| 摘要 |
1298907 Gas turbine engine fuel systems UNITED AIRCRAFT CORP 19 April 1971 [20 March 1970] 22598/71 Heading F1G [Also in Division G3] An isochronous governing system for a turbine as described in Specification 1297601 includes a valve 116 which is actuated by the difference between the scheduled and actual operating conditions of the turbine so that the governing signal is interrupted should the acceleration of the turbine be over the prescribed limit. The position of the fuel metering valve, which is indicative of the square root of the fuel flow, is fed to an arm 190 where a dividing mechanism actuated in accordance with compressor discharge pressure creates a signal which is proportional to the square root of the fuel flow divided by the square root of the compressor discharge pressure. This is compared with a signal of the scheduled condition, which is a function of compressor inlet temperature and compressor speed, from a three dimensional cam 164 by a linkage 160. During steady state condition flow through the valve 116 is undisturbed. The chamber 72 of the fuel metering valve is therefore placed in communication with the governor signal via line 114, the high pressure port 222 or drain pressure port 214 of the valve 116 according to the output of the linkage 160. Alternatively the valve 116 may be placed in parallel with the governor signal Fig.4 (not shown) in which case a selector valve (330) is additionally provided to select the lower pressure signal from the governor and "acceleration" signals and the greater pressure signal from the governor and "deceleration" signals to actuate the fuel metering valve.
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