Abstract: A planetary gear mechanism 3 is provided at one end portion of a housing 2 in a direction of the rotation axis L. The planetary gear mechanism 3 comprises a planetary gear 31 which is disposed at the housing 2 such that the planetary gear 31 is rotatable about its own axis and revolvable about the rotation axis L in unison with the housing 2, and an inner gear 33 and a sun gear 34 which are in meshing engagement with the planetary gear 31 at its outer side and inner side, respectively. A differential gear mechanism 4 is provided at the other end portion of the housing 2 in a direction of the rotation axis L.

Abstract: The present invention relates to the automatic transmission in general, and in particular to the speed of the car automatically converting according to the difference of the turbine runner's torque gained from the engine, and the load transmitted to the ring gear of the gear reduction device. Further, utilizing the energy of the electricity.

Abstract: A wheel end assembly having a dual wheel configuration includes independently rotating wheel hubs to reduce tire wear. The wheel end includes a first planetary gear assembly with a sun gear driven by a differential side gear and a ring gear for driving one wheel hub. A second planetary gear assembly with a sun gear driven by a differential side gear and a ring gear drives another wheel hub. A differential assembly is coupled to the first and second sun gears to allow the first and second wheel hubs to rotate relative to one another as the vehicle executes turning maneuvers.

Abstract: A casing 23 of a second differential gear mechanism 2 is constituted by a carrier 19 and a sun gear 22 which are separately formed. Owing to this arrangement, the casing 23 is divided into two parts in a direction of its axis. The carrier 19 is movable in a direction of an axis L. By meshing engagement between a pinion gear 26 and a side gear 27A, the carrier 19, which forms a part of the casing 23, is press contacted with a housing 11 through a washer 29.

Abstract: The present invention provides a integral subassembly for the power train of an all wheel drive automotive vehicle. The subassembly includes a final drive unit coupled to a transmission output. The final drive unit itself includes a torque multiplier and an output adapted to provide power to the front wheels of the vehicle. Also included in the subassembly is a front differential coupled to the final drive's output. The front differential includes a left front wheel output and a right front wheel output. A power transfer unit in the subassembly is also coupled to the transmission output and provided with a non-parallel gear set and a rear driveline output, the latter being adapted to provide power to the rear wheels of the vehicle. The power transfer unit is coupled to the transmission output independently of the final drive unit. Finally, a housing commonly encloses the final drive unit, front differential and power transfer unit allowing them to be integrally provided as a subassembly.

Abstract: A full-time all-wheel drive system for a motor vehicle equipped with a transversely mounted engine and transaxle includes a power take-off unit. The power take-off unit includes an interaxle differential which drives a first power path connected to the front wheels and a second power path connected to the rear wheels. The first power path includes a planetary final drive unit which drives a double planetary front differential unit that is interconnected to a pair of front axleshafts. The second power path includes a helical gearset and a bevel gearset which deliver power to a rear propshaft.

Abstract: A normally interlocked universal differential device comprises four differentials and two power distributors, in which a central composite differential is disposed in the central portion thereof, and includes an outer differential and an inner differential fitted into said outer differential, two side differentials are connected to both side ends of said central composite differential, power is transmitted to said power distributors from both ends of said two side differentials. The differential device can prevent a vehicle from slipping in the desert zone or the marsh land. The differential device is easy to assemble and has small size, thus increasing the steering ability, and it can be applied to the all-wheel drive automobile, the tractor, the wheeled engineering machinery and the wheeled engineering vehicle.

Abstract: An all wheel drive system for use in a vehicle where that system includes a front axle having a front differential. The all wheel drive system also includes a center differential connected to the front differential via a prop shaft. The all wheel drive system also includes a rear axle having a rear differential wherein the rear differential is connected to the center differential. The rear differential having a reduction gear integrated therein.

