Abstract: A device for supplying and modifying the cylinder cubic capacity of a hydraulic motor, comprising: a first conduit (1) for supplying and discharging an operating fluid to a first side of the hydraulic motor (M); a second conduit (2) for supplying and discharging an operating fluid to a second side of the motor (M); an actuator (3) provided to modify the cubic capacity of the motor (M); an increase conduit (31) for increasing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3) which produces an increase of the cubic capacity of the motor (M); a reduction conduit (32) for reducing the cubic capacity of the motor (M), connected to the actuator (3) for supplying operating fluid to a side of the actuator (3), which produces a reduction of the cubic capacity of the motor (M). The device is structured to supply to the increase conduit (31) and to the reduction conduit (32) a proportional pressure to the load acting on the winch.

Abstract: A steam turbine system and method of operating a steam turbine system including a steam generator coupled to a high pressure section and a low pressure section. The steam turbine system may further include to a first portion of a drive shaft coupled to the high pressure section and a clutching device for releasably coupling to a power generator coupled to the first portion of the drive shaft. The steam turbine system may also include a second portion of the drive shaft for coupling to the power generator coupled to the low pressure section. The method may be implemented using a controller of the steam turbine system.

Abstract: A system for providing pressurized hydraulic fluid includes an engine driven main pump and an electrical motor driven auxiliary pump. The auxiliary pump provides hydraulic fluid at line pressure to shift control subsystems during a vehicle launch while the main pump provides hydraulic fluid to cooler or lubrication subsystems during the vehicle launch. A pressure regulation valve regulates the pressure of the hydraulic fluid from the main pump. Once the main pump reaches a critical speed, the main pump provides hydraulic fluid at line pressure to the hydraulic control system and the auxiliary pump is turned off.

Abstract: A system includes a compressor, a control unite and a clutch assigned to the compressor. The control unit is suitable for opening and closing the clutch in order to economize energy. The control unit is suitable for carrying out a monitoring routine during which the clutch is opened or closed in order to prevent the clutch, the compressor and the components arranged downstream of the compressor from being damaged. A method for controlling the system, including the compressor, the control unit and the clutch associated with the compressor, is also provided.

Abstract: A hydraulic control unit provided with oil pumps includes a first oil discharging outlet and a second oil discharging outlet, a high pressure route connected with the first oil discharging outlet, a medium pressure route with an oil pressure therein being lower than that in the high pressure route, a low pressure route with an oil pressure therein being lower than that in the medium pressure route, and a connection mode switching mechanism for selectively connecting a second oil discharging outlet with the high pressure route, the medium pressure route or the low pressure route. The connection mode switching mechanism includes a changeover valve selectively connecting the second oil discharging outlet with the medium pressure route or the low pressure route; and a changeover valve controlling device connecting the second oil discharging outlet with any of the medium pressure route and the low pressure route. The hydraulic control unit can minimize drive loss of an oil pump.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. An approach for facilitating the application of a clutch when it is not a simple on/off mechanism provides an enhanced interface for the conversion between hydraulic energy and mechanical energy, thereby improving efficiency within the hydraulic drive system.

Abstract: The present invention includes a hydraulic pump (11), a variable displacement hydraulic motor (5) for traveling driven by pressure oil from the hydraulic pump (11), a motor displacement control means (17, 18) for adjusting a displacement of the hydraulic motor (5) in correspondence to a drive pressure at the hydraulic motor (5), an operating member (22) through which a forward travel command and a backward travel command for the vehicle are issued, a control means (12) to be driven in response to an operation of the operating member (22), for controlling a flow of pressure oil from the hydraulic pump (11) to the hydraulic motor (5), a reverse operation detection means (41A, 41B) for detecting a reverse operation of the operating member (22) performed to a reverse side opposite from a direction along which the vehicle is advancing, and a cavitation preventing means (25A,25B) engaged in operation so as to prevent occurrence of cavitation at the hydraulic motor (5) when the reverse operation at the operating mem

