Abstract: The object of the present invention is to provide a vehicle drive system which enables setting of appropriate start-up torque and restraining of progress of battery deterioration. A vehicle drive apparatus having an electric motor, which is driven with electricity supplied by a battery, for driving a vehicle or assisting it while driven by an engine includes: a temperature sensor for detecting the battery temperature, an discharge power upper limit setting means for setting an upper limit for discharge power of the battery depending on the battery temperature, a discharge power computing means for computing battery discharge power, a revolution speed sensor for detecting a revolution speed of the engine, a basic start-up torque setting means for setting basic start-up torque requirement depending on the revolution speed and a start-up torque adjust means for decreasing the start-up torque requirement if the discharge power exceeds the discharge power upper limit during engine start-up.

Abstract: A drive assembly including an electric motor and frequency variable generator for use with a multi-axle vehicle. The vehicle generally includes an engine driving a first axle and a drive assembly with an electric motor driving a second drive axle. The drive assembly includes a frequency variable generator with an input shaft driven by the engine and the electric motor electrically communicates with the generator to receive output power from the generator. Other details of selected embodiments of the invention include the frequency variable generator having a rotor coupled to rotate with the engine output shaft and a stator electrically connected to the electric motor. An inverter is electrically connected to an electrical power source, such as a battery or the frequency variable generator, as well as to the rotor. A controller communicates with the inverter and is configured to control the magnitude and frequency of the power communicated from the inverter to the rotor winding.

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

Abstract: A drive apparatus basically comprises left and right drive units each including at least a reduction gear, an electric motor without a permanent magnet, and a brake disc. Each of the left and right drive units is housed substantially within a rim of each of rear wheels which are driven wheels. A 4WD control unit is configured to control a pair of inverters to separately drive the electric motors when a vehicle speed is in a range between a standing start speed and a prescribed vehicle speed, and to stop driving the electric motors when the vehicle speed is equal to or greater than the prescribed vehicle speed to place the rear wheels in a driven state. Accordingly, a friction loss due to a cogging torque encountered in a conventional permanent magnet-type motor is eliminated, and a lightweight drive apparatus is obtained. Fuel efficiently is accordingly improved.

Abstract: A four-wheel drive assist for electric machines includes an electric drive system for driving wheels at a non-steering end and a selectively operable hydraulic system for driving wheels at a steering end. A controller controls the operation of the drive system according to operator selection and/or by detecting slipping of the electric drive system. Preferably, at least one hydraulically driven operating arm, including boom functions, lift platform, etc., is driven by the same hydraulic pump that drives the steering end hydraulic system. The machine thus is capable of effecting four-wheel drive when necessary, while operating as efficiently as a conventional two-wheel drive full electric machine when the four-wheel drive system is not engaged.

Abstract: A hybrid system or a control method for a vehicle having a first set of road wheels and a second set of road wheels is disclosed. The system comprises an engine controller for receiving a torque request for an engine driving torque and combining an idle speed torque and the engine driving torque to generate an engine torque command signal. An engine, drivingly coupled with the first set of road wheels, applies a first driving torque to the first set of road wheels in response to the engine torque command signal. A hybrid controller is in communication with the engine controller. The hybrid controller generates the torque request and a motor torque command signal taking into account a creep torque portion of the first driving torque and a desired driving torque during starting the vehicle from standstill. A motor is drivingly coupled with the second set of road wheels. The motor applies a second driving torque to the second set of road wheels in response to the motor torque command signal.

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: A hybrid vehicle system is provided with an internal combustion engine driving one set of wheels and an electric motor connected to the other wheels via an active clutch system. A power take-off unit is provided for selectively providing driving torque from the internal combustion engine to the electric motor to operate the motor in a regenerative operating mode. The active clutch system is selectively engaged and disengaged based upon whether the vehicle is operating in an internal combustion engine operating mode, an electric motor operating mode, a combined electric motor and internal combustion engine operating mode, or a regenerative operating mode.

Abstract: A differential drive for use on a vehicle to control the transfer of torque between the front and rear axles of a vehicle. The differential drive includes a rotatably driven differential housing supported in a housing. The differential drive also includes a differential gear set arranged and supporting in the differential housing. The differential gear set has at least two side shafts gears and at least two differential gears. The differential drive also includes a torque distribution device having a viscous transmission. The viscous transmission has an inner hub and an outer casing. The inner hub is connected to a first side shaft. The outer casing is connected to one of the side gears. The viscous transmission also connects the output of the first side shaft to one of the side shaft gears.

Abstract: A vehicle control apparatus for controlling a four-wheel-drive automotive vehicle of a type which comprises a first drive power source for driving one of a pair of front wheels and a pair of rear wheels, and a second drive power source for driving the other of the pairs of front and rear wheels, wherein an operator's desired value of a vehicle drive force for driving the automotive vehicle is obtained on the basis of an amount of operation of a manually operated vehicle accelerating member and a running speed of the vehicle, and a front drive force for driving the pair of front wheels and a rear drive force for driving the pair of rear wheels are controlled on the basis of a static and a dynamic state of the vehicle such that a sum of the front drive force and the rear drive force is equal to the obtained operator's desired value of the vehicle drive force.

Abstract: A hybrid vehicle including: an engine and a motor-generator for outputting drive forces to run a vehicle; and a brake pedal for applying a braking force to the running vehicle. While an engine braking force is being established, it is detected that the brake pedal is depressed. After this depression of the brake pedal, the vehicle speed is detected so that the regenerative braking is effected by the motor generator on the basis of the detected vehicle speed.

Abstract: A drive force distribution apparatus for a hybrid vehicle having an engine for driving a pair of first drive wheels and an electric motor for driving a pair of second drive wheels. The drive force distribution apparatus includes a first clutch interposed between the electric motor and one of the second drive wheels, a second clutch interposed between the electric motor and the other of the second drive wheels, and a battery for supplying electric energy to the electric motor and storing electric energy regenerated by the electric motor.

Abstract: A drive assembly for vehicles with front wheels and rear wheels, especially for tractors, agricultural machinery, construction machinery or for self-driving machines, has an engine (1), a first drive (15) to drive the rear wheels, a second drive (27) to drive the front wheels, an adjustable hydraulic pump (5) driven by the engine (1), and an adjustable first hydraulic motor (9). The first hydraulic motor (9), with respect to drive, is connected to the first drive (15) to drive the rear wheels. Also, the first hydraulic motor, with respect to drive, may be connected to the second drive (27), to drive the front wheels. A second hydraulic motor (10), with respect to drive, can be connected to the second drive (27) to drive the front wheels. The first hydraulic motor (9) has a high coefficient of efficiency within a first driving speed range of the vehicle. The second hydraulic motor (10) has a high coefficient of efficiency within a second driving speed range of the vehicle.

Abstract: Either the front wheels and rear wheels of a front wheel- and rear wheel-drive vehicle are driven by an engine and the other thereof are driven by an electric motor. The electric motor is operated when the vehicle starts. A driving torque detecting circuit detects a driving torque of wheels to be driven by the engine. Control circuit prohibits the operation of the electric motor when the driving torque to be detected at vehicle start-up exceeds a predetermined value.

Abstract: A four-wheel drive vehicle is provided in which the main driven wheels are driven by an engine via a torque converter and the auxiliary driven wheels are driven by an electric motor. The response of the vehicle to the operation of the accelerator is improved by suppressing in advance the slip of the main driven wheels due to an excess output of the engine. The main driven wheels are driven by an engine via a torque converter and auxiliary driven wheels are driven by an electric motor. The vehicle is started by the output of the electric motor in the region in which the speed ratio of the torque converter is small (that is to say, the region in which the efficiency is low) such as when the vehicle is starting, and when it enters the region in which the speed ratio of the torque converter exceeds 0.8 and the efficiency exceeds 85% the drive of the electric motor is stopped or suspended and the vehicle is made to travel by means of the output of the engine.

Abstract: Apparatus for providing drive assistance in a vehicle having a main transmission that is mechanical. The apparatus comprises a hydraulic motor of the type having radial pistons that is powered by a main pump. The pistons can be retracted into their cylinders in a free-wheel configuration of the motor or they can co-operate with the reaction member of the motor when they are in a working configuration. The apparatus comprises means for implementing successive stages of a sequence for causing the motor to pass from its free-wheel configuration to its working configuration. The sequence comprises an initialization stage in which the case of the motor is filled with fluid at a “service” pressure by means of an auxiliary duct and a service duct, and in which the main feed and exhaust ducts of the motor are placed at a filling pressure that is lower than the service pressure.

