A geared motor having a gear case and a motor housing. The gear case contains reduction gears and a viscous grease which lubricates the reduction gears and fills the a gear case. An integrally formed main oil seal having a main lip and a dust lip and a sub oil seal having a sub lip are disposed between a rotor shaft of the motor and the motor housing. The sub oil seal is disposed between the gear case and the main seal to prevent the viscous grease and metal powder in the viscous grease resulting from wear of the gear (101) from jeopardizing the main seal. In some embodiments, a second grease is retained in a space formed between the sub lip and the main lip. An outer wheel of a ball bearing supports the rotor shaft and is fixed to the bottom of the motor housing so that the rotor shaft cannot move in its axial direction and so that the rotor shaft will be firmly sealed by the main oil seal and the sub oil seal.