The wear and thermal mechanical contact behaviour of machine cut polymer gears

The present paper will concentrate on an extensive investigation of machine cut acetal gear wear and thermal mechanical contact behaviour. The results for machine cut acetal gears will be compared to previously published results obtained for polymer gears manufactured through injection moulding. The machine cutting manufacturing process can be economical for small batch runs due to the expense of the mould for injection moulding. Injection moulding becomes economical for larger batches. A new and unique polymer gear test rig has been employed to investigate the polymer gear wear behaviour. The unique test rig design allows the effect of misalignment on polymer gear engagement to be considered and the gear surface wear to be recorded continuously. Extensive experimental tests have been carried out to investigate machine cut acetal gear wear performance. Further examinations have been carried out using a scanning electron microscope to understand the gear wear mechanisms. An equation has been presented to predict polymer gear flank temperature and correlated well with the tests.