Patent ID: 8647229

Claim:
A method for designing a gear transmission (A), having a plurality of torque pathways between an input and an output, to achieve a selected load distribution among a set of drive planet pinions ( 22 ) and idler planet pinions ( 70 ), supported in a planet carrier ( 60 , 160 , 460 ) each disposed between a first reaction gear ( 30 ) and a second reaction gear ( 40 ), comprising: determining a load portioning ratio LR T for said first and second reaction gears; determining a force ratio for a pair of bearings ( 50 , 55 ) supporting each of said drive planet pinions, and a force ratio for a pair of bearings ( 80 , 90 ) supporting each of said idler planet pinions; determining a pitch diameter ratio for a cluster gear assembly ( 20 , 120 ) carrying said drive pinions; selecting initial positions (L 1 , L 2 ) for each pair of bearings supporting said drive planet pinions, and selecting initial positions (L 3 , L 4 ) for each pair of bearings supporting said idler planet pinions; calculating actual force ratios for each of said pairs of bearings at said selected initial positions; calculating actual gear load proportioning ratios for said drive planet pinions and said idler planet pinions; comparing said calculated actual support stiffness ratios and said calculated actual gear load ratios with associated predetermined ratio goals; and iteratively adjusting at least one bearing position for said bearings supporting said drive planet pinions or said bearings supporting said idler planet pinions with re-calculation of said support stiffness ratios for said pairs of bearings until said comparison step indicates that said actual support stiffness and said actual gear load proportioning ratio values are within an acceptable tolerance of said predetermined goals.