Abstract: This invention relates to an electromechanical brake system, in particular for automotive vehicles, which includes a pedal module and at least two brake modules. Further, a central module may be provided. Connection between the aforementioned modules can be made by a data bus. The data bus is provided redundantly. In one embodiment, the central module can evaluate signals of a sensor system and examine them for their errors. Further, the central module can emit a corresponding nominal braking value which then is emitted to the brake modules. Thereupon, the brake modules determine appropriate actuating signals for the actuators which interact with the wheels in order to realize the driver's braking intention.

Abstract: A hybrid vehicle including: an engine and a motor-generator for outputting drive forces to run a vehicle; and a brake pedal for applying a braking force to the running vehicle. While an engine braking force is being established, it is detected that the brake pedal is depressed. After this depression of the brake pedal, the vehicle speed is detected so that the regenerative braking is effected by the motor generator on the basis of the detected vehicle speed.

Abstract: A front-and-rear wheel drive vehicle includes: an engine driving one of pairs of front wheels and rear wheels; a motor driving the other pair of wheels; a wheel speed sensor detecting wheel speeds of the other pair of wheels; a dog clutch provided between the motor and the other pair of wheels; a motor rotation number estimating unit estimating the motor rotation number from the current value and the duty value of the motor; and a control unit controlling the motor rotation number and the engagement of the dog clutch. The control unit engages the dog clutch after the control unit controls the motor rotation number such that the motor rotation number estimated by the motor rotation number estimating unit coincides with motor rotation number corresponding to wheel speeds detected with the wheel speed sensor.

Abstract: A hydraulic vehicle drive, particularly for mobile hoisting platforms, has a first pair of wheels drivable by means of first wheel motors (8, 9) in dependence of a first control valve (2) and a second pair of wheels provided with second hydraulic motors (15, 16). A switching arrangement (19) short-circuits the second hydraulic motors (15, 16) in the driving-free state and for cooling supplies them with a flushing flow. In the driven state a second control valve (5), in dependence of which the second hydraulic motors (15, 16) are drivable, is activated, and if required connected with the first control valve (2). Thus, optionally, the first wheel pair can be driven alone or together with a certain driving output from the second wheel pair.

Abstract: A hybrid vehicle is provided including an internal combustion engine mounted in a forward portion of the vehicle for driving engagement of a pair of wheels attached to a front axle. An electric motor is mounted in a rear portion of the vehicle for driving engagement of another pair of wheels through a rear axle. A set of batteries for powering the electric motor are stored in the trunk of the vehicle or beneath the trunk floor. A controller is used for controlling the driving engagement of the pair of axles by the electric motor and the internal combustion engine. More particularly, the electric motor is automatically operated to drive the rear wheels when increased horsepower is demanded such as during heavy acceleration or high speed cruising or when enhanced traction is required due to a slip condition.

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 system for propelling a vehicle, and with the system arranged with a pump and vehicle drive motors and valves and pilot lines. The operator can select an all-wheel drive or a lesser number of wheel drives. Also, there is a system automatic response to certain conditions of vehicle drive, whereupon the system activates to alter the drive to the various vehicle wheels, including changing from a four-wheel drive mode to a two-wheel drive mode. Further, the operator can override the system's own activation and thereby establish the two-wheel drive mode desired.

Abstract: A vehicle propel system, including a hydrostatic transmission having wheel motors (37L,37R) and a variable displacement pump (39), variable in response to a pump displacement command signal (51). The system involves determining (67) anticipated motor flow, and generating a signal (69) corresponding thereto. A pressure command signal (77) corresponds to the desired pump pressure. Actual motor flow is sensed (75), and a processor (49) calculates pump flow and compares it to actual motor flow (75) to determine system leakage (107). The processor then modifies the anticipated motor flow signal (69) to compensate for system leakage (107), and generates the appropriate pump displacement command signal (51). The use of feed-forward terms, such as anticipated motor flow (69), pump speed and commanded pressure times leakage gain to calculate desired pump displacement allow a lesser gain to be used for the feedback term (measured pump pressure 59), thereby reducing "wheel hop".

