| 摘要 |
<P>PROBLEM TO BE SOLVED: To avoid an excessive torque acting on a valve or a gate by controlling a motor not to generate torque larger than necessary at the every opening section of the valve or the gate. <P>SOLUTION: The electric actuator 1 for opening/closing a vale 2 or a gate includes an AC motor 4, an inverter 8 for driving the AC motor 4, a control unit 11 for controlling the inverter 8, gear trains 5, 6 for reducing the rotation speed of the AC motor 4, and an opening detector 7 for detecting the opening of the valve 2 or the gate. The actuator controls the output torque at the very opening section of the valve 2 or the gate, to avoid an excessive torque acting on the valve or the gate. <P>COPYRIGHT: (C)2009,JPO&INPIT |
