Non-Linear Wear Propagation Property and Prediction Method Having Influencing Pitting Failure of Helical Gears

A simulation method taking into account sequential changes of the tooth contact state due to the tooth surface wear was developed in order to evaluate the influence of wear on pitting durability. As a result of calculating the tooth end relief shape as a parameter, the variation in the wear propagation rate was obtained depending on the contact stress distribution. The study also obtained the nonlinear wear propagation property, in which the initial wear propagation was rapid and then changed gradually. In order to verify the wear characteristics, gear durability tests were conducted using gears with tooth tip modification and end relief, and sequential changes in the tooth surface wear state were observed. The test results revealed that the non-linear wear propagation property was obtained as in the calculation results. Wear propagation in the tooth lead direction and pitting life were able to be predicted. Using this calculation method and the experimental evaluation, it was made clear that the temporal alteration of contact stress and the non-linear propagation changed the pitting initiation timing and position, and may also have an effect on the pitting durability.