热阻网络法在轴系温度场求解中的应用

Thermal Resistance Network for Solving Temperature Field in Spindle System

为了获得主轴系统的温度场,建立了主轴、轴承、套筒、轴承座、端盖的传导和对流换热热阻模型.通过热节点的热量平衡分析,建立了热节点的热量平衡方程组.采用Newton-Raphson法对热平衡方程组进行求解,获得了轴系温度场,对轴承预紧力和主轴转速、轴承初始接触角以及润滑剂黏度对轴系温度场节点温度的影响进行了数值分析和试验.结果表明,在不同的工况下,主轴系统温度场的分布是不同的,轴承的预紧力和主轴的转速越大,轴承的温度就越高,而轴承的初始接触角越大,轴承的温度则越低,并且润滑剂对轴承温度的影响在主轴高速运转时表现得更加明显.因此,通过对轴承预紧力的调节和轴承初始游隙的设定,不仅能够控制轴承工作时的温度场分布,而且可有效地避免滚动轴承的内、外圈因温度过高而导致的失效,从而提高滚动轴承的服役性能.

To reveal the temperature field in spindle system,the conduction and convection thermal resistance model including spindle,bearings,sleeve,bearing cap was constructed.The heat balance equations for hot nodes were analyzed and solved to gain the temperature field in spindle system with Newton-Raphson method.The influences of the bearing preload,spindle rotational speed and lubricant viscosity,on the key node temperature were also discussed.The results of numerical simulation and experiments demonstrate that under some conditions,the spindle system temperature distributes quite differently.The higher the bearing preload and the spindle speed,the higher temperature gets in the bearing;the greater the initial bearing contact angle,the lower the temperature.The influence of lubricant for the temperature distribution in bearings at high speed is more evident.Setting the initial bearing clearance and adjusting bearing preload facilitate controlling the spindle system temperature field.It can effectively avoid the failure of inside and outside rings caused by the high temperature,so the service performance of the rolling bearing can be improved.