Abstract: A two-stage power-split gear unit for automobiles consists of an input shaft (2), of a planetary gear unit as an off-road gear stage, of a differential gear unit, of a first output shaft (13) and of a second output shaft (15) which is connected to an offset output (19), the input shaft (2) being capable of being coupled selectively to the sun wheel (5) and to the planet carrier (7) of the planetary gear unit, the planet wheels (8) of which roll in a ring gear (9) fixed in space, and the differential gear unit having compensating wheels (11) and first and second output wheels (14, 16) driven by these and in each case located on the first and the second output shafts (13, 15).

Abstract: In a working vehicle such as an agricultural tractor, a front wheel change speed device for transmitting drive to front wheels includes an equal speed clutch for driving the front wheels substantially at the same speed as rear wheels, and an accelerating clutch for driving the front wheels substantially at a higher speed than the rear wheels. In the front wheel change speed device of this invention, the equal speed clutch and accelerating clutch are arranged coaxially. The front wheel change speed device further includes a shift member axially shiftable for selectively operating the equal speed clutch and accelerating clutch, and an actuator for axially shifting the shift member.

Abstract: A four-wheel driven wheel has a rear-wheel driving system branching at the intermediate thereof into a front-wheel driving system comprising a first transmission for driving the front wheels at a peripheral speed substantially identical with that of the rear wheels and a second transmission for driving the front wheels at a peripheral speed higher than that of the rear wheels. A hydraulic clutch device is provided, including a hydraulically operable first friction clutch for connecting and separating the first transmission with the rear-wheel driving system, a hydraulically double-acting first piston for engagement and disengagement of the first friction clutch, a first fluid chamber for the clutch-engaging action provided at one side the first friction clutch, a second fluid chamber for the clutch-disengaging action provided at the other side thereof, and a biasing member for biasing the first friction clutch to engage disposed in the first chamber.

Abstract: An engine drive torque is distributed to an extra wheel at a predetermined distribution ratio. When the vehicle makes a turn at low speed and when the torque distribution ratio to the extra drive wheel is high, a torsion is produced in the vehicle body, suspension and tires, etc., due to a rotation radius difference between the main and extra drive wheels. After the vehicle has stopped, and the engine is stopped, torque is no longer distributed to the extra drive wheel, the torsion is suddenly released and the vehicle vibrates. According to this invention, the release of torsion is performed gradually by decreasing the torque distribution ratio when the vehicle has stopped, with the engine still running in order to prevent this vibration.

Abstract: An automatic clutch for a vehicle drive train to selectively connect and disconnect a drive portion of the drive train to a driven portion of the drive train, the drive and driven portions having adjacent and mated spline portions at a designated position in the drive train. A clutch ring slidably mounted to one of the spline portions and slidable into engagement with the other spline portions. The designated position adjacent a portion of the vehicle frame and a remote controlled actuator secured to the portion of the vehicle frame. A bearing member of the actuator engaging the clutch ring for urging sliding movement of the clutch ring. Improvements to the above include application of the actuator clutch to front and rear wheel ends for conversion of the vehicle between two-wheel and four-wheel drive, the actuator being mounted to the steering knuckles. Also, improved bearing packs are provided for better performance and to facilitate assembly.

Abstract: An attachment structure for free-axle air pumps in differentials positions the free-axle air pump in the dead space behind the front bumper. This simplifies the harness arrangement by removing the free-axle air pump from inside the bonnet, and prevents flying pebbles, water and the like from damaging the free-axle air pump. A rearward extension from the bottom of the front bumper passes below the free-axle air pump to provide additional protection from flying objects and splashing water.

Abstract: A transfer case includes a double overrunning or two-way clutch and torque limited centrifugal cone clutch disposed in mechanical parallel between a primary and secondary output of the transfer case. The double overrunning clutch includes a plurality of rollers disposed between concentrically arranged drive and driven members. The centrifugal cone clutch includes a preload or preset biasing spring which sets a minimal torque throughput, a plurality of weights which adjust the clutch force and thus torque throughput dependent upon the speed and stops which limit motion of the weights and thus determine the maximum clutch compressive force and torque throughput.

