Abstract: An open center (OC)-open center load sense (OCLS) conversion valve and hydraulic circuits therewith configured to control flow from a hydraulic pump to multiple hydraulic functions. The conversion valve includes cartridge, load sense, pump, first function supply, first function return, and downstream ports. When an OC cartridge is inserted in the cartridge port, regardless of load sense, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is detected, the pump and first function supply ports are connected and the first function return and downstream ports are connected. When an OCLS cartridge is inserted in the cartridge port and load sense is not detected, the pump, first function return and downstream ports are connected.

Abstract: A hydraulic drive unit for use in a vehicle or other application incorporates a motor disposed in a housing and connected to a pump through a porting system, and an output shaft driven by the motor. A mechanical brake is used to brake the motor, while a valve provides a hydraulic brake for preventing flow between the hydraulic motor and the hydraulic pump. A brake actuator is connected to both the mechanical brake and the hydraulic brake, whereby actuation of the brake actuator causes both the mechanical brake and the hydraulic brake to be actuated.

Abstract: A hydraulic drive unit for use in a vehicle or other application incorporates a motor connected to a pump through a porting system and an output shaft driven by the motor. A mechanical brake is used to brake the motor, while a valve provides a hydraulic brake for preventing flow between the hydraulic motor and the hydraulic pump. A brake actuator is connected to both the mechanical brake and the hydraulic brake, whereby actuation of the brake actuator causes both the mechanical brake and the hydraulic brake to be actuated.

Abstract: A work vehicle includes an engine, an idling stop execution portion, a determination portion, a counting portion, and an idling stop time period adjustment portion. The engine can rotate in a first idling state and a second idling state in which the engine rotates at the number of rotations higher than a prescribed number of rotations. The idling stop execution portion performs an idling stop operation for stopping the engine. The determination portion determines whether or not stop has been made from the second idling state. The counting portion counts the number of times of stop of the engine from the second idling state. An idling stop time period adjustment portion makes a prescribed time period of the second idling state longer than a current time period, when the number of times of stop of the engine is equal to or greater than the prescribed number of times.

Abstract: When an excitation of a servo motor is released due to an emergency stop, a power outage, or another operation performed on a positioning device, the positioning device uses air supplied from an air supply source to vary pressure of an air balance, which cancels a self-weight of a vertical axis driven by the servo motor, thereby moving the vertical axis.

Abstract: A swing system for construction machinery or a vehicle, particularly an excavator or a crane, includes a swing brake for blocking or unblocking a rotational movement of a first portion of the vehicle relative to a chassis portion of the vehicle, and a swing pump and a swing motor are provided for performing the rotational movement. The swing pump can be positioned in a neutral position where no rotational movement of the first portion takes place. At least one brake control actuator is provided for automatically engaging the brake when the swing pump is in its neutral position. The swing system can provide an improved control of the swing movement on a slope and an improved comfort during operation of the swing movement.

Abstract: An improvement to the component based hydraulic systems is an integrated electro-hydraulic actuator (EHA) that contains all components necessary to achieve power up, gravity return actuation of a lift mechanism such as the forks of a pallet truck. Further, improvements to known power-up, gravity-down component-based hydraulic circuits are described herein. The improvements provide for power up, gravity return functionality with fewer components as compared known systems. Finally, a method for controlling the EHA and/or hydraulic circuits described above is detailed herein and provides a user with maximum control of a lift mechanism during lower or “down mode,” but also provides for the least amount of energy consumption by the actuator.

Abstract: A construction machine includes a negative parking brake whose braking state is released by a supply of hydraulic fluid. It also includes a parking brake hydraulic circuit that is branched from a hydraulic fluid supplying circuit, which supplies the hydraulic fluid to a transmission of the construction machine, and supplies the hydraulic fluid to the parking brake. The parking brake hydraulic circuit includes a check valve that prevents backflow of the hydraulic fluid of the parking brake to the hydraulic fluid supplying circuit, and it includes an operation switching valve, which is provided closer to the parking brake than the check valve, for switching between an activation and a release of the parking brake. The parking brake hydraulic circuit also includes a relief valve, which is interposed between the check valve and the operation switching valve and which discharges the hydraulic fluid of the parking brake when the relief valve is opened.

