Epicyclical gear transmissions with dual gear ratio
Publication Date: 2015-Jul-30
The IP.com Prior Art Database
Mechanical couplings having a variable transmission ratio are disclosed. The couplings can be used for drivingly connecting a prime mover to a load, e.g. for con-necting a gas turbine engine with a load comprising a turbomachine, e.g. a compressor or a pump.
Mechanical couplings having a variable transmission ratio are disclosed. The couplings can be used for drivingly connecting a prime mover to a load, e.g. for connecting a gas turbine engine with a load comprising a turbomachine, e.g. a compressor or a pump.
In Fig. 1 a rotating machinery train is disclosed:
The train comprises a prime mover 1 with a gas turbine engine 5, a load 2 driven into rotation by the prime mover 1 and a mechanical coupling, i.e. a mechanical transmission 3 therebetween. The gas turbine engine 5 comprises a compressor 7 and a combustor arrangement schematically shown at 9. Fuel F is mixed with the compressed air and the air-fuel mixture is burnt to generate hot, compressed combustion gas. The gas turbine engine 5 further comprises a turbine section 11 in fluid communication with the combustor arrangement 9. The turbine section 11 comprises a first, high-pressure turbine 11A and a second, low-pressure turbine 11B. The high-pressure turbine 11A is mechanically connected to compressor 7, while the low-pressure turbine 11B is mechanically connected to an input shaft 13 of the mechanical coupling 3.
The load 2 usually comprises a rotating machinery, and in particular rotating turbomachinery, such as a compressor or a pump.
The mechanical coupling 3 comprises a joined planetary gear train 15, which transmits the rotary motion from input shaft 13 to an output shaft 17, mechanically connecting the joined planet gear train 15 to load 2.
The joined planetary gear train 15 comprises a first, input central gear 21, which can be mounted on input shaft 13 for co-rotation therewith. The rotation axis of input shaft 13 and first, input central gear 21 is designated A. The joined planetary gear train 15 further comprises one or more first planet gears 23. The rotation axes of the first planet gears 23 is labeled B and the shafts whereon the first planet gears 23 are torsionally constrained for co-rotation therewith are labeled 25. The first planet gears 23 mesh with the first, input central gear 21. The shafts 25 of the first planet gears 23 are rotatingly supported by a planet carrier 26. On one, some or each shaft 25 a respective second planet gear 27 is further mounted. The second planet gears 27 mesh with a second, output central gear 29. The second, output central gear 29 can be keyed on output shaft 17 for co-rotation therewith. On one, some or each shaft 25 a respective third planet gear 31 is mounted. The third planet gears 31 mesh with a third central gear 33. The third central gear 33 is mounted on a control shaft 35 for co-rotation therewith.
The planet gears 23, 27, 31 all rotate around their respective rotation axes B with the same angular speed. If the planet carrier 26 is free to rotate, the shafts 25 carrying the planet gears 23, 27, 31 can rotate around the central, rotation axis A of input shaft 13 and outputs shaft 17.
The mechanical coupling 3 further comprises...