Influence of Different Manufacturing Processes on Properties of Surface-Densified PM Gears

摘要

PM technology offers great opportunities for the reduction of the carbon footprint and improvement of the cost efficiency of gear production. PM gears can achieve flank load-carrying capacities comparable to wrought steel gears if the loaded volume is densified completely. Still, the tooth-root strength is of major concern. The tooth-root stresses can be minimized by optimizing the tooth-root geometry; this usually leads to a target conflict since fully optimized tooth-root geometries cannot be manufactured by generating processes such as hobbing, generating-grinding or rolling. To use the increase in tooth-root load-carrying capacity of a fully optimized root geometry on PM gears, a non-generating method for surface densifying is needed. The shot-peening process is used as an alternative densification process for PM gears. The properties of both shot-peened and cold rolled PM gears are analyzed and compared. To quantify the effect of both manufacturing processes, the tooth root bending fatigue strength will be evaluated and compared to wrought gears.