Modelling gear contact with twin-disc setup

Efficiency of polymer/steel gear-drive depends on friction phenomenon. Earlier research on polymer/steel gears identifies that region close to pitch-point has uncertain behaviour until a maximum of 30% slip due to the abrupt change from pure rolling to sliding. Calculation and testing methodology were developed for NaPA6/steel pairs. Influence of speed on friction-force was studied, where established boundaries are found at 170 rpm, above which the frictional-force depends on velocity and increases linearly. A high influence on rate sensitivity for polymer deformation at low velocity confirms the rapid increase in friction-force at low speeds. The threshold recommends for efficient performance as a function of speed for gear-drive during running-in before the formation of transfer layer.