Abstract: A hydraulic transaxle facilitates mounting a parking brake unit which requires no link mechanism and is compact. The parking brake unit includes a brake rotor provided on a rotation shaft and a locking member being displaceable between a first position where the brake rotor is locked and a second position where the brake rotor is unlocked. The locking member includes a locking portion which is engaged in a recess formed in the brake rotor that locks the brake rotor in the first position, and a non-locking portion which is placed at a position corresponding to the recess and which separates from the brake rotor in the second position. The hydraulic transaxle further includes an oil-supply mechanism capable of displacing the locking member to the second position.

Abstract: An example hydrostatic transmission includes (i) a motor section having a motor interface; (ii) a pump section configured to generate fluid flow, where the pump section comprises a pump interface having a first pump port to provide fluid flow therethrough and a second pump port to receive returning fluid flow therethrough; and (iii) an interface block coupled to the motor interface and coupled to the pump interface so as to couple the pump section to the motor section, where the interface block includes internal fluid passage to facilitate fluid communication between the pump section and the motor section.

Abstract: A power-split transmission device for a vehicle, which connects a drive engine to a drive output, having a hydrostatic unit for continuous adjustment of the transmission ratio at a transmission unit, and two range clutches that alternately operate for respectively associated driving ranges with different transmission ratios. A control unit, during regular vehicle deceleration, implements the driving range change from a first range, with higher transmission ratios, to a second range, with lower transmission ratios, by switching from the first to the second range clutch in accordance with a synchronous point dependent deceleration control logic. In the special case of an unexpected increase of the deceleration dynamic at the beginning of an already initiated driving range change from the first to the second driving range, the control unit immediately forces the change by bypassing the synchronous point dependent deceleration control logic when other boundary conditions are fulfilled.

Abstract: A housing assembly for a side-by-side (SBS) piston pump may define a pump cavity enclosing first and second piston pumps having parallel longitudinal axes. The housing assembly may include a shroud partially or wholly separating the piston pumps to substantially reduce churning of lubricating fluid flow flowing around the piston pumps and pooling in a fluid intersection area between the piston pumps. The shroud may be a planar shroud plate extending between the piston pumps, or a curved shroud plate between the piston pumps and having sections partially encircling each of the piston pumps. The shroud may alternatively be first and second shroud portions extending inwardly from the cavity walls and directing the lubricating fluid flows the merge in a combined lubricating fluid flow area.

Abstract: Hydraulic transmission apparatus including a pressurized fluid source and at least one hydraulic motor fed by said pressurized fluid source. The motor has two motor ducts for feed/discharge, and one casing duct. The motor can be operated in assisted mode, in which it generates torque or in unassisted mode in which it does not generate any torque and its pistons are maintained in the retracted position under the effect of the pressure in the casing duct. The apparatus further includes an accumulator suitable for feeding: the motor ducts during a stage of passing from the unassisted mode to the assisted mode in order to facilitate deployment of the pistons; and the casing duct during a stage of passing from the assisted mode to the unassisted mode in order to facilitate retraction of the pistons. This apparatus thus enables the motor to be positively clutched/declutched quickly.

Abstract: A cooling fan control unit, in response to an operation performed at the rotation direction selector switch to select a reverse rotation setting while the cooling fan is rotating forward, lowers a relief pressure setting at the variable relief valve to a predetermined lower limit value over a predetermined length of time, and once the discharge pressure at the hydraulic pump detected by the pressure sensor is lowered to a predetermined switch-over pressure, executes control so as to switch the direction of flow of pressure oil to the hydraulic motor to the reverse direction by switching the direction switching valve and raises the relief pressure setting at the variable relief valve to a reverse rotation pressure setting, at which the hydraulic motor rotates in the reverse direction, over a predetermined length of time.

Abstract: A hydraulic transmission system for a vehicle is provided. The system includes a main pump serving to feed with fluid at least one hydraulic motor for driving a vehicle mover member; an auxiliary pump, the main pump and the auxiliary pump being suitable for being actuated jointly; and a “bypass” connection between a delivery orifice of the auxiliary pump and an unpressurized reservoir. In addition, a first constriction is arranged on the bypass connection, and configured to maintain a pump protection pressure in a pump protection portion of the bypass connection. This pressure is applied to the main orifices of the main pump when said pump is actuated but is not delivering, thereby ensuring that the pump is protected.

