| 摘要 |
A fuel pump and delivery system for gas turbine engines is disclosed having a plurality of interrelated pumping circuits to meet the engine fuel requirements over the entire range of engine operation. The system has three distinct but interrelated circuits for (1) start up and low-speed operating requirements, (2) normal operating requirements above engine idle speed, and (3) high altitude cruise requirements. A positive displacement gear pump functions in the low speed and start up circuit to provide the necessary dry lift and high pressure, and after the start-up requirements have been met this part of the displacement gear pump is unloaded to terminate its pumping action, but the gear train is employed to drive selectively operative centrifugal pumps of different capacities suitable to meet the engine fuel requirements for either normal operations or for high altitude cruise.
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