Abstract: A dual path hydrostatic drive system having an electronic auxiliary drive auxiliary drive controller controlling the hydraulic output of left and right variable displacement pumps in response to the speed of the main drive wheels and a speed ratio signal from a speed ratio input control. In addition, the auxiliary drive auxiliary drive controller controls the outputs of the pumps within three basic boundary conditions; a hydraulic pressure boundary condition, a motor speed boundary condition and a power boundary condition. A clutch mode activation switch has two positions for signaling the auxiliary drive auxiliary drive controller to operate in a first mode in which the auxiliary drive system is shut down upon activation of the main clutch or a second mode where the auxiliary drive controller attempts to mirror the operation of the main drive wheels.

Abstract: The invented vehicle includes a chassis, a cabin mounted on a first side of the chassis on a forward portion thereof, and a plurality of wheels coupled to the chassis to movably support the chassis. The vehicle also includes a boom unit, a tool coupled to an end of the boom unit, and turntable unit mounted to the chassis at a central portion thereof, the turntable unit coupled to and supporting the boom unit for rotation relative to the chassis. The turntable unit is capable of moving the boom unit and the tool over a second side of the chassis opposite the first side between a first position at which the tool is positioned forward of the chassis to pick up the load and a second position at which the tool is positioned over the dump body to dump the load into the dump body. The vehicle also includes a dump body mounted to a rear portion of the chassis. The dump body can be tilted to the rear or either side of the vehicle.

Abstract: A hydraulic motor (2) with a braking device (8), is acted upon by means of a control fluid via a brake release line (6). The brake release line (6) is used to allow a continuous flushing flow of control fluid through the hydraulic motor at the same time as the release of the brake. The braking device (8) is connected to the casing of the hydraulic motor (2). An outlet opening (12) of the hydraulic motor (2) leads via a leakage-oil line (13) to the tank for the control fluid. In a hydraulic travel drive with a closed hydraulic circuit, the brake release line (6) can be connected to the shut-off device (4) for the servo adjustment system of the variable-displacement pump (1), and the leakage-oil line (13) of the hydraulic motor (2) can lead to the tank for the entire hydraulic fluid in the system.

Abstract: An electronic traction control system for a vehicle having multiple hydraulically driven wheels includes a pump, a plurality of hydraulic drive motors each fluidly connected to the pump for driving one of the wheels, a corresponding plurality of speed sensors for generating a motor speed signal for each of the motors, and an electronic flow control valve. The electronic flow control valve includes a microcontroller electrically connected to the speed sensors for receiving and comparing the motor speed signals and a plurality of normally open anti-slip valves each electrically connected to the microcontroller for receiving a flow command signal therefrom based upon comparison of the motor speed signals. Each anti-slip valve fluidly connects to a drive motor between the drive motor and the pump. This electronic traction control system provides a method of controlling motor speed without changing the displacement of the motor.

Abstract: A hydrostatic traction drive includes a first hydrostatic motor and at least one drive unit effectively connected with the motor. The motor is connected with a second motor into a modular unit, and the motors are positioned coaxially with respect to each other. At least one of the motors has a variable displacement. Between the motors and/or between at least one motor and the drive unit that is effectively connected with it, there is a clutch that can be disengaged in operation. On the motor-side of the hydrostatic traction drive, it thereby becomes possible to vary the transmission ratio continuously and without interrupting the traction. The clutch connected between the motors makes it possible to disconnect one of the motors and thereby reduce power loss and wear. Output-side clutches make it possible to disengage drive units from the motors.

Abstract: A first hydraulic pump P1 driven by power of an engine and a first hydraulic motor M1 are fluidly connected so as to form a closed fluid circuit. An output shaft 2 of first hydraulic motor M1 is drivingly connected with a sub-transmission 3. The output power from sub-transmission 3 drives main-driving wheels 5 and also drives a second hydraulic pump P2 fluidly connected with a second hydraulic motor M2 for driving sub-driving wheels 6. A clutch 7 is interposed between an output shaft 4 of sub-transmission 3 and an input shaft 9 of second hydraulic pump P2 or on the output side of second hydraulic motor M2. Second hydraulic pump P2 or second hydraulic motor M2 has variable displacement, so that second hydraulic motor M2 is drivingly accelerated in proportion to the degree of turning operation of a steering operating tool 31.

