A generator module for a vehicle includes a housing with a first conical surface, a rotor assembly with a second conical surface, aligned with the first conical surface, and a spring arranged to push the second conical surface into contact with the first conical surface. In an example embodiment, the first conical surface or the second conical surface includes a plastic surface or a friction paper surface. In an example embodiment, the rotor assembly is axially displaceable within the housing to compress the spring and move the second conical surface away from the first conical surface.