A Central Cooling Structure for Motorized Spindles: Principle and Application

A central cooling structure for a grinding motorized spindle (150SD) is proposed under the inspiration of principle of miniature revolving heat pipes (MRVHPs). Firstly, a single MRVHP is experimentally investigated at different heat loads (2.5~30 W) and rotational speeds (1000~3000 rpm). An empirical correlation between the Nusselt number of MRVHP and rotational Reynolds number is obtained on the basis of the experimental data. And then, a transient thermal simulation of motorized spindle is conducted on ANSYS Workbench, based on the experimental data of MRVHP and the thermal boundary conditions of the motorized spindle. The results show that the introduction of the central cooling structure can reduce highest temperature of 150SD by 35%.