Abstract: A work machine includes: hydraulic actuators 21, 22, 23, 31, and 32; a capacitor 61 for storing electric power when a generator motor 44 operates as a generator and for supplying electric power when the generator motor 44 operates as a motor; and a swing electric motor 10, the hydraulic actuators 21, 22, 23, 31, and 32 and the swing electric motor 10 are operated by operation of operating levers 50, 70. The work machine includes an idling stop control unit 110 for stopping the idling of an engine 40 and retains the swing electric motor 10 in an operation prohibited state at least on the condition that stored voltage of the capacitor 61 is predetermined voltage or higher when the neutral states of the operating levers 50, 70 continue for a predetermined stop time during operation of the engine 40.

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

Abstract: An electro-hydraulic actuator has a master cylinder, an electric motor and an electro-mechanical brake. The master cylinder has a hydraulic cylinder and an actuation piston slidably received within the hydraulic cylinder to vary pressure within a hydraulic circuit. The electric motor is adapted to drive the actuation piston into the hydraulic cylinder. The motor has a stator and a rotor. The electro-mechanical brake is arranged to selectively and releasably hold the rotor with respect to the stator to prevent relative rotational motion there between.

Abstract: Provided an electrically-operated hydraulic actuator unit that includes an electrically-operated motor controlled by a control apparatus and actuating a volume adjusting mechanism through driving-side and driven-side arms, and a clutch mechanism in which the driven-side arm presses a contact member against a clutch case so that the driven-side arm is locked when a force from the volume adjusting mechanism is applied to the driven-side arm. The control apparatus can set duties of first to fourth drive signals to be output to the electrically-operated motor in a neutral-side start period, a neutral-side ordinary actuation period, a higher-volume-side start period and a higher-volume-side ordinary actuation period. The duties of the first and fourth drive signals are larger than that of the second drive signal, the duty of the third drive signal is larger than that of the fourth drive signal, and an integrated ON-time of the third drive signal is larger than that of the first drive signal.

Abstract: A cylinder block brake for a hydrostatic transmission or transaxle is provided. A pawl and return spring are located in a housing adjacent to a motor cylinder block. The pawl has a first, biased position where it is not engaged to the motor cylinder block and a second, braking position where it is engaged to the motor cylinder block. A brake actuation shaft which engages the pawl is located in and supported, at least partially, by at least one housing member. The brake actuation shaft is retained in the housing through the interface of features on the brake actuation shaft with a housing member, the pawl and the center section. The pawl may be installed in a first position or in a second, mirrored position.

Abstract: With regard to a transaxle comprising a housing, which houses a hydrostatic stepless transmission constructed by fluidly connecting a hydraulic pump with a hydraulic motor and an axle drivingly connected to the transmission, the housing is constructed by detachably joining a first housing element with a second housing element through a joint surface in parallel to the lengthwise direction of the axle, a counter shaft, drivingly interposed between the hydrostatic stepless transmission and the axle in the housing, is located its axis in the first housing element, a leg member is engaged with the first housing element, and one of ends of the leg member is engaged with a part of the counter shaft, and the other end of the leg member is engaged with the second housing element so as not to be movable.

Abstract: A cylinder block brake for a hydrostatic transmission or transaxle is provided. A braking member is located in a housing adjacent to a motor cylinder block and has a first position where it is not engaged to the motor cylinder block and a second, braking position where it is engaged to the motor cylinder block. A brake actuation shaft is located in the housing and has a cam portion located along its longitudinal axis. The cam portion is positioned to engage the braking member so that rotation of the brake actuation shaft moves the braking member between the engaged and disengaged positions.

