Abstract: An epicyclic gear system includes sun and ring gears (2, 4), planet pinions (6, 8) arrayed (a, b) between these gears, and a carrier (10) to which planet pinions are coupled through flexpins (30). The pinions are located between carrier walls (20, 22) with flexpins for the respective arrays cantilevered from opposite walls. The carrier is subjected to externally applied torque which transfers through the system. The load path (pa) for one array is shorter than that (pb) for the other array, which disparity causes carrier distortion with flexpins on one wall angularly displaced from flexpins on the other wall. The system compensates for this by one wall having areas (40, 44) of weakness where the flexpins cantilever from it. This enables the pinions of the two arrays to better mesh under a load and share torque transfer more evenly.

Abstract: An epicyclic gear system includes sun and ring gears (2, 4), planet pinions (6, 8) arrayed (a, b) between these gears, and a carrier (10) to which planet pinions are coupled through flexpins (30). The pinions are located between carrier walls (20, 22) with flexpins for the respective arrays cantilevered from opposite walls. The carrier is subjected to externally applied torque which transfers through the system. The load path (pa) for one array is shorter than that (pb) for the other array, which disparity causes carrier distortion with flexpins on one wall angularly displaced from flexpins on the other wall. The system compensates for this by one wall having areas (40, 44) of weakness where the flexpins cantilever from it. This enables the pinions of the two arrays to better mesh under a load and share torque transfer more evenly.

Abstract: An epicyclic gear system (A) includes sun and ring gears (2, 4) and planet pinions (6, 8) arranged in two side-by-side arrays (a, b) between the sun and ring gears, there also being a carrier (10, 50) to which planet pinions are coupled through flexpins (30). The carrier has primary and secondary walls (20, 22) between which the pinions are located and webs (24) connecting the walls. The flexpins for one array of pinions are cantilevered from the primary wall and the flexpins for the other array of pinions are cantilevered from the secondary wall. When the gear system operates, the carrier along its primary wall is subjected to an externally applied torque which transfers through the system at the planet pinions of the two arrays. The load path (pa) for the pinions at the primary wall is shorter than the load path (pb) for the pinions at the secondary wall, and this disparity causes the carrier to distort.