Abstract: A four-wheel drive vehicle of the present invention includes: a first differential mechanism for distributing engine drive force to front drive wheels and rear drive wheels; a second differential mechanism for distributing engine drive force to left and right main drive wheels (the main drive wheels get more drive force than other drive wheels); first differential-limiting device for operating differential-limiting control by the first differential mechanism; second differential-limiting device for operating differential-limiting control by the second differential mechanism; rotational speed detection device for detecting rotational speed of each drive wheel; turn direction detection device for detecting the direction of a turn that the vehicle is making; and control means for, based on detection signals from the rotational speed detection device and the turn direction detection device, controlling differential-limiting force provided by the second differential-limiting device according to a difference betwee

Abstract: A four-wheel drive vehicle includes a first transmission system for transmitting power from an engine to a left and a right first driving wheel provided with a braking unit, and a second transmission system branching off from the first transmission system to transmit power to a second pair of driving wheels serving as steerable wheels. The second transmission system is provided therein with a frictional transmission passage having a frictional torque, which is smaller than that between the second driving wheels and a road surface, and a direct transmission passage disposed in parallel with the frictional transmission passage, so that either passage can be selected. The frictional transmission passage is selected when a speed-changing operating tool is set to its high speed position or when a steering device is operated beyond a predetermined angle, and the direct transmission passage is selected in all other cases.

Abstract: A shift lever assembly is provided including a cylindrical member having a fixed axis. An annular member is supported for rotation about the axis of the cylindrical member. A lever is connected to the annular member and is moveable within a first shift lane and a second shift lane substantially parallel the first shift lane. The second lane is connected to the first lane by a bisecting lane. A compliant member is provided to move the lever from the first lane to the second lane. The compliant member is provided between the cylindrical member and annular member.

Abstract: An automatic clutch for a vehicle drive train to selectively connect and disconnect a drive portion of the drive train to a driven portion of the drive train, the drive and driven portions having adjacent and mated spline portions at a designated position in the drive train. A clutch ring slidably mounted to one of the spline portions and slidable into engagement with the other spline portions. The designated position adjacent a portion of the vehicle frame and a remote controlled actuator secured to the portion of the vehicle frame. A bearing member of the actuator engaging the clutch ring for urging sliding movement of the clutch ring. Improvements to the above include application of the actuator clutch to front and rear wheel ends for conversion of the vehicle between two-wheel and four-wheel drive, the actuator being mounted to the steering knuckles. Also, improved bearing packs are provided for better performance and to facilitate assembly.

Abstract: An adaptive torque control and distribution system for a motor vehicle having a transfer case, primary driveline and drive wheels and secondary driveline and drive wheels for operation in extreme off road conditions such as sand. The transfer case includes a modulating clutch and a lockup clutch disposed in parallel between its primary (rear) output and secondary (front) output. The system detects abnormally high magnitude and rapidly repeating wheel spin transients which are characteristic of operation in sand or similar highly randomly variable tractive conditions and overrides the on demand torque distribution program for a predetermined time interval. During this predetermined time interval, the transfer case lockup clutch is activated thereby coupling the primary and secondary drivelines and achieving a fifty-fifty torque split therebetween while the modulating clutch is inactive.

Abstract: A rear differential in a four-wheel drive vehicle includes a left and right clutches adapted to distribute a driving force transmitted from front wheels through a propeller shaft to left and right rear wheels. If the engagement of the left and right clutches is released, only the front wheels are driven and in this manner, the vehicle is brought into a front wheel-drive state. If the left and right clutches are brought into their engaged states, both of the front wheels and the rear wheels are driven and in this manner, the vehicle is brought into a four-wheel drive state. By changing the engagement forces of the left and right clutches, different driving forces can be distributed to the left and right rear wheels. In addition, when a driver operates a differential lock switch, the left and right clutches, are brought into their engaged states with the maximum engagement force, thereby integrally coupling the propeller shaft to the left and right rear wheels to provide a differential-locked state.

Abstract: A rotation transmission device is mounted in a drive train of a four-wheel drive vehicle to selectively distribute driving force to selected vehicle wheels according to the travel condition of the vehicle. This device includes an outer ring and an input shaft. A cylindrical face is formed on one of the opposed surfaces of the outer ring and the input shaft, while cam faces are formed on the other opposed surface to define a wedge-shaped space between the cylindrical face and each cam face. Rollers are mounted in pockets formed in a retainer mounted between the input shaft and the outer ring. An electromagnetic clutch is coupled to the retainer. A switch spring is mounted between the retainer and the input shaft. A two-way clutch is provided between the outer ring and the input shaft.

