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: An expander (M) employing steam as a working medium is formed from a first radially inner group of axial piston cylinders (49) arranged annularly on a rotor (27) so as to surround the axis (L) of an output shaft (28), and a second radially outer group of axial piston cylinders (57) arranged annularly so as to surround the first group of axial piston cylinders (49). The first and second groups of axial piston cylinders (49, 57) are driven by a common swash plate (39), and the first and second groups of axial piston cylinders (49, 57) are arranged with circumferentially displaced pitches. High-temperature, high-pressure steam firstly operates the first group of axial piston cylinders (49), then operates the second group of axial piston cylinders (57), and the outputs from the two are combined to drive the output shaft (28). This achieves a further reduction in the size and a further increase in the output of the axial type expander (M).

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 hydraulic driving unit is provided with a directional control valve 23 and directional control valve 24 for controlling a boom cylinder 6 and arm cylinder 7, both of which are driven by pressure oil delivered from a main hydraulic pump, respectively, a boom control device 25 for selectively controlling the directional control valve 23 and an arm control device 26 for selectively controlling the directional control valve 24, and is mounted on a hydraulic excavator.

Abstract: The invention relates to steerable vibration plates that are set vibrating by rotating unbalanced masses. By twisting the unbalanced masses relative to one another the resulting forces and their direction of action can be changed, thereby influencing the travel speed of the vibrating plate and its direction of travel. The inventive vibration plate is characterized in that the unbalanced masses disposed on a common shaft can be adjusted independent of external forces and torques since the adjustment piston adjusting the unbalanced masses is braced in the adjustment cylinder to a much higher degree than would be possible with conventional coil springs. To this end, every adjustable unbalanced mass is associated with a double-action hydraulic cylinder that comprises two liquid chambers. The connection of said chambers to a storage and a pump can be locked in order to fix the piston which can be adjusted within the hydraulic cylinder.

Abstract: The invention relates to a hydrostatic traveling mechanism (1) which comprises a hydraulic pump (4), a first hydraulic engine (8) that is linked with the hydraulic pump (4) via a hydraulic work circuit (2) and that drives a first drive train (17). The traveling mechanism further comprises a second hydraulic engine (10) that is linked with the hydraulic pump (4) via a hydraulic work circuit (2) and that drives a second drive train (19). The inventive traveling mechanism is also provided with a third hydraulic engine (23) that is coupled with the first drive train (17) and a fourth hydraulic engine (24) that is coupled with the second drive train (19). The third hydraulic engine (23) and the fourth hydraulic engine (24) are linked with each other via a hydraulic secondary circuit (3) that is independent of the work circuit (2).

Abstract: An inflatable structure includes a plurality of inflation cells each have a respective internal gas generator connected to an external control processor for sequential inflation of the inflatable structure. Power and control lines feed through the inflation cells for powering the internal gas generator and for communicating control signals between the gas generators and the external control processor. A method of sequence inflation can use various types of exemplar gas generators, such as cellular containment evaporation gas generators and laser ablation gas generators.

Abstract: An inflatable structure includes a plurality of inflation cells each have a respective internal gas generator connected to an external control processor for sequential inflation of the inflatable structure. Power and control lines feed through the inflation cells for powering the internal gas generator and for communicating control signals between the gas generators and the external control processor. A method of sequence inflation can use various types of exemplar gas generators, such as cellular containment evaporation gas generators and laser ablation gas generators.

Abstract: A hydraulic rescue system comprises a fluid reservoir, a pump assembly having a plurality of pump modules, and a manifold assembly having a corresponding number of manifold modules. Each pump module includes an input port for drawing hydraulic fluid from the fluid reservoir and an output port for supplying hydraulic fluid under pressure to a hydraulic rescue tool. Each manifold module includes a fluid circuit that is adapted to fluidly connect the output port of one of the pump modules with a hydraulic rescue tool. A PTO adapter is connected to the pump assembly and is operably connectable to a PTO shaft of a vehicle transmission for operating the pump modules. In this manner, a number of different hydraulic rescue tools can be operated simultaneously with full pressure from the pump assembly.

