Starter-generator with automatically reverting freewheel

Starter generator comprises a pulley, a shaft arranged within the pulley, and a free-wheel having a clamping body loaded with a spring arrangement. The free-wheel is formed as a double free-wheel and has clamping bodies (49, 51) with a spring unit (53) between them. The clamping bodies interact with clamping gaps. A hub (19) surrounds the shaft and the clamping bodies are arranged between the hub and the pulley. A spring coupling with springs (37, 39) is provided between the hub and the shaft. An independent claim is also included for a pulley for a starter generator. Preferred Features: The springs of the spring coupling have different strengths. The first spring (37) provides a relative movement between the hub and the shaft and the second spring (39) provides a relative movement between the hub and the shaft in the opposing direction.