Abstract: An electric drive axle for use in hybrid vehicles has an electric motor driving a compact gearbox. The gearbox includes a planetary reduction unit and a differential assembly. The planetary reduction unit has a sun gear driven by the electric motor, and compound planet gears supported from a planet carrier which have a first gear segment meshed with a fixed first ring gear and a second gear segment meshed with a second ring gear. The sun gear is also meshed with one of the first and second gear segments of the compound planet gears. The second ring gear drives the differential which transfer motive power to a pair of output shafts adapted for connection to one set of wheels. When used with a conventional engine-based powertrain for the other set of wheels, the electric drive axle establishes a four-wheel drive powertrain for the hybrid vehicle. The electric motor and gearbox are mounted in a common housing assembly to provide a compact drive axle assembly.

Abstract: The present invention relates to the automatic transmission in general, and in particular to the speed of the car automatically converting according to the difference of the turbine runner's torque gained from the engine, and the load transmitted to the ring gear of the gear reduction device. Further, utilizing the energy of the electricity.

Abstract: An electric drive axle for use in hybrid vehicles has an electric motor driving a compact gearbox. The gearbox includes a planetary reduction unit and a differential assembly. The planetary reduction unit has compound planet gears supported from a planet carrier which mesh with a fixed ring gear and a sun gear driven by the electric motor. The planet carrier drives the differential which transfer motive power to a pair of output shafts adapted for connection to one set of wheels. When used with a conventional engine-based powertrain for the other set of wheels, the electric drive axle establishes a four-wheel drive powertrain for the hybrid vehicle. The electric motor and gearbox are mounted in a common housing assembly to provide a compact drive axle assembly.

Abstract: The differential engine comprises a motor, a torque conversion stage, and a loading mechanism. The torque conversion stage includes first and second differential stages which are coupled together with a pair of shafts, with the shafts rotating in opposite directions. The first differential stage comprises an input shaft which is coupled to the output shaft of the motor, and first and second output shafts which are coupled to the respective shafts. The second differential stage comprises an output coupled to the output drive shaft, and first and second input shafts which are coupled to the respective shafts. The second differential stage includes a gear mechanism which applies a rotational torque to the output drive shaft when a difference occurs between the rotational speeds for the shafts. The rotational speeds of the shafts are varied by loading one or both of the shafts.

Abstract: A drive axle assembly for use in an all-wheel drive vehicle having a first hydraulic coupling operable to automatically transfer drive torque to a secondary driveline in response to slip of the primary driveline and a second hydraulic coupling operable to bias torque and limit slip between the wheels of the secondary driveline.

Abstract: In a motor-vehicle drive train containing a differential, which has an differential input part and two differential output parts, a friction clutch with a limited transmittable torque is arranged between two of the differential parts, so that, with a small predetermined difference in torque between the two coupled differential parts, said friction clutch can slip to accommodate torque shocks. A temperature-dependent adjusting means is provided, which reduces the clutch engagement pressure with increasing clutch temperature.

Abstract: A hydrostatic power transmitting device in combination with a speed reducing apparatus together disposed within a common housing having an interior space divided by partitioning device into a first region in which the hydrostatic unit is disposed and a second region in which said speed reducer is accommodated. First and second regions are segregated from each other by the partitioning device being in the form of a flexible non-porous barrier. The elastically deformable partitioning device can therefore adjust its shape to take up any change in the amount of hydrostatic transmitting fluid in the first region due to temperature changes of the fluid and facilitates the regulation in depth of lubricant held by the second region. Thereby an initially low level of lubricant in the second region lessens the adverse effect of power-retarding drag losses, especially during cold weather winter operation, and a rising level of lubricant ensures good lubrication when temperatures are elevated and viscosity is low.

Abstract: The invention relates to a new vehicle differential that will rotate both axle sections under all conditions. Having positive traction capabilities and still allow variability between axle sections.

Abstract: Provided is a power train system for a vehicle, for transmitting power from a motor to a differential gear unit. The motor and the differential gear unit are disposed so that the output shaft of the motor and an axis of rotation of an output portion of the differential gear unit are parallely offset in the longitudinal direction of the vehicle. The power train system comprises a planetary reduction gear unit connected to the motor to be driven thereby and a parallel reduction gear unit drivingly connecting between the planetary reduction gear unit and the differential gear unit. The planetary reduction gear unit and the parallel reduction gear unit are disposed within a stationary casing.

