Abstract: A four-wheel drive vehicle has a center differential which transmits the output torque of a power plant to both front and rear wheels in such a manner as to permit the front and rear wheels to rotate at different speeds. A differential control system has a differential rotation limit member which acts on the center differential to limit differential rotation of the front and rear wheels to a degree which is increased as the difference in rotational speed between the front and rear wheels increases. The degree of limitation on the differential rotation of the front and rear wheels is changed according to a predetermined characteristics which nullifies the degree of limitation in a range where the difference in rotational speed is relatively small and provides a gain in a range where the difference in rotational speed is relatively large. The gain is changed according to a factor which governs the running condition of the vehicle.

Abstract: A drive shaft for driving supplemental apparatuses is disposed in or penetrates an oil pan disposed under an engine in order to provide a compact supplemental apparatus layout or arrangement. In the oil pan, a supplemental apparatus drive unit, including the drive shaft, an idle gear meshing with an output gear fixed on an engine crankshaft, and a chain for transmitting drive power from the idle gear to the drive shaft, is supported, and is simultaneously assembled so as to be linked with the idle gear and the output gear when the oil pan is assembled to the engine. The output gear is preferably fixed on the inner side of an endmost journal of the crankshaft to reduce vibrations from the crankshaft. Moreover, providing a damper associated with the output gear fixed to the crankshaft reduces the vibrations from the crankshaft.

Abstract: A power transmitting system for a vehicle includes an input shaft, left and right output shafts, a speed reduction mechanism for transmitting a driving force from the input shaft to the output shafts, a left hydraulic clutch disposed between the speed reduction mechanism and the left output shaft for transmitting the driving force, a right hydraulic clutch disposed between the speed reduction mechanism and the right output shaft, and an oil pump for supplying a hydraulic pressure to the left and right clutches. The left and right hydraulic clutches being disposed in the speed reduction mechanism, and the input shaft constitutes a primary element of the oil pump. A compact power transmitting system can be obtained in accordance with the invention.

Abstract: A power train includes a transmission disposed in a transverse direction of a vehicle, in which an engine crankshaft extends. The power train has a wheel drive shaft, disposed in alignment with a transmission shaft, a front differential, having differential output shafts aligned with the transmission shaft, and a speed reduction gear, disposed between the transmission shaft and differential input shaft. The speed reduction gear has an input gear, having an axis of rotation placed parallel to the transmission shaft. The transmission shaft is one of input shaft and output shaft, having axes of rotation which are placed parallel to the engine crankshaft. The wheel drive shaft and differential output shaft are aligned with the one of the transmission input and output shafts. The speed reduction gear, connected to the one of the transmission input and output shafts, is preferably parallel to both of the transmission input and output shafts.

Abstract: An engine unit includes an engine and a power train which are disposed in parallel to each other. The power train includes a transmission and a differential. The engine and the power train are housed in one engine housing formed of upper and lower parts which are mated with each other along respective mated surfaces. Upper halves of bearings for the crankshaft and upper halves of bearings for a rotational shaft of the power train are formed in the mating surface of the upper part of the engine housing and lower halves of bearings for the crankshaft and lower halves of bearings for said rotational shaft of the power train are formed in the mating surface of the lower part of the engine housing. The upper part of the engine housing is formed integrally with the cylinder block of the engine.

Abstract: A four-wheel drive vehicle has a center differential which transmits the output torque of a power plant to both front and rear wheels in such a manner as to permit the front and rear wheels to rotate at different speeds. A differential control system has a differential rotation limit member which acts on the center differential to limit differential rotation of the front and rear wheels to a degree which is determined according to the difference in rotational speed between the front and rear wheels. The degree of limitation on the differential rotation of the wheels is determined according to the difference in rotational speed between the front and rear wheels based on first characteristics when the rotational speed of the front wheels is higher than that of the rear wheels and based on second characteristics when the rotational speed of the rear wheels is higher than that of the front wheels. The first and second characteristics are set separately from each other.