Abstract: In stopping apparatus and method for an oil pump, which are applied to a hydraulic actuator that works based on a hydraulic pressure derived from the oil pump driven by a motor, a backward rotation of the oil pump is prevented by resisting a remaining pressure that is acting on the oil pump from the hydraulic actuator after the hydraulic actuator is deactivated. A one-way clutch disposed on an oil pump drive train between the motor and the oil pump mechanically prevents the backward rotation of the oil pump. Moreover, in order to prevent the backward rotation, a controller of the stopping apparatus gradually decreases the rotation of the motor after the hydraulic actuator is deactivated, and eliminates the remaining pressure within the hydraulic actuator while decreasing the rotation of the motor.

Abstract: To moderate the efficiency of engine braking when it is applied while a continuously variable transmission produces a large transmission ratio. Such a continuously variable transmission is constituted by a hydraulic pump having an input rotary member connected to an internal combustion engine of a vehicle, a hydraulic motor having an output rotational axis connected to a driving wheel. The hydraulic pump and hydraulic motor are coupled via a first oil passageway, which has a low oil pressure during the normal load operation of the engine but has a high oil pressure during the reverse load operation of the engine, and a second oil passageway, which has a high oil pressure during the normal load operation but has a low pressure during the reverse load operation, thereby forming a closed oil passageway circuit. At least the hydraulic pump or the hydraulic motor has a variable capacity.

Abstract: An apparatus, for controlling a plurality of hydraulic motors and a clutch for driving a drive shaft, can prevent a speed change shock and a load slip of a hydraulic motor as well as making a structure simple. The apparatus includes: a first volume variable hydraulic motor (1), connected to the drive shaft (3) through the clutch (5); a second volume variable hydraulic motor (2), which is always connected to the drive shaft (3); first tilt rotation control means (7, 8), for controlling a tilt rotation amount (a discharge volume cc/rev) of the first hydraulic motor by receiving a drive side pressurized oil (Pac) of the first hydraulic motor; and a zero tilt rotation holding means (10, 10A), for holding the tilt rotation amount of the first hydraulic motor at substantially zero in a state wherein the tilt rotation amount of the first hydraulic motor is controlled to be substantially zero.

Abstract: This invention relates to a hydraulic fluid circuit comprising a reversible hydraulic motor, a braking device, two principal conduits respectively connected to the two principal supply and exhaust ports of the motor, a principal selector adapted to occupy a position of rest and two active positions in order to select the circulation of the fluid between the principal ports of the motor and the principal conduits to which they are connected. The circuit also comprises an intermediate system of selection capable of occupying a first configuration in which the principal selector is maintained in its position of rest and a second configuration in which the principal selector is allowed to leave its position of rest. The control means of the intermediate system of selection are connected to the braking device so that this intermediate system can pass from its first to its second configuration only when the brake is de-activated.

Abstract: A drive shaft assembly is provided for allowing rotation of a drive shaft in a single direction. The drive shaft assembly includes a housing, a drive shaft and an overrunning clutch. The overrunning clutch includes an inner race having an outer annular contact surface and an outer race having an inner annular contact surface spaced radially from the inner race. The inner annular contact surface and the outer annular contact surface form an annular space therebetween. Provided within this annular space are a plurality of sprags which allow the inner race to rotate in a first direction relative to the outer race while preventing the inner race from rotating in a second direction to the outer race.

Abstract: A hydrostatic continuously variable transmission is provided in which a hydraulic pump and a hydraulic motor are communicated to each other through a low pressure oil passage and a high pressure oil passage and a clutch valve capable of releasing an oil pressure of the high pressure oil passage is connected to the high pressure oil passage. The clutch valve can be automatically operated by making use of an oil pressure of the low pressure oil passage. A clutch valve is applied with an oil pressure of a low pressure oil passage for biasing the clutch valve in a valve opening direction, and an oil pressure governor is connected to a supply oil passage for supplying an oil pressure from an oil supply pump to the low pressure oil passage through a check valve for increasing an oil pressure of the oil passage in accordance with an increase in an input rotational speed of a hydraulic pump.