Abstract: A coupling device to be provided between left and right wheels of a vehicle has an electric motor and a switching mechanism switchable between a starting assistance state in which a torque is transmitted in the same direction of rotation from the electric motor to left and right wheels, and a cornering assistance state in which a torque for acceleration is transmitted from the electric motor to one of the left and right wheels. When the switching state of the switching mechanism is for starting assistance control, lamps in the central indicator of an indicating device are lighted in a number corresponding to the electric current value of the electric motor. When the switching state is for cornering assistance control, the lamps of the left and right indicators corresponding to the outer wheel are lighted in a number corresponding to the electric current value.

Abstract: A difference rotation generating apparatus which generates a difference rotation between the left and right idler wheels by an output torque of an electric motor. When the driving condition of the vehicle is power-off state or when the slip angle is above a predetermined value, a yawing moment to decrease the slip angle is generated by an independent operation of the left and right brakes. When the slip angle is below the predetermined value, the difference rotation generating apparatus is operated to thereby generate the yawing moment to decrease the slip angle.

Abstract: This is a connecting device (7) to be interposed between left and right wheels (5L, 5R) of a vehicle. It enables to perform a starting assistance control, a cornering control to improve the cornering performance by positively generating a difference rotation between left and right wheels, and a differential limiting control for restricting the difference rotation between the left and right wheels. There are provided: a differential gear (8) having a first rotational element (8a), and second and third rotational elements (8b, 8c) so arranged that, when one of them rotates in the forward direction relative to the first rotational element (8a), the other thereof rotates in the reverse direction; and a driving source (9) connected to the first rotational element (8a). One of the second and third rotational elements, e.g.

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: A hybrid vehicle including: an engine and a motor-generator for outputting drive forces to run a vehicle; and a brake pedal for applying a braking force to the running vehicle. While an engine braking force is being established, it is detected that the brake pedal is depressed. After this depression of the brake pedal, the vehicle speed is detected so that the regenerative braking is effected by the motor generator on the basis of the detected vehicle speed.

Abstract: This is a connecting device (7) to be interposed between left and right wheels (5L, 5R) of a vehicle. It enables to perform a starting assistance control, a cornering control to improve the cornering performance by positively generating a difference rotation between left and right wheels, and a differential limiting control for restricting the difference rotation between the left and right wheels. There are provided: a differential gear (8) having a first rotational element (8a), and second and third rotational elements (8b, 8c) so arranged that, when one of them rotates in normal direction relative to the first rotational element (8a), the other thereof rotates in the reverse direction; and a driving source (9) connected to the first rotational element (8a). One of the second and third rotational elements, e.g.

Abstract: A clutch motor 30 that includes a rotatable outer rotor 32 and a rotatable inner rotor 34 and is driven to carry out power operation or regenerative operation is attached to an output shaft of an engine 50. The output of the clutch motor 30 is transmitted to front wheels 26 and 28 via a drive shaft 22A. An assist motor 40 is directly linked with a drive shaft 22B that transmits power to rear wheels 27 and 29. Slip rotation in the clutch motor 30 enables part of the energy of the engine 50 to be regenerated. The assist motor 40 is driven with at least part of the regenerated energy or energy stored in a battery 94. This structure allows torques to be output to the two different shafts and thereby realizes four-wheel-drive. In accordance with another possible structure, the assist motor 40 regenerates electric power, while the clutch motor 30 carries out over-drive operation.

Abstract: An auxiliary driving system is provided to ensure that a vehicle equipped with an automatic transmission can be moved or permitted to travel without use of the driving force of the vehicle engine in the event of an emergency. The main driving wheels are normally driven through an engine and an automatic transmission and a pair of auxiliary driving wheels are driven by motors. In a usual state, the motors are used to generate an auxiliary driving force or a creep force in the vehicle. However, if the vehicle engine is stopped due to engine trouble or failure, the motors can be driven based on the amount of accelerator pedal depressed to rotate the auxiliary driving wheels and thereby permit the vehicle to travel. Thus, movement of the vehicle can be easily accommodated in the event of an emergency such as when the vehicle engine has failed.

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 drive system is provided including first and second primary drive motors that are connected to drive opposing wheels at one end of a vehicle. Each primary drive motor is connected to and drives a variable displacement hydraulic pump. Each pump is connected via a separate hydraulic drive circuit to at least one hydraulic motor. The hydraulic drive motors drive opposing wheels at a second, opposite end of the vehicle.

