| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electric actuator having a structure capable of reducing an external force and impact acting on a screw shaft when a piston rod is at a stretched position, the electric actuator driving the piston rod by an electric motor via the screw shaft. <P>SOLUTION: The electric actuator 1 includes: a cylinder body 2 storing oil therein; a screw shaft 3 disposed within the cylinder body 2 and driven and rotated by an electric motor 23; a piston rod 4 linearly moving as the screw shaft 3 rotates; a first port 6 formed on an inner face of a rod-side cylinder chamber 5a of the cylinder body 2, toward which the piston rod 4 advances; a second port 7 formed on an inner face of a head-side cylinder chamber 5b of the cylinder body 2, toward which the piston rod 4 retracts; and a cylinder chamber connecting passage 9 connecting the first port 6 to the second port 7. In the electric actuator 1, a piston part 4a of the piston rod 4 closes the first port 6 when the piston rod 4 advances. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