Abstract: In a torque converter, in order to reduce the cost, simplify the manufacturing process and ensure the centering precision of of the stator relative to the outer race of a one-way clutch, the stator and the outer race of the one-way clutch have first engaging surface portions preventing relative rotation therebetween and second engaging surface portions providing concentricity therebetween. The first and second surface portions are axially offset from each other.

Abstract: An electrohydraulic control system that includes a bidirectional electric motor responsive to application of electrical power for rotation in either of two directions, and a hydraulic pump coupled to the motor and having ports for supplying hydraulic fluid in either of two flow directions as a function of direction of rotation of the electric motor. A hydraulic actuator is coupled to the pump for receiving fluid in either of two flow directions and performing work as a function thereof. An electronic controller applies electrical power to the electric motor so as to obtain a desired level of work at the actuator. The electronic controller includes one or more sensors operatively coupled to the actuator for applying electrical power to the motor as a function of motion at the actuator.

Abstract: A hydraulic system comprises a mechanical brake assembly having a brake piston engageable with an output rotation shaft of a hydraulic motor, a cylindrical casing having the brake piston slidably received therein and a brake spring resiliently urging the brake piston to engage with the output rotation shaft of the hydraulic motor. The brake piston and the cylindrical casing collectively define a main hydraulic chamber held in fluid communication with a release fluid passageway which is communicable with a hydraulic pump and a reservoir tank through a shuttle valve and a directional control valve. The brake piston and the cylindrical casing further collectively define a secondary hydraulic chamber held in fluid communication with the release fluid passageway through a fluid feed/return passageway on which a brake resistance restrictor provided for restricting flow of the working fluid in the fluid feed/return passageway.

Abstract: A inching system adapted for releasing a transmission clutch to disconnect engine power delivery in an industrial vehicle comprises a main pump for creating pump pressure; a brake pedal operated by a driver; a master cylinder communicating with the main pump through a pump pressure supply conduit for producing brake pressure in to perform a brake operation as the brake pedal is pressed; a charging pump for discharging clutch actuation fluid to be fed to the transmission clutch; an inching valve including a valve housing having a pilot chamber provided at a first end thereof to receive the pump pressure and a valve spool slidably fitted within the valve housing, the valve spool having a first operative position for feeding the clutch actuation fluid to the transmission clutch to engage the clutch and a second operative position for cutting off the clutch actuation fluid to release the transmission clutch when the pressure within the pilot chamber becomes higher than a predetermined valve; and a pilot conduit f

Abstract: A door operator having a fluid drive motor and a manual override. The bidirectional hydraulic motor connects to a drive shaft through a power train including a shiftable --quill--type manual clutch mechanism which allows an alternate connection of the drive shaft to a manually-operated wheel. When the cable which shifts the clutch for manual drive is pulled, a switch disables the control for the hydraulic motor. When the motor is not provided with pressured fluid from the pump a hydraulic brake engages the motor.

Abstract: A hydraulically powered actuator (16) for moving a member (28 or 30) into and away from a position at which the member is under a preload is disclosed. A hydraulically powered motor (22) is utilized which is coupled to the member for moving the member to and from the position at which the member is preloaded. A source (40) of pressurized hydraulic fluid is coupled to the hydraulic motor for supplying power to the motor for moving the movable member. A brake (32) is provided which is coupled to the movable member for holding the movable member in the position at which the member is preloaded. A hydraulic fluid control is provided which is coupled to the motor, the brake and the source of pressurized fluid which activates the brake after the motor has moved the member to the position at which the member is preloaded and deactivates the motor while maintaining the member under preload.

