| 摘要 |
<p>An actuator for a pilot for a hydraulic control valve including a direct-current servo-motor (1) provided with a high-ratio gear (4) and arranged to be operated by a battery (2) with an associated battery charger (13), and an oil return port (10), a pilot port (11) and a hydraulic supply (12) and via the gear (4), the servo-motor (1) is arranged to move a valve stem (5) which bears via a first valve ball (7) on a spring-loaded pilot needle (8) which bears, opposite the first valve ball (7), on a second spring-loaded valve ball (7), a spring and a return spring (9) being arranged to move the valve balls (7) towards the pilot needle (8), and a microprocessor with an associated controller (3) being arranged to determine the position of the valve stem (5) by registration of the rotational position of the servo-motor; and, if a control signal is interrupted, the controller (3) is arranged to drive the valve stem (5) into a predetermined position by means of current from the battery (2).</p> |
