Ball ramp driveline clutch actuator with unidirectional apply

摘要

A vehicle driveline clutch using a ball ramp actuator including a ball ramp mechanism supplying a clamping force on a clutch disc in response to an electromagnetic field where the clutch clamping force is maintained and increased with clutch slip using a planetary gearset having an annulus connected to rotate with a clutch ring and a sun gear connected to rotate with the transmission input shaft. A primary one-way clutch acts between the planetary gearset and a flywheel work in conjunction with the planetary gearset in preventing rotation of the control ring in a direction to deactivate the ball ramp mechanism and a plurality of secondary one-way clutches acting in the planetary gearset with a secondary one-way clutch acting on each planet gear and supported on the clutch ring which is frictionally connected to the ball ramp control ring upon energization of an electrical coil by a clutch control unit thereby creating relative rotational motion between the control ring and an actuation ring causing a plurality of rolling elements to travel along identical opposed variable depth ramps thereby creating an axial separation force between the control ring and the actuation ring generating the clamping force on the clutch disc. Upon slippage of the clutch disc, the planetary gearset acts in concert with the primary one-way clutch to further energize the ball ramp actuator to increase the clutch clamping force when the vehicle is in either a drive or coast driving mode.