轴芯冷却电主轴热特性分析的 数值模拟与实验研究
Thermal Characteristics Analysis for a Motorized Spindle with Shaft Core Cooling Based on Numerical Simulation and Experimental Research

为了改善高速高精密机床电主轴“外冷内热”的现状,基于电主轴热薄弱点分析,提出了一种轴芯冷却结构及系统;进行了轴芯冷却电主轴热特性实验,并结合热特性有限元数值计算模型研究了转速、负载和冷却油流量对电主轴热特性的影响。实验结果表明:该轴芯冷却结构和系统可显著减小不同转速和负载下电主轴系统内部各部件的温升;与没有轴芯冷却的常规电主轴相比,在轴芯冷却油流量为2.5 L/min时,轴芯和轴承测点温升均减小了50％左右,轴芯轴向热变形减小了50.8％,系统热平衡时间减小了66.7％,从而提高了机床电主轴的加工精度和加工效率;轴芯冷却油流量从1.5 L/min增大到2.5 L/min时,系统热平衡时间减少。
To improve the existing situation of “cool exterior and hot interior” of a motorized spindle for high speed and precision machine tools, a shaft cooling structure and system for motorized spindle was designed based on thermal weak point analysis. A thermal characteristic experiment for a motorized spindle with shaft cooling was carried out, and the effects of rotating speed, load and oil flow rate on the thermal characteristics of the motorized spindle were investigated experimentally combined with the finite element numerical calculation model. The experimental results show that the cooling structure and system can effectively reduce the temperature rise of the motorized spindle internal components under different speed and load conditions. Compared with the conventional spindle without shaft core cooling, when the oil flow rate for shaft core cooling is 2.5 L/min, the temperature rise of the shaft core and the bearing decreases by about 50％, the axial thermal deformation of the shaft decreases by 50.8％, the thermal balance time is shortened by 66.7％. Therefore, this shaft cooling structure can improve the machining accuracy and efficiency of the motorized spindle. When the axial cooling oil flow rate increases from 1.5 L/min to 2.5 L/min, the thermal balance time is reduced