Abstract: To improve the dynamic behaviors of high speed motorized spindles under work conditions, a dynamic thermo-electro-mechanical coupled model for motorized spindles is constructed. The integrated model consists of a thermo-mechanical bearing model, a thermal model and a dynamic shaft model with unbalanced electromagnetic force. These sub-models interact on each other based on the bearing configuration. The main design parameters (DVs) of the system are identified and a design flow chart is developed. The related tests are carried out to validate the integrated model and design flow chart, and a design sensitivity analysis of the DVs is presented. The good agreement between the theoretical results and the experimental data indicates that the proposed model is capable of accurately predicting the thermo-electro-mechanical properties of motorized spindles and the coupled relationship among them. Meanwhile, the sensitivities of the DVs to the first two natural frequencies of the system with different configurations are obtained.

Key words: high speed motorized spindle;dynamic optimization;bearing configuration;natural frequency