Hysteresis device to clutch a shaft and a pulley and motor bloc with such a device

摘要

The device has clutching units permitting driving or non-driving of a shaft (14) by a pulley along rotation speed of the pulley, where the pulley is located around the shaft. The clutching units include clutches (36, 37) permitting coupling of the shaft with respect to the pulley under the coupling effects. The clutching units include inertial masses (40) displaced with respect to a rotation axis (15) during rotation of the pulley. A generating unit generates hysteresis in coupling and/or uncoupling process of the clutches. A hub (38) is integrated to the shaft and a pusher plate (39). The inertial masses and the pusher plate are made of ferromagnetic material. An independent claim is also included for an engine block comprising a reversible alternator permitting starting of a heat engine.