Effect of a cooling unit on high-speed motorized spindle temperature with a scaling factor

Abstract

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.

An efficient thermal model for high-speed angular contact ball bearings based on oil-air two-phase flow and gray-box model

“…In contrast with the thermal assessment based on the latest multi-node model with a structural factor (Zheng and Chen, 2022), the prediction accuracy is not decreased as a whole, but rather improved, though the nodes are significantly reduced. And this also verifies our proposed thermal models for angular contact ball bearings and high-speed spindles.…”

“…Clearly, the model in Figure 3 is with 49 nodes, among which there are only 10key nodes. When the latest multi-node mode is applied to model the same target (Zheng and Chen, 2022), however, the arranged total and key node numbers are 71 and 14, respectively. The nodes, in contrast, are reduced by more than 20.…”

“…Figure 3 presents a simple thermal network employing our proposed bearing model after some idealizations, where the structural constraint effect, coolant/lubricant influence and spindle motor heating impact are integrated more specifically and accurately, and the node planning details of bearings are as stated in Section 3. For the explanations on other arranged nodes and thermal resistance determination in Figure 3, please refer to our previous work (Zheng and Chen, 2022).…”

Effect of Coolant Temperature on the Thermal Compensation of a Machine Tool

“…D-xing et al [40] investigated the coolant passage that affects the heat dissipation of the front and rear halves of spindles by considering the scaling factor and accordingly created thermal modeling of the spindle. Results showed that the coolant operating at 2 • C lower than room temperature was the most effective for the accuracy of the spindles.…”