Abstract: The apparatus comprises two hydraulic motors to which two displacement members in line are respectively coupled. Each of the motors has three main connections, namely one main connection that is common to both of its cylinder capacities, and two main connections, one for each of its two cylinder capacities. The first main connection of the first motor is connected to the fluid feed and the first main connection of the second motor is connected to the fluid return. The two main connections of the motors are interconnected. A selector having at least two positions is connected to the fluid feed, to the fluid return, and to the third main connection of at least one of the motors. For each of the two selector positions, the total cylinder capacity fed by the pump differs.

Abstract: A driving apparatus is used in a vehicle wherein both the front and rear wheels are driven. The apparatus prevents the steerable wheels from skidding while transmitting power to the steerable wheels when turning the vehicle. The apparatus includes a transmission unit 13 for receiving a rotational output from a main HST 50, a steerable wheel drive shaft 6 and a nonsteerable wheel drive shaft 5 for receiving the rotational output from the transmission unit and delivering the output respectively to an axle for driving the steerable wheels and an axle for driving the nonsteerable wheels, and a differential unit for rotating the drive shaft 6 at an increased speed and the drive shaft 5 at a decreased speed.

Abstract: A four-wheel drive vehicle in which the engine output is transmitted to front wheels and to rear wheel through a transfer clutch. The control unit determines a road gradient from the output value of a longitudinal acceleration sensor at a stop, sets a lower limit on the basis of the road gradient and is prepared for a start by outputting a drive signal corresponding to lower limit to a clutch control valve for controlling the applying force of the transfer clutch. Thus, the applying force is set according to the road gradient so that the main drive wheels at the slope can be prevented from slipping by the minimum transmission torque.

Abstract: A single-seater motor vehicle includes (1) a support body having a plurality of supporting arms that are mounted in a horizontally and vertically displaceable manner; (2) a vehicle seat arranged on a support body; (3) a control device; and (4) a plurality of wheels, wherein each of said wheels is arranged adjustably or pivotably on a supporting arm. The support body the supporting arms can be set in at least three positions by automatic or manual adjustment of the vehicle seat height.

Abstract: Hydrostatic transmission apparatus for a vehicle having drivable front and rear wheels coupled to front and rear hydraulic motors. A group of motors comprises at least two motors coupled respectively to two wheels situated on either side of the vehicle. The other group of motors comprises at least one motor driving a wheel. The two motors of the first group are dual-capacity motors, each comprising a first elementary motor connected to the pump in parallel with a motor of the second group, and a second elementary motor which is connected in series with said motor of the second group. Two series pipes are thus defined. The apparatus comprises a selection valve connected to the two series pipes and to a port of the pump. This valve can take up a straight-ahead configuration in which the series pipes are isolated from the port of the pump, as well as a left-turn configuration and a right-turn configuration in which the series pipes are connected to said port.

Abstract: Turning radius is calculated from steering angles of steering-wheels (2, 3) and articulation angles of respective frames, and the steering-wheels (2, 3) are automatically rotated faster than rear-wheels (4, 5) based on the turning radius, the revolution number of the rear-wheels (4, 5), engine speed of an engine (6) and a speed range of hydraulic motors (14, 15), so that conventional trouble for manipulating operation lever etc. while turning a motor grader (1) and skill-requiring work for adjusting the revolution number of the steering-wheels (2, 3) in accordance with the revolution number of the rear-wheels (4, 5) can be eliminated, thereby easily and accurately controlling the revolution number of the steering-wheels (2, 3) and securely preventing tight-corner braking phenomenon.

