Vehicular rotational apparatus

A housing of a compressor (C) supports a rotary shaft (16). The rotary shaft (16) is coupled to a pulley (17) with a pulley one-way clutch (66) and is coupled to a rotor of an electric motor (77) with a motor one-way clutch (83). The pulley (17) is supported by the housing with a pulley bearing. The electric motor (77) overlaps a power transmission portion in the axial direction of the rotary shaft (16). At least two of the bearing, the pulley one-way clutch (66), the motor one-way clutch (83), and a brush device (78) of the electric motor (77) overlap each other in the axial direction of the rotary shaft. As a result, the size of the compressor (C) is reduced in the axial direction of the rotary shaft (16).