Abstract: A control system for a four-wheel drive vehicle with a continuously variable transmission having a drive pulley having a hydraulically shiftable disc and a hydraulic cylinder for operating the disc, a driven pulley having a hydraulically shiftable disc and a hydraulic cylinder, and a pressure regulator valve for regulating pressure of oil supplied to the hydraulic cylinders. A hydraulic actuator is provided for engaging a transfer clutch for establishing four-wheel driving. The pressure regulator valve has a pressure level changing port to increase the pressure of oil supplied to the cylinders. A solenoid operated valve is provided for supplying the oil regulated by the pressure regulator valve to the hydraulic actuator and to the pressure level changing port or for draining the actuator and the port. An orifice is provided in an inlet side of the solenoid operated valve.

Abstract: A vehicle equipped with four-wheel drive has a transfer case including a center-differential which delivers driving power to both front and rear axle assemblies when needed and is shiftable between a two-wheel and a four-wheel drive mode of operation and between a differential-locked and a differential-unlocked drive mode of operation. A free wheeling drive mechanism with a clutch member is incorporated in an output shaft of an axle differential in association with wheels non-driven in the two-wheel drive mode of operation and is adapted to disconnect when the vehicle is in the two-wheel drive mode of operation. A controller causes a forced drive mode shift of the center-differential from the four-wheel differential-underlined drive mode of operation either to the four-wheel differential-locked or to the two-wheel drive mode of operation when the disconnection of the free-wheeling drive mechanism is detected while the vehicle is in the four-wheel differential-unlocked drive mode of operation.

Abstract: A transfer device for a four-wheel drive vehicle has a transfer shaft rotatably mounted by first and second bearings and a transfer gear rotatably mounted on the transfer shaft between the bearings. A coupling device is provided outside the first bearing for engaging the transfer gear with the transfer shaft, and a bevel gear is secured to the transfer shaft at a portion outside of the second bearing.

Abstract: A power transmission device for four wheel drive vehicle includes a differential motion limiting device, for limiting differential motion of a center differential device, which is made up by a wet-type frictional clutch and a hydraulic actuator. Under running condition, the frictional clutch is engaged by certain engaging force, and considering frictional coefficient of roads, the clutch is engaged with some slips so that torque distribution to front and rear wheels becomes even (50:50), then torque is distributed from the center differential device to front and rear wheels. The line pressure is applied to the hydraulic actuator through a regulator valve. In normal running condition, the regulator valve reduces the line pressure pre certain ratio, the reduced pressure is applied to the hydraulic actuator. In the case the manual valve being shifted to R range or low speed position, the regulator valve is switched to apply the line pressure directly to the hydraulic actuator.

Abstract: A differential mechanism of a four-wheel driving apparatus for vehicles has a planetary gear and transmits the driving torque from an input shaft to a front wheel driving shaft and a rear wheel driving shaft in a distributing manner. The differential mechanism includes a first spline rotated by the driving torque from the input shaft, a second spline connected so as to the integrally rotated with a sun gear of the differential planteary gear, a third spline connected so as to be integrally rotated with a carrier, fourth spline formed on an outer circumferential surface of the ring gear, and a differential change sleeve mounted in an outward radial direction from the first spline to the fourth spline for axially sliding between two positions, one position for connecting first and fourth splines, and the other position for connecting first, second and third splines.

Abstract: A full-time four-wheel drive apparatus for an automotive vehicle includes a planetary gear unit for shifting purposes, a shift changeover unit, a differential unit and a transfer unit for transferring rotating power from the rear-wheel side to the front-wheel side or vice versa. The shift changeover unit is arranged on the side of said planetary gear unit directed to the input shaft of the four-wheel drive apparatus, the carrier of the planetary gear unit is connected to the output shaft of the four-wheel drive apparatus, the differential unit is arranged between the planetary gear unit and the transfer unit, and a rotating force outputted by the planetary gear unit is transferred to the rear-wheel side and front-wheel side. Fluxure force exerted on a main shaft caused by the transfer unit based on a chain is eliminated and axial length of the apparatus is reduced.

Abstract: A planetary sub-transmission for a vehicle has a planetary gear unit with a carrier member fixedly mounted on an output shaft, a sun gear mounted on the output shaft for rotation, and a ring gear fixedly supported by the sub-transmission case. A remotely operable shift member supported by an input shaft for axial movement selectively couples the input shaft to the output shaft, either directly or through the sun gear of the planetary unit, to shift the sub-transmission between high speed and low speed drive ranges.