Abstract: A driving force control device for a four-wheel drive vehicle including one pair of front or rear driven wheels which are driven directly by a prime mover and another pair of front or rear driven wheels which are driven via a hydraulic clutch, a first hydraulic pump which is driven by being operatively connected to the one pair of driven wheels, and a second hydraulic pump which is driven by being operatively connected to the other pair of driven wheels. The engagement force of the hydraulic clutch is controllable based on the difference in rotation of the first and second hydraulic pumps. The torque transmission to the other pair of the front or rear driven wheels can thus be controlled according to the driving conditions of the vehicle.

Abstract: A hydraulic vehicle drive, particularly for mobile hoisting platforms, has a first pair of wheels drivable by first wheel motors in dependence of a first control valve and a second pair of wheels provided with second hydraulic motors. A switching arrangement short-circuits the second hydraulic motors in the driving-free state and for cooling supplies them with a flushing flow. In the driven state a second control valve, in dependence of which the second hydraulic motors are drivable, is activated, and if required connected with the first control valve. Thus, optionally, the first wheel pair can be driven alone or together with a certain driving output from the second wheel pair.

Abstract: An electric generating system for automobiles comprising a primary generator which is driven by an internal combustion engine of an automobile and supplies power to an electric load of the automobile and an electric motor for driving wheels of said automobile which are not driven by said internal combustion engine, further comprising a secondary generator which is driven by said internal combustion engine and drives said motor and a control unit which controls said secondary generator and said electric motor; wherein said control circuit controls the output of said generator according to a driving force requested by said automobile and the driving force of said electric motor is controlled by the output of said secondary generator.

Abstract: A hydrostatic drive for a utility vehicle includes a prime mover (engine) which drives a variable rate hydrostatic pump. In a two-wheel drive system, the hydraulic fluid flow from the pump is split evenly and directed to the rear wheel motors. This flow turns the rear wheel motors and then exits the wheel motors where it is directed back to the pump. In a four-wheel drive system the flow from the pump is split evenly between the front wheel motors. The flow exiting the front motors is directed to the rear wheel motors on the opposite sides of the vehicles. This flow turns the rear motors and then is directed back to the pump. Direction and speed of the vehicle is regulated by an operator-controlled actuator which controls the direction and displacement of the hydrostatic pump. A neutral valve is interconnected between the pump and the motors.

Abstract: This is a new motor-driven transport trolley comprising a frame with a rotating plate on top, having two sets of wheels, right and left, and two or more hydraulic motors which move the two sets of wheels separately to obtain differentiated drive. The motors are hydraulic and are fed by a pressure pump; the motion is differently distributed to the various hydraulic motors by means of valves connected to a control unit which controls the operation of the hydraulic motors, the pressure pump and the valves. This control unit is controlled by a push-button panel connected to it by means of an electric cable, infrared rays or radio waves, etc.

Abstract: A feller-buncher includes a first axle having a number of first wheels attached thereto and a second axle having a number of second wheels attached thereto. The feller-buncher also includes a first hydraulic motor operable to rotate the first axle and a second hydraulic motor operable to rotate the second axle. The feller-buncher also includes a first hydraulic pump operable to supply pressurized hydraulic fluid. Yet further, the feller-buncher includes a first flow sharing valve fluidly coupled to each of the first hydraulic pump, the first hydraulic motor, and the second hydraulic motor. The first flow sharing valve is configured to distribute the pressurized hydraulic fluid from the first hydraulic pump evenly between the first hydraulic motor and the second hydraulic motor, whereby the first axle and the second axle are driven at a substantially equal speed relative to one another. A method of operating a feller-buncher is also disclosed.

Abstract: An electronic engine speed control system is used on a work machine utilizing an engine with a governor control movable between a plurality of positions. The governor control is operated by an operator so that a desired engine speed may be selected for driving a plurality of wheels through a transmission. The transmission is specifically controlled to obtain a desired ground speed independent of the selected engine speed. The engine speed control system includes an electronic control module. An operator switch is connected to the control module and is movable to a set position which sends an input signal with a desired engine speed value corresponding to a selected engine speed to the control module. An engine sensor is connectable between the engine and the control module for sensing the speed of the engine and sending an input signal with an actual engine speed value to the control module.