Abstract: The cover member has an outer edge portion configured by the upper end extending portion, the front end extending portion, and the rear end extending portion in which a front end of the upper end extending portion and an upper end of the front end extending portion are connect to each other, and a rear end of the upper end extending portion and an upper end of the rear end extending portion are connected to each other.

Abstract: Ultra efficient hydraulic hybrid drivetrain of vehicle with a single cylinder module of engine, air compressor, hydraulic pump and motor transmit power without crankshaft, pipes and hoses. The engine piston fastened to pump plunger located within rotor comprised two diametrically opposite axial rods associated with the plunger, compressor piston and swash plate. This plate turn and independently shift by digital control changes the engine piston stroke, changes the engine compression ratio for super efficient homogeneous charge compression ignition and either kind of fuel use. The hybrid by hydraulic accumulator provides start, idling and work mode of operation. Compressor's piston diameter greater than engine piston diameter and plunger pumping fluid and simultaneously driving additional plungers enables to provide more than 130 hp per liter engine displacement. Such unique features and energy recuperation enables to achieve 80 mile per gallon for the 1500 kg weight medium car in city conditions.

Abstract: A lubrication system is provided that includes a pump operatively connected to one or more supply lines for delivery of a lubricant, the system including a first pressure sensor associated with the supply line at a first position, and a second pressure sensor associated with the supply line at a second position downstream of the first position and pump, a controller configured to receive pressure signals and control operation of the pump based upon the pressure differential between the pressures at the first position and second position. The pressure differential may be employed to determine when a pressure at a third position downstream of the second position has been achieved. At least one of the pressure sensors may be positioned adjacent to the pump, the controller further being operable to deactivate the pump in the event that a maximum pump pressure has been met.

Abstract: A control method for a hydraulic type continuously variable transmission for suppressing a harmful effect due to the reacceleration just after deceleration of a vehicle. In a hydraulic type continuously variable transmission, the operation of a shifting actuator is stopped to suspend the shift control (S7) when a throttle valve is rapidly opened just after fully closed (S4: Yes) and an engine speed NE [rpm] is being rapidly increased (S6: Yes). Accordingly, even when the actual engine speed NE becomes much greater than a target engine speed T_NE during reacceleration just after deceleration of a vehicle, unexpected shift control (upshifting) can be prevented, so that more desirable torque can be produced.

Abstract: A hydrostatic drive in an open circuit is provided. The hydrostatic drive has a hydraulic pump and a hydraulic motor. The hydraulic pump and the hydraulic motor are connected to one another via a feed line. In addition, the hydrostatic drive has a storage element for storing pressure energy. A first valve device, which is arranged downstream of the hydraulic motor, alternately connects the downstream connection of the hydraulic motor to a tank volume or to the storage element.

Abstract: A hydraulic drive apparatus having a center section assembly for mounting inside a housing is disclosed. The center section includes generally flat side edge surfaces formed adjacent and perpendicular to a cylinder block running surface, and shaped to engage a channel formed in an internal surface of the housing to secure the center section to the housing. The assembly may also include a filter using a connection member to permit the filter to slide on and engage the peripheral edge of a flange formed on the center section.

Abstract: A pressure recovery system according to the present invention comprises a pump, a flow control valve and a flow amplifier. The flow control valve has an inlet connected to the outlet of the pump, an outlet for supplying fluid to the load to which pressurized fluid is to be supplied, and a bypass flow outlet connected to the flow amplifier. The bypass flow drives the flow amplifier for supplying fluid to an inlet of the pump.

Abstract: A hydraulic motor 11 is switched to a high-speed mode when pressure oil is supplied to a pressure chamber 23 of a tilt piston 17 based on the transmission of a speed signal to a high-low speed switching valve 18, and the hydraulic motor 11 is switched to a low-speed mode when pressure oil is discharged from the pressure chamber 23 of the tilt piston 17. A first braking purpose speed changing mechanism 13 operates so as to discharge pressure oil from the pressure chamber 23 of the tilt piston 17 when the pressure of pressure oil between a counterbalance valve 15 and a direction changeover valve 103 becomes equal to a tank pressure. Therefore, it is possible to provide a variable hydraulic motor driving device which is capable of preventing braking operation from being excessively long and also capable of preventing a large shock from occurring at a time of stoppage due to a large braking force generated from an early stage of braking operation.

Abstract: A lubricating structure for a static hydraulic continuously variable transmission includes a central oil path axially formed at a center of a shaft of the transmission. A circumferential oil path is arranged at an inner circumferential part of a retainer between the retainer and an outer circumferential part of the transmission shaft. A diametrical oil path is in communication with the circumferential oil path and the central oil path of the shaft of said transmission. The diametrical oil path is provided with an orifice. A lubricant oil ejection hole is arranged at the retainer to eject lubricant oil from the circumferential oil path.

Abstract: A hydraulic transmission comprises a hydraulic pump and a hydraulic motor, which are mounted onto a center section to be fluidly connected to each other through a closed fluid circuit formed in the center section. A neutral valve is connected to the closed fluid circuit. The neutral valve is fitted into an outward opened end of a vertical slanted oil hole of the closed fluid circuit. Alternatively, the neutral valve is fitted into an outward opened end of a straight oil hole having an opposite outward opened end into which a charge check valve is fitted.

Abstract: A hydraulic motor assembly having a motor and gear reduction set mounted in a housing. The housing may be formed of separate components, including the external surface of the ring gear and the hydraulic motor port block. The motor assembly may also include pressure relief valves or neutral valves in the motor port block and a brake assembly mounted in the port block or on the motor housing to provide braking for the output axle.

Abstract: A hydrostatic continuously variable transmission is configured by connecting a swash plate type plunger hydraulic pump P and a swash plate type plunger hydraulic motor via a hydraulic closed circuit. A continuous shift control is executed by variably controlling an inclined angle of the swash plate of the hydraulic motor. A valve spool movably arranged in a spool hole axially extends in a shaft that supports the hydraulic pump and the hydraulic motor and is configured by coupling a first spool member provided with a guide land fitted in a guide member and a second spool member provided with a central land and a left land and provided with a valve that connects and cuts off a clutch oil passage on the high pressure side and a clutch oil passage on the low pressure side according to axial movement by a coupling pin.

Abstract: A center section assembly for mounting inside the housing of a hydrostatic or hydraulic drive apparatus is disclosed. The center section includes generally flat side edge surfaces formed adjacent and perpendicular to a cylinder block running surface, and shaped to engage a channel formed in an internal surface of the housing to secure the center section to the housing. The assembly may also include a filter using a connection member to permit the filter to slide on and engage the peripheral edge of a flange formed on the center section.

Abstract: The invention concerns a hydraulic axial piston machine with a housing, in which a cylinder drum having at least one cylinder is arranged to be rotatable around an axis, in which cylinder is located a piston that is supported on a swashplate, whose inclination angle is adjustable in an adjustment plane. It is endeavoured to keep the cost of manufacturing individual parts of the axial piston machine small. For this purpose it is provided that on the side facing away from the cylinder drum (4) the swashplate (12) has a spherical bearing surface (15), which rests on a spherical supporting surface (16) in a bottom part (3) of the housing (2) and comprises an inclination protection (31-34), which counteracts an inclination of the swashplate (12) perpendicularly to the adjustment plane.

Abstract: The monocylindrical hybrid powertrain is provided having a continuously variable volume hybrid engine, a pump, and a hydrostatic motor. A direct energy transmission, a variable displacement volume engine, a pump, and a hydrostatic motor and energy recuperation increases the specific power, decreases the weight, and installation space and enables the vehicle to achieve a fuel economy of 80 miles per gallon for the vehicle in city conditions.

Abstract: A transmission for a vehicle includes a fixed displacement pump operable to produce a high pressure flow and a fixed displacement motor. A fluid flow path is disposed between the pump and the motor. The fluid flow path is integrated into a housing containing at least one of the pump and the motor. A single control valve controls the direction and the speed of the motor.