Abstract: A hydraulic device having two hydraulic actuators, in particular a motor and a double-acting jack, each having two couplings for the entry and/or the exit of a control fluid. Two pipes are coupled to the two actuators and designed so that one conveys a pressurized fluid to a respective coupling of each actuator while the other discharges the fluid to the other respective coupling, and vice versa, in such a way that the jack can be controlled to selectively produce a movement in opposite directions. A selective reversing gate reverses, between the two pipes, the supplying of pressurized fluid and the discharging of the fluid so as to control the direction of the movement of the jack.

Abstract: To perform boom-down operation by operating a boom cylinder (6) by an external load (W) while simultaneously operating an arm cylinder (26) or a bucket cylinder (27) in the state the bucket is off the ground, a first boom directional control valve (2) and a regeneration boom valve (13) are controlled to the neutral position and the open position respectively so that the hydraulic oil is regenerated from a line (9) located at the oil-returning side of the boom cylinder (6) through the regeneration boom valve (13) to a line (5) located at the oil-feeding side. Therefore, the volume of the hydraulic oil that can be supplied from the pressurized oil source (4) to the arm cylinder (26) or the bucket cylinder (27) via the second arm directional control valve (24) or the bucket directional control valve (25) is increased by the amount equivalent to the amount of the oil that is not supplied from the pressurized oil source (4) to the boom cylinder (6).

Abstract: An actuator drive unit in which either of two types of actuators and a drive direction thereof (either forward direction or backward direction) are corresponded to respective four pistons. When one of the four pistons in one of four displacement signal generating units generates a displacement signal, the actuator corresponding to the piston generating the displacement signal is driven in a corresponding drive direction, by an amount of drive corresponding to the displacement signal.

Abstract: A control circuit for a construction machine using a control lever for revolving a boom swing in common with a traveling motor and switching pilot pressure via a switching valve has a switch for supplying a switching signal to the switching valve. A pressure switch detects whether the pilot pressure is output from a remote control valve or not. A switching control circuit switches a position of the switching valve to a position for the boom swing cylinder when the switching signal is output from the switch and holds the position of the switch at the position for the boom swing cylinder when the pilot pressure is detected by the pressure switch, to thereby prevent wrong operation in switching.

Abstract: Differential pressures across flow control valves 6a, 6b and 6c are controlled by pressure compensating valves 7a, 7b and 7c to be held at the same value, i.e., a differential pressure &Dgr;PLS, and the differential pressure &Dgr;PLS is maintained at a target differential pressure &Dgr;PLSref by a pump displacement control unit 5. For changing the target differential pressure depending on change in revolution speed of an engine 1, a flow detecting valve 31 is disposed in a delivery line 30a, 30b of a fixed displacement hydraulic pump 30, and a differential pressure &Dgr;Pp across a variable throttle portion 31a of the flow detecting valve 31 is introduced to a setting controller 32. A selector valve 50 operable to shift between a fully closed position and a throttle position is disposed in parallel to the flow detecting valve 31 and is shifted by a control lever 51.

Abstract: The invention relates to a hydraulic drive with a plurality of hydraulic consumers also comprising a differential cylinder which are located in particular on a plastics injection-molding machine. There are a first hydraulic machine and a second hydraulic machine, which can both operate as pump and as motor. A first of the two hydraulic machines is connected to a tank by means of a second port and rests against a pressure line by means of a first port, which pressure line can be connected to that working chamber of the differential cylinder which is remote from the piston rod via a shut-off valve. The second hydraulic machine is likewise connected to the pressure line by means of a first port and can be connected, by means of a second port, to a tank via a nonreturn valve which opens toward the second port and to the piston-rod-side working chamber of the differential cylinder via a shut-off valve.

Abstract: A hydrostatic transmission with an integral actuator for a vehicle having an engine and a frame. The assembly includes a transmission housing for connection to a vehicle frame, a shaft for coupling the hydrostatic transmission to an output of a vehicle engine, a pump driven by the shaft and an actuator operatively coupled to the pump that is attached to the transmission housing.