Abstract: A first hydraulic pump P1 driven by power of an engine and a first hydraulic motor M1 are fluidly connected so as to form a closed fluid circuit. An output shaft 2 of first hydraulic motor M1 is drivingly connected with a sub-transmission 3. The output power from sub-transmission 3 drives main-driving wheels 5 and also drives a second hydraulic pump P2 fluidly connected with a second hydraulic motor M2 for driving sub-driving wheels 6. A clutch 7 is interposed between an output shaft 4 of sub-transmission 3 and an input shaft 9 of second hydraulic pump P2 or on the output side of second hydraulic motor M2. Second hydraulic pump P2 or second hydraulic motor M2 has variable displacement, so that second hydraulic motor M2 is drivingly accelerated in proportion to the degree of turning operation of a steering operating tool 31.

Abstract: A splitter gearbox for a four wheel drive, hydrostatically driven tractor integrates both the input drive train and the output drive train into a single gearbox. The drive mechanism eliminates the need for a separate mechanical gearbox by establishing pre-set fixed displacement settings that are electronically controlled along with the variable displacement of the hydrostatic motor and hydrostatic pump, to provide a smooth power shift through all ranges without requiring the tractor to stop. The drive mechanism is configured so that essentially all components are individually controlled so that the entire power generated by the tractor engine can be diverted to any one of the traction drive, the PTO mechanism, the auxiliary hydraulic drive or, to a somewhat lesser extent, the tractor hydraulic system. The splitter gearbox is mounted to the rear axle housing to allow the sharing of a common oil sump.

Abstract: A splitter gearbox for a four wheel drive, hydrostatically driven tractor integrates both the input drive train and the output drive train into a single gearbox. The drive mechanism eliminates the need for a separate mechanical gearbox by establishing pre-set fixed displacement settings that are electronically controlled along with the variable displacement of the hydrostatic motor and hydrostatic pump, to provide a smooth power shift through all ranges without requiring the tractor to stop. The drive mechanism is configured so that essentially all components are individually controlled so that the entire power generated by the tractor engine can be diverted to any one of the traction drive, the PTO mechanism, the auxiliary hydraulic drive or, to a somewhat lesser extent, the tractor hydraulic system. The splitter gearbox is mounted to the rear axle housing to allow the sharing of a common oil sump.

Abstract: A first hydraulic pump P1 driven by power of an engine and a first hydraulic motor M1 are fluidly connected so as to form a closed fluid circuit. An output shaft 2 of first hydraulic motor M1 is drivingly connected with a subtransmission 3. The output power from sub-transmission 3 drives main-driving wheels 5 and also drives a second hydraulic pump P2 fluidly connected with a second hydraulic motor M2 for driving sub-driving wheels 6. A clutch 7 is interposed between an output shaft 4 of sub-transmission 3 and an input shaft 9 of second hydraulic pump P2 or on the output side of second hydraulic motor M2. Second hydraulic pump P2 or second hydraulic motor M2 has variable displacement, so that second hydraulic motor M2 is drivingly accelerated in proportion to the degree of turning operation of a steering operating tool 31.

Abstract: A four-wheel hydraulic drive system for a working vehicle comprising a hydraulic pump, a first hydraulic motor fluidly connected with said hydraulic pump, a pair of first driving wheels driven by said first hydraulic motor, a second hydraulic motor fluidly connected with said hydraulic pump, and a pair of second driving wheels driven by said second hydraulic motor, wherein the drive mode of said vehicle can be switched between a first four-wheel drive mode for substantially equaling the torque of said second hydraulic motor to that of said first hydraulic motor and a second four-wheel drive mode for making the torque of said second hydraulic motor smaller than that of first hydraulic motor.

