Abstract: There is provided a power transmission unit comprising an input member for receiving a torque input from a ring gear connected to a drive pinion which is connected to a propeller shaft, first and second output members supported by the input member in a freely rotatable manner and engaged with right and left rear wheels, and first and second clutches arranged between the input member and the first and second output members respectively to release the connections between the input member and the first and second output members respectively with the help of the actions of cam devices for releasing clutches when the angular speed of the input member becomes smaller than those of the first and second output members.

Abstract: A transfer case for four-wheel-drive vehicles for distribution of the power from an input shaft through a transmission route to the rear propeller shaft and the front propeller shaft is shown. The transfer case is provided with a torque detection unit for detecting the torque on the input shaft side and is equipped also, on the transmission route between the rear propeller shaft side and the front propeller shaft side, a friction clutch whose coupling force is adjusted in accordance with the variations in the values of the torque detected by the torque detection unit.

Abstract: A power transmission apparatus having an input shaft connected, by planetary gearing, to two coaxially arranged output shafts. The planetary gearing permits differential rotation between the output shafts. A limiting device located between the output shafts to limit the differential rotation thereof. The limiting device includes a clutch member mounted on the first output shaft and alternating first and second clutch plates. The first plates are axially movable relative to and rotatably fixed to the clutch member, and the second plates are axially movable relative to and rotatably fixed to the second output shaft. An interengaging cam mechanism is carried on the clutch member and the first output shaft, and arranged such that upon relative angular movement between the clutch member and the first output shaft, the clutch member is moved axially to frictionally engage the first and second clutch plates.

Abstract: A power transmission device is provided. The device comprises a casing for receiving a torque input, output members arranged inside the casing, movable members provided movably around the output members respectively, one side face of each of the movable members forming a cam face, clutches adapted for connecting the casing with the output members, and a cam shaft fixed to the casing and located between the movable members, wherein the torque input of the casing is transmitted to the output members through two routes, i.e., through the cam and the movable members, and through the clutches. The power transmission device is further provided with several improved parts such as improved friction faces, resistant members, cam faces, and pin.

Abstract: A viscous coupling for a drive shaft has an elongated tubular first shaft and an elongated cylindrical second shaft extending into and cooperating with the first shaft to define a cylindrical clearance therebetween. Bearings for accommodating both relative rotation and axial displacement of the first and second shafts are interposed therebetween at opposite ends of the clearance. Seals are associated with the bearings to hermetically seal the ends of the clearance, which is filled with a viscous fluid. The viscous resistance of the fluid to rotation of one shaft relative to the other provides a means of transmitting torque therebetween.

Abstract: A hydraulic power transmission device of the viscous shear type provides a rotatable driving connection between first and second shaft assemblies. A centrifugal clutch is interposed between the shaft assemblies to provide an overriding rotatable driving connection therebetween when the angular velocity of the first shaft assembly exceeds a predetermined level.

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 speed change gear shift rod with cushioning function which is performed when the speed change gear is being operated is shown. The shift rod is supported in a freely slideable manner in the direction of the shaft, within a blind supporting hole provided inside a main case. An oil containment section is provided at the back of the supporting hole, formed between the end surface of the shaft end section and the back surface of the supporting hole during a speed change operation, when the shaft end section slides to the back of the supporting hole. An oil channel is also provided in the shaft end section or in the supporting hole, making it possible to divert oil from the inside to the outside of the previously mentioned shaft end section.