Abstract: A hydraulic switching device (1; 101) for use in a circuit (7; 107) that comprises at least two movable drive units (2; 3) with a first direction of movement in the functional direction or a counter-direction, where said drive units can be pressurized with a pressure medium via at least two connection lines (13, 26; 24; 31), whereby externally controllable selector switches (14; 15; 16) are provided for controlling the pressurization with a pressure medium, is designed so that exactly one controllable selector switch (14; 15; 16) is provided for each drive unit (2; 3; 6) and at least two drive units (2; 3) are interconnected via logical AND and/or OR valve elements (22, 25; 141, 142, 143, 144) so that at least with a resulting introduction of force to the first drive unit (2) in the functional direction (F), a force release of the second drive unit (3), and with an introduction of force to the first drive unit (2) in the counter-direction (G), an introduction of force to the second drive unit (3) in the funct

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 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 free piston engine system, particularly suitable for use in a motorized vehicle, is provided with at least one hydraulic pump, each pump having a first fluid port and a second fluid port. A free piston internal combustion engine includes a combustion cylinder and a hydraulic cylinder. A low pressure accumulator is fluidly coupled with the hydraulic cylinder. A first control valve interconnects the low pressure accumulator with the hydraulic cylinder. At least one high pressure accumulator is fluidly coupled with the hydraulic cylinder. At least one second control valve is provided, with each second control valve interconnecting a respective high pressure accumulator with the hydraulic cylinder. A third control valve interconnects the hydraulic cylinder with the first fluid port of each pump. A fourth control valve interconnects the hydraulic cylinder with the second fluid port of each pump. A first working pressure accumulator is coupled between each pump and the third control valve or fourth control valve.

Abstract: A hydraulic system controls the flow of fluid to and from several functions on a machine. Each function has a valve assembly through which fluid is supplied under pressure from a source to an actuator and through which fluid returns from the actuator to a shared return line connected by a return line metering valve to the system tank. There are several regeneration modes of operation in which fluid exhausted from one port is supplied into the other port of the same actuator, which eliminates or reduces the amount of hydraulic fluid that must be supplied from the source. In some regeneration modes, input fluid for an actuator is obtained from another hydraulic function via the shared return line. In these regeneration modes an electronic controller operates the return line metering valve to restrict fluid from flowing into the tank from the shared return line, so that the fluid will be available to be supplied into an actuator port.

Abstract: A hydraulic system is provided for a vehicle having front, middle and rear portions. The hydraulic system includes a main pump located in the front portion, and a secondary pump located in the front portion which supplies fluid to an inlet of the main pump and to lube circuits. High pressure hydraulic functions are located in the middle and rear portions and receive high pressure fluid from the main pump. A hydraulic filter is located in the front portion and is connected to an outlet of the secondary pump for filtering fluid communicated to the inlet of the main pump. A relief valve is located in the front vehicle portion and is connected between the outlet of the secondary pump and the hydraulic filter. An inlet suction screen is located in the rear portion and is connected between a sump and the inlet of the main pump. An oil cooler is located in the front vehicle portion and is connected between the hydraulic filter and an inlet of the main pump.

Abstract: A pressure oil energy recovery apparatus or pressure oil energy recovery/regeneration apparatus that does not require much room and can be mounted within a narrow space, capable of broadening the range of applications for recovered energy. A hydraulic pump motor is actuated by the inflow of the return pressure oil flowing out of a hydraulic actuator. The drive force of the hydraulic pump motor is input to allow an electric motor to generate electric energy. The electric energy generated by the electric motor is stored in a battery. When the energy of pressure oil is regenerated, the energy expended during the actuation of the hydraulic actuator by the hydraulic pump is supplemented with the electric energy stored in the battery.

Abstract: A hydraulic system comprises a variable displacement pump. The hydraulic system includes a first device capable of being hydraulically powered by the pump and a reversing device adapted to cause the first device to autoreverse. The hydraulic system also includes an isolation device adapted to prevent pressure surges resulting from a source other than the first device from actuating the reversing device, thereby preventing undesirable autoreversing of the first device.