Abstract: In combination with a power transfer device, a power transmission includes a first shaft rotatably mounted within a housing and having an input end for connection to an output shaft of the transmission and an output end for drive connection to a pair of rear road wheels, a second shaft rotatably mounted within the housing in parallel with the first shaft for drive connection to a pair of rear road wheels, a drive member rotatable on the first shaft, a driven member mounted on the second shaft for rotation therewith and being drivingly connected to the drive member, a limited-clip differential in the form of viscous clutch coupling having an outer casing mounted on the first shaft for rotation therewith and coupled in a liquid-tight manner with an inner sleeve rotatably on the first shaft for defining a viscous fluid chamber and for relative rotation thereto, and a clutch sleeve axially movably mounted on a hub portion of the drive member for rotation therewith and shiftable between a first position where it i

Abstract: A four wheel drive working vehicle comprises a first shaft for driving rear wheels, and a second shaft for driving front wheels. The first and second shafts are coaxially and relatively rotatably supported by a transmission case. The first shaft carries a first gear relatively rotatably mounted thereon, and the second shaft carries a second gear fixed thereto. A gear transmission unit is detachably bolted to the transmission case to transmit drive from the first gear to the second gear. A clutch device is mounted on the first shaft to be switchable between a position to directly interconnect the first shaft and the second gear for driving the front and rear wheels at the same speed, and a position to directly interconnect the first shaft and the first gear for driving the front wheels at a higher speed than the rear wheels.

Abstract: A power transfer device includes a planetary gear unit which includes a sun gear, a carrier, a ring gear, and a plurality of planet gears journaled on the carrier and in mesh with the sun and ring gears. The planetary gear unit is shiftable between first, second and third positions to establish a high speed two-wheel drive mode in the first position wherein the carrier is engaged with an input shaft and a first output shaft, and the sun gear is engaged with a second output shaft, and the ring gear is disengaged.

Abstract: A power transmission for a four wheel drive vehicle having a transfer gear assembly consisting of a planetary gear unit, a center-differential gear assembly consisting of a planetary gear unit which is located coaxially relative to and adjacent to the transfer gear assembly, and two shift mechanisms one individual to each gear assembly. One shift mechanism shifts the transfer gear assembly in a desired drive range and is located coaxially relative to and adjacent to the transfer gear assembly opposite to the center-differential gear assembly. The other shift mechanism shifts the center-differential gear assembly and is located coaxially relative to and adjacent to the center-differential opposite to the transfer gear assembly. Each shift mechanism consists of three splined clutch rings disposed coaxially relative to the gears and an axially movable clutch sleeve for selectively engaging with the three clutch rings so as to shift the gear between different operating modes.

Abstract: A two-and-four-wheel drive shifting system of the type not including a differential gear unit comprises a pair of output shafts extending opposedly from each other and mounted rotatably independently of each other, an input member mounted concentrically and rotatably on one end of one of the pair of output shafts, and a sliding clutch mounted operatively on the other of the pair of output shafts. The sliding clutch having an engagement claw adapted to commonly engage with claws provided on one output shaft and on an input member in such a manner that the sliding clutch may be shifted in sliding motion in the axial direction along the other output shaft so as to selectively engage and disengage with either of the output shafts and the input member so that either the two-wheel or four-wheel drive position can be selected.

Abstract: A power transmission system for a four-wheel drive vehicle has, for the front and rear wheels, a driving power transmitting system for transmitting the output of a transmission with a forward overrunning clutch and a reverse overrunning clutch. Either or both of the overrunning clutches are engaged with a sleeve of a selecting device. An outer race of each overrunning clutch has outer toothings on the periphery thereof and the sleeve has inner toothings. Each inner toothing of the selecting device has chamfers on both axial ends thereof, and each outer toothing has a chamfer on an end opposing the inner toothing. Opposed chamfers of the inner and outer toothings have an angle so that a component in a free rotational direction of the outer toothing is produced by the engagement of the chamfer of the inner toothing.

Abstract: A motor vehicle having a front engine and all-wheel drive, wherein the wheels of the front axle are continuously driven, while the drive for the wheels of the rear axle is capable of being made either connectable or permanent via a lockable center differential or automatically by way of a viscous-coupling device arranged in the driveshaft line between the front axle and the rear axle. The coupling is arranged in such a way that the front and rear axles are coupled together essentially rigidly with regard to torque, there being provided in the train of the driveshaft line transmitting the torque between the front and rear wheels at least one free-wheeling mechanism with free-wheel lock. The free-wheeling mechanism is arranged so that--in the unlocked state--its free-wheel part coupled with the rear-axle drive is capable of overriding its free-wheel part coupled with the front axle drive, the free-wheeling mechanism being locked during drive operation and released upon actuation of the service brake.