Abstract: A power transmission mechanism for a front and rear-wheel drive vehicle in which the power of an electric motor is transmitted to rear wheels includes an output shaft adapted to rotate together with the electric motor, a middle shaft which is parallel with the output shaft, a drive shaft which is parallel with the output shaft and is adapted to rotate together with the rear wheels, a firs pair of reduction gears for reducing the speed of rotation of the middle shaft relative to the output shaft, a second pair of reduction gears for reducing the speed of rotation of the drive shaft relative to the middle shaft and a rear differential disposed closer to an electric motor side than the second pair of reduction gears and coupled to the reduction gear and the drive shaft.

Abstract: An electric drive axle for use in hybrid vehicles has an electric motor driving a compact gearbox. The gearbox includes a planetary reduction unit and a differential assembly. The planetary reduction unit has a sun gear driven by the electric motor, and compound planet gears supported from a planet carrier which have a first gear segment meshed with a fixed first ring gear and a second gear segment meshed with a second ring gear. The sun gear is also meshed with one of the first and second gear segments of the compound planet gears. The second ring gear drives the differential which transfer motive power to a pair of output shafts adapted for connection to one set of wheels. When used with a conventional engine-based powertrain for the other set of wheels, the electric drive axle establishes a four-wheel drive powertrain for the hybrid vehicle. The electric motor and gearbox are mounted in a common housing assembly to provide a compact drive axle assembly.

Abstract: A control for a differential for controlling the relative rotation of a pair of axles extended from the differential to a front or rear pair of wheels. An indicator shaft is coupled to the axles, e.g., through a planetary gear arrangement (the indicator shaft being the sun gear) whereby when the axles rotate in unison the ring gear and planet gear set of the planetary gear arrangement are synchronized to not drive the sun gear/indicator shaft. When one axle rotates at a rate different than the other, the sun gear is rotated. A brake mechanism is coupled to the sun gear. A sensor senses the rotational rate as well as the acceleration of the sun gear. A controller is provided to control the braking of the sun gear. Braking of the sun gear will force the axles to rotate in unison.

Abstract: This is a connecting device (7) to be interposed between left and right wheels (5L, 5R) of a vehicle. There are provided: a differential gear (8) having a first rotational element (8a), and second and third rotational elements (8b, 8c). The third rotational element (8c) is coupled to one (5R) of the rear wheels via the first power transmission system (10), and the second rotational element (8b) is coupled to the other (5L) of the rear wheels via second and third power transmission systems (11, 12). The gear ratios of both the first and second power transmission systems (10, 11) are identically set, and the gear ratio of the third power transmission system (12) is set so as to be opposite in direction to, but be equal in absolute value to, the above-mentioned gear ratio.

Abstract: A differential for a part-time 4-wheel drive vehicle. The differential includes a differential assembly disposed on a front axle shaft to allow front wheels to turn at different speeds when the vehicle is in a turn, an outer case for receiving power from a power transfer case via a front propeller shaft, the outer case being disposed around the front axle shaft while enclosing the differential assembly, and a clutch lever assembly disposed between the outer case and the differential assembly to selectively couple the outer case to the differential assembly, the clutch lever assembly being mounted on the outer case so as to operate in a coupling direction to the differential assembly by centrifugal force generated when the outer case is rotated by power transmitted from the power transfer case.

Abstract: A gear engaging stepless speed variator having orientational ON-OFF properties of worm transmission for a gear transmission mechanism to realize ON-OFF orientation, so as to achieve stepless speed change of gear engagement. The variator has an orientational ON-OFF device having two sets of ON-OFF mechanisms, each set of ON-OFF mechanisms contains a driving worm, driven worm, a pair of driving gears, a pair of driven gears and a worm wheel. The power output device has two sets of differential gear composed of a frame and four bevel gears mounted in the frame, and an output shaft, and is provided with a speed adjustment device such that through an eccentric mechanism and the speed adjustment device it realizes output of rotary motion with stepless change of speed.