Abstract: A vehicle including a battery (61) powering an electrical motor (60), the electric motor (60) operating when the vehicle is driving at a nominal speed in order to drive, at a constant speed, a variable displacement hydraulic pump (4) which is connected to at least one variable displacement hydraulic motor (3). The hydraulic motor indirectly drives wheels of the vehicle. The variable displacement pump is electronically controlled and managed by a circuit which monitors, manages and controls (9) an angle of a cam plate which controls variable displacement of hydraulic pump (4).

Abstract: A bicycle drive mechanism has an oil pressure pump, two crank arms disposed on the oil pressure pump, a first three-way pipe connected to the oil pressure pump, a second three-way pipe connected to the oil pressure pump, a first oil pressure motor, a second oil pressure motor, a first oil pipe connected to the first three-way pipe and the first oil pressure motor, a second oil pipe connected to the second three-way pipe and the first oil pressure motor, a third oil pipe connected to the first three-way pipe and the second oil pressure motor, and a fourth oil pipe connected to the second three-way pipe and the second oil pressure motor.

Abstract: A heavy-duty transporting system has motor-driven drive modules each having a motor and at least one drive roller connected therewith, the motors being formed as hydraulic motors, a central hydraulic unit connected with the hydraulic motors through hydraulic hoses, two hydraulic circuits which are supplied by the central hydraulic unit, the central hydraulic unit controlling a throughflow for each of the hydraulic circuits, each of the hydraulic motors being connected with one of the hydraulic circuits by a hydraulic hose.

Abstract: A hydraulic system for a motor vehicle having a convertible top (2) which can be folded back has a convertible-top control system (1) and further hydraulic control devices (3, 4) which can be activated by a common hydraulic pump (6). In hydraulic lines (8, 9) leading to the convertible-top control system (1) there are arranged hydraulic valves (13, 14) which enable optional operation of the convertible-top control system (1) or of the further control devices (3, 4). Because of this, the hydraulic system turns out to be particularly simple structurally.

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 target fan rotational speed (R.P.M.) corresponding to a temperature detected by a temperature detector is determined according to a set correlation and the capacity of a variable-capacity hydraulic pump is varied so that the rotational speed of a cooling fan becomes that determined target fan rotational speed. It thereby becomes possible to precisely control the blowing air volume (R.P.M.) of the cooling fan, and, when the cooling fan is driven with a hydraulic source, to construct a hydraulic circuit with fewer parts. Moreover, in cases where the torque absorbed by the fan-drive hydraulic motor fluctuates, control is effected to suppress fluctuations in the cooling fan rotational speed and stabilize the rotation. Furthermore, in cases where the load on the fan-drive hydraulic motor fluctuates, control is effected to suppress fluctuations in the cooling fan rotational speed and stabilize the rotation.

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: A discharged pressurized fluid of a primary hydraulic pump 2 driven by an engine 1 is supplied to an actuator 5 through an operating valve 4. A first hydraulic rotary machine 8 for rotating a cooling fan 7 is driven to rotate by a returning pressurized fluid of the actuator 5. A second hydraulic rotary machine 9 for rotating the cooling fan 7 is driven to rotate by the discharged pressurized fluid of an auxiliary hydraulic pump 3 which is driven by the engine 1. By utilizing the returning pressurized fluid of the actuator 5, the air blowing ability of the cooling fan is made high and the wasting of engine horse power is prevented.

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: The invention is embodied in a closed-cycle lubrication oil system used during turbine start-up to provide both lift oil and hydraulic oil from one system using a single variable volume pump that supplies fluid at a high pressure for lift oil requirements. The pump discharge pressure is reduced, through a pressure regulating/reducing valve, down to hydraulic system demands. During steady-state gas turbine operation, the system provides only a flow of hydraulic oil to position the inlet guide vanes and gas valves as required by the gas turbine controls logic. During gas turbine shut-down, the system again meets both lift oil and hydraulic oil requirements. A second pump is advantageously incorporated in the preferred embodiments of the system to provide 100% redundancy in providing either lift or hydraulic oil.

