Transient thermoelastohydrodynamic lubrication analysis of an involute spur gear

A meshing of a gear is a typical example where non-stationary condition exists. Load, velocity, curvature of meshing point vary along the line of action at any time. A complete numerical solution to the transient thermoelastohydrodynamic lubrication (EHL) problem of an involute spur gear is obtained by using simplified multigrid method. A Newtonian fluid model is assumed and the surface roughness of gear teeth is ignored. ar teeth are assumed to be rigid. The load is first assumed to be carried by either two pairs of gear teeth or by only one pair. This transition from two to one pair and vice versa is modelled as a trapezoidal variation of the load by simplifying the experimental load spectrum. sults show that thermal effects can strongly influence the approach and recess point film thickness. It also reveals that, the maximum pressure, the maximum friction coefficient and the highest film temperature all occur in the vicinity of pitch point. The minimum film thickness usually occurs at the approach point except reduction ratio equals to one. The effects of slip ratio, velocity and load on the film temperature and friction coefficient are discussed in the paper.