VEHICLE FRONT AND REAR WHEELS DRIVE SYSTEM AND CLUTCH CHANGEOVER METHOD

摘要

Changeover clutch discs for a direct coupling clutch and a change-speed clutch, respectively, are disposed in two stages in a radial direction across a movable element which can move in axial directions of an input shaft. A carrier and the movable element are brought into meshing engagement with each other such that the movable element does not rotate relative to the carrier. The changeover clutch discs mesh with clutch discs which are disposed on the input shaft and a casing, respectively. A coned disc spring and an electromagnetic actuator are disposed such that operating directions of the spring and the actuator are opposed to each other. The coned disc spring keeps the direct coupling clutch in a normally engaged condition with its biasing force, and the electromagnetic actuator brings a change-speed clutch into engagement after it has released the engagement of the direct coupling clutch by virtue of its thrust.