Abstract: A hydraulic operating apparatus, especially for a vehicle covering, includes a reversible pump (2) which, via hydraulic lines (3, 4), one of which is in all cases provided with an unblockable check valve (7), is connected with the working chambers of at least one double-acting piston-cylinder arrangement (1). In order to make possible a very flexible supply and control of mutually independently operated piston-cylinder arrangements with a minimum of constructive and control-technical effort, additional hydraulic lines (10, 11) branch off from both hydraulic lines (3, 4) of the reversible pump, into which the check valves are placed, which additional hydraulic lines lead into a common hydraulic line (12) to at least one additional piston cylinder arrangement (13, 14).

Abstract: A fluid control system (50) is provided for a work machine (10) having first and second compacting drums (14,16). First and second hydraulic motors (28,32) are connected in series and power first and second vibratory mechanisms (26,30) located within the first and second compacting drums (14,16). A control valve (60) supplies pressurized fluid to the first hydraulic motor (28). The pressurized fluid is transferred through a bypass circuit (74) around the second hydraulic motor (32). A sequencing device (80) closes the bypass circuit (74) transferring the pressurized fluid to the second hydraulic motor (32) after actuation of the first hydraulic motor (28).

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: The present invention is directed to a computer based control system for controlling hydraulic and electromechanical actuators on a power machine, such as a skid steer loader. The computer based control system is configured to implement a number of features to enhance certain operational aspects of the power machine. One such feature includes an operator actuable selector which provides a selector signal based on an operator input. A controller receives the selector signal and provides an auxiliary output signal to control an auxiliary valve in a selected one of an on/off mode and a proportional mode based on the selector signal.

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: A hydraulic system for a detachable implement such as draper platform for a combine utilizes a platform-mounted pump supplied with return oil from the existing reel drive motor. The system utilizes the existing combine hydraulic connection for the reel drive to supply oil to the draper belt drive motors. Oil from the combine powers the reel drive motor and then flows into a manifold block (mixing chamber) before entering the inlet of the draper belt drive pump. This pump is sized to provide sufficient oil flow to power the draper belt drive motors, arranged in series. Return oil from the belt drive motors is routed back to the manifold block where it can mix with incoming oil from the reel drive pump before returning to the combine reservoir or being recirculated to the belt drive motors. The hydraulic system avoids the need to equip the platform with a complete hydraulic system and avoids the need to modify the existing hydraulic system of the combine.

Abstract: A hydraulic tilting device intended to be fitted on a vehicle with a tiltable cab for the purpose of tilting the tiltable cab. The tilting device has a hydraulic tilting unit with a double-acting hydraulic tilting cylinder for tilting the cab, and also a reservoir and a pump. The tilting device furthermore has an additional hydraulic cylinder, for example a locking cylinder, which additional cylinder is connected to the tilting unit via a system of lines. Each of the connecting lines comprises a part associated with the additional cylinder and a part associated with the tilting unit, which parts can be coupled to one another by a disconnectable coupling.

Abstract: The present invention provides a novel power generating device, wherein the rotary inertial force of a fly wheel cooperating with a pneumatic auxiliary power apparatus is employed to maintain that the fly wheel rotates continuously and acceleratingly and outputs power. The part of the output force of the fly wheel is used to drive an air compressor for generating compressed air, to be input into a pneumatic motor of the pneumatic auxiliary power means so that the output power of the pneumatic motor is fed back to the fly wheel in order that the fly wheel maintains the inertial force to rotate continuously. The fly wheel also drives a cam type control apparatus so to control the compressed air that it supplies intermittently to the pneumatic motor for driving the fly wheel. Additionally, the fly wheel is preferably mounted with a weight, and a compensation device for beating the fly wheel in order to increase inertial torque each time when the weight rotates to a predetermined angle.