Abstract: A shifting arrangement for the shifting between a single-axle standard drive and an all-wheel drive having a first clutch for the locking of a central differential gear and a second clutch for the connecting and disconnecting of one vehicle axle actuated by first and second pressure medium control element respectively against the force of a spring having first and second shift valve respectively controlled by an electronic control unit, to either supply working pressure or relieve from pressure respective control elements. The improvement including a hydraulic identifying valve for bringing the control elements into a mutual interaction. The identifying valve operates, as a function of the working pressure of at least one of the control elements and exclusively during the simultaneous controlling of both shift valves, in such a way that the clutch torque at both clutches increases and decreases approximately to the same extent.

Abstract: A drive mechanism for motor vehicles having two drive axles is disclosed. The drive mechanism includes a transmission drive followed by a differential gear unit. The differential gear unit includes first and second driven members. The first driven member is drivingly connected to the first drive axle and, via a spur gear drive system, to a first set of friction plates in a fluid friction clutch unit. The second driven member is drivingly connected to the second drive axle and, also via a spur gear drive system, to a second set of friction plates in a fluid friction clutch unit. The first set of plates and the second set of plates of the clutch unit are frictionally coupled to each other and thus act to equalize the rotational speeds of the two drive axles.To enhance the operation of the drive mechanism, the spur gear drive system connecting the driven members to the clutch unit provides a gear ratio greater than one.

Abstract: A system is provided with a viscous coupling which is filled with a viscous material and adapted to transmit the output of a transmission through the viscous material. A first clutch and a second clutch are provided for selectively transmitting the output of the transmission to front and rear wheels. Each clutch is arranged to selectively transmit the output without interposing the viscous coupling and to selectively transmit the output through the viscous coupling.

Abstract: A power transfer device includes an input shaft for connection to an output shaft of a power transmission, a first output shaft rotatably coupled at the inner end thereof with the input shaft, a second output shaft arranged in parallel with the input and first output shafts, an output member rotatably mounted on the first output shaft and being operatively connected to the second output shaft, a planetary gear unit mounted on the input shaft and having an input member connected with the input shaft and an output element for providing a low speed drive power train, a first sleeve member mounted on the first output shaft between the planetary gear unit and the output member and shiftable between a first position where the first sleeve member is retained to connect the first output shaft to the input shaft and a second position where the first sleeve member is retained to connect the first output shaft to the output element of the planetary gear unit, and a second sleeve member mounted on the first output shaft

Abstract: A dual planetary differential for a two wheel/four wheel drive vehicle transfer case mechanism providing an unequal torque split between the front and rear wheels during its full-time four wheel drive operation. The dual planetary gear set may be shifted by means of a mode clutch to provide either four wheel drive with full-time differentiation between the front and rear wheels or a part-time four wheel drive mode wherein the dual planetary is in a locked-up condition. The first and second sun gears of the dual planetary have unequal diameters with differing numbers of teeth such that, for example, proportionally more torque is transferred to the rear wheels than the front wheels. The sun gears have complementary frusto-conical web portions arranged in a juxtaposed compact manner within the transfer case.

Abstract: A vehicle transfer case (10) includes first and second planetary gear sets (68,70) and a selector (146) for selectively positioning (a) the first planetary gear set (68) in an operating position and the second planetary gear set (70) in a locked position to provide low speed driving without any differential action between first and second outputs (36,38) or (b) the first planetary gear set (68) in a locked or nonoperating position and the second planetary gear set (70) in an operating position to provide high speed driving with differential action between the first and second outputs (36,38). The second planetary gear set (70) which selectively provides the differential action between the first and second outputs (36,38) has components (106,108,122) all of which are rotatable about a central axis A, and planet gears (126,128) of the planet carrier component (122) are rotatable about axes parallel to the central axis.

Abstract: A device for the distribution of motive power having a compact size and a light weight is shown. The device comprises a hollow shaft receiving input power, a pinion shaft with a pinion gear rotatably supported thereon, which is meshed with a pair of side gear, one of the side gear integrally formed with a front wheel drive shaft, the other side gear integrally formed with differential case coupled to a rear wheel drive shaft. Thereby it is possible to maintain the height above ground of the rear wheel drive shaft.

Abstract: A power dividing differential has a hollow shaft subdivided into an input side section and an output side section. The input side section is connection to a drive, and the output side section is drivingly connected to a differential pinion meshing with a pair of side gears. One side gear drives a front wheel drive shaft extending axially through the hollow shaft, and the other side gear is drivingly connected to a differential housing which in turn is drivingly connected to a rear wheel drive shaft. A sleeve is slidable on the hollow shaft between a first position spaced from the differential housing and a second position engaged with the differential housing, thereby locking the differential.

Abstract: A four wheel drive gear box having a planetary internal differential concentric with a reduction gear driven by an output gear of a transmission, a planetary carrier driven by the reduction gear, a ring gear driving a first shaft concentric with the reduction gear, a sun gear driving a second shaft which carries a gear which drives, via other gearing, an inter-wheel differential, the first shaft driving the other inter-wheel differential, a support member enclosing the inter-axle differential and connected with the reduction gear, and a connecting member between the ring gear and the first shaft.

