| 摘要 |
PROBLEM TO BE SOLVED: To provide a novel and useful excavator which has a simple and inexpensive mechanism and exhibits stable excavating performance thought the weight is low, and a drill bit unit used therefor. SOLUTION: A drill bit which is rotated in the direction reverse to the rotating direction of a motor is laminated using a planetary gear mechanism. By compensating for a rotating reaction force resulting from a dynamic friction which occurs in the drill bit due to the rotation of the motor, a tower serving as the base of the excavator is prevented from rotating to increase the stability of the excavator. COPYRIGHT: (C)2010,JPO&INPIT |
