| 摘要 |
PROBLEM TO BE SOLVED: To provide a power tool for simultaneously and effectively air-cooling a motor, a planetary speed reduction part, and an impact part. SOLUTION: This power tool has the planetary speed reduction part 10 having a ring gear 3, a sun gear 5, a planet gear 4 and a gear case 2 for covering the outer peripheral side of the ring gear 3, the motor 6 for transmitting motive power to the planetary speed reduction part 10, the impact part 8 to which the motive power is transmitted from the planetary speed reduction part 10, and a housing 1 for incorporating these members. An outside air introducing fan 23 is arranged in the motor 3. An outside air introducing hole 22 is bored in an impact part peripheral part 32 of the housing 1. A ventilable void A is arranged between the ring gear 3 and the gear case 2. The gear case 2 is provided with a ventilating hole 21 for passing outside air introduced into the housing 1 from the outside air introducing hole 22, to the motor 6 side via the void A. The ring gear 3 is formed of a thermally good conductor. COPYRIGHT: (C)2005,JPO&NCIPI
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