Thermal characteristics analysis of high-speed motorized spindle system with thermal-solid coupling

Abstract

The internal heat source of machine tool will directly induce deformation and failure in spindle during run-time, reducing accuracy of machining process. Physical factors like thermal resistance and temperature at key nodes can be computed more precisely by using the thermal network approach to solve the changes in the spindle, such as the variation of temperature or the deformation, which can be useful for the examination of spindle dynamic characteristics. To calculate the system dynamic characteristics, it is first need to establish a thermal network model of the motorized spindle system to calculate its heat generation and transfer. Subsequently, the heat balance equation is proposed according to motor air gap change and bearing thermal deformation, and to solve the system’s temperature and thermal deformation, so as to study the system thermal characteristics. Then, the dynamic equations of the spindle system were solved adopting numerical method to study the system’s dynamic behaviors. Through these studies, this paper proposes a thermal network model that can calculate system’s thermal characteristics more quickly and precisely. It can also depict changes in the temperature and deformation of the important nodes more clearly, providing useful guidance for studying the dynamic characteristics of systems under thermal influence.