Abstract: A feller-buncher includes a work tool having a hydraulically powered blade. The feller-buncher also includes a first axle having a number of first wheels attached thereto and a first hydraulic motor operable to rotate the first axle. The feller-buncher also includes a first hydraulic pump operable to supply pressurized hydraulic fluid to the first hydraulic motor and a second hydraulic pump operable to supply pressurized hydraulic fluid to both the work tool and the first hydraulic motor. Yet further, the feller-buncher includes a load sensing circuit for sensing a load on the work tool when the work tool is contacting a tree. The first hydraulic pump is configured to adjust hydraulic fluid flow to the first hydraulic motor based on the load on the work tool sensed by the load sensing circuit. A method for operating a feller-buncher is also disclosed.

Abstract: A multiple wheel drive assembly including front and wheel axles and four independent gear boxes one for each wheel axle and two intermediate gear boxes each of which is connected to a pair of front and rear wheel axle gear boxes. Each of the gear boxes has a ring gear disposed therein and is capable of effectively reducing the inputted rpms up to eight times and also allows the user to easily adjust the wheel bases to any width and length without having to effect the gear boxes including the ring gears. Each pair of front and rear wheel axles are actuated independently of one another.

Abstract: A hydraulic drive system for a vehicle includes a pressurizing circuit and a working circuit. The pressurizing circuit incorporates a pump driven by a prime mover having a nominal horsepower rating. The prime mover is either shut off or idled when the pressure sensed within the pressurizing circuit is within a desired range and run at an optimum high RPM range when the pressure falls below the desired range. At least one accumulator is provided in the pressurizing circuit. The working circuit includes a plurality of motors for driving at least one vehicle wheel and a motor control valve arrangement which isolates one or more motors from the flow of pressurized fluid while deactivated and drives the motors while activated. As vehicle speed increases and drive resistance decreases, the number of motors propelling the vehicle is progressively reduced. A flow control valve alters flow to the motors.

Abstract: A system for accelerating the front wheels of a vehicle, eg an agricultural tractor, on turning a corner, comprises steering angle sensors (21) which, via a control unit (22) enable or disable drive to the front wheels from a hydraulic motor (11). The drive from the hydraulic motor from the front wheels is via a one-way clutch (14). The hydraulic motor (11) is powered by a pump (6) driven either directly from the vehicle engine or from the main transmission.

Abstract: Hydrostatic unit for driving an industrial truck with a pump, a hydrostatic propulsion unit and additional users of hydraulic energy, wherein the pump is located on an axle body of a drive axle. A control valve for the pressurization of the propulsion unit and at least one control valve for the pressurization of an additional user are located on the axle body or at least partly integrating into the axle body. In one embodiment, the axle body is a control seat receptacle of the pump and at least one traction motor of the hydrostatic propulsion unit. The control valves can be actuated electrically or hydraulically.

Abstract: A drive system for a hydraulically driven vehicle which includes bidirectional hydraulic motors. Two front hydraulic motors are in parallel as are two rear hydraulic motors. One of the front hydraulic motors is in series with the rear hydraulic motor on the same side of the vehicle. The other front hydraulic motors is in series with the rear hydraulic motor in the other side of the vehicle. The rear hydraulic motors include mechanical brakes in combination. The front hydraulic motors are mounted as part of the spindles which pivot about king pins.

Abstract: In a coupling device which is disposed between left and right wheels of a vehicle, pair of differential gears are provided. First rotational elements of both the differential gears are coupled to each other, and second rotational elements are respectively coupled to left and right wheels of the vehicle. A third rotational element of one of the differential gears is driven for rotation by a driving source. The third rotational element of the other of the differential gears is made switchable by a switching device between a state in which the third rotational element is prevented from rotating and a state in which the third rotational element is coupled to the first rotational element or the second rotational element of the other of the differential gears. Otherwise, the third rotational element of the other of the differential gears may be arranged to be always prevented from rotating.