Abstract: A four wheel drive system for a vehicle includes comprising a power plant for producing a driving force, a front wheel driving mechanism for transmitting the driving force to drive right and left front wheels, a rear wheel driving mechanism for transmitting the driving force to drive right and left rear wheels, and right and left wheel clutches provided in one of the driving mechanisms for controlling the amount of the driving force transmitted to the wheels. A cut-off clutch is provided for controlling the driving force transmitted to the wheels of the one of the driving mechanisms, and a control device causes the cut-off clutch to engage before the wheel clutch is engaged. The driving force is transmitted sequentially rather than instantly from the cut-off clutch, the wheel clutches and to the wheels so as to suppress the torque shock creative in connection with a change in the drive condition.

Abstract: A four wheel drive system of a vehicle including a power plant for producing driving force, has a front wheel driving mechanism for transmitting the driving force to drive a right and left front wheels and rear wheel driving mechanism for transmitting the driving force to drive right and left rear wheels. Right and left wheel clutches provided in one of the driving mechanisms for control the amount of the driving force transmitted to the wheels, and steering angle detecting device detects a steering angle of a steering wheel. A control device increases torque distribution for the rear wheel driving mechanism in a cornering condition of the vehicle as a steering angle change rate is increased. The system provides the vehicle with a desirable torque distribution during a cornering operation so that improved cornering property is obtained.

Abstract: A gear mechanism has a plurality of gears provided on a shaft and is housed in a housing. Oil is filled into a lower part of the housing. The bottom of the housing is raised to conform to the contour of the gears and an oil return passage in the form of a groove extending in the direction of the row of the gears is formed in the bottom surface of the housing.

Abstract: A transmission is equipped with a planetary gear type transmission unit disposed between an input member and an output member within a casing. The transmission unit is comprised of a sun gear, a ring gear and a plurality of planet gears carried by a carrier coupled with the output member. The planet gears are in mesh with the sun gear and the ring gear. The input and output members are coupled with each other by bypassing the gears of the transmission unit in direct drive or via these gears in reduction ratio drive. The transmission is further provided with a first change-over member in mesh with the input member for selectively connecting the input member with the carrier in direct drive or with the sun gear in reduction ratio drive and a second change-over member secured to the first change-over member for engaging the ring gear with the casing in reduction ratio drive or disengaging the former from the latter in direct drive.

Abstract: An operating system used in a vehicle equipped with a part-time four-wheel drive comprises; a center-differential shiftable between at least a two-wheel drive mode and a four-wheel differential-locked drive mode; a free-wheeling device with a clutch mechanism incorporated in an output shaft of an axle differential associated with wheels which are rendered non-driven when the vehicle is traveling in the two-wheel drive mode and adapted to connect and disconnect the transmission of driving power between the axle differential and the non-driven wheel; a drive mode selecting member operated by a driver in the driver's compartment to select a desired driving mode of operation of the center-differential; and a shift control device which sequentially shifts the center-differential responding to an operation of the drive mode selecting member.

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: A transfer case operating apparatus for shifting a part-time four-wheel transfer case of a vehicle having a transfer gear assembly and a center-differential gear assembly, with their associated gear shift devices. The operating apparatus comprises a power drive actuator coupled to one of the shift devices; a mechanical actuator directly coupled to the other; a shift control device operated by a driver in the driver's compartment of the vehicle shift the transfer case between at least two-wheel high-speed drive mode; four-wheel, differential-free drive mode; and four wheel, differential-locked, low-speed drive mode; and a mechanism for, when the shift control device is operated to shift one gear assembly associated to the power drive actuator, disconnecting the mechanical actuator from the shift control device so as not to shift the other gear assembly. The mechanism works with different operating forces for causing the power drive and mechanical actuators.

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: Within a case a main television circuit, a liquid crystal display panel for producing an image on a front side thereof, an EL light illuminating panel and a driving circuit which is driven to cause said EL light illuminating panel to emit light are accommodated. The EL light illuminating panel is mounted on the reverse side of said crystal display panel so as to emit light through and out of the front side of the panel.

Abstract: A video signal analog-to-digital converter for an image display device comprises a reference signal generator, which can detect variations of the average level of a video signal and generate a variable upper and a variable lower reference potential in accordance with the variations detected. An analog-to-digital converting circuit A/D converts the video signal between present variable upper and lower reference potentials to produce a digital code signal. Brightness control of an LC display panel is done according to the digital code signal.