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: In a four-wheel drive traveling system for a tipper, an output side of an engine is connected to rear wheels via a power transmission, at least one variable hydraulic motor for driving the front wheels and a hydraulic pump driven by the engine are provided, and the variable hydraulic pump and the variable hydraulic motor are connected into a closed circuit. The system includes arrangements for controlling displacement of the variable hydraulic pump, for detecting slippage of the rear wheels, for setting a discharge pressure of the hydraulic pump between a high pressure and a low pressure, and for controlling the displacement of the variable hydraulic pump so that the discharge pressure is a low pressure while slippage is not caused for the rear wheels and so that the discharge pressure is a high pressure while slippage is caused for the rear wheels.

Abstract: A torque control lever override of an all wheel drive system matches the front wheel fluid flow, as the wheels are turning, to the flow the pump is generating before the two are connected together. The torque control lever normally controls the pressure and therefore the rim pull delivered to the front wheels. The pump will supply fluid based upon the aggressiveness of the torque control lever which may not always match the current wheel speed. The torque control lever override enhances operation of an all wheel drive system and eliminates excessive harshness when engaging or disengaging the all wheel drive system.

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: Dynamic braking on the all wheel drive front wheel motors of a motor grader is implemented by turning on all the wheel drive system, depressing the inching pedal, sensing brake pressure, determining ground speed, determining a pump set point current using the ground speed, and setting actual pump current to 90% of set point current. Both sides of the drive loop are monitored and the high side pressure is used to control loop pressure. Motor displacement which is normally controlled by shift lever position is set to low displacement for braking. When the all wheel drive system is turned off, the inching pedal is released, or there is a loss of brake pressure the all wheel drive system disengages. The pump upstrokes to provide an anti-lock feature when the desired brake pressure is less than 30% of the set point. The pump upstrokes to reduce pressure and thereby limit maximum pressure when the desired brake pressure exceeds 30,000 kPa.

Abstract: A method is provided for controlling hop in an all wheel drive machine having a torque control lever and a pump for supplying pressurized fluid to wheel motors for effecting all wheel drive. The method includes monitoring machine speed and motor pressure, sensing a first motor pressure fluctuation and subsequent motor pressure fluctuations indicative of a hop, determining desired pump pressure based upon machine speed, and overriding the torque control lever and holding pump pressure constant at desired pump pressure for a preselected time in response to detecting a predetermined number of hops occurring at a predetermined frequency.

Abstract: An electronic control is provided for controlling the drive speed of a supplemental drive relative to an engine driven main drive of a vehicle. A fluid pump driven by the engine provides pressurized fluid flow. The supplemental drive is driven by the pressurized fluid. A main drive sensor senses the speed of the main drive and responsively produces a main drive speed signal. A command knob is provided for selecting a desired speed relationship between the main and supplemental drives. A knob sensor senses the position of the command knob and responsively produces a modifier signal. A modifier circuit receives the main drive speed and modifier signals and responsively produces a modified main drive speed signal. A supplemental drive sensor senses the speed of the supplemental drive and responsively produces a supplemental drive speed signal. A processor produces an error signal responsive to a difference between received modified main and supplemental drive speed signals.

Abstract: A drive apparatus for driving front and rear wheels of a motor vehicle, either the front and rear wheels being mechanically driven, through a power transmission mechanism, by a motive power generated by an engine of the motor vehicle and the other wheels being driven by hydraulic motors rotationally driven by a hydraulic pump. The drive apparatus limits driving forces of the other wheels, rotationally driven by the hydraulic motor, to be below a predetermined driving force and further detects occurrences of acceleration slips of the one wheels, rotationally driven through the power transmission mechanism, on the basis of speeds of the other wheels in which the driving force is limited to be below the predetermined driving force. The driving forces of the one wheels are adjusted in accordance with the acceleration slip detection result so as to suppress the occurrences of the acceleration slips.

Abstract: An electronic control is provided for controlling the drive speed of a supplemental drive relative to an engine driven main drive of a vehicle. A fluid pump driven by the engine provides pressurized fluid flow. The supplemental drive is driven by the pressurized fluid. A main drive sensor senses the speed of the main drive and responsively produces a main drive speed signal. A command knob is provided for selecting a desired speed relationship between the main and supplemental drives. A knob sensor senses the position of the command knob and responsively produces a modifier signal. A modifier circuit receives the main drive speed and modifier signals and responsively produces a modified main drive speed signal. A supplemental drive sensor senses the speed of the supplemental drive and responsively produces a supplemental drive speed signal. A processor produces an error signal responsive to a difference between received modified main and supplemental drive speed signals.

