Effect of a Cooling Unit on High-speed Motorized Spindle Temperature With a Scaling Factor

Forced cooling, as an efficient way of heat dissipation, significantly affects the spindle temperature. Although a full cooling passage was factored into the finite element analyses by some scholars, often only the model for the front or rear half of a spindle is need for the purpose of the thermal evaluation simplification and data overhead reduction in engineering applications. So far, how the coolant passage affects the heat dissipation of the front or rear half of a spindle has not been well characterized. This paper devotes to constructing a scaling factor to represent the coolant unit effect on the thermal growth of spindles. The experiments about the effect of coolant units on spindle temperature were first implemented, and then the qualitative conclusions were got with various coolant parameter settings. To further quantify these influences, the regressive analysis was carried out. As a result, the peak temperature area was found and the scaling factors were proposed to describe the effect of the cooling system on the front or rear half of spindle temperature. In this process, the thermal equivalent convection for coolant passage was modeled based on the thermal resistance theory. In the meantime, we planned a novel thermal network of a motored spindle for contrast and validation, in which the cooling mechanism was integrated, and the structural constraints were considered by the aid of the proposed scaling factors. The result is indicative of a better agreement with real values when employing the proposed model.