Patent ID: 9145967
Filing Date: 2015-09-29
Classification: F16H

Abstract:
1. An epicyclic gear system comprising: a sun gear having an axis; a ring gear surrounding the sun gear and having an axis that coincides with the axis of the sun gear; first planet pinions meshing with the sun and ring gears in a first array; second planet pinions meshing with the sun and ring gears in a second array that is offset axially from the first array; a carrier having first flexpins coupled to the first planet pinions and second flexpins coupled to the second planet pinions, the carrier further having a coupling region at which torque is applied to the carrier when the gear system is subjected to a load, the torque transferring between the coupling region and the first flexpins through first load paths and between the coupling region and the second flexpins through second load paths that are longer than the first load paths, and with the difference in lengths of the load paths causing a distortion in the carrier; and, means for compensating for the distortion to effectively adjust the stiffness of the carrier and enable the first and second pinions to mesh more evenly with the sun and ring gears when torque is applied to the carrier, said means for compensating including one of: an angular offset of the first flexpins from the second flexpins in the absence of a torque being applied to the carrier; having teeth on the first planet pinions be narrower than teeth on the second planet pinions; forming areas of weakness in the carrier at the first flexpins; and, having the first flexpins be more flexible than the second flexpins, whereby any of the means for compensating results in the first flexpins and second flexpins undergoing substantially the same deflection when torque is applied to the carrier regardless of any carrier distortion caused by differences in the length of the load paths.