Abstract: A variable wheel base vehicle includes a vehicle body having front end rear ends supporting body members one of which is capable of displacement relative to the other. Drive motors mounted to the vehicle body are linked to the body members. A carriage assembly including drive wheels provide support for the vehicle body. An extension assembly responsive to the drive motor is connected to at least one of the body members. Upon actuation of the drive motor, the extension assembly enables one body member to displace relative to the other body member to enable extension and retraction of the vehicle wheel base. Each body member includes at least one wheel of the carriage assembly and, as a result of displacement of one body member relative to the other body member, the displaced body member provides increased counterbalance in the vehicle.

Abstract: An air powered drive system for a vehicle such as an automobile or a propeller driven aircraft. In a land vehicle air pumps are connected to drive, or be driven by, each wheel. At least two air storage tanks are connected to the air pumps. A fuel is burned in one tank to provide hot, high pressure air that can be directed to selected air pumps to drive associated wheels. Meanwhile, other air pumps connected to a cool, lower pressure tank are driven by an associated wheels to act as an air compressor to compress cool ambient air in the tank. When air pressure in the heated tank drops, combustion is shut off there and begun in the other tank and the driving and filling tanks and pumps are reversed. Similarly, two such tanks are connected through air pumps to an aircraft propeller shaft. Alternately, on tank is heated to produce hot, high pressure air to drive one air pump while the other air pump is driven by the shaft to compress air in the cooler tank.

Abstract: A drive unit for a hybrid vehicle includes: an internal combustion engine 1; a transmission 3 connected to the internal combustion engine 1 via a clutch 2; a primary differential gear 11 for distributing a driving force transmitted from the transmission 3, to primary driving wheels 17 and 18; a transfer 20 connected to the primary differential gear for taking out a part of the driving force transmitted from the transmission 3 to the primary differential gear 11; a pair of propeller shafts 26 and 27 formed by dividing two parts in axial directions for transmitting part of the driving force from the transfer to a secondary differential gear 33; an electric motor 31 provided between these propeller shafts 26 and 27; and a pair of clutches 29 and 30, each connecting the electric motor 31 to one of the pair of propeller shafts 26 and 27. Therefore, the drive unit can be used for 2WD or 4WD hybrid vehicles without changing the main components.

Abstract: A left hydraulic pump connected to a left wheel and a right hydraulic pump connected to a right wheel of a vehicle are connected by a first oil passage and a second oil passage to constitute a closed circuit, and first and second variable throttle valves are provided between the first and second oil passages and the tank. Either one of the first and second variable throttle valves is throttled to cause the first and second hydraulic pumps to produce a braking force and a driving force, respectively, thereby controlling a yaw moment. At the same time, when either one of left and right wheel suspensions expands, the roll rigidity of the vehicle increases or decreases to vary the cornering forces of the wheels, thereby producing a yaw moment which assists in the yaw moment produced by the first and second hydraulic pumps.

Abstract: A vehicle having a hydrostatic drive and transmission having multi-range speed modes, a counter configured steering assembly providing for a turning radius less than would normally be commensurate with the length of the wheel base, and a suspension system having a resiliently deformable device for maintaining stability of the vehicle body and cargo during operation and for maximum operator comfort.

Abstract: A four wheel drive working vehicle having a hydraulic block for covering one side of a propelling transmission case, an engine, and an HST attached to a side of the hydraulic block remote from the transmission case. The HST includes an input shaft for transmitting drive from the engine, and an output shaft extending through the hydraulic block for transmitting the drive to a transmission line in the transmission case. The vehicle further includes a drive transmission mechanism for selectively transmitting the drive from the transmission line to rear wheels, and a transmission shaft for transmitting the drive between the drive transmission mechanism and the transmission line in the transmission case. The drive transmission mechanism is attached to the side of the hydraulic block where the HST is attached. The transmission shaft extends through the hydraulic block.

Abstract: A road surface finisher with a tire drive and a chassis that carries a material bin in the front and, in the rear, a transverse spreading device with an installation beam. A primary drive unit which includes an internal combustion engine and at least one main pump, which drives hydraulic secondary drives of steerable front wheels and of rear wheels, is also mounted on the chassis. The front wheels are driven by hydraulic front wheel motors, and the rear wheels, respectively, are driven by a master drive that includes a hydraulic transport motor and a hydraulic working motor. The hydraulic master drive of the rear wheels and the hydraulic front wheel motors are fed by a single shared drive pump, which is driven by the primary drive unit.

