| 摘要 |
1,034,233. Gas turbine engines; starting engines. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Feb. 8,1965 [March 3,1964], No. 8953/64. Headings FIG and F1K. The invention relates to means for driving the fuel pump of a gas turbine engine particularly during starting of the engine. The engine shown comprises compressor 1, combustion equipment 3 and turbine 7 which drives the compressor through shaft 15 which also drives the load. The engine comprises also a starter motor 23 shown as an electric motor, and a fuel pump 11 shown as a centrifugal type pump which supplies fuel to the combustion equipment 3 through line 13. The fuel pump 11 is arranged to be driven by the starter motor 23 at starting, the drive of the pump being taken over by the turbine and compressor assembly when the engine has reached a predetermined speed. The starter motor 23 is connected to a shaft 43 through a first one-way drive 45, and the shaft 43 is connected through gearing 41, 37B, intermediate shaft 33 and gearing 35, 39 to the extension 21 of the turbine and compressor shaft, the gear 37B constituting one element of a second one-way drive 37 which allows drive from shaft 43 to shaft 33 but not vice versa. The shaft 43 is also connected through the gearing 41, 37B to the gear 29 which is secured to the drive shaft 27 of the fuel pump 11. Thus at starting, the turbine and compressor assembly is rotated, also the fuel pump. The gear 35 secured to the intermediate shaft 33 is also in engagement with a gear 31B which constitutes one element of a third one-way drive 31, the second element 31 A of which is connected to the drive shaft 27 of the fuel pump 11. The gear ratios are such that the drive to the fuel pump 11 from the turbine and compressor assembly through the gearing 39, 35, 31B and one-way drive 31 occurs only when the speed of that assembly attains a certain pre-determined value. The motor 23 may also be used to accelerate the engine rapidly from idling speed, the motor then being used to drive the fuel pump, and possibly also the turbine and compressor assembly, the increased speed of the fuel pump and thus the increased flow of fuel to the combustion chamber serving to boost the rate of acceleration.
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