Abstract: A transfer case having a primary output shaft, a secondary output shaft, and a transfer clutch disposed therebetween. The transfer clutch includes an inner drum journalled on the primary output shaft and which has clutch teeth that are selectively engageable with clutch teeth on the primary output shaft, an outer drum rotatably supported on the primary output shaft and which is fixed for rotation with the secondary output shaft, and a clutch pack operably interconnected between the inner and outer drums.

Abstract: A power transmission changeover device for an automatic-transmission, four-wheel drive vehicle which can prevent rattling of gears while the gear position of the sub-transmission is being changed over. Air pipes extending from a negative pressure source for actuating an actuator for changing over gears of a sub-transmission, and electromagnetic valves have inner diameters of 4 mm or over. An accumulator is provided between the electromagnetic valves in the air pipes and the negative pressure source. This makes it possible to increase the operating speed and operating force of the actuator and, to shorten the duration of the neutral position when gears are changed over, and to increase the meshing force with new gears. It is thus possible to prevent rattling of gears due to improper meshing of gears.

Abstract: A transfer case for a four-wheel drive vehicle having a planetary gear assembly and a synchronized range clutch which can be selectively shifted on-the-move establishing high-range and low-range drive modes. The planetary gear assembly includes a ring gear, a sun gear, a carrier coupled for rotation with an output shaft of the transfer case, and a pinion gear rotatably supported from the carrier and which is meshed with the ring gear and the sun gear. The range clutch includes a first sleeve coupled for rotation with the ring gear and which is rotatably supported from a second sleeve coupled for rotation with an input shaft of the transfer case. With the range clutch in a first position, the first sleeve is uncoupled from the housing and the second sleeve is coupled to the carrier for driving the output shaft at a first speed ratio relative to the input shaft.

Abstract: A rotation transmission device is mounted in a drive train of a four-wheel drive vehicle to selectively distribute driving force to selected vehicle wheels according to the travel condition of the vehicle. This device includes an outer ring and an input shaft. A cylindrical face is formed on one of the opposed surfaces of the outer ring and the input shaft, while cam faces are formed on the other opposed surface to define a wedge-shaped space between the cylindrical face and each cam face. Rollers are mounted in pockets formed in a retainer mounted between the input shaft and the outer ring. An electromagnetic clutch is coupled to the retainer. A switch spring is mounted between the retainer and the input shaft. A two-way clutch is provided between the outer ring and the input shaft.

Abstract: A control system for a 4WD vehicle has a rotation transmission device which can prevent a two-way clutch of the rotation transmission device from vibrating by repeatedly locking and unlocking when the vehicle is started in a cold environment. The rotation transmission device is mounted in the transfer. The transfer is provided with a temperature sensor for measuring the temperature of oil in the transfer. If the oil temperature as measured by the temperature sensor is below a predetermined value when the vehicle is started with the drive mode set at the 2WD position, the hub clutches are engaged to reduce the idling speed of the two-way clutch and thus to prevent the two-way clutch from locking.

Abstract: For automatically controlling a differential lock in drive axles of a motor vehicle, an arrangement has a lock coupling, an actuator for actuating the lock coupling, a plurality of rotary speed sensors associated with wheels of the vehicle for forming the rotary speed signal, a control unit for receiving the rotary speed signals and forming a control signal for controlling the actuator means, the control unit including computing means for computing a nominal rotary speed value associated with each of the wheels so that a computed nominal rotary speed value is determined continuously in dependence from a corresponding traveling condition, a first comparing unit for forming a difference rotary speed value from a comparison of a measured rotary speed value with the computed nominal rotary speed value, and a second comparing unit for forming the control signal so that when the difference rotary speed value exceeds a predetermined threshold value the lock coupling is engaged and when the difference rotary speed va

Abstract: A two/four wheel drive shifting device capable of detecting a success or failure in shifting of a free wheel mechanism to a locked state without encumbering components for detecting free and locked states of the free wheel mechanism being directly disposed in the free wheel mechanism. The two/four wheel drive shifting device has a two/four wheel drive shifting mechanism disposed in a transfer mechanism, a device for detecting shifting between two wheel and four wheel drive, an indicator for showing the shifting, an actuator for shifting a free wheel mechanism which is disposed in either a front wheel or a rear wheel differential mechanism, a pressure pump for supplying working pressure, a pressure detector for detecting the working pressure, and a control to actuate the pressure pump to supply working pressure to the actuator when shifting to four wheel drive is successful.

