| 摘要 |
PROBLEM TO BE SOLVED: To enhance a cooling effect of a motor of a hub unit of an assist bicycle. SOLUTION: This hub unit has a motor 9 provided with a stator 3 and a rotor 4, and a hub 7 storing the motor 9 therein and rotated and driven by rotation of the rotor 4. The hub unit is provided with a pump 8 to discharge air in the hub 7 according to rotation of the hub 7. Intake of outside air is performed from a ventilation hole 59 formed in the hub 7 by discharge of air in the hub 7 accompanying an operation of the pump 8, the outside air is supplied to the motor 9 to cool the motor 9, and overheat of the motor 9 is surely prevented. A tube is connected to the ventilation hole 59, and an end portion of the tube is extended to a place where water does not enter. COPYRIGHT: (C)2009,JPO&INPIT |
