On-demand four-wheel drive transfer case with controllable bi-directional clutch assembly

摘要

A controllable, multi-mode, bi-directional overrunning clutch assembly (58) and a mode shift system (60) are adapted for use in a transfer case (16) for transferring drive torque from a primary output shaft (18) to a secondary output shaft (32) so as to establish four-wheel drive modes. The clutch assembly (58) includes a first ring (118) journalled on a first rotary member (32), a second ring (124) fixed to a second rotary member (114), and a plurality of rollers (134) disposed in opposed cam tracks formed between the first and second rings. The first ring (118) is split to define an actuation channel having a pair of spaced end segments. An actuator ring (138) is moveable between positions engaged with and released from the end segments of the first ring (118). The shift system (60) includes a moveable clutch actuator which controls movement of the actuator ring (138) for establishing an on-demand four-wheel drive mode and a locked or part-time four-wheel drive mode.