Patent ID: 11970982
Assignee: RTX CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 0:
1. A gas turbine engine comprising:
a propulsor section including a propulsor;
a gear reduction;
a first spool including a first compressor, a first turbine and a first shaft, wherein the first shaft interconnects the first compressor and the first turbine, each of the first compressor and a second compressor includes a plurality of stages, and the first turbine drives the propulsor through the gear reduction;
a second spool including the second compressor, a second turbine and a second shaft, wherein the second shaft interconnects the second compressor and the second turbine;
wherein the gear reduction is an epicyclic gear system that includes a carrier and a plurality of gears, and the plurality of gears including a sun gear, a ring gear, and a plurality of intermediate gears that engage the sun gear and the ring gear;
wherein at least two of the plurality of gears are double helical gears in meshed engagement, each of the double helical gears disposed to rotate about respective axes, each of the double helical gears having a first plurality of gear teeth separated from a second plurality of gear teeth such that a first end of the first plurality of gear teeth and a first end of the second plurality of gear teeth are spaced apart by an axial distance;
wherein each of the first plurality of gear teeth is offset a first circumferential offset distance in relation to a next gear tooth of the second plurality of gear teeth when moving in a circumferential direction relative to the respective axes, each of the second plurality of gear teeth is offset a second circumferential offset distance in relation to a next gear tooth of the first plurality of gear teeth when moving in the circumferential direction, a third circumferential offset distance being a total of the first circumferential offset distance and the second circumferential offset distance, and a ratio of the first circumferential offset distance and the third circumferential offset distance is between 0.25 and 0.75; and
wherein each gear tooth of the first plurality of gear teeth and the second plurality of gear teeth is disposed at a respective helix angle relative to the respective axes, and the helix angle of the first plurality of gear teeth is different from the helix angle of the second plurality of gear teeth.