Abstract: An improved hydraulic drive system is provided for a vehicle having a plurality of ground engaging wheels which are each individually driven by a hydraulic motor to provide all wheel drive. The ground engaging wheels include a first pair of such wheels at or adjacent a first end of the vehicle and at least one other such wheel at or adjacent a second end of the vehicle. The hydraulic drive system includes a hydraulic flow circuit that connects the hydraulic motors for the wheel(s) at the second end of the vehicle in series to each other, to the fluid source, and to the drive motors for the wheels at the first end of the frame, which latter drive motors are connected in parallel to each other. Such a vehicle will provide superior traction ability as at least one wheel on each end of the vehicle must slip to bring the vehicle to a halt.

Abstract: A torque is transmitted between a fluid pressure pump driven together with drive of a vehicle, and a fluid pressure motor that rotates together with driven wheels. The fluid pressure motor has two ports, and rotates in accordance with the direction of fluid supply to the ports. Fluid is circulated from one port to the other according to the input of rotation torque from the driven wheels. A high pressure flowpath connected to the pump outlet, and a low pressure flowpath connected to the pump inlet, are connected to these ports, and the connection direction is reversed when the rotation direction of the drive wheels is reversed. The low pressure flowpath is therefore always at low pressure regardless of the rotation direction of the drive wheels, and by controlling the pump supply flowrate so as not to exceed a predetermined value, torque is not transmitted when the vehicle is running at high speed.

Abstract: A scraper is provided with a hydrostatic rear wheel assist that is operated by foot pedals in the operators cab. A reversible variable displacement hydrostatic pump is operatively coupled to an engine mounted to the front frame section of the scraper. An engagement/disengagement valve is hydraulically positioned between the pump and the rear wheel hydraulic motors. The engagement/disengagement valve has two positions: a engagement position for directing pressurized hydraulic fluid to the motors and a disengagement position for preventing the flow of pressurized hydraulic fluid to the motors. In its disengagement position the wheel motors are free to free wheel as the motors are coupled to sump. A traction control valve is positioned between the engagement/disengagement valve and the wheel motors. The traction control valve has an uncontrolled flow divider position and a differential lock or controlled flow divider position. Both valves are operated by an electrical controller.

Abstract: A hydraulic drive system for a vehicle includes a pressurizing circuit and a working circuit that are interconnected by suitable valving. The pressurizing circuit incorporates a fixed displacement pump which is driven by a prime mover having a nominal horsepower rating. The prime mover is shifted between an idling speed when the pressure sensed within the pressurizing circuit is within a desired range and an optimum high RPM range when the pressure within the pressurizing circuit falls below the desired range. At least one accumulator is provided in the pressurizing circuit. The working circuit includes a plurality of motor units for driving the vehicle wheels and a plurality of motor control valves which can be placed in a de-activated position to isolate the associated motor unit from the flow of pressurized fluid and an activated position wherein the motor unit aids in driving the vehicle.

Abstract: In a vehicle transmission comprising a hydrostatic transmission (13) and a rear-wheel drive assembly (20) including a two-stage speed change mechanism (28), a front-wheel drive assemly (22) having a front-wheel drive shaft (24) is disposed at a front side of the output shaft (17) and includes a clutch (55; 155; 255) such that when the change mechanism is shifted to its high-speed position the clutch is disengaged so as to provide a non-drive mode for front wheels. A selective drive mode is preferably provided by a one-way clutch (56) which is operable to connect the drive shaft to the output shaft only when forward directional rotation speed of the output shaft is larger than that of the drive shaft. In a preferred embodiment, the front-wheel drive assembly is shiftable at a low-speed position of the change mechanism between a constant drive mode and the selective drive mode.