Abstract: A vehicle provided with an engine 1 which generates a driving energy for the vehicle, planetary gears 4 and 6 comprising sun gears, planet gears and ring gears, motors 8 and 9 for respectively controlling the sun gears, and a clutch 14, the planet gears being connected to an input shaft driven by the engine and the ring gears connected to an output shaft for driving wheels, wherein gear ratios from the input shafts to the output shafts in the planetary gears 4 and 6 are set at a value different to each other. A stepless speed changing function which permits vehicular operation in a high engine efficiency region while minimizing an electrical energy loss is realized by a small-sized transmission using small-sized motors. The vehicle, which uses the transmission, can be operated in a high engine efficiency region while keeping an electrical energy loss to a minimum.

Abstract: Disclosed herein is a transmission comprising a mechanism for distributing energy of a drive source into a plurality of differential mechanisms; a plurality of motors connected to said plurality of differential mechanisms, respectively; and a mechanism for synthesizing energies outputted from said plurality of differential mechanisms.

Abstract: A hybrid four-axis drive apparatus has an engine and a generator on a first axis, a motor on a second axis, a counter gear mechanism on a third axis, and a differential device on a fourth axis. The engine and the generator are connected to the countershaft through a differential gear device. The differential gear device and the countershaft are connected by a first pair of gears. The motor and the countershaft are directly connected by a second pair of gears. The countershaft and the differential device are directly connected by a third pair of gears. Therefore, it becomes possible to change the gear ratio of the pair of gears without changing the positions of the four axes relative to one another. At least one embodiment of the invention has the motor disposed on the first axis, thus, reducing the number of axes to three.

Abstract: A dual wheel assembly is provided that includes a spindle having an axle shaft defining a rotational axis. The axle shaft has a drive pinion. A first wheel hub is supported on the spindle and is positioned to be rotatably driven about the rotational axis. A second wheel hub is arranged adjacent to the first wheel hub and is also rotatable about the rotational axis. The second wheel hub may be supported by the first wheel hub or the spindle. A differential assembly is interconnected between the first wheel hub and the second wheel hub. The differential assembly permits both wheels to be driven for increased traction while allowing the second wheel hub to rotate relative to the first wheel hub. A gear reduction assembly interconnects the differential assembly and the drive pinion to provide torque multiplication to the wheel hubs. In this manner, the gear reduction assembly provides the additional torque required for heavy vehicles while the differential assembly allows relative rotation of the wheel hubs.

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 range shift mechanism is provided for establishing a high-range power transmission route and a low-range power 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. A transfer clutch is provided for automatically controlling slip and torque biasing between the outputs of the interaxle differential.

Abstract: A gear type automated torque converter used to provide a continuously variable minimum torque required in a transmission system subject to the changing of the loading is provided. The gear type automated torque converter includes a torque changing main unit formed of a drive gear set to receive an input power, the drive gear set including a differential gear system, a left gear at the left side, and a right gear at the right side; and a feedback gear mechanism formed of a plurality of feedback gear sets arranged in pair in force couples, the feedback gear sets each including a differential gear system, a left gear at the left side, and a right gear at the right side, the output rotational speed of the feedback gear mechanism and the input rotational speed of the torque changing main unit are equal, enabling the power at the feedback gear mechanism be fed back to the torque main unit through a converter.

Abstract: An inter-axle differential assembly for a tandem drive axle set is disclosed that permits a rear drive assembly and a forward drive assembly to have the same input axis. The forward drive assembly includes a hollow pinion gear. An inter-axle differential assembly receives input from a driveline connection and transfers this input to the hollow pinion gear and to a through shaft that extends through the hollow pinion gear. The hollow pinion gear drives a main differential assembly that in turn drives a forward axle. The through shaft extends toward a rear drive assembly and provides input to the rear drive assembly. The rear drive assembly utilizes a rear pinion gear to drive a rear differential. The rear differential in turn drives a rear axle. Thus, the present design permits a common axis to be shared by the input to the forward drive assembly and the input to the rear drive assembly. In addition, the present design eliminates the traditionally required helical gears from the forward drive assembly.

Abstract: Method and apparatus for rotary motion converting power transmission assembly with counter-rotating outputs on the same axis as the rotary input.

