DRIVING UNIT

摘要

PROBLEM TO BE SOLVED: To provide a small driving unit having a cooling apparatus capable of cooling under any circumstance. SOLUTION: This driving unit involves a liquid-cooled electric motor 1 and a planetary gear drive 3. One of the main three factors of the planetary gear drive, or a factor used as a reaction factor, drives the positive-displacement pump of a cooling circuit. It is preferable that this factor is a ring-type gear involving an internal gear part 23, and the ring-type gear itself forms the rotor of the pump. A circuit for liquid enters the hollow shaft 11 of the rotor for a motor and passes through a radiator 31 built in a common casing 5 including the motor and the gear. Such type of driving unit is applicable to driving of a machine or a vehicle.