Abstract: A fluid pressure control circuit for a working vehicle having a transmission operable by a fluid pressure and a negative type fluid pressure parking brake. The control circuit comprises a fluid pressure cylinder movable to a first end position to place the transmission in a low speed position and to a second end position to place the transmission in a high speed position, a fluid supply line for supplying pressure fluid to the cylinder, and a control valve mounted on the fluid supply line. The control valve comprises a three position valve having a first position to release the pressure fluid from the parking brake and the fluid supply line, a second position to supply the pressure fluid to the parking brake and set the cylinder to the first end position, and a third position to supply the pressure fluid to the parking brake and set the cylinder to the second end position.

Abstract: A reservoir for holding pre-fill hydraulic fluid is connected at its bottom to the power input side of a hydraulic motor. A stand pipe within the reservoir is connected to a hydraulic fluid drain outlet for expulsion of excess volume hydraulic fluid. Compressed air is introduced to the reservoir at a level above the top of the stand pipe. Valving in the compressed air line is operable to three states: opened between the compressed air source and the reservoir; opened between the reservoir and the atmosphere and closed. A valve connected in the drain outlet may be opened or closed. A check valve between the reservoir and the hydraulic motor is held opened by pilot operation during return of the hydraulic fluid to the reservoir and checked closed during high pressure input to the hydraulic motor.

Abstract: Hydrostatic transmissions are commonly employed in the drive train of earthmoving and industrial vehicles. It is difficult to stop some such vehicles at a precise location on a slope due to the presence of a delay valve included in the controls for delaying application of a friction brake until the vehicle has been stopped by the hydrostatic transmission. In the present control system, a manual control valve (74) is moved to a first operative position and a hand control lever (25) is manipulated in combination therewith to reduce the displacement of a variable displacement pump (12) to establish a minimum drive condition sufficient to hold the vehicle motionless. Thereafter the manual control valve (74) can be moved to a second operative position to apply a friction brake (18) while the transmission maintains the vehicle motionless.

Abstract: A control system for a hydraulically driven vehicle having a variable displacement hydraulic motor connected with a variable displacement hydraulic pump in a closed loop and driven thereby.A spring-applied and fluid-released brake is mounted on an output shaft of the motor. A regulator is operatively connected to the motor for controlling the displacement thereof in response to a fluid pressure at both ports thereof. When fluid pressure at either one of the ports of the motor exceeds a predetermined level, the variable displacement motor is changed over to a high displacement position thereby generating a large braking force when the vehicle is to be stopped.

Abstract: A hydraulic power system having a variable displacement hydraulic pump, a hydraulic motor driven by the hydraulic pump for actuating a load, the pump and motor being connected to constitute a closed hydraulic circuit, hydraulic servo for controlling the displacement volume of the pump, and motor stopping device including a brake arrangement adapted to release the motor from a braked condition when a control pressure from a hydraulic fluid source is received.

Abstract: A hydrostatic transmission coupled with a gear transmission for operating a motor vehicle driven by an internal combustion engine has its accelerator pedal connected to the throttle valve of the engine and to the servovalve of the stepless hydrostatic transmission via an engine characteristic storage which modulates the accelerator travel signal applied to the servovalve to optimize the fuel consumption. The servovalve also receives input from an electric signal comparator which compares the engine speed with an output signal from the output unit of the hydrostatic transmission or the output shaft of the gear transmission.

Abstract: A hydraulic circuit for a hydraulically driven vehicle comprising an engine, a variable displacement pump driven by the engine, a hydraulic motor connected with the variable displacement pump and driven thereby, the hydraulic motor having an output shaft connected thereto, a first fixed displacement pump driven by the engine, an inching brake valve connected with the first fixed displacement pump, a control valve connected with the output side of the inching brake valve for controlling the forward and reverse movement of the vehicle and speed thereof, the output side of which is connected with the variable displacement pump, a parking brake coupled with the output shaft of the hydraulic motor, the parking brake being normally applied by a spring and hydraulically released, a pilot operated first brake control valve connected with the parking brake, a manually operated pump connected with the first brake control valve and the inching brake valve, a pilot operated second brake control valve connected with the f