Electric actuators comprise a drive motor, reduction mechanism, transmission mechanism, and control part. The drive motor, including AC (simple, easy to maintain, for general use) and DC (good for speed control, for high - precision work), converts electricity to mechanical power. The reduction mechanism, such as gear (efficient, compact) or worm gear (large ratio, self - locking), slows motor speed and boosts torque. The transmission mechanism, like screw (for linear motion) or crank - link (for reciprocating valves), transfers torque to controlled objects. The control part's controller receives signals to precisely regulate the actuator.