摘要 |
<p>A sealed valve body housing a rotary valve rotated by a spindle. The spindle is connected to a disc mounted in a chamber in the valve body adjacent a valve body wall. Polyphase drive coils on the valve body wall induce a current in the disc, causing it to rotate. A pulse sensor mounted on the valve body detects the rotative position of the disc and a counter signals the power source to stop movement of the valve. The periphery of the disc is notched to permit the pulses to pass through the rotating disc and be counted. The torque of the disc can be increased through use of more sets of coils, more discs or gears interconnecting the spindle and the rotary valve.</p> |