Abstract: A control system for a vehicle having a hydraulic drive device such as a hydrostatic transmission or integrated hydrostatic transaxle with a return to neutral feature and a brake mechanism. The system includes a pair of linkages connected to the vehicle brake pedal; one is engaged to the return to neutral arm and the other is engaged to the brake of the drive device, so that actuation of the vehicle brake pedal first causes the return to neutral feature of the drive device to engage to reduce vehicle speed and eventually to return the device to the neutral position. As the vehicle brake pedal is further actuated, the brake mechanism of the drive device is also engaged.

Abstract: A hydrostatic axial piston machine has a cylinder block with bores holding reciprocating pistons, a swashplate supporting the pistons, and control cams to supply the bores with hydraulic fluid. The swashplate is a pivoting cradle mounted on friction bearings in a cradle receptacle. Hydraulic fluid channels empty into the cradle receptacle and are in communication with supply channels in the cradle connected to the control cams. An actuator piston to adjust the cradle is located between two friction bearing segments of the cradle receptacle and has a toothed rack segment engaging a gearing segment on the back side of the cradle.

Abstract: A method and apparatus for operating a load lifting device to move a load and hold the load steady is disclosed. In the conventional arts, a lifted or lowered suspended load had a tendency to move from its desired position, as hydraulic fluid in the lifting system cooled, e.g. a stick slip condition. The present invention monitors a fluid pressure in the lifting system and compensates the fluid pressure to accommodate any pressure drop due to fluid cooling. Thereby, the load can be effectively held steady at a desired position, and the stick slip condition can be avoided.

Abstract: Hydraulic driving device with a hydraulic motor and a bearing arrangement in which the output shaft of the hydraulic motor is supported. Typically, the bearing arrangement is axially supported on the output shaft between a shoulder of the output shaft and a nut screwed onto the output shaft. To reduce overall length, the invention provides that the shoulder is located on the side of the bearing arrangement opposite from the end of the output side of the output shaft, and a friction-disc pack directly bears on the bearing arrangement. The motor has a braking device, including the friction-disc pack and at least one braking cylinder with a spring chamber and a release chamber. A braking valve in the braking position supplies the spring chamber with the load pressure and the release chamber with the tank pressure, and in the release position supplies the spring chamber with the tank pressure and the release chamber with the load pressure.

Abstract: The present invention is so designed that a housing of a transmission which can drive front wheels and rear wheels and a power take-off shaft is constructed having a first chamber and a second chamber. A hydrostatic transmission is housed in the first chamber. A gear-type speed changing unit is housed in the second chamber. A hydraulic pump and a hydraulic motor are separately disposed on the inner and outer surfaces of the front wall of the first chamber. A clutch mechanism for engaging or disengaging with or from the front wheels for supplying power thereto is also provided. On the housing is provided a restraint mechanism for restraining rearward acceleration more than a predetermined speed by a speed control lever of the hydrostatic transmission when the gear-type speed changing unit is switched to the high speed setting.

Abstract: A neutral brake system for use in a hydrostatic transmission to automatically apply a brake when the hydrostatic transmission is shifted to neutral. The neutral brake system includes a hydraulically-released, spring-activated brake mechanism in direct fluid communication with the main hydraulic passages which form a hydraulic circuit between the pump and the motor. When the hydrostatic transmission is shifted to neutral, a brake spring biases a brake lever into contact with a pair of friction pads to engage a brake disk splined to the output shaft of the motor to stop the vehicle. When the hydrostatic transmission is shifted out of neutral, a charge of hydraulic pressure within the hydraulic circuit causes a piston within a brake release chamber to override the biasing force of the brake spring, and to urge the brake lever out of contact with the friction pads such that the friction pads are disengaged from the brake disk, and the output shaft of the output shaft of the motor may freely rotate.

Abstract: A pilot control system for maintaining a constant operating hydraulic fluid pressure in a hydraulic system throughout a range of hydraulic fluid flow and temperature conditions. The pilot control system has a pilot pump and a pilot relief valve in fluid communication with the pilot pump. A first pressure reducing valve is in fluid communication with the pilot pump and the pilot relief valve so as to reduce the pressure to components downstream of the pressure reducing valve.

