| 摘要 |
A transmission system which may comprise a front differential, a rear differential, a centre differential and a disconnect unit having a clutch with plates 88 that are engaged by a ball 96 and cam arrangement 82, 94. The disconnect unit disconnects drive to, for example, rear wheels of a rally car when a handbrake is applied thereby allowing handbrake turns to be executed. The disconnect unit can be operated by hydraulic pressure generated by manual operation of a handbrake lever, so avoiding the need to provide pump-generated hydraulic power. When the disconnect unit disconnects drive to the rear differential, the centre differential is preferably locked by a differential lock comprising a splined positive locking collar (114, fig 5) moved by a fork 122 operated by a hydraulic actuator 125 which receives hydraulic pressure from a second master cylinder (26'). The second master cylinder (26') is connected to a first master cylinder (26) so that the disconnect unit and the differential lock are actuated almost simultaneously. |
