Discussion: “Modeling and Analysis of the Meshing Losses of Involute Spur Gears in High Speed and High Load Conditionsâ€‌ (Chang, L., Jeng, Y. R., and Huang, P. Y., 2013, J. Tribol., 135, p. 011504)

Abstract

In this paper, the authors present a simplified elastohydrodynamic lubrication (EHL) model applied to the prediction of traction forces and friction losses in spur gears. The theoretical approach is validated by comparison with the experimental evidence of PetryJohnson et al. [1]. One of the important conclusions of this paper is that tip relief has negligible influence on the tooth friction losses, contrary to what is suggested by other authors [24]. This result appears as somewhat surprising especially when it is realized that, contrary to what is claimed by the authors, the model validation (results in Figs. 3 and 4 in the authors' paper) relies on experiments conducted using gears with profile modifications (defined in Table 2 of Ref. [5]) and as confirmed by one of the authors of Ref. [1]. Their nominal values are: