Abstract: A hydrostatic stepless transmission (“HST”) includes a center casing into which a plunger block of a hydraulic pump and a plunger block of a hydraulic motor are inserted. Plunger ports are open and aligned peripherally on an outer peripheral surface of each plunger block. A pair of main fluid passages of a closed fluid circuit fluidly connecting the hydraulic pump to the hydraulic motor are formed in opposite side portions of the center casing. Each of the main fluid passage includes peripheral grooves formed on an inner peripheral surface of the center casing so as to face the plunger ports of the respective plunger blocks, and includes an axial fluid duct formed to be interposed between the peripheral grooves. A bearing gap is provided between the inner peripheral surface of the center casing and the outer peripheral surface of the plunger block so as to cause a dynamic pressure action of fluid.

Abstract: This invention consists of the addition of a novel clutch arrangement which facilitates speed changing gears on both the output and input of the transmission and provides for a compact packaging configuration for a plurality of hydraulic pump/motors. The use of a small accumulator without a valve and a related reservoir absorbs the pressure shocks from rapidly opening and closing the valves that that select or de-select the pump/motors. It is also disclosed that two adjacent pump/motors on the same shaft can be constructed such that they share an input or output port thereby reducing the size of the combination. The transmission can perform the retarder function by placing a flow retarding valve in the re-circulating path in one or more of the pump/motors.

Abstract: A hydraulic accumulator system for providing pressurized oil to a transmission in a vehicle. The system includes a transmission oil storage chamber to store oil at a predetermined level; and a hydraulic accumulator mounted in the oil storage chamber and including an accumulator piston mounted below the level of oil, separating an accumulator oil area from a remainder of the oil storage area and movable to increase and decrease the oil in the accumulator oil area, and a spring biasing the piston toward the accumulator oil area. The system also has a hydraulic assembly including a first oil passage for removing the oil from the remainder of the oil storage area, a second oil passage for directing oil into and out of the accumulator oil area below the predetermined oil level and a hydraulic circuit directing the oil from the first oil passage into the second oil passage.

Abstract: This invention consists of two or more fixed displacement hydraulic pump/motors mounted on a common input shaft hydraulically connected to two or more fixed hydraulic pump/motors mounted on a common output shaft. The relative displacements of the pump/motors are chosen such that by selectively activating the individual pump/motors, the transmission ratio can be changed in the case when the input devices and acting as pumps driving the output devices as motors (conversely when driving the vehicle in reverse). Further, a hydraulic accumulator and reservoir are attached in a manner that allows the pressurized fluid to augment the flow produce by the input pumps in order to increase the transmission ratio. Similarly, the transmission ratio can also be reduced by causing the input pumps to pump fluid into the accumulator at the same time they are pumping fluid through the output motors.

Abstract: A hydrostatic continuously variable transmission includes a swash plate type plunger hydraulic pump and a swash plate type plunger hydraulic motor connected via a hydraulic closed circuit, an inclined angle of a swash plate of the hydraulic motor is variably controlled for continuous shift control. A lock-up mechanism closes the hydraulic closed circuit to make lockup executed when the quantity of oil that flows from the hydraulic pump into the hydraulic motor decreases according to variable control over the inclined angle of the swash plate. The input rotation of the hydraulic pump and the output rotation of the hydraulic motor are substantially synchronous. The lock-up mechanism is operated when lockup control oil pressure is applied and closes the hydraulic closed circuit. A lockup control oil passage that supplies the lockup control oil pressure is provided with an opening opened and closed according to the inclination of the swash plate.

Abstract: The invention relates to a drive system (1) having a first driving shaft (2) and having a second driving shaft (3). The second driving shaft (3) is connected to a cylinder barrel of a hydrostatic piston machine (4) in a torsionally rigid manner. The displacement volume of the hydrostatic piston machine (4) can be shifted by means of a shifting means (5), and the first driving shaft (2) can be mechanically coupled to the second driving shaft (3) through a clutch (6). The shifting means (5) and the clutch (6) can be actuated hydraulically and, for the purpose of actuation, are connected to a common control-pressure connection (11) or a common working-line connection (134).

Abstract: A hydrostatic continuously variable transmission includes a swash plate type plunger hydraulic pump and a swash plate type plunger hydraulic motor connected via a hydraulic closed circuit, an inclined angle of a swash plate of the hydraulic motor is variably controlled for continuous shift control. A lock-up mechanism closes the hydraulic closed circuit to make lockup executed when the quantity of oil that flows from the hydraulic pump into the hydraulic motor decreases according to variable control over the inclined angle of the swash plate. The input rotation of the hydraulic pump and the output rotation of the hydraulic motor are substantially synchronous. The lock-up mechanism is operated when lockup control oil pressure is applied and closes the hydraulic closed circuit.

