| 摘要 |
1297607 Fluid-pressure servomotor systems UNITED AIRCRAFT CORP 19 April 1971 [20 March 1970] 22600/71 Heading G3P An isochronous governor for controlling fuel to a jet engine comprises a bell-crank 28, 30 receiving a speed error which is the difference between the predetermined speed and the scheduled speed, an integrating valve 36 whose output is the integral of the error, a proportional valve 50 whose output is proportional to the error, and an actuator 75 controlled by the outputs to regulate the fuel flow. The spool 34 of the integrating valve 36 is moved in response to movement of the bell-crank 28, 30 to either admit pressure regulated fluid P R to the output line 70 via a channel 98 or allow fluid in line 70 to communicate with a drain P D depending on the polarity of the error. The spool 34 is constantly rotated at a set speed, and fluid enters the line 70 by way of vanes 100. The piston 52 of the proportional valve is biased downwardly by pressure regulated fluid P R and upwardly by pressure regulated fluid P R acting over a smaller area. A flapper 46 controls fluid discharge from the chamber 60 fixed to the piston so that an error signal conveyed to the flapper via a lever 40 causes a corresponding movement in the piston 52 and a consequential displacement of fluid from beneath the piston into or out of the line 70. Adjustable stops limit the stroke of piston 52 so that full travel to the corrective position is prevented thus minimizing overshooting or undershooting. |