Abstract: A differential apparatus includes a differential casing, a pair of output side gears disposed in the differential casing, a differential mechanism distributing driving force of an engine, a clutch for operatively connecting the differential casing with the axles of the vehicle, an actuator for releasing the clutch from its connecting operation, and an urging member for causing the clutch to connect the differential casing with the axles of the vehicle. When the actuator is inactivated, the urging member serves to attain the connecting operation of the clutch. Therefore, even if the actuator is in a bad condition, four-wheel driving condition of the vehicle can be maintained. Therefore, the differential apparatus allows the vehicle to escape from a bad road.

Abstract: An automatic transmission and transfer case operatively mounted in a four wheel drive vehicle controlled by a single selector lever that is moved to predetermined detented positions along a longitudinal gate to select the transmission drive ranges, reverse, neutral and park. A special pivot construction allows the selector lever to be moved laterally with respect to the normal longitudinal movement for transfer case gear ratio changes and neutral selection. A small lateral gate is employed to receive the selector lever located in alignment with the neutral detent position of the automatic transmission requiring the transmission to be in neutral when the transfer case is shifted. When moved into the lateral gate, the selector lever activates electronic controls effecting operation of a motor for shifting transfer case gear ratios and for selecting transfer case neutral.

Abstract: A vehicle drive system includes a compact drive mode-shifting mechanism that is mounted in the final drive gearset of a vehicle. The drive mode-shifting mechanism includes a first shaft, a second shaft, and a clutch assembly. The first shaft forms an input shaft for the differential for a pair of wheels, the second shaft transmits engine power and the clutch assembly connects and disconnects the first and second shafts to one another to effect either the two-wheel-drive mode or the four-wheel-drive mode. The first shaft has an outer surface provided with a first spline, the second shaft has an outer surface provided with a second spline, and said clutch assembly includes an axially movable shifting member provided with an internal spline.

Abstract: A dual disconnect differential assembly for four-wheel drive (4WD) vehicle is disclosed. This disconnect differential assembly connects both output shafts of a differential assembly (and correspondingly both axle shafts which are driven by the respective output shafts) simultaneously. The dual differential assembly herein also disconnects both output shafts simultaneously. A clutch mechanism associated with the two differential side gears (which may be otherwise conventional) and with annular driven gears which are in driving engagement with respective output shafts, is provided for simultaneous connection and simultaneous disconnection of the output shafts. The dual disconnect differential assembly herein is simple, compact, and reliable. It overcomes the disadvantages associated with single axle disconnect mechanisms presently in use. It also provides a simpler, more compact, and more reliable dual disconnect differential mechanism than any such mechanism presently known.

Abstract: A four-wheel drive transfer case including a force sensor and associated electronics for sensing the reaction forces on driven members within the transfer case, such as in association with an output shaft and its bearings. The force sensor and associated control system establish an output signal which varies depending upon the magnitude of the reaction force and yields an indication of the torque distribution between the output shafts of the transfer case. The output voltage signal is used by a torque monitoring and control system to vary and/or limit the magnitude of torque transmitted to the output shaft.

Abstract: A transmission for a four-wheel drive vehicle having a multi-speed geartrain and power transfer mechanism incorporated into a common housing assembly. The multi-speed geartrain includes a input shaft, a mainshaft, and a plurality of constant-mesh gearsets arranged for selectively coupling the mainshaft to the input shaft for driven rotation at various speed ratios. The mainshaft can be selectively coupled to the power transfer mechanism for establishing two alternative power transmission routes. In particular, a synchronized range shift mechanism is provided for establishing a high-range transmission route and a low-range transmission route from the mainshaft to a primary driveline to define a two-wheel drive mode. A portion of the drive torque delivered to the primary driveline can be transferred automatically through a transfer clutch to the secondary driveline to establish an on-demand four-wheel drive mode.