Abstract: An auxiliary hydraulic motor comprises a fixed casing having a cam, a cylinder block, an internal fluid distributor, and a through shaft which extends inside the casing along the axis of rotation of the cylinder block. The through shaft is constituted by a length of a vehicle transmission shaft. The motor includes an axially moving coupling member suitable, in a first position, for being engaged with the cylinder block and the shaft via first and second mechanical engagement means, and in a second position, for being disengaged from the cylinder block and/or the shaft.

Abstract: The present invention relates to a method and system for controlling a split torque transmission having a hydrostatic transmission and a mechanical transmission. The control system employs a transmission control and includes a transmission input speed sensor, a transmission output speed sensor, a motor speed sensor, a speed input mechanism, a direction control mechanism, and a range selector mechanism. A microprocessor including a fuzzy controller controls the transmission in response to a input from the speed sensors and the speed input mechanism, the direction control mechanism and the range control mechanism.

Abstract: A hydraulic pressure supply system for a variable torque transfer of a four-wheel drive vehicle in which a driving-torque distribution ratio between front and rear road wheels is varied by adjusting a clutch pressure applied to a variable torque clutch assembled in said transfer, comprises an oil pressure source supplying a pressurized working fluid into a hydraulic line, at least one pressure regulating valve fluidly connected to the line for decreasingly regulating the pressurized working fluid at a predetermined clutch pressure, and a directional control valve fluidly connected to the pressure regulating valve for directing the clutch pressure to a transfer clutch. An electromagnetic solenoid valve is provided for controlling the pressure regulating valve and the directional control valve for selectively supplying one of a stand-by pressure and a clutch engaging pressure to the transfer clutch.

Abstract: A transmission and control mechanism for a hydrostatic-mechanical power transmission system, provided with a mechanical transmission driven through an input shaft connected to a engine, a hydrostatic transmission connected to the input shaft, and a differential unit for connecting an output shaft to the mechanical and hydrostatic transmissions. The hydrostatic transmission includes a swashplate type pump and motor, with at least one of the swashplates being variable in angle. There is an engine revolution speed sensor, a target motor speed ratio setting device for setting a target motor speed ratio based on whether the engine speed is above, below or within a predetermined speed range, and a swashplate angle controller for controlling the swashplates according to the target motor speed ratio.

Abstract: A power transmitting system for a four-wheel drive vehicle includes a first hydraulic pump driven interlockingly with the rotation of front wheels, a second hydraulic pump driven interlockingly with the rotation of rear wheels, and a hydraulic clutch for connecting the front wheels and rear wheels. The hydraulic clutch is adapted to be brought into an engaged state by an increase in oil pressure based on the difference between the amount of oil discharged from one of the hydraulic pumps and the amount of oil drawn into the other hydraulic pump. The hydraulic clutch, first hydraulic pump and second hydraulic pump are arranged in that sequence from the front toward rear of the vehicle on an axis extending longitudinally of the vehicle to maximize the air cooling effect on the hydraulic clutch and minimize the length of oil passages between the two hydraulic pumps.

Abstract: To ensure the benefits of four-wheel drive when the vehicle is accelerating or when the front wheels are slipping, and to eliminate the disadvantage of undesirably transmitting the braking force to the rear wheels when the vehicle is decelerating or when a braking action is applied to the vehicle, the front wheels and the rear wheels are coupled with each other when the rotational speed of the front wheels is higher than that of the rear wheels, but this coupling is disconnected when the rotational speeds of the front and rear wheels are substantially identical or when the rotational speed of the rear wheels is higher than that of the front wheels.

Abstract: A power recovery speed control apparatus for use in a system driven by a substantially constant-speed power source driving a turbine type water pump. The system includes a hydromechanical trimmer device controlled by pump output pressure to modify the turbine pump speed over a relatively small range as a function of pump output pressure. In series between the power source output shaft and the turbine pump drive shaft is a mechanical differential gear assembly having input, output and differential (speed difference) shafts. A fixed displacement hydrostatic transmission unit (pump) extracts a fraction of the source power at the differential shaft and applies it through hydraulic feed lines to a variable displacement hydrostatic transmission unit operated as a hydraulic motor. The hydraulic motor unit has its displacement controlled by a pump output pressure sensor and its output torque is introduced into the power train at the power source output or alternatively, at the turbine pump input shaft.

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: An anti-plug control for a drive to prevent jamming of a driven working element in response to an overload wherein said drive includes a hydrostatic transmission having a variable displacement unit and a fixed displacement unit connected in closed circuit. A servo control cylinder is connected to a swash plate of the variable displacement unit for causing positioning thereof. A normally closed pressure-responsive valve monitors the pressure in the high pressure side of the closed circuit and is openable when the pressure reaches a predetermined value to deliver fluid from the closed circuit to the servo control cylinder and modify the displacement of the variable displacement unit to increase the speed of the working element to attempt clearing the overloaded condition of the working element.