Abstract: A vehicle drive transmission includes a hydrostatic transmission (14) which comprises a hydraulic motor (16) of a variable displacement type. Swash plate (29) of this motor is displaced from its neutral position in one direction in a stepwise manner to plural angular positions. The motor is used for setting one of plural speed ranges or low-speed and high-speed ranges of vehicle within which vehicle speed can be changed in a non-stepwise manner by a hydraulic pump (15) having a non-stepwisely displaceable swash plate (28). Output shaft (18) driven by the motor is connected to rear wheels (2) for a constant drive thereof through a mechanical transmission mechanism (21) and to front wheels (1) for a selective drive thereof through a clutch mechanism (26; 126; 226). The clutch mechanism preferably includes a one-way clutch (85) for providing a selective drive mode in which front wheels are additionally driven automatically when slipping of the rear wheels is caused during the two wheel-drive condition.

Abstract: A diagnosing apparatus and method for determining an occurrence of failure in a rear road wheel steering angle sensor of a motor-driven four wheel steering system of an automotive vehicle which can achieve a highly accurate detection of the occurrence of failure in the single rear road wheel steering angle sensor at an appropriate timing irrespective of a sensor failure mode. The detection of failure in the rear road wheel steering angle sensor is carried out on the basis of whether a target deviation between a rear road wheel steering angle sensor value and a target rear road wheel steering angle exceeds a predetermined deviation value and whether a generation time duration during which the target deviation exceeds the predetermined deviation value has continued over a predetermined period of time. In addition, the detection of failure in the rear road wheel steering angle sensor is carried out on the basis of whether an accumulated value of a rear road wheel steering angle estimated deviation .intg..DELTA..

Abstract: The left rear wheel is driven with the left motor and the right rear wheel is driven with the right motor. Selection of a control mode is made from a first control mode in which the left and right motors are driven in common and a second control mode in which the left and right motors are driven discretely and separately. A region in which the motors are driven is so arranged as to be altered in accordance with the running state of the vehicle, such as the lateral acceleration acting upon the vehicle body, the road surface friction coefficient .mu., the vehicle speed, the steered angle of the steering wheel, etc. A clutch can be disposed to couple the left and right wheels to be driven with the motors when a predetermined condition is met.

Abstract: An articulated tracked vehicle for agricultural harvesting which reduces damage to fields and can be driven on paved roads at reasonable speeds. The vehicle has front and rear elements, linked by an articulating joint which permits turning and rotation of one element with respect to the other. Each element is motivated by a pair of tracked power units which are hydraulically driven by a heavy duty differential between the units. Each power unit is rotatably mounted solely on a shaft sleeve of the differential and is free to oscillate vertically and independently to absorb irregularities in its path. Each unit includes an endless elastomeric track which has two rows of lugs on its inner surface. A novel drive mechanism engages these lugs to motivate the vehicle. A sealed transmission housing in each power unit protects key drive elements from environmental damage without interfering with operation of the unit.

Abstract: A motor continuously drives rear wheels during medium and low-speed running, while an engine drives front wheels in a high-speed running area. In this case, transfer of an engine-generated driving force to wheels is controlled by a transmission. In a medium- or low-speed running area, the engine is used only for power generation and engine-driven running is not carried out.

Abstract: The present invention is a combination trailer and self propelled vehicle which combines the maximum gradeability of all wheel drive with the ability to be efficiently and conveniently towed by conventional means at maximum permissible highway speeds. As this invention relates to concrete mixing, it provides an advance in the ability to get to a job site quickly and then efficiently transport and place concrete mix at the job site.

Abstract: Steering is actively assisted in a turning motor vehicle including a hybrid drive having both an internal combustion engine and a generator unit. The inner and outer wheels are each associated with an individual drive which is controlled in accordance with the steering angle of the steered wheels. Specifically, the torque differential is adjusted such that the percentage actual wheel differentials approach the percentage reference wheel speed differentials. A substantial reduction in the force which must be applied via the steering system to adjust the steering wheels, as compared to an absence of torque differential, is achieved because the outer wheel is driven at a higher output than the inner wheel when making a turn.