Abstract: A vehicle power transmission and a vehicle powertrain capable of being continuously controlled over a predetermined range of operation. The powertrain includes two power units, the power transmission unit and a control device for receiving command input and determining performance parameters associated with the operation of the powertrain, an outer transmission and an inner differential gear assembly. The main transmission has two rotatable inputs, each operable connected to one power unit for receiving rotational power and operably connected to a rotatable output so that the rotational speed of the output can vary in proportion to the algebraic mean of the speeds of ratios of the two inputs. The differential gear assembly is arranged internally of the main transmission with a rotatable input operably connected to two differentially rotatable outputs. The output of the main transmission is operably connected to the input of the differential gear assembly.

Abstract: In a transfer case for a four-wheel drive vehicle having a front wheel drive axle assembly which includes a first wheel drive axle shaft arranged in parallel to the engine output shaft and connected to a transmission output shaft through a first helical ring gear meshed with the transmission output gear and a second wheel drive axle assembly which includes a second wheel drive axle arranged in parallel to the engine output shaft and connected to a transfer case through a transfer shaft arranged in parallel to the engine output shaft and equipped with a transfer input gear meshed with a second helical ring gear, the first and second helical ring gears are integrally formed as an integral ring gear and bolted to a differential housing as one whole.

Abstract: The present invention aims at realizing with a simple structure a differential gear capable of arbitrarily producing a difference in speed of rotation between output side rotary members. When a difference in speed of rotation occurs between drive shafts 3 and 4, if clutches 12 and 17 are disconnected, a first input side sun gear 8 and a first output side sun gear 9 are allowed to rotate at arbitrary speed ratios independently of each other due to the rotation and the revolution of first planetary gears 10, besides a second input side sun gear 13 and a second output side sun gear 14 are allowed to rotate at arbitrary speed ratios independently of each other due to the rotation and the revolution of second planetary gears 15. When the first clutch 12 for example is brought into connection, the revolution of the first planetary gears 10 is controlled.

Abstract: A housing (2) includes first and second housing components (3A, 3B). The first and second components (3A, 3B) are fixed by bolts (6). Each bolt (6) extends through a central portion of a planet gear (72) of a planetary gear mechanism (7). The planet gear (72) is rotatably supported on the housing (3) through the bolts (6).

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 transaxle assembly comprising, a planetary gear unit including a planetary gear set to shift receiving torque from a power source, a differential including a differential case, a cross pin having a pinion gear and a pair of output members, each output member having a differential side gear to engage with the pinion gear respectively, the differential transmitting the torque from the planetary gear unit to the output members via a circled carrier connecting between the planetary gear unit and the differential, wherein the planetary gears located outside of the differential case, the carrier supporting both ends of the cross pin and contacting with the differential case.

Abstract: A drive unit for tandem axles with two planetary transmissions is proposed, wherein a second planetary transmission is a "measuring" transmission interposed in such a manner between a chassis and a rocker of the tandem axle that the difference required for lifting the axle is determined and balanced.

Abstract: An all wheel drive transmission has a transfer gearing apparatus disposed in axial alignment between a hydrodynamic input drive and an input member of a planetary transmission. The transfer gearing apparatus delivers power from the hydrodynamic drive to the planetary transmission and from a differential output of the planetary transmission to a first output drive member. A second output drive member is connected to the differential output. One output drive member is connectable with the front drive wheels of a vehicle and the other output drive member is connected with the rear drive wheels of the vehicle.

Abstract: A mechanical assembly is operable as a variable speed transmission. The output shaft has a rotational force at speeds variable from an input applied to an input shaft. The mechanical assembly is a transmission device using a "positive traction" effect with a differential using a speed control (control shaft or hydraulic device) of relatively small controlling power to control transmission of power from the input shaft to the output shaft. Planetary gearing at a two-to-one ratio is used to convert the speed and direction supplied by the speed control to the output axle. The power input is applied to a differential carrier by a shaft mounted opposite of and collinear to the output axle. This eliminates the ring gear and pinion normally required. The carrier of a planetary gearing is used for speed control and is connected to the control shaft by a one-to-one ratio.

