Effect of Planetary Gear Set Designs on Thrust Bearing Power Loss in Automatic Transmission

Powertrain development to fundamentally improve performance is an essential task, and the development of automatic transmissions that convert power based on driving situations and then transmit it to the vehicle is continuously promoted. This study investigates the effect of planetary gear set design on thrust bearing power losses in automatic transmissions. To analyze axial loads, which contribute significantly to the power-loss model of thrust bearings, a sample automatic transmission model was selected and modeling was performed. One planetary gear set in the transmission was selected and design specifications were created based on pressure-angle and helix-angle variations. These design specifications were applied to automatic transmission modeling and the axial load was analyzed. Based on the load-analysis results, the power loss in the thrust bearing was analyzed.