Abstract: An adaptive torque control and distribution system for a motor vehicle having a transfer case, primary driveline and drive wheels and secondary driveline and drive wheels for operation in extreme off road conditions such as sand. The transfer case includes a modulating clutch and a lockup clutch disposed in parallel between its primary (rear) output and secondary (front) output. The system detects abnormally high magnitude and rapidly repeating wheel spin transients which are characteristic of operation in sand or similar highly randomly variable tractive conditions and overrides the on demand torque distribution program for a predetermined time interval. During this predetermined time interval, the transfer case lockup clutch is activated thereby coupling the primary and secondary drivelines and achieving a fifty-fifty torque split therebetween while the modulating clutch is inactive.

Abstract: An adapter for installation between a single-offset transfer case and a transmission unit. The adapter includes an adapter input shaft coupled to an output shaft of the transmission, an adapter output shaft coupled to an input shaft of the transfer case, and a drive mechanism connecting the adapter input and output shafts. The adapter input shaft is rotatably driven by the transmission output shaft about a first rotary axis. The adapter output shaft is rotatably driven by the adapter input shaft about a second rotary axis. The input shaft and a first output shaft of the transfer case are commonly aligned for rotation with adapter output shaft for rotation about the second rotary axis. The transfer case has a second output shaft supported for rotation about a third rotary axis.

Abstract: A hub clutch assembly is designed so that fluid pressure is used only while the driving mode is being changed over between a four-wheel drive position and a two-wheel drive position, while eliminating the necessity of holding a coupling member in position once the driving mode has been changed over. A driven member and a driving member are coupled together and uncoupled from each other by a slider which is moved under a negative or positive air pressure. A spring is used to maintain the slider in the two-wheel drive position, while a magnet is used to maintain the slider in the four-wheel drive position.

Abstract: An automatic transmissions for an automotive vehicle includes a variator of the traction drive type, the variator including two input discs, two output discs, and rollers driveably engaged with the discs and adapted to vary continuously the ratio of the speeds of the output discs and input discs. Each of two planetary gearsets includes a carrier driven by an engine and driveably connected to an input disc, a sun gear driven by an output disc, and a sun gear connected to one of two driveshafts, which drive the front and rear wheels, respectively, of a motor vehicle. Independent angular variation of the rollers causes the variator to drive the forward drive sun gear and rear drive sun gear at different, variable speeds.

Abstract: A vehicle transfer case for movement between two- and four-wheel drive includes a stop cushion as an end of travel range is approached. The cushion is preferably provided by a generally U-shaped spring that is contacted by the stop at either of its ends of travel. The cushion prevents the stop from locking into a housing for the gear.

Abstract: A multi-speed offset transfer case for a four (4) wheel drive motor vehicle having a plural stage torque transfer and speed changing mechanism which provides four (4) or more output speeds for each input speed. A modified planetary gear assembly forms the first stage and provides selectively either speed reduction or an output speed which is equal to the input speed. This planetary gear assembly receives torque from an input shaft and includes a sun gear in driven engagement with the input shaft, a planetary gear carrier which supports a plurality of planet gears and a ring gear. The planetary gear carrier includes an output sleeve, which is preferably an integral part of the planetary gear carrier.

Abstract: A drive train arrangement for a motor vehicle that includes a pair of front and rear transfer cases each having a single-input shaft and dual-output shafts for providing drive to a front axle and to a pair of rear axles located in tandem and in which the arrangement is such that the rear transfer case normally provides a full-time four-wheel drive through the tandem axles and the front transfer case is selectively activated to direct power to the front axle so as to provide a full-time six-wheel drive for the vehicle.

Abstract: A transfer case for a four-wheel drive vehicle having a planetary gear assembly which integrates a gear reduction unit and an interaxle differential into a common assembly. A synchronized range clutch is operably associated with the input to the planetary gear assembly and can be selectively shifted on-the-fly for establishing high-range and low-range speed ratios. A synchronized mode clutch is operably associated with the output of the planetary gear assembly and can be selectively shifted on-the-fly for establishing two-wheel, full-time four-wheel and locked four-wheel drive modes.

Abstract: An automatic transmission for an automotive vehicle includes a continually variable drive mechanism having one sheave assembly fixed to an intermediate shaft and the input sheave assembly supported on an input shaft, a low speed gearset driveably connected to the input shaft and an output shaft, a fixed ratio drive mechanism in the form of a chain drive providing a torque delivery path between the intermediate shaft and the carrier of the gearset, a transfer clutch for connecting and releasing the first sheave of the variable drive mechanism and input shaft, a low brake, a reverse gearset, a reverse brake, and a clutch for selectively driveably connecting the output of the fixed drive mechanism and a front output shaft.