Abstract: A drive mechanism for 4WD automobiles is disclosed. In the drive mechanism, the center differential (C/D) unit, used for distributing the drive power of an engine to front and rear wheels, is an epicyclic gear train. The C/D unit is operated by a differential drive (D/D) gear. The front differential (F/D) unit, used for transmitting the drive power from the C/D unit to the front wheels, is a bevel gear train. The viscous coupling is connected to the C/D unit, thus limiting the differential operation of the C/D unit. The middle shaft is positioned at a side of the transmission and is rotated by the C/D unit. The middle shaft has a spiral bevel gear for transmitting the drive power to the rear wheels. Due to such a middle shaft, the transfer case is easily installed without causing any interference between the transfer case and the cylinder block of an engine.

Abstract: Continuously driven machine steering differentials have heretofore been complex for counter-rotating a pair of oppositely located planetary elements. The planetary steering differential includes a differential powered by a transmission input and a planetary gearing mechanism which receives an input from a steering motor for interacting with the outputs to achieve a steering correction.

Abstract: A gear assembly is used to adjust the phase of a plurality of rotating driving devices, such a rotary cover cams in a collecting and folding cylinder. The plurality of rotating driving devices can be phase adjusted with respect to each other through the use of individual sets of planetary gears. The planetary gear sets are coaxially and successively arranged on a shaft.

Abstract: A compound type planetary gear set lacking ring gears has been applied to a differential limiting apparatus for distributing driving force between left and right wheels of a vehicle. The driving force conveyed from an engine is inputted to a first sun gear through a differential case and dividedly transmitted to a second sun gear through first and second pinions composed of helical gears and to a carrier supporting the first and second pinions, respectively. The driving force conveyed to the second sun gear is transmitted to a left drive axle and the driving force conveyed to the carrier is transmitted to a right drive axle. When slipping occurs in the left or right wheels, the first and second pinions rotate around the first and second sun gears. The helix angles of the first and second pinions produce thrust forces which generate a differential limiting torque between the left and right drive axles.

Abstract: A power transfer system is disclosed for a four-wheel drive vehicle operable for permitting a vehicle operator to select between various full-time and part-time four-wheel drive modes. The power transfer system includes a dualplanetary gear reduction unit that is operable for establishing high-range and low-range speed ratios, and a synchronized range shift mechanism that is adapted to permit the vehicle operator to shift on-the-fly for establishing full-time and part-time high-range and low-range four-wheel drive modes. The power transfer system includes an slip limiting/torque-biasing arrangement including an interaxle differential and a transfer clutch operable for controlling the magnitude of speed differentiation and torque biasing across the interaxle differential.

Abstract: A vehicular driving force distribution apparatus includes a first helical sun gear to which an input torque is applied, a first helical pinion meshing with the first sun gear, a second helical pinion rotating integrally with the first pinion, a second helical sun gear from which an output torque is outputted in mesh with the second pinion, a carrier from which another output torque is outputted. And an initial torque generating apparatus comprises a multiple disc clutch and provides between the second sun gear and the carrier for generating an initial torque as a differential limiting torque in between so as to secure a required driving force even on a very slippery road.

Abstract: A transmission particularly a vehicular transmission for the driving and steering of a vehicle comprising a first differential having outputs to left and right wheels of the vehicle and an input powered for forward and reverse propulsion of the vehicle and a second differential controlling the outputs of the first differential for steering the vehicle.

Abstract: A support perpendicular to a rotational axis of a housing is secured to one of one of first side gears. One pair of second planet gears are rotatably mounted on the support shaft. The one pair of second planet gears are meshed with one pair of second side gears. A second and a third output shaft are connected respectively to the one pair of second side gears. A first output shaft is connected to the other first side gear.

Abstract: A tandem rear axle assembly for vehicles including trucks comprises an interaxle differential and a differential lockout mechanism which includes a friction clutch or clutch pack comprising a multiplicity of parallel annular clutch disks arranged in interleaved first and second sets. The clutch pack may be concentric with an input shaft which transmits torque from a vehicle drive shaft to the interaxle differential. The first set of clutch disks may rotate with the input shaft. The second set of clutch disks is in driving engagement with an output gear of the interaxle differential, which drives a pinion shaft to transmit torque to a forward rear axle of the vehicle. The clutch is disengaged under normal driving conditions.

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.