An experimental method to measure gear tooth stiffness throughout and beyond the path of contact

A method is presented that allows the accurate measurement of the tooth pai r stiffness of a pair of spur gears. The method reveals the stiffness behav iour throughout the full length of the normal path of contact and also into the extended contact region when tooth corner contact occurs. The method m akes use of the properties of transmission error plots for mean and alterna ting components over a range of tooth loads (Harris maps). It avoids the us ual problem when measuring tooth deflections that deflections of other test rig components are difficult to eliminate. Also included are predicted Har ris maps for a pair of high contact ratio spur gears, showing the effects o f various simplifying assumptions, together with a measured map.