Abstract: This invention is directed to a wobble-torque hydraulic transmission device which has variable forward and reverse speeds and is also provided with a straight-through drive feature. The device is provided with a coaster brake feature that prevents the device from running away when going downhill. Also, the device is provided with a brake assembly that prevents rotation of the piston-pump means during forward and reverse operation but permits rotation for straight-through drive.

Abstract: A fuel-saving energy storage vehicle drive system which saves fuel, primarily under stop-and-go driving conditions, by collecting, storing and using energy normally lost in the braking or deceleration of the vehicle, by automatically controlled operation of the engine under certain conditions, and by automatically controlled use of the stored energy and engine respectively as alternative or supplemental prime movers for each other for driving the vehicle. Subsystems for preventing waste of deceleration energy and stored energy are provided, and compact transmission layout and packaging are provided which facilitate installation of the new system in existing vehicles.

Abstract: An automotive energy managing transmission comprising a differential for splitting the power to mechanical and hydrostatic branches. The transmission is adapted to operate in several modes: hydrostatic in the city, hydromechanical and mechanical on the highway, regenerative braking and engine starting. The transmission includes an energy storage means and allows the engine to operate intermittently during city driving.

Abstract: A hydromechanical/hydrostatic automotive energy management system comprising two hydraulic units, the system adapted to provide: An efficient, continuously variable optimal transmission ratio, an intermittent optimal engine operation in city traffic and regenerative braking, thereby, the system is able to reduce a car's fuel consumption by as much as one half while improving drivability.

Abstract: A motor vehicle engine is arranged to drive the vehicle wheels through a mechanical transmission, an hydraulic system including a variable-output, reversible, hydraulic pump, a variable-output hydraulic motor usable reversibly as a pump and a two-speed gear box. The outlet and inlet of the pump are reversibly connected by delivery and return conduits respectively, through a distributor, to the inlet and outlet of the motor and an hydraulic accumulator is connected through a closable valve to the delivery conduit, the operation of the system being controlled by a microcomputer so that when the vehicle decelerates at a rate greater than that due to natural resistance, kinetic energy which is normally lost in the engine is stored in the accumulator and can subsequently be reused to drive the vehicle wheels, the engine being cut out or maintained at minimum power.

Abstract: A gearless split torque (mechanical/hydrostatic), twin range (reduction/ overdrive) with a direct mechanical drive in-between, hydrostatic transmission with regenerative braking and engine starting capabilities comprising two hydraulic pumps tied together by a clutch.

Abstract: A gearless split torque (mechanical/hydrostatic), twin range (reduction/overdrive) with a direct mechanical drive in-between, hydrostatic transmission with regenerative braking and engine starting capabilities comprising two hydraulic pumps tied together by a clutch.

Abstract: A gearless split torque hydromechanical transmission with regenerative braking and engine starting capabilities comprising two hydraulic pumps tied together by a one-way clutch.

Abstract: In a torque converter equipped with a fluid operated lock-up clutch to provide either a fluid or a rigid mechanical connection between an input and an output shaft, the reactor member is arranged for movement along the converter axis between a working and a retracted position by a fluid operated actuating piston. Upon engagement of the lock-up clutch, the reactor member simultaneously travels from the working to the retracted position, in which latter position the reactor member closes the flow path in the impeller member, in order to minimize power loss incurred by the hydraulic fluid.

Abstract: A gas turbine engine for vehicles in which an infinitely variable transmission in the form of a hydraulic transmission is coupled to the engine. A flywheel stores and releases braking energy, and has a disengageable coupling connecting the flywheel with the variable transmission to at least one wheel drive shaft. The hydraulic transmission has a pump unit and a motor unit which are hydraulically operable. The pump unit and motor unit are reversible for braking the vehicle, whereby the motor is driven by the wheels of the vehicle and operates as a pump, and the pump unit operates as a motor.

Abstract: A power transmission having both mechanical and hydraulic power paths to a simple planetary differential unit to provide a double hydro-hydromechanical transmission with a low-speed, high torque, hydrostatic drive range by causing counterrotation of two gear members of the simple planetary, an intermediate speed range hydromechanical drive with inputs to the differential from both power paths and a high-speed, hydrostatic drive range.

Abstract: A control system for an engine driven power train having a variable torque absorption transmission mechanism typically including a torque converter, in conjunction with a hydraulic control circuit for the implement of an excavating-loading vehicle such as a loader. The control circuit comprises lift and tilt cylinder means connected via respective control valves to a pump driven by the vehicle engine. The pump also communicates with the transmission mechanism via a variable pressure regulator valve which functions to condition the transmission mechanism for a relatively high torque absorption characteristic during vehicle propelling operation so that engine torque may be efficiently transmitted to the drive wheels of the vehicle.