Regulation of thermo-fluid-solid coupling characteristics in high-speed spindle-bearing system for boring machine tool based on sintered-core heat pipes

The precision of boring machine tool is significantly compromised by the thermal deviation inherent in the high-speed spindle-bearing assembly. Conventionally, the internal heat of this system is mitigated by using heat pipes. However, the heat dissipation capacity of these pipes does not suffice in reducing the thermal deviation to acceptable levels. The sintered-core heat pipe shows promise. In this research, a sintered-core heat pipe tailored to minimize thermal inaccuracies under rotational condition is pioneered. A gas-liquid phase transition model is devised for the sintered-core heat pipe under rotating working condition, providing a validation of heat dissipation efficacy and elucidating the phase change phenomena within the evaporation segment. Furthermore, the intricate relationship between convective coefficient and the design and operational parameters is determined through the response surface analysis and the variables with the most pronounced impact on the thermal performance of the sintered-core heat pipe are ascertained. Integrating the sintered-core rotating heat pipe into the shaft core of the spindle-bearing system has demonstrated remarkable proficiency in reduction of thermal distortion. Crucially, the thermal deformation of the shaft core with designed sintered-core heat pipe is reduced by over 95% compared to that of a core with an axial rotating heat pipe.