摘要 |
The actuator (1) has a screw-nut unit for displacement of a clutch bearing. A driving nut (5) is in rotation with an assistance nut (9) for an axial displacement between engagement and disengagement positions. The assistance nut includes a friction ring (26) co-operating with the driving nut and rotated by an annular diaphragm of a clutch. The screw-nut unit is reversible such that an immobilization unit i.e. electromagnet (17), immobilizes the controlled rotation of the driving nut in the engagement position. The immobilization unit is coupled with the driving nut by a gear reducer (18). |