Abstract: In a brake (53) for a hydraulic motor (10), a braking piston (66) is added that can move toward and away from fixed friction discs (54) and rotating friction discs (55). A braking passage (73) leads a high-pressure fluid into the braking piston (66) to press the braking piston (66) to the friction discs (54, 55).

Abstract: A hydraulic motor (1) comprising a casing (2A, 2B) a reaction member having a reaction profile (4), a cylinder block (6), an internal fluid distributor (16) suitable for putting the cylinders (12) of the cylinder block (6) in communication with fluid feed and exhaust ducts, and a braking system which comprises first and second braking elements (42, 44), constrained to rotate respectively with the reaction member (4) and with the cylinder block (6). The braking system further comprises a brake piston (40) suitable for being displaced axially so as to urge the braking elements into braking contact or so as to enable braking to be released. The brake piston is constrained to rotate with the casing about the axis of rotation, and it has a substantially radial active face, a first brake member (42) belonging to the first braking means being integral with said active face.

Abstract: A hydrostatic motor unit designed as a wheel drive comprises at least two hydraulic motors, at least one of which has a variable capacity. The hydraulic motors can be switched hydraulically in parallel and have output rotors that can be coupled with each other. The invention teaches that the output rotors are oriented coaxially to one another and are connected to each other in rotational synchronization. The output rotors are preferably part of a one-piece rotor block that contains the work chambers of the two hydraulic motors. The motor unit consists of an internally pressurized, in particular multiple-stroke radial piston motor that has a constant capacity, and a reversible axial piston motor utilizing the swash plate construction that has an adjustable capacity. From a common, axially oriented control surface for the radial piston motor and the axial piston motor, there are hydraulic channels of approximately the same length that lead to the work chambers of the hydraulic motors.

Abstract: A hydraulic continuously variable transmission for use on a vehicle comprises a hydraulic variable pump, which is driven by an engine, and a hydraulic variable motor, which is driven by oil discharged from the hydraulic variable pump to drive wheels. In addition, this transmission includes shift position detecting means, which detects a shift position, and vehicle stop detecting means, which detects whether the vehicle is in halt. In this transmission, when the vehicle stop detecting means detects that the vehicle is in halt and the shift position detecting means detects that the shift position is in a forward or rearward drive position, the discharge capacity of the hydraulic variable motor is set to a maximum, and the discharge capacity of the hydraulic variable pump is controlled to a predetermined capacity (first predetermined capacity) in correspondence with the shift position. Thereby, the vehicle is prevented from relapse phenomenon, i.e.

Abstract: A brake mechanism is provided for use in braking an axle within an axle housing on an associated vehicle. The brake mechanism includes a brake stack, an actuation plate, a pressure plate, gears means for operatively connecting a brake pedal to the actuation plate and for indicating the wear condition of the brake mechanism.

Abstract: A hydraulic continuously variable transmission for use on a vehicle comprises a hydraulic closed circuit, first and second pressure controlling means, brake operation detecting means and deceleration detecting means. The hydraulic closed circuit includes a hydraulic pump, a hydraulic motor, a first oil passage connecting a port of the hydraulic pump with a port of the hydraulic motor and a second oil passage connecting another port of the hydraulic pump with another port of the hydraulic motor, and first and second pressure controlling means control the pressures of the first and second oil passages, respectively. If the deceleration of the vehicle is greater than a standard deceleration when the operation of the brake is detected, then the pressure of the first or second oil passage whose pressure is higher than that of the other is lowered to a predetermined low pressure that is higher than the pressure of either oil passage which is lower by either the first or second pressure controlling means.

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 hydrostatic transmission including a fluid pump and fluid motor mounted within a transmission housing, and a brake connected to the motor shaft. The housing includes upper and lower sections. The brake includes rotor and stator plates, and a pin for urging the rotor and stator plates into frictional engagement. The upper and lower sections are joined along a split line and each has a mating half-round section, for positioning the pin.

