| 摘要 |
<p>An actuator comprising an electric motor capable of developing a torque greater than 10 Nm is axially mounted directly on the actuating shaft of a valve or damper without any gear box therebetween. Motor is preferably a constant torque, permanent magnet, direct current DC motor operated by pulse width modulation to provide variable output speed over given speed range. Control and monitoring by set parameters is by (optionally remote) keypad and microprocessor. Motor drive shaft may be decoupled from the motor by a hand operated lever (46, 47) actuating coupling (38, 40, 41) and may be manually operated by hand wheel (20). Schematic figs (6 and 7) show microprocessor control and safety monitoring using rotor speed, temperature sensor, valve actuator shaft position and torque sensors.</p> |
