Influence of indexing errors on dynamic response of spur gear pairs

In this study, a dynamic model of a spur gear pair is employed to investigate the influence of gear tooth indexing errors on the dynamic response. This transverse-torsional dynamic model includes periodically-time varying gear mesh stiffness and nonlinearities caused by tooth separations in resonance regions. With quasi-static transmission error time traces as the primary excitation, the model predicts frequency-domain dynamic mesh force and dynamic transmission error spectra. These long-period quasi-static transmission error time traces are measured using unity-ratio spur gear pairs having certain intentional indexing errors. A special test setup with dedicated instrumentation for the measurement of quasi-static transmission error is employed to perform a number of experiments with gears having deterministic spacing errors at one or two teeth of the test gear only and random spacing errors where all of the test gear teeth have a random distribution of errors as in a typical production gear.