Abstract: An axle driving apparatus, which contains two separately driven hydrostatic transmissions (HSTs) in a single housing, is made compact to improve the running operational efficiency of a working machine. In particular, power from a prime mover is transmitted to an input pulley so that the power is speed-changed by the two HSTs to drive left and right axles through left and right power transmitting means. The HSTs, power transmitting means and the axles are disposed substantially symmetrically laterally in the housing. The housing comprises parts coupled with each other such that joints between the parts are disposed in horizontal planes substantially parallel to the axes of rotation of the axles.

Abstract: An axle driving apparatus, which contains two separately driven hydrostatic transmissions (HSTs) in a single housing, is made compact to improve the running operational efficiency of a working machine. In particular, power from a prime mover is transmitted to an input pulley so that the power is speed-changed by the two HSTs to drive left and right axles through left and right power transmitting means. The HSTs, power transmitting means and the axles are disposed substantially symmetrically laterally in the housing. The housing comprises parts coupled with each other such that joints between the parts are disposed in horizontal planes substantially parallel to the axes of rotation of the axles.

Abstract: Hydraulic device for directional control of a vehicle using a single lever. The device includes a hydraulic manipulator (1) with four outlets, forward/reverse and right/left. A selection device (4) with four selectors (5) in a bridge is connected to the manipulator, and the outputs are connected to four motors for reverse-left, forward-left and reverse-right and forward-right control of the running components of the vehicle. A slide valve (7) with two positions, respectively one with direct connections and one with crossed connections, is inserted into the two feed lines of the motors (6 AVG, 6 AVD or respectively 6 ARG, 6 ARD). A control input (10) of the slide valve is connected to the FORWARD and REVERSE outputs of the manipulator, by virtue of which the control of the vehicle remains fully ergonomic, including for a rotation of the vehicle about a central vertical axis.

Abstract: The invention relates to a drive system for a hydraulic press. The drive system is of the type of secondary controlled system maintaining an impressed pressure of substantially constant magnitude in a pressure system. A hydraulic transformer comprises a pair of mechanically coupled hydrostatic machines each having a variably capacity. The first machine is connected to the pressure system and the second machine to the press cylinder. The invention provides a drive system in which biasing the press cylinder, rapid tranverse and pressing stroke, decompressing the fluid and flushing of hot fluid is accomplished in a closed loop free of throttling losses. The hydraulic transformer further allows to recover energy to the pressure system.

Abstract: A hydraulic device provided with a plurality of hydraulic actuators directly connected to a hydraulic pump for control. A hydraulic pump is operable in both rotational directions when the electric motor is rotated forwards and in reverse. Ports of each hydraulic actuator are connected via a connecting line in parallel with ports of the hydraulic pump. A plurality of electromagnetic valves are provided in the connecting lines to the hydraulic actuators. By opening or closing each electromagnetic valve, the operation of the associated hydraulic actuator is controlled. The operation direction of each hydraulic actuator is controlled by rotating the electric motor clockwise or counterclockwise. Further, a position sensor is provided for detecting displacement of the specified hydraulic actuator and the electric motor is controlled based on a signal transmitted from the position sensor.

Abstract: A hydraulic drive apparatus for example for driving the header of a combine harvester includes a pump, at least one motor driven by the pump, a reservoir in which the hydraulic fluid is cooled and degasified and a hydraulic circuit connecting the elements. The pump is driven by a shaft of the combine which can be reversed for short periods of time for discharging blockages. The hydraulic circuit is arranged with check valves so that when operating in the normal forward condition it operates in open circuit arrangement including the reservoir. When operating in the reverse condition, the reservoir is bypassed and the fluid is directed in closed circuit condition from the pump through the motor and back to the pump. This allows the drive apparatus to accommodate the necessary reverse condition for short periods of time using a simple hydraulic circuitry rather than the conventional mechanical drive arrangements.

Abstract: A hydraulic system for controlling a mower unit through a raising and lowering mechanism. This system includes a hydraulic cylinder connected to the raising and lowering mechanism, a control lever for controlling the mower unit, and a valve unit including a main control valve, an auxiliary control valve and a throttle valve connected in series between a hydraulic pressure source and the hydraulic cylinder.