基于热阻网络法的一种新型双驱动进给系统热动态特性研究

摘要

设计了一种新型的微量进给机构,以"螺母旋转式滚珠丝杠副"为主要传动部件,丝杠和螺母分别由两个电机驱动并同向旋转,其运动合成微量进给,研究在不同电机速度组合下该新型微量进给机构的温度场及丝杠热伸长变化情况.基于传热学理论以双驱动进给系统为研究对象,利用热网络法建立该系统的热平衡方程组,获得温度场分布模型,结合机械热变形理论,用所建立的温度场模型预测双驱动滚珠丝杠的轴向热误差.得到双驱动微量进给机构随螺母、丝杠速度变化的温度场及丝杠热伸长模型,并通过实验验证了所建立模型的准确性.%In this paper,a new kind of micro-feeding mechanism is designed. With"nut-rotating ball screw pair"as the main transmission part,the screw-nut and the nut are driven by two motors respectively and ro-tate in the same direction,and its motion synthesizes micro-feed,study on the temperature field and screw′s heat elongation of the new micro feed mechanism under different motor speed. In this paper, the double-driven feed system is the object of study. Through the heat balance analysis,the heat balance equation group of the feed system is established by the thermal network method, and obtain the feed system temperature field distribution model. Based on the mechanical thermal deformation theory,the axial thermal error of the double-driven ball screw is predicted by the established temperature field model. The temperature field and the heat elongation model of the dual driven micro feed mechanism with nut and screw speed were obtained, and the accuracy of the model was verified by experiments.