| 摘要 |
<p>A control system (10) for supplying an operational chamber (38) in an air motor with pressurized fluid causing rotors (18 and 20) therein to move and develop an output torque in response to an input signal. Electrically operated valves (52 and 54) selectively controlling the flow of fluid from first and second bellows means (48 and 50) which are normally seated to seal distribution conduit (34 and 36) connecting the operational chamber (38) to the atmosphere. A select high disc valve (104) in the fluid pressure supply passage provides operating fluid to the distribution conduit (34 or 36) opposite the one which is vented to the atmosphere. In a two position air motor powered actuator, the electrical signals for the valves (52 and 54) may be derived as a simple function of actual rotor rotation and rotor rotational speed. As the total number of rotations approaches a set number, the scheduled rotational speed approaches zero, and the signal to the valves (52 and 54 ) terminates and allows the bellows means (48 and 50) to reseal the distribution conduit (34 or 36) as needed to stop rotor motion or slow it enough to assure stop engagement without excessive impact force. For other actuator applications, the signals to valves (52 and 54) may be provided by control means as used for a doser actuator piston controller (Reference U.S. Pat. No. 4,386,553).</p> |
