Patent ID: 7011599
Filing Date: 2006-03-14
Classification: F16H,Y10T

Abstract:
1. A speed reduction gear train, for transmission between a gas turbine and a compressor in a turbomachine, said reduction gear train comprising a sun gear coaxial with an axis of said reduction gear train and connected to said turbine, a planet carrier connected to a first element of said turbomachine coaxially with said sun gear and on which there are mounted a plurality of planet gears meshing with said sun gear, and an annular gear fixed to a second element of said turbomachine and with which said planet gears mesh, one of said first and second elements being a fixed structure of said turbomachine and the other of said elements driving said compressor in rotation, said planet carrier comprising firstly an annular cage having a plurality of pairs of seats for supporting bearings parallel to the axis of said reduction gear train and each bearing having one of said planet gears turning thereon, and a plurality of axial housings, each housing disposed between two adjacent planet gears, and secondly an annular cage carrier connected to said first element and having a plurality of axial arms, each arm being disposed in one of said housings and being fixed to an adjacent portion of said cage by a pin disposed substantially in the radial midplane of said cage, wherein the housings of the arms are disposed radially at the intersections between the lines of the forces to which adjacent planet gears are subjected, and wherein each pin for fixing an arm to the adjacent portion of the cage is rigidly secured to one of the parts constituted by said arm and said cage portion, and is mounted to the other one of said parts by a spherical finger type connection which is radially rigid relative to the axis of the reduction gear train and flexible in tilting and in axial displacement, the connection between the pin and the other part being provided by a sleeve surrounding the pin and disposed in an orifice of the other part, said sleeve comprising two axial end plates and a plurality of coaxial bushings disposed between said end plates, at least one of said bushings being made of an elastomer.