Analysis of bulk temperature field and flash temperature for locomotive traction gear

• The maximum temperature of the gear tooth surface appears near the addendum.
• Steady temperature of the meshing point whose friction heat flux is minimum is lowest.
• Theoretical value of the transient temperature is calculated by Blok criterion.
• Simulation result of the transient temperature rise is lower than the theoretical value.
• Transient temperature rise obtained by the finite element method is more accurate.

Sliding velocity variation for gear meshing surface was researched based on theories of gear tribology, heat transfer and Hertz contact, and a model of contact stress considering friction force was derived. The model design process culminated in a comparison of theoretical values and simulated values. Heat flux of friction for different meshing positions and the convective heat transfer coefficient at gear tooth surface and tooth face were initially calculated accurately. The finite element method was then adopted to establish the gear bulk temperature field model and, after the steady state temperature field of the locomotive traction gear was obtained, the distribution law of the steady-state temperature for the gear teeth was analyzed. Transient thermal analysis on the gear was implemented utilizing the steady-state thermal analysis to obtain the transient temperature field of the locomotive traction gear. Applying the Blok flash temperature criterion, theoretical value of the transient temperature rise for the gear tooth surface was calculated. Comparison of the simulation values and the theoretical values for the transient temperature rise indicated that the theoretical values were higher than the simulation values as the Blok flash temperature criterion considers the heat conduction only in the direction vertical to the tooth surface and disregards heat conduction in other directions. The simulation results were then concluded to be superior in practicality and accuracy.