| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a linear actuator having construction permitting expansion/ contraction with a slight force with reduced outer diameter size and axial size. <P>SOLUTION: When a ball nut 13a is rotated via a worm wheel 34 fixed to the outer periphery face thereof, an output shaft 51 is displaced in the axial direction. During the displacement of the output shaft 51 against a thrusting load, a roller clutch 27 is not locked and the ball nut 13a is rotated with slight force. During the rotation of the ball nut 13a in accordance with the thrusting load on the output shaft 51, the roller clutch 27 is locked. For rotating the ball nut 13a in such a state, it is necessary to overcome friction force between a friction plate 31 and a counter face. As a result, the linear actuator is not carelessly expanded/contracted or forced to be expanded/contracted. <P>COPYRIGHT: (C)2004,JPO |
