumatic valves, which are operated via a signal manifold electrically. The valve range is so designed that it is suitable for the combined operation or control both of pneumatic valves and also of hydraulic valves. For the control of hydraulic valves it is provided with at least one control connection, from which the respective control signals may be taken. It is in this manner that, starting with a central valve range both pneumatic and also hydraulic valves may be operated and controlled in a comparatively simple fashion.

Abstract: A hydraulic system 10 provides a positive supply of hydraulic fluid at a controlled pressure to plurality of pumps. The system comprises a fluid reservoir 15 having outlet means to supply fluid to an auxiliary pump 30. A pressure chamber 16 communicates with a reservoir 15 and has outlet means to supply fluid to a plurality of working pumps 11, 12, 13. An inlet manifold 18 is provided for receiving fluid returned from the working and auxiliary pumps.

Abstract: A hydraulic control system is designed to permit the use of a plurality of small substantially identical existing valve assemblies in place of a lesser number of larger valve assemblies. In one embodiment, a first pair of variable displacement load sensing hydraulic pumps communicate with a manifold connected to a first valve assembly and another pair of variable displacement load sensing hydraulic pump communicate with a second manifold connected to second and third valve assemblies. A crossover conduit interconnects the manifolds so that fluid from all four pumps can be used by any one of the valve assemblies or shared by two or all three of the valve assemblies. In another embodiment, a third pair of variable displacement load sensing hydraulic pumps communicate with the first manifold 12 which also has another valve assembly connected thereto.

Abstract: A method for controlling a drive for a hydraulic press employed for at least one of forming and cutting sheets of metal. The method involves a press comprising: a press ram and at least one piston-cylinder unit operatively connected to the press ram and including a drive piston having an upper side and a lower side, the drive piston further comprising an upper cylinder chamber communicating with the upper side, and a lower cylinder chamber communicating with the lower side. The method comprises the step of pressurizing the drive piston with hydraulic medium on at least one of its upper side and its lower side for driving the press ram.

Abstract: A hydraulic system for a vehicle adapted for operating a plurality of reel mower cutting units and for driving at least one vehicle component such as drive wheels or power steering. The vehicle carries an engine near the front of the vehicle which generates heat. The system includes a fluid reservoir located remote from the engine and near the rear of the vehicle. An input line is coupled with the reservoir, and a first pump is operatively coupled with the input line. A first motor receives fluid from the first pump for driving a reel mower, and a branched line having first and second branches receives fluid from the first motor. The first branch is a first return line extending to the reservoir. A second pump having a lower capacity than the first pump is operatively coupled with the second branch, and a second motor receives fluid from the second pump for driving the vehicle component.

Abstract: A flotation apparatus for floating minerals from fluid containing minerals in particulate form. The flotation apparatus includes a hydraulic motor directly connected to a drive shaft for driving a rotor located in the flotation cell, the hydraulic motor being powered by a hydraulic power pack having dual gear pumps to circulate hydraulic fluid at pressures of up to 2900 psi to drive the hydraulic motor. The dual gear pumps include a smaller gear pump for developing high pressure at low flow for quick, soft start of the flotation apparatus. Once started, the larger pump automatically takes over to provide high flow at lower pressure to develop rotor speed of approximately 160 RPM.

Abstract: A pump system is disclosed which operates at high efficency in either a high volume, low pressure mode or a low volume, high pressure mode. First and second internal gear pumps are driven by a common drive shaft. The first pump has a smaller displacment than the second pump and both pumps deliver pressurized fluid to a common discharge passage. An unloading valve is operative to dump the output of the second pump in response to fluid pressure in the discharge passage so that it delivers fluid to the load device only when the pressure is below a predetermined value. The unloading valve also performs the function of a low capacity accumulator. A check valve is provided to prevent back flow in the outlet of the second pump.

Abstract: An engine-driven pump supplies pressurized hydraulic fluid to vehicle brake and steering circuits. A ground driven variable displacement pump controlled by a control circuit is de-stroked when the engine-driven pump is operational. The variable displacement pump includes a movable piston which divides a bore into a pilot chamber and a pump chamber. An outlet line with a check valve communicates fluid one way from the pump chamber to the vehicle circuits. An inlet line with a check valve communicates fluid one way from a reservoir to the pump chamber. A ground-driven rotatable cam member reciprocates the piston. A spring urges the piston towards the cam member and towards a full stroke position. A pilot line which communicates fluid pressure from an outlet of the engine-driven pump to the pilot chamber. When the engine-driven pump is operational the pressure in the pilot line moves the piston away from the cam member, thus de-stroking the variable displacement pump.

Abstract: In order that a hydraulic pump and a hydraulic motor of a hydrostatic transmission hitherto disposed to the exterior are attached to a hydrostatic transmission support member provided in a mission case, a charging pump hitherto attached to the hydraulic pump at the hydrostatic transmission is also attached to the hydrostatic transmission support member, and an oil filter hitherto attached to the outside of mission case is disposed therein, they are interposed between the lower surface of hydrostatic transmission support member and the charging pump. Furthermore, an outward takeout pump also is supported in the mission case.