Abstract: A dual bevel gear differential transaxle assembly for a front transverse engine vehicle with front and rear pairs of road wheels providing a constant four wheel drive system. A first interaxle bevel gear differential and a second front wheel bevel gear differential are aligned on a transverse axis. The differentials are connected by a side gear shaft and inner and outer side gear sleeves concentric about the side gear shaft. The first differential achieves front axle to rear axle differentiation while the second differential provides differentiation for the front pair of road wheels. The dual differential transaxle assembly includes clutch means providing selective lock-out of the first differential. With the clutch means disengaged the first differential is in its unlocked mode whereby the transaxle assembly provides differentiation between the front and rear axles.

Abstract: A four-wheel drive system has a center differential between front and rear wheels, and differential restraining or locking means for restraining or locking the center differential. The four-wheel drive system is equipped with an automatic control system for automatically locking the center differential in accordance with the deceleration of the vehicle. The control system may have means for determining a coefficient of friction between the tire and road surface in order to lock the center differential at a low vehicle deceleration when the sensed coefficient of friction is low.

Abstract: A multi-position positive clutch is disclosed for use with a between-front-and-rear axle (center) differential of a multiple drive axle vehicle. One clutch member is biased to an overrun position by a fork slideably biased on a piston shaft from a main piston which, when operated, moves to bias the one clutch member in an engaged position. An annular piston, slideable on the shaft, responds to vehicle fluid brake pressure above a predetermined minimum to disengage the clutch. Clutch teeth have a dovetail shape for camming the clutch plate into engagement whereupon switch means are operated to indicate the locked position as well as opposite rotation in the overrun position.

Abstract: A four-wheel drive system for a vehicle, comprising a power unit having an output shaft in a lateral direction of the vehicle, a power transmission gear unit including transmission input and output shafts each having an axis of rotation parallel with an extension of the axis of rotation of the output shaft of the power unit; an intermediate drive gear parallel with the axes of rotation of the transmission input and output shafts, the transmission output shaft being held in driving engagement with the intermediate drive gear, a first wheel drive unit comprising differential-action power splitting means operative to split driving power from the drive gear into two power components and a differential gear assembly operative to transmit one of the two power components to a first pair of road wheels, a second wheel drive unit comprising right-angle power transfer gear means engaging the differential-action power splitting means and operative to transmit therethrough the other of the two driving power components in

Abstract: A power distributing device for four-wheel-drive vehicle including an input shaft, a first output shaft for transmitting power to rear wheels, a second output shaft for transmitting power to front wheels, a plane planetary gear set, a power train changing means and a synchronizing means. The plane planetary gear set includes a sun gear having a hollow shaft, a ring gear connected with the first output shaft, a planet carrier drivably connected with the input shaft, and planet gears carried by the planet carrier and engaged with the sun gear and the ring gear.

Abstract: A method and apparatus for modifying and converting full-time four-wheel drive vehicle transfer cases to adapt them for optional two-wheel drive operation are described. A gear arrangement is provided for locking the main drive shaft from the transmission to the rear output gear of the transfer case, while permitting the differential cage of the transfer case to be engaged or disengaged with a forward drive gear for the front wheels, as desired.

Abstract: A method for converting a full-time four-wheel drive transfer case for part-time four-wheel drive operation includes substituting an output shaft having a radially extended mounting flange at the forward end thereof. The original output shaft has a rear wheel drive gear secured thereon for engagement with the spider gears of a differential assembly, the spider housing of which is mounted on the transfer case input shaft for rotation therewith. The mounting flange of the substitute output shaft is adapted for connection to the rearward end of the spider housing upon removal of the spider gears from the differential assembly thereby to connect the substitute output shaft to the input shaft for rotation in unison. With the spider gears removed, the front wheel drive mechanism is selectively actuated by the sliding lock clutch on the input shaft, the spider housing and lock clutch including coacting gears which are meshed when the clutch is engaged.

Abstract: A multi-position clutch is disclosed for use with a between-front-and-rear axle differential of a multiple drive axle vehicle, having an engaged position to eliminate differential action in transmitting power between front and rear axle, normal intermediate overrun clutch position to prevent front wheel spinout faster than the rear, and a completely disengaged position for elimination of overrunning clutch lockup and excessive front driveline torque loads during moderate to panic brake applications. The clutch includes a linear fluid motor responsive to front-axle braking of the vehicle for applying fluid pressure in a first direction to the fluid motor to transfer the clutch to the disengaged position at a predetermined vehicle deceleration to prevent excessive drivetrain torque buildup between the front wheels and the rear brakes.