Abstract: An automatic transmission for an automotive vehicle includes a continually variable drive mechanism having one sheave assembly fixed to an intermediate shaft and the input sheave assembly supported on an input shaft, gearset driveably connected to the input shaft and an output shaft, a fixed ratio drive mechanism in the form of a chain drive providing a torque delivery path between the intermediate shaft and the carrier of the gearset, a transfer clutch for connecting and releasing the first sheave of the variable drive mechanism and input shaft, a low brake, and a reverse brake.

Abstract: A multiple disc clutch pack includes a pilot magneto-rheological operator which controls operation of an associated ball ramp operator which, in turn, compresses a clutch pack to selectively transfer torque between and input member and an output member. The pilot operator includes an electromagnetic coil disposed proximate a magneto-rheological fluid contained within a chamber of a pilot clutch. Activation of the electromagnetic coil creates a magnetic flux which travels through the magneto-rheological fluid and couples the fluid clutch members, creating drag and relative rotation between members of the ball ramp operator. Such relative rotation of the ball ramp operator selectively compresses the clutch pack and transfer torque from the input member to the output member.

Abstract: A hub locking system for a part-time four-wheel drive vehicle including a wheel hub, drive axle, and clutch meaner and an automatic actuator remotely operable by an operator to induce movement of the clutch member axially inwardly and a biasing means acting against the clutch member opposing operation of the automatic actuator to urge movement of the clutch member outwardly. A manual override allows manual operation when the automatic actuator is not actuated and includes a first member mounted for shifting axially inwardly and outwardly in the system and when shifted inwardly urges the clutch member against the force of the biasing means. A second member is mounted contiguous the first member and is manually rotatable. A ramp shaped cam is interposed between the first and second members and when the second member is rotated, it directly urges the first member to shift axially to actuate the clutch member.

Abstract: A transmission for a four-wheel drive vehicle having a multi-speed geartrain and power transfer mechanism incorporated into a common housing assembly. The multi-speed geartrain includes a input shaft, a mainshaft, and a plurality of constant-mesh gearsets arranged for selectively coupling the mainshaft to the input shaft for driven rotation at various speed ratios. The mainshaft can be selectively coupled to the power transfer mechanism for establishing two alternative power transmission routes. In particular, a synchronized range shift mechanism is provided for establishing a high-range transmission route and a low-range transmission route from the mainshaft to the input of an interaxle differential. The torque delivered to the interaxle differential is split between the front and rear drivelines to establish a full-time four-wheel drive mode. As an option, a lock-out clutch can be provided for permitting the interaxle differential to be locked for establishing a locked four-wheel drive mode.

Abstract: A 4-wheel drive vehicle has a driving force control method in which a portion of a driving force for front wheels is distributed to rear wheels through clutches. In a 4-wheel drive state in which a driving force T.sub.p is distributed to rear wheels, for example, if the vehicle is turned leftwards to generate a difference W.sub.R -W.sub.L between left and right rear wheel speeds, it is ensured that a driving force T.sub.R distributed to the right rear wheel, which is an outer wheel during turning of the vehicle, is larger than a driving force T.sub.L distributed to the left rear wheel, which is an inner wheel during turning of the vehicle, thereby providing an enhancement in turning performance. As the difference W.sub.R -W.sub.L between the left and right rear wheel speeds is increased as a result of decreasing of the turning radius of the vehicle, the driving force T.sub.P (=T.sub.L +T.sub.R) distributed to the rear wheels is decreased to avoid an increase in travel resistance.

Abstract: A two wheel drive motorcycle is provided with an unsteerable rear wheel, a steerable front wheel, a drive unit having a driving motor for driving the rear wheel and a transmission device coupled to the drive unit for driving the front wheel. The transmission device has a hydrostatic drive having a hydraulic pump driven by the driving motor and whose hydraulic motor is mounted on an arm of the front fork. The hydraulic pump has constant output and the hydraulic motor has a constant input matched to the pump output. Hydraulic fluid is delivered from the hydraulic pump to the hydraulic motor by a pressure line. The pressure in the pressure line is controlled by a pressure control valve which can be adjusted to maintain a pressure in the range of approximately 20 to 200 bars.

