摘要
滚珠丝杠相邻滚珠之间存在零卷吸速度接触,与常见的纯滚动或滚滑接触相比工况更恶劣,周期性载荷作用下相邻滚珠之间的接触则更为复杂。建立零卷吸工况下正弦波载荷作用的滚珠丝杠相邻滚珠间热弹流数值计算模型,采用多重网格法求解压力,多重网格积分法求解弹性变形,逐列扫描技术求解温度场,实现对线接触热弹流润滑的数值模拟。并以R100-25Y2型滚珠丝杠为研究对象,分析其油膜特性以及载荷幅值和表面波纹度对油膜特性的影响,结果表明:在加载过程中,由于挤压效应增强,“温度-黏度楔”效应增强,油膜凹陷深度及中心膜厚增大,最小膜厚减小,接触区最大温升增大,摩擦系数减小,卸载过程则相反;由于载荷变化的时变效应,油膜变化相比载荷变化存在一定的滞后性,而载荷波动幅值的增大进一步增强了该滞后性;表面波纹度的存在造成油膜压力和膜厚曲线的波动,特定的波纹度长度可导