Patent ID: 6015361
Filing Date: 2000-01-18
Classification: F16H

Abstract:
A differential apparatus in combination with a partial four-wheel drive vehicle having an engine and a two-wheel/four-wheel driving switching mechanism arranged on the side of the two axles to which engine driving force is not transmitted under the vehicle's two-wheel driving condition, said differential apparatus comprising:a differential casing having an input gear fixed thereto, said differential casing being rotated by the engine through the intermediary of said input gear;a pair of output side gears disposed in said differential casing, opposing each other and rotating coaxially with an axis of said differential casing;a differential mechanism distributing driving force of said engine, which has been inputted from said differential casing, into both of said axles of said vehicle through said output side gears;a clutch for operatively connecting said differential casing with said axles of said vehicle so that driving torque applied on said differential casing is transmitted to said axles;an actuator for releasing said clutch from connecting operation thereof in a manner that the driving torque applied on said differential casing is not transmitted to said axles;an urging member for causing said clutch to connect said differential casing with said axles on condition that said actuator is inactivated, whereby said driving torque applied on said differential casing can be transmitted to said axles;wherein said clutch, actuator and urging member constitutes said two-wheel/four-wheel drive switching mechanism, said two-wheel/four-wheel drive switching mechanism arranged nearby the differential casing; andsaid urging member comprises an annular urging member disposed coaxially with the rotational axis of said differential casing, said actuator comprising an annular actuator disposed coaxially with the rotational axis of said differential casing, said actuator comprising and fluid pressure actuator disposed between a side wall of said differential casing and a bearing for carrying said differential casings, said fluid pressure actuator having an operating chamber filled with fluid, whereby the associated operation of said clutch can be released since said clutch is shifted in a direction of the rotational axis of said differential casing by changing a volume of said fluid accommodated in said operating chamber.