The Effects of Stress Concentration Factor on Metallic Rack-Pinion Drive

A finite element analysis is carried out on the static loading of the rack-pinion drive. The complexity of this problem becomes evident especially at gear teeth and rack-pinion drive due to the significant effect of kinematics and geometric conditions and fabricating precision for finding the working and critical stress which are important for checking the gear teeth working capability. The geometry is modeled by plane stress elements with variable depth of 10, 11, 12 and 15 mm to find the optimal rack depth that gives minimum stress concentration factor. Tooth failure is predicted when the tensile strength is exceeded in the gear tooth root. The results show that the stress concentration factor “Kt” variesalong the flanks of the rack and displays its maximum value at the point of contact between the flank of the rack tooth and the root of the tooth. The rack-depth ratio also significantly influences the stress concentration factor “Kt”, where depth ratio of 2.2 shows the minimum stress concentration factor.