Abstract: A hydromechanical transmission which includes a swash-plate type hydrostatic axial piston motor with a rotary cylindrical drum having work cylinders and a driven shaft. A planetary gear is located adjacent to and coaxial with the piston motor and includes a rotary hub surrounding both the planetary gear and the axial piston motor, A ring gear is located at the inner surface of the rotary hub and a stationary hub support having an open ended cavity to hold the axial piston motor is mounted within and coaxial with the rotary hub. The end wall of the cavity is a control surface for the axial piston motor and pressure medium channels which open on the control surface for periodic connection with the work cylinders in the cylindrical drum are formed in the stationary hub support.

Abstract: An axle driving apparatus wherein a brake disk is fixed to one of the output shaft of a hydraulic motor and a rotary shaft of a power transmission, and the disk, and a brake disk and an actuator cooperative therewith are held immersed in oil retained in a housing. The advantage of compactness of the disks is utilized, and the disks are given improved durability by being immersed in the oil for cooling and suppression of heat generation.

Abstract: This invention relates to an assembly of a hydraulic motor and of a brake which is coupled thereto, comprising in particular a brake shaft which traverses said motor and brake entirely. According to the invention, the brake shaft comprises an axial through recess allowing passage of a link, such as a movement transmission shaft. One application of the invention is the production of a reliable compactor.

Abstract: This invention relates to an assembly of a hydraulic motor and a combined device for immobilization, comprising: a reaction cam; a cylinder-block mounted to rotate with respect to the reaction cam; a first immobilization member fast with the cylinder-block; a second immobilization member fast with the reaction cam and capable of being disposed in a first position, in which the first and second immobilization means are fast with one another, and a second position, in which these first and second immobilization members do not cooperate for their mutual immobilization. The device for adjusting the relative position of the first and second immobilization members comprising a jack comprising a chamber.

Abstract: The present invention relates to an assembly of a pressurized fluid mechanism and a brake coupled thereto. The assembly comprises an internal fluid distributor value having a communication face defining, within the housing of the assembly, two enclosures separated by the communication face and a brake comprising a brake-release chamber. The brake-release chamber is in permanent communication with at least one of the two enclosures resulting in a high yield motor of moderate cost.

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 brake actuator for use in combination with a hydraulic motor which includes a port structure. The port structure defines an interface with a motor block of the hydraulic motor and includes ports for supplying fluid to the motor. A brake is operatively associated with the hydraulic motor. A hydraulically operated piston is disposed substantially within the confines of the port structure for actuating the brake.

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 vehicle includes at least a pair of drive wheels, each wheel being independently controlled by an integrated transmission, each transmission being powered by an input shaft operably driven by a common engine. Each transmission is of a type wherein a pump head with pistons is driven by the input shaft and conveys output fluid to a motor head which is driven thereby and rotates and output shaft. Pump head output is controlled by an operator variable swash plate. The transmission integrally includes a dampening mechanism for the swash plate, a positive neutral structure for the swash plate, an automatic parking brake with override mechanism to allow setting of the brake or release of the brake by the operator, a porting block communicating fluid flow between the pump heads and providing for overpressure relief, and a charge pump for communicating makeup fluid to the pump head and to circulate the fluid so as to cool same.

Abstract: A control valve (10) is disclosed for use in controlling a winch motor (12) on a winch. The control valve (10) is employed with a conventional operating valve (32). When the operating valve is in the neutral position, the control valve (10) acts as a hydraulic brake and an unloading valve for a brake cylinder (20). When the operating valve (32) is moved to raise a load with the winch, the control valve provides a flow path to and from the winch motor (12) to rotate the motor to raise the load and provides sufficient hydraulic pressure in the brake cylinder chamber (18) to release the brake even if the winch has no load. When the operating valve is operated to lower the load, the control valve (10) acts as an over center valve to prevent the load and winch from running away from the winch motor (12). The control valve (10) accomplishes each of these functions with only a single valve spool (132) slidable in a valve housing (100).

Abstract: A hydraulic circuit system for use in hydraulically operated vehicles having a bidirectionally rotatable hydraulic motor with a brake unit, a directional control valve for controlling a pressurized fluid supply to the motor, bypass circuits connected between a fluid supply circuit and a drain circuit, a shadow valve provided in the bypass circuits, and an ON-OFF changeover valve provided in the bypass circuits for allowing the bypass circuits to connect with and disconnect from the shadow valve. The system further includes a cavitation preventing circuit device connected through check valves between the bypass circuits and the shadow valve so as to allow the bypass circuits to communicate with each other in co-operation with the shadow valve.

Abstract: A fluid pressure control circuit for operating a bidirectional hydraulic motor comprises first and second main conduits for selectively supplying the pressurized fluid delivered by a main hydraulic pump through a pilot fluid pressure operated three-position directional control valve and via a brake valve device into first and second ports of the bidirectional hydraulic motor; two pilot fluid supply conduits located in parallel relationship with each other for selectively supplying the pressurized fluid delivered by an auxiliary hydraulic pump as a pilot fluid pressure through a three-position directional control valve into the left and right pressure receiving portions of said pilot fluid pressure operated three-position directional control valve; a conduit for selectively supplying the pressurized fluid delivered by the auxiliary hydraulic motor through a solenoid operated control valve into the pressure chamber of a gyratory brake device; and a conduit for short-circuiting said two pilot fluid supply condui

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: The invention is an integrated hydraulic control circuit for actuating the thrust reversers and variable exhaust nozzle on high preformance gas turbine engine powered aircraft. The hydraulic circuits for both systems are integrated into a single housing and are served by common elements. The circuit for the deployment and stowage of the thrust reverser buckets is hydraulically sequenced inhibiting the application of hydraulic power to the actuators prior to withdrawal of the locking pin. In a like manner, the thrust reversers must be fully retracted before the locking pin is deployed. The hydraulic circuit for the thrust reversers also includes a pressure compensating circuit which reduces the pressure applied to thrust reverser actuators with the thrust reversers in the stowed position.

Abstract: A hydrostatic transmission has an engine-driven, bidirectional, variable-displacement drive pump connected in circuit with a bidirectional, variable-displacement propelling motor. A charging pump is also connected to the circuit of the drive pump and the propelling motor. A brake assembly normally locks the output shaft of the propelling motor against rotation and releases same only while being supplied with a hydraulic brake release signal. The control system for the hydrostatic transmission comprises a speed control valve actuated manually to deliver fluid pressure signals to servo controls for adjusting the outputs from the drive pump and the propelling motor, and a brake control valve pilot-operated to deliver the brake release signal to the brake assembly. Also included are a charge sensor valve and a speed control sensor valve.

Abstract: An automatic neutral point detecting system for a hydraulic pump equipped with a displacement varying device capable of shifting both in a (+) direction and in a (-) direction and connected to at least one hydraulic actuator to form a hydraulic circuit to drive the hydraulic actuator. The system includes pressure sensors for sensing the port pressures of the hydraulic pump, a shifting detector for detecting the shifting of the displacement varying device, a closing device for closing the hydraulic circuit and blocking the flow of a hydraulic fluid, a start switch for giving a command to start detection of the neutral point of the hydraulic pump, and a control unit for detecting the neutral point of the hydraulic pump.

Abstract: A failure detection system for a hydraulic pump (1) having a displacement volume varying device (1a) and connected to at least one hydraulic actuator (4) to constitute a hydraulic circuit for driving the hydraulic actuator. The system includes means (7a, 7b) for sensing the discharge pressure of the pump, means (6) for detecting the value of shifting of the displacement volume varying device, means (5, 24) for closing the hydraulic circuit to block the flow of a hydraulic fluid through the circuit, starting means (9) for giving a command to start checking on the pump to see if it is normally functioning, and a control unit (2, 23, 28, 29) for performing checking on the pump to see if it is normally functioning. The control unit includes means (S-5, S-5') responsive to the command given by the starting means for giving a command to activate the closing means, data collecting means (S-11) for causing the displacement volume varying device to shift based on information (P.sub.a, P.sub.

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.