Model-based design of motorized spindles with different bearing configurations

This paper conducts a dynamic design of motorized spindles with different configurations using an integrated dynamic electro-thermo-mechanical model. The dynamic electro-thermo-mechanical model consists of a thermo-mechanical bearing model, a shaft dynamic model and a thermal model. These sub-models interact on each other based on the bearing configuration, and general cases of bearing configurations can be modeled with the use of the pertinent mapping between shaft stiffness and bearing stiffness matrices. Based on the integrated model a design flow chart is developed and four design variables (DVs) are identified. The proposed model is validated experimentally and a design sensitivity analysis of the four DVs is then presented with a 170MD15Y20 type motorized spindle. The good agreement between the theoretical results and the experimental data indicates that the integrated model is capable of accurately predicting the multi-physics coupled dynamic behaviors of motorized spindles, and the sensitivities of the four DVs to the nature frequencies of the spindle system are obtained with different configurations.