Abstract: A power transmitting device for a four-wheel drive vehicle which includes main driven wheels driven directly by an engine and speed-change transmission, a left sub-driven wheel driven through a first hydraulic pressure clutch, a right sub-driven wheel driven through a second hydraulic pressure clutch, a first hydraulic pump driven in operative association with the main driven wheels, a second hydraulic pump driven in operative association with the left sub-driven wheel, a third hydraulic pump driven in operative association with the right sub-driven wheel, a first oil passage which connects a discharge port of the first hydraulic pump to intake ports of the second and third hydraulic pumps, and a second oil passage which connects the first oil passage to a working chamber in the first hydraulic pressure clutch and a working chamber in the second hydraulic pressure clutch.

Abstract: A hydraulic system including hydraulic units serving as wheel motors and pumps is disclosed. The hydraulic units include a stationary member supporting cylinders with piston assemblies reciprocating therein. The piston assemblies have bodies and follower assemblies which follow lobes on a rotary cam. The piston assemblies serve both as pistons and as timing valves for controlling the flow of fluids. The piston assemblies may have either undercuts or internal passages in their bodies. The follower assemblies have compliant springs elastically positioning rollers between arms of a yoke to allow lateral movement of these rollers relative to the arm of the supporting yokes. Sealing mechanisms are provided which seal between the rotary cam and the stationary member to form an annular scavenge chamber. At least one sealing mechanism has a non-rotating annular intermediate member which pilots relative to the rotary cam. A static seal accommodates radial movement between the stationary and intermediate members.

Abstract: A hydraulic regenerative braking and four wheel drive system for a vehicle is provided. The system includes a fluid accumulator, hydraulic units locating within vehicle wheels and comprising stationary members and cooperating rotary cams, filter assemblies, and spool valves for controlling the flow of fluid in the system. The system may be operated in a regenerative mode wherein at least some of the hydraulic units operate as pumps to provide high pressure fluid to the accumulator during vehicle deceleration or braking, and wherein at least some of the hydraulic units operate as motors, receiving high pressure fluid from the accumulator during vehicle acceleration. The system may also be operated in a four-wheel drive mode wherein a pair of hydraulic units, connected to a pair of mechanically driven wheels, act as pumps to drive a pair of hydraulic units, acting as motors, to rotate a pair of non-mechanically driven wheels.

Abstract: A drive arrangement for earth moving machines of simplified structure which allows ready access to the various parts thereof for servicing. The arrangement includes a controlled hydrostatic motor dispersed between a fluid power pump associated with the internal combustion engine of the machine and which is connected through its drive shaft to the universal drive shaft of the machine at a point between the rear wheel driving axle and the universal joint associated therewith.

Abstract: In a hybrid vehicle in which the front or rear set of wheels is driven by an engine (7) and the other set of wheels is driven by a motor (8), a traveling mode deciding unit (4) is provided with a table for deciding engine throttle opening and motor output, with driving force being distributed in accordance with the engine throttle opening and motor output decided by referring to the table. The table decides the traveling mode based on signals from a detector (2) which detects the remaining life of a battery, a vehicle velocity sensor (1) and an accelerator opening sensor (3). By deciding the traveling mode using such a table, it is possible to distribute driving efficiently in dependence upon the remaining life of the battery.

Abstract: An electronic control is provided for a vehicle having an engine, a main drive driven by the engine, a fluid pump driven by the engine for providing pressurized fluid, and a supplemental drive driven by the pressurized fluid. The electronic control includes a main drive sensor for sensing the speed of the main drive and responsively producing a main drive speed signal. A vehicle speed sensor senses the speed of the vehicle relative to the ground and produces a vehicle ground speed signal. A pressure sensor senses the pressure of the pressurized fluid supplied to the supplemental drive by the pump and responsively produces an actual pressure signal.

Abstract: A hydraulic wheel motor and pump are provided for use with a motor vehicle having a pair of mechanically driven wheels and a pair of non-mechanically driven wheels. The hydraulic pumps cooperate with the mechanically driven wheels, and the hydraulic motors are coupled to the non-mechanically driven wheels. The pumps and motors are diagonally connected to one another to create a four wheel drive vehicle. Also shown is an apparatus and method for independently controlling the tractive force of the vehicle wheels during a turning maneuver.