Abstract: A differential apparatus for a part-time four-wheel drive vehicle is provided. The differential apparatus includes an outer differential casing, an inner differential casing, a clutch member adjacent to the inner differential casing, a pair of dog clutches, a differential gear system arranged in the inner differential casing and an actuator body for actuating the clutch member. One of the dog clutches is connected with the inner differential casing, while the other of the dog clutches is formed on the clutch member. When the vehicle is traveling under two-wheel drive, the inner differential casing and the differential gear system are raced, while the outer differential casing and the clutch member do not race. Accordingly, it is possible to reduce the racing loss of these members and the noise caused by the racing loss.

Abstract: A transfer system for a four-wheel drive vehicle comprising: a transfer case for transferring driving modes; a transfer-operating part for activating and controlling said transfer; a button shifting assembly for selecting driving mode; a speed sensor for detecting a vehicle speed; a neutral switch which switches on when a transmission mode is neutral; and an electronic control unit which controls the transfer-operating part regarding the vehicle speed, the transmission mode sensor and the button shifting assembly.

Abstract: A hub clutch assembly is designed so that fluid pressure is used only while the driving mode is being changed over between a four-wheel position and a two-wheel drive positions, while eliminating the necessity of holding a coupling member in position once the driving mode has been changed over. A driven member and a driving member are coupled together and uncoupled from each other by a slider which is moved under a negative or positive air pressure. A spring is used to maintain the slider in the drive position, while a magnet is used to maintain the slider in the four-wheel drive position.

Abstract: A driving-torque control system for a four-wheel-drive vehicle includes a transfer clutch employed in a transfer of the four-wheel-drive vehicle for varying a distribution ratio of driving torque between front and rear road wheels depending on a front-and-rear wheel revolution-speed difference. A calculation unit derives a command value of the engaging force of the transfer clutch from the front-and-rear wheel revolution-speed difference. A load-condition detection unit detects an input load condition of the transfer clutch, on the basis of the front-and-rear wheel revolution-speed difference and the command value of the engaging force. A comparing unit compares the input load condition detected by the load-condition detection unit with a predetermined threshold. A compensation unit compensates the engaging force of the transfer clutch so that the transfer clutch is held in a completely engaged state for a predetermined holding time duration, when the input load condition exceeds the predetermined threshold.

Abstract: A planetary gear assembly is disclosed having a sun gear fixed for rotation with an input, a ring gear, and a planet carrier fixed for rotation with an output and which has a plurality of planet gears rotatably supported thereon that mesh with the sun gear and the ring gear. To establish the high and low-range drive connections between the input and the output, a first range sleeve is supported for rotation with the input and is movable between a neutral position and an engaged position whereat the input is coupled to the planet carrier. In addition, a second range sleeve is supported for rotation with the ring gear and is movable between a neutral position and an engaged position whereat the ring gear is coupled to a stationary brake plate. Accordingly, the high-range drive connection between the input and the output is established when the first range sleeve is in its engaged position and the second range sleeve is in its neutral position.

Abstract: A two speed planetary gear assembly and double disconnect mechanism for a motor vehicle transfer case or similar device achieves full decoupling of the speed reduction assembly from the power path when either neutral or the high speed gear ratio, typically direct drive, is selected. The double disconnect mechanism includes an axially slidable clutch collar freely rotatably disposed within a correspondingly movable reduction hub which may selectively be translated to engage either a direct drive member or an input to a planetary gear assembly. When the reduction hub is positioned to engage the input of the planetary gear assembly, a gear set on the carrier of the planetary gear assembly engages the reduction hub which drives it and the output member at reduced speed.

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 system for controlling a four-wheel drive for a motor vehicle comprises a drive mode switch for detecting a drive mode of the motor vehicle selectable between a two-wheel drive mode and a four-wheel drive mode. The four-wheel drive mode is selectable between a direct-coupled four-wheel drive mode. A an auto four-wheel drive mode, a controller controls the distribution of traction between main and secondary driving wheels. A traction transmission train distributes traction between the main and secondary driving wheels. The traction transmission train has an oil pressure supply system having a friction clutch and a solenoid.