Abstract: A differential apparatus includes a differential casing, a pair of helical side gears and a pairs of helical pinion gears. The helical pinion gears are accommodated in bores formed in the differential casing, respectively. When it is expected that a helix angle of tooth trace of the helical pinion gear would be decreased by the vehicle's driving, one of the helical pinion gears is formed in advance so that the tooth depths are gradually decreased from axial ends of the helical pinion gear toward the axial intermediate potion. Conversely, when it is expected that a helix angle of tooth trace of the pinion gear would be increased by the vehicle's driving, one of the helical pinion gears is formed in advance so that the tooth depths are gradually increased from the axial ends of the helical pinion gear toward the axial intermediate potion.

Abstract: A differential apparatus includes a differential casing, a pair of helical side gears and a pair of helical pinion gears. The helical pinion gears are accommodated in bores formed in the differential casing, respectively. The long and short helical pinion gears have respective first gear portions meshing with the side gears, respectively, and second gear portions meshing with each other. Each gear tooth of the long pinion gear is so tapered that tip thickness of the gear tooth is gradually decreased from an axial end of the gear portion toward the other gear portion. Even if the long pinion gear is inclined by meshing reactive forces, it is possible to ensure sufficient tooth bearing areas at respective tooth faces of the pinion gears.

Abstract: A hub clutch for locking or unlocking a wheel drive shaft to or form a hub clutch housing, comprises: a drive gear fixed to the wheel drive shaft; a slide gear slidably engaged or disengaged with or from the drive gear to lock or unlock the wheel drive shaft to or form the hub clutch housing; an elastic member for urging the slide gear into engagement or disengagement with or from the slide gear; a pressure source for supplying pressure into a pressure chamber formed between the wheel drive shaft and the hub clutch housing to shift the slide gear against an elastic force of the elastic member; and in particular a pressure supplementing switch for supplementing pressure supplied from the pressure source into the pressure chamber, whenever pressure within the pressure chamber drops below a predetermined value.

Abstract: A hub clutch device for connecting and disconnecting an axle and a wheel in a part time four-wheel drive vehicle is disclosed closed. The hub clutch device is provided with an outer race secured to a vehicle body, an inner race having a flange portion secured to the wheel and a hub portion provided with a gear portion at a peripheral inner portion, defining a fluid passage with the axle, and a roller member positioned between the outer race and the inner race. A movable wall is positioned inside of the hub portion. The movable wall defines a sealed chamber with the hub portion and is movable in an axial direction of the axle. The sealed chamber communicates with the fluid passage. A sliding gear always engages the gear portion of the hub portion and is axially movable according to the motion of the movable wall to engage a gear part of the axle to connect the axle with the wheel in a rotational direction.

Abstract: To simplify propeller shaft supporting structure and to reduce propeller shaft vibration when a viscous coupling and a clutch mechanism are both provided on a propeller shaft of a 4WD vehicle, the power transmission apparatus comprises a housing rotatably supported to receive power; a differential gear disposed on one side of and within the housing; a viscous coupling disposed on the other side of and within the housing; and a clutch for transmitting power from the housing to the differential gear via the viscous coupling when engaged, and transmitting no power from the housing to the differential gear when disengaged.

Abstract: To stably control clutch engagement torque of a multidisk friction plate clutch provided between two rotary members, without being directly subjected to the influence of friction plate wear or of fluctuations in friction coefficient between two clutch plates, the coupling apparatus comprises a pilot clutch, a main clutch and dual cam ring members disposed between the two clutches. When the pilot clutch is engaged by an actuator in a first direction, since a first slidable cam ring rotation is limited by the pilot clutch relative to a second fixed cam ring, the first slidable cam ring is shifted in a second opposite direction by a cam thrust force to engage the main clutch. The coupling apparatus is suitably incorporated in a differential gear assembly mounted on automotive vehicles in order to controllably and stably limit the differential motion between two shafts.

Abstract: To realize three functions of twin viscous coupling in four-wheel drive, free coupling in two-wheel drive, and further direct (lock) coupling in four-wheel drive, the power transmission apparatus for transmitting power from a propeller shaft (9A) to two right and left rear wheel drive shafts (21A, 23A), comprises first and second hubs (4, 5) coupled to the drive shafts; cylindrical inner and outer casings (3a3b) for forming two working chambers (11, 12) in cooperation with the two hubs; first and second resistance plates (8, 9), and a driven member (17) for selectively engaging the inner casing with the outer casing (TWIN VISCO IN 4WD) and disengaging the inner casing from the outer casing (FREE IN 2WD).

Abstract: To prevent dust or muddy water from entering a hub housing or to prevent a hub clutch from being allowed to be inoperative, a hub clutch for selectively coupling or decoupling a wheel shaft to or from a clutch housing (to which a wheel is fixed), the hub clutch comprises a drive gear fixed to the wheel drive shaft; a slide gear axially slidably coupled to the clutch housing; a diaphragm fixed to the slide gear so as to partition an inner space of the clutch housing into an inner enclosed chamber and an outer enclosed chamber; and a control valve connected to an engine intake manifold vacuum, for selectively applying vacuum into the inner chamber and atmospheric pressure into the outer chamber or vice versa to move the diaphragm. Further, a piston plate and a spring can be used instead of the diaphragm.

Abstract: A free wheel hub apparatus comprises a drive gear engaged with a drive shaft and having a gear portion on the outer circumferential face thereof; a housing disposed outside the drive gear and fixed to a wheel hub and having a gear portion on the inner circumferential face thereof; a slide gear engaged with the gear portions of the housing and the drive gear and movable in the axial direction; a drive device for moving the slide gear in the axial direction to engage and disengage the gear portions from each other; and a controller for controlling the operation of the drive device.

Abstract: A hub clutch is operable as an automatic hub clutch and as a manual hub clutch, and includes a hollow housing secured to a wheel hub, the inner circumference of which is provided with a spline, and on the outside end surface of which an opening is defined; a manually operable knob rotatably mounted in the opening of the housing and provided with a boss section having an inclined cam surface; a drive gear fixed to a drive shaft at the extreme end thereof, and provided with a spline and a gear section; a ring clutch supported in an axially transferable manual on the spline and which is engaged with the gear section on the circumference of the drive gear when displaced outwardly in the axial direction; a retainer rotating integrally with the housing and engageable with the cam surface of the knob; a return spring extending between either the retainer and the drive gear or the retainer and the housing for urging the retainer and the ring clutch inwardly in the axial direction; a shift spring extending between the

Abstract: A hub clutch used for a four-wheel driving free-wheel device in which, when a knob for manual operation and mounted on a casing is set to an automatic position, a pawl portion of a retainer becomes disengaged with a cam surface defined by a boss portion of the knob so that the device operates in the automatic condition, while when the knob is rotated in a manual lock direction, the pawl portion is engaged by the cam surface of the knob and is cammed to a lock position. When the pawl portion is in the lock position, the device assumes a manually locked state so that a drive gear and a clutch ring are maintained in an engaged condition with each other and stationary system members are separated from rotating system members. Accordingly, no contact force is applied to stationary system members when in the manually locked state.

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 hub clutch in which when an axle shaft commences to be driven, protruding cam portions of a first cam which is axially movably splined to the outside circumference of a driving gear formed integrally with the axle shaft is displaced from the inside of respective grooved cam portions of a second cam and a cam ring to the outside along an axial direction. Thereafter, the first cam is further displaced to the outside in the axial direction along a second cam portion of the cam ring, and a clutch ring is displaced in the direction of clutched engagement through a shift spring, at which a casing is engaged integrally with the driving gear.