Optimization of thread root undercut in the planetary roller screw

The paper presents the optimization problem of a thread root undercut in the roller of planetary roller screw using FEM. The depth and shape of the undercut as well as the radii of thread profiles curvature were optimized for the series of cooperating threads. The maximum HMH reduced stress in the undercut was accepted as an objective function. The limitation to the maximum contact pressure was assumed. The procedure aimed at limiting the range of variables was accepted in order to improve the efficiency of optimization method.