| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric actuator with a piston rod to be driven by an electric motor through a screw shaft, wherein its structure reduces an external force or impact acting on the screw shaft when the piston rod is at a stretched position. <P>SOLUTION: The electric actuator 1 includes a cylinder body 2, the screw shaft 3 placed in the cylinder body 2 and rotatably driven by an electric motor 23, a nut 5 screwed onto the screw shaft 3, the piston rod 4 that is caused to make linear motion through the nut 5 by the rotation of the screw shaft 3; recesses 6 formed on the outer circumferential surface of the nut 5, keys 7 each provided to a recess 6, holes 8 formed on the outer circumference of the piston portion 4a of the piston rod 4, into which the keys 7 are fit, and a tapered portion 9 formed on an inner wall of the cylinder body 2, into which the keys 7 are fit. When the piston rod 4 is caused to advance, the keys 7 are moved outward and fit into the tapered portion 9 and the backward movement of the piston rod 4 is arrested by the keys 7. <P>COPYRIGHT: (C)2010,JPO&INPIT |