Abstract: A method of operating a vehicle with a hydrostatic circuit. The method includes providing a hydrostatic circuit having first and second hydraulic kits that are fluidly connected to one another by first and second fluid lines. A by-pass valve is placed between the first and second hydraulic lines and is controlled in order to actuate the by-pass valve when certain predetermined conditions are present in order to relieve pressure within the hydrostatic circuit.

Abstract: A hydraulic circuit associated with a hydraulic actuator is provided having a reservoir situated to hold a supply of fluid and a pump situated to supply pressurized fluid to the hydraulic actuator. The hydraulic circuit also has a pressure intensifying valve fluidly connected to the reservoir and the hydraulic actuator. The pressure intensifying valve is situated to direct fluid to the reservoir while in a first position and direct fluid to the hydraulic actuator while in a second position. The hydraulic circuit further has a flow divider including a housing with an inlet fluidly connected to the pump, a first outlet fluidly connected to the hydraulic actuator, and a second outlet fluidly connected to the pressure intensifying valve. The flow divider also includes a first fluid transporting portion fluidly connected to the inlet and the first outlet and a second fluid transporting portion fluidly connected to the inlet and the second outlet.

Abstract: A concrete agitating drum (1) is driven by a hydraulic motor (81). A connection switch-over valve (20) is arranged to have a function to regulate a flow cross-sectional area of pressurized working oil supplied to the hydraulic motor (81) from a variable capacity hydraulic pump (10). The variable capacity hydraulic pump (10) is driven by a combustion engine (60) together with a charge pump (11). When a discharge pressure of the charge pump (11) is low, the connection switch-over valve (20) maintains a small flow cross-sectional area to rotate the agitating drum (1) at a low rotation speed so that fuel consumption of the combustion engine (60) is suppressed to be small. When the discharge pressure of the charge pump (11) becomes high, the connection switch-over valve (20) enlarges the flow cross-sectional area, thereby realizing a rated rotation speed of the agitating drum (1).

Abstract: A hydraulic transmission system features a first hydrostatic motor (1) and a second hydrostatic motor (4), which are connected to an output shaft (3) by way of a compound transmission, and which, in order to reach a minimum and a maximum rotation speed of the output shaft, are, on the one hand, adjustable with respect to their displacement volume by way of electric valves (9, 17) and, on the other hand, can be connected or, as the case may be, separated from a conveyor line (7) and a suction line (8) of a hydraulic pump.

Abstract: There is provided a neutral valve structure applied to at least one of a pair of operation fluid lines in an HST, including: a valve body slidable in the axis line direction so as to take a closing position where the corresponding operation fluid line is liquid-tightly closed and a releasing position where the corresponding operation fluid line is released to a low-pressure area; and a biasing member for urging the valve body toward the releasing position on one side of the axis line direction.

Abstract: A hydraulic motor 11 is switched to a high-speed mode when pressure oil is supplied to a pressure chamber 23 of a tilt piston 17 based on the transmission of a speed signal to a high-low speed switching valve 18, and the hydraulic motor 11 is switched to a low-speed mode when pressure oil is discharged from the pressure chamber 23 of the tilt piston 17. A first braking purpose speed changing mechanism 13 operates so as to discharge pressure oil from the pressure chamber 23 of the tilt piston 17 when the pressure of pressure oil between a counterbalance valve 15 and a direction changeover valve 103 becomes equal to a tank pressure. Therefore, it is possible to provide a variable hydraulic motor driving device which is capable of preventing braking operation from being excessively long and also capable of preventing a large shock from occurring at a time of stoppage due to a large braking force generated from an early stage of braking operation.

Abstract: A hydraulic drive system is provided with a front casing 50 and a rear ceasing 51. The front casing 50 is formed of a single member, and accommodates therein rotary members, which include a cylinder block 30A and the like, and a part of an output shaft 36 of a hydraulic motor 30 and rotary members, which include a cylinder block 31A and the like, and a part of an output shaft 32 of a hydraulic motor 31. The rear casing 51 is joined to the front casing 50, and has a ports plate 30C and a ports plate 31C arranged therein. The rear casing 51 has an oilway 52 communicating to a first port 30C1 of the ports plate 30C, an oilway 53 communicating to the oilway 52 and also communicating to a first port 31C1 of the ports plate 31C, an oilway 54 communicating to a second port 30C2 of the ports plate 30C, and an oilway 55 communicating to the oilway 54 and also communicating to a second port 31C2 of the ports plate 31C.

