Thermo-Mechanical Modelling of Bearing Chambers of a High-Speed Starter/Generator

This paper describes the thermal-mechanical characterisation methodology for the bearing chambers of a high-speed (32,000 rpm) electrical starter/generator [1]; presenting a low cost analysis approach and design guideline for future machines. The methodology includes the estimation of the friction losses, overall thermal properties, bearing contact resistances and heat transfer coefficients. An analysis of the heat paths within the chambers, as well as within the whole rotor was carried out, allowing to quantify the heat extracted by the lubricant. The model was developed as part of the thermal-mechanical design of a specific starter/generator but the modelling approach presented within this paper is applicable to any high speed application.