Temperature Distribution in Teeth and Blanks of Ultra-High-Speed Gears

(2nd Report, Calculation of Temperature Distribution in Teeth and Blanks)

Abstract

Currently in industries, high-speed turbo machineries such as compressors and steam or gas turbines are required to have increased power capacities. Due to this, a large gear size is required which leads to nonuniform temperature distribution. As the result of nonuniform temperature distribution, nonuniform thermal distortion occurs. Change in load distribution due to this thermal distortion is considered to be closely related to scoring and pitting failures. In order to ensure reliability of high-speed gear units, it is necessary to improve the following techniques. (1) The method of predicting the temperature rise of gears and thermal distortion. (2) Tooth correction against thermal distortion. In this paper, a three-dimensional model for calculating the temperature of teeth surfaces and blanks is presented. This model includes the effects of convective cooling by lubricating oil and the change in load distribution due to mechanical deformation. The calculated results of gear teeth temperature and bending stress are in reasonable agreement with the experimental results. It is confirmed that the analytical method is practical and useful.