Abstract: A two piece center section assembly for mounting inside the housing of a hydrostatic or hydraulic drive apparatus is disclosed. The assembly includes separate pump and motor support portions that are preferably generally identical in structure. The need for fasteners between the pump and motor portions is eliminated.

Abstract: A hydraulic differential with a variable displacement hydraulic unit of the axial piston type, a fixed displacement hydraulic unit of the axial piston type, a stationary housing for mounting the hydraulic units, an input shaft for coupling to a variable speed power source and an output shaft for coupling to a constant speed load, comprises: a wobbler and a port plate for the variable displacement hydraulic unit coupled to the stationary housing; an axial block and piston set for the variable displacement hydraulic unit, a port plate for the fixed displacement hydraulic unit and a wobbler for the fixed displacement hydraulic unit coupled to the input shaft; and an axial block and piston set for the fixed displacement hydraulic unit coupled to the output shaft; wherein the variable displacement hydraulic unit port plate and the fixed displacement hydraulic unit port plate couple together through a circumferential interface to minimise hydraulic thrust forces developed by the hydraulic unit.

Abstract: An axle driving apparatus in which a hydraulic pump and a hydraulic motor which constitute a hydrostatic transmission are disposed on a center section. In a horizontal portion of the center section are provided a pair of linear oil passages in parallel to each other. A pair of arcuate ports are provided on a pump mounting surface formed on the horizontal portion of the center section. The pair of arcuate ports are substantially perpendicular with respect to the direction in which the oil passages extend. The axis of slanting movement of a movable swash plate of the hydraulic pump extends laterally of the vehicle body on which the axle driving apparatus is provided. The rotating direction of an arm provided on a control shaft for slantingly operating the movable swash plate is coincident with the operating direction of a control rod connected with a speed changing member. Thus, the link mechanism for connecting the speed changing member and the control arm for the movable swash plate is simplified.

Abstract: A hydraulic motor assembly having a motor and gear reduction set mounted in a housing. The housing may be formed of separate components, including the external surface of the ring gear and the hydraulic motor port block. The motor assembly may also include pressure relief valves or neutral valves in the motor port block and a brake assembly mounted in the port block or on the motor housing to provide braking for the output axle.

Abstract: The monocylindrical hybrid powertrain comprises a continuously variable volume hybrid engine, pump and hydrostatic motor. The pump plunger fastened to engine piston and the engine cylinder fastened to the hydrostatic motor by valve plate and formed solid monoblock. The hybrid synchronize mechanism swash plate turn changes the engine piston stroke and remains the engine compression ratio. The swash plate shift changes the engine compression ratio for the either kind of fuel use. The hybrid and pneumohydraulic accumulator association transforms the single pump plunger supply pulsation into uniform fluid flow feeding the hydrostatic motor. The hydrostatic motor and the electric motor association allow electric energy accumulation by means of plug-in. Direct energy transmission, variable displacement volume engine, pump and hydrostatic motor and energy recuperation increases the specific power, decreases the weight and installation space and enables to achieve 80 mile per gallon for the car in city conditions.

Abstract: The invention related to a hydrostatic drive comprising a hydraulic pump (3) which is driven by a drive machine (2) and pumps into at least one first working line(4), and a pressure line (18) in which a feed quantity dependent on the speed of the drive machine (2) flows. When a differential pressure value in the pressure line (18) is exceeded, the pressure means can be extracted from the first working line (4).

Abstract: To provide a short connection hydraulic path structure with a sufficiently large diameter to adequately lower the pressure in a high-pressure hydraulic path while the clutch is off, in a static hydraulic continuously variable transmission for sliding a clutch valve installed within the transmission shaft, to change the power being transmitted and shorten the high-pressure hydraulic path and low-pressure hydraulic path. A high-pressure fluid path is provided for sending hydraulic fluid from the hydraulic pump side to the hydraulic motor side with a low-pressure fluid path for sending hydraulic fluid from the hydraulic motor side to the hydraulic pump side. A hydraulic circuit includes a switching valve for switching the plungers to the high-pressure path or the low-pressure path as a dual structure within a valve body between the hydraulic pump made from multiple plungers, and a hydraulic motor made from multiple motors.

Abstract: An axle driving apparatus in which a hydraulic pump and a hydraulic motor which constitute a hydrostatic transmission are disposed on a center section. In a horizontal portion of the center section are provided a pair of linear oil passages in parallel to each other. A pair of arcuate ports are provided on a pump mounting surface formed on the horizontal portion of the center section. The pair of arcuate ports are substantially perpendicular with respect to the direction in which the oil passages extend. The axis of slanting movement of a movable swash plate of the hydraulic pump extends laterally of the vehicle body on which the axle driving apparatus is provided. The rotating direction of an arm provided on a control shaft for slantingly operating the movable swash plate is coincident with the operating direction of a control rod connected with a speed changing member. Thus, the link mechanism for connecting the speed changing member and the control arm for the movable swash plate is simplified.

Abstract: A hydrostatic transmission apparatus has a housing, a hydraulic pump disposed in the housing so as to be driven by a prime mover and a first hydraulic motor disposed in the housing. A first port is provided on the housing and opens outward from the housing. A first fluid passage is disposed in the housing and interposed between the hydraulic pump and the first hydraulic motor. A second port is provided on the housing and opens outward from the housing. A second fluid passage is disposed in the housing and extended from the hydraulic pump to the first port, wherein the first and second ports are adapted to be fluidly connected to a second hydraulic motor disposed outside of the housing so as to constitute a closed fluid circuit fluidly connecting the first and second hydraulic motors in series to the hydraulic pump. A third fluid passage is disposed in the housing and extends from the first hydraulic motor to the second port.

Abstract: A hydrostatic transaxle comprises: a housing, an interior space of the housing serving as a fluid sump; an axle supported by the housing; a hydrostatic transmission disposed in the housing so as to drive the axle, the hydrostatic transmission including a hydraulic pump disposed in the housing, a hydraulic motor disposed in the housing, and a center section disposed in the housing, wherein the hydraulic pump and the hydraulic motor are mounted onto the center section, and wherein the center section is formed therein with a fluid circuit for circulation of fluid between the hydraulic pump and the hydraulic motor, and formed with an outwardly opened hole connected to the fluid circuit; a valve holding member fitted into the hole; and a relief valve connected to the fluid circuit through valve holding member.

Abstract: A rotary control valve for a vehicle hydrostatic transmission includes a hydraulic pump and a hydraulic motor. The valve is configured to control both a direction and a speed of the hydrostatic transmission. The rotary control valve includes a rotary valve plate configured to oscillate through a range of less than 180 degrees independently of the pump and the motor.

Abstract: An improved valve for use in a hydrostatic drive apparatus for a vehicle such as a zero turn vehicle. For each hydraulic drive system in the vehicle, a valve is located between the high and low pressure sides of the closed hydraulic circuit connecting the hydraulic pump and motor. The valve opens when the pressure rise rate in the high pressure side reaches a set level to minimize pressure spikes in the high pressure side and thus improve performance of the vehicle. A valve block may be used to mount the valve, and a second valve may also be included therein to connect the two pressure sides of the hydraulic circuit in a similar manner when the vehicle is operated in reverse.

Abstract: The present invention relates to hydraulic equipment comprising input shaft (2) and output shaft; first and second plungers (8, 10) and first and second spool valves (9, 11) which are moved reciprocally axially; a cylinder block (7) which houses the plungers and spool valves and is rotated integrally with the input shaft; an input side swash plate (6) which touches the first plungers; and an output side swash plate (12) which touches the second plungers and is rotated integrally with the output shaft. The purpose of the present invention is to reduce number of parts concerning to the accuracy of the reciprocal movement of the first and second spool valves. Spool valve guides (37 and 47) on which guide grooves (37b and 47b) slanted against axis of the rotary shaft are formed, and the first or second spool valve is engaged with a holding member (38 or 48) attached to the guide groove or the guide groove.

