Device for changing the transmission ratio between a turbine shaft and a shaft of a starter-generator of an aeroengine

摘要

A device for changing a transmission ratio between a turbine shaft and a shaft of a starter-generator of an aeroengine, the device including: first and second fixed gear wheels carried by the shaft of the starter-generator; first and second idler gearwheels carried by the turbine shaft, and meshing respectively with the first and second fixed gearwheels to define different gear ratios; a changeover sleeve interposed between the idler gearwheels and mechanically coupled to the turbine shaft, the changeover sleeve being movable in translation on the turbine shaft between two coupling positions; and a mechanism causing the changeover sleeve to move in translation automatically from either one of its coupling positions to the other one when the sum of torques between the turbine shaft and the starter-generator shaft changes sign.

主权项

1. A device for changing the transmission ratio between a turbine shaft and a shaft of a starter-generator of an aeroengine, the device comprising:
first and second fixed gear wheels carried by the shaft of the starter-generator; first and second idler gearwheels carried by the turbine shaft, and meshing respectively with the first and second fixed gearwheels to define different gear ratios; a changeover sleeve interposed between the idler gearwheels and mechanically coupled to the turbine shaft, the changeover sleeve being movable in translation on the turbine shaft between two coupling positions of: a position in which it meshes with the first idler gearwheel, and an opposite position in which it meshes with the second idler gearwheel; and means for causing the changeover sleeve to move in translation in automatic manner from either one of its coupling positions to the other one when the sum of torques between the turbine shaft and the starter-generator shaft changes sign.