EXPANSION AND CONTRACTION ACTUATOR

摘要

PROBLEM TO BE SOLVED: To surely inhibit an expansion and contraction actuator using a ball screw mechanism from being expanded and contracted by external force while using a small size motor. SOLUTION: A reduction gear 66 is composed of a worm gear comprising a worm 50 and a worm wheel 65 in conversion of rotation of a rotary shaft of the motor 39 to expansion and contraction motion of an output rod 34 via the reduction gear 66 and the ball screw mechanism 57. Rotation of the motor 39 can be inhibited by irreversible properties of the worm gear and unnecessary expansion and contraction motion of the output rod 34 can be prevented without supplying electricity to the motor 39 when load is reversely transmitted from the output rod 34 side to the motor 39 side while improving transmission efficiency of drive force from the motor 39 side to the output rod 34 side by the ball screw mechanism 57. Consequently, the motor 39 can be miniaturized. COPYRIGHT: (C)2010,JPO&INPIT