Abstract: A bypass mechanism is provided for use in a hydrostatic transmission, to enable the user to open or close a valve between the two pressure sides of the hydraulic circuit of the transmission. An electrical mechanism is positioned to open or close the valve based on a signal which may be generated by a switch associated with the hydrostatic transmission.

Abstract: In a hydrostatic continuously variable transmission, a hydraulic pump is linked to a hydraulic motor by a hydraulic closed circuit to change the capacity of the hydraulic motor so as to change the speed of a motorcycle continuously. A clutch device comprising a clutch valve for connecting and disconnecting a high pressure side oil passage and a low pressure side oil passage constituting the hydraulic closed circuit. A governor mechanism for generating governor force corresponding to the input rotation speed of the hydraulic pump and applying this governor force in the closing direction of the clutch valve. A spring for giving urging force in the opening direction of the clutch valve, and a buffer mechanism having a variable oil chamber and an oil pool chamber for easing the opening and closing movements of the clutch valve activated according to the governor force and the urging force.

Abstract: Disclosed is a vehicle comprising a transaxle and a bypass mechanism. The transaxle has a plurality of mounting holes for use in attaching the transaxle to the vehicle. Further, the transaxle has at least one mounting hole more than is used to attach the transaxle to the vehicle. The bypass mechanism comprises a bypass linkage. Finally, the bypass linkage is supported by the mounting hole.

Abstract: An electro-hydraulic system for operating a cooling fan and providing hydraulic fluid to a power steering system of the vehicle includes a hydraulic pump unit including first and second fixed displacement pumps and a common drive shaft for these pumps. A hydraulic fluid reservoir is connected to the inlet of each of the pumps. A priority valve is operatively connected to the outlet of the first pump and has an outlet connectible to the power steering system. This valve also has a second outlet connectible to a hydraulic motor for the cooling fan. This valve is arranged to provide a constant flow of hydraulic fluid to the power steering system. A hydraulic line connects an outlet of the second pump to the hydraulic motor. Hydraulic fluid flow through this line is combined with hydraulic fluid flow from the first pump to drive the motor.

Abstract: In a hydrostatic continuously variable transmission, a hydraulic pump and a hydraulic motor are connected through a hydraulic closed circuit and the capacity of the hydraulic motor is varied to vary the speed continuously. The transmission has a valve spool in a spool hole made in a transmission output shaft which rotatably holds the hydraulic pump and hydraulic motor; and the transmission output shaft incorporates outer branch oil paths which are connected with an outer passage and open to the spool hole, and an inner branch oil path which is connected with an inner passage and open to the spool hole.

Abstract: An improved valve for use in a hydrostatic drive apparatus for a vehicle such as a zero turn vehicle. For each hydraulic drive system in the vehicle, a valve is located between the high and low pressure sides of the closed hydraulic circuit connecting the hydraulic pump and motor. The valve opens when the pressure rise rate in the high pressure side reaches a set level to minimize pressure spikes in the high pressure side and thus improve performance of the vehicle. A valve block may be used to mount the valve, and a second valve may also be included therein to connect the two pressure sides of the hydraulic circuit in a similar manner when the vehicle is operated in reverse.

Abstract: A hydraulic pump of a driving force distribution apparatus for right and left axles includes a pump shaft, a swash plate supported tiltably, swash plate tilting and holding mechanism unit for tilting and holding the swash plate to one side or to the other side depending on the direction of rotation of the pump shaft, and a hydraulic oil supply mechanism unit having a cylinder block. The cylinder block holds pistons which reciprocate inside cylinder holes while making contact with a tilt surface of the swash plate at their extremities. When the pump shaft rotates in a forward or reverse direction, the pistons reciprocate to supply hydraulic oil sucked from a tank to a suction port of an operation control valve. Thus, the driving force distribution apparatus can apply relative rotating forces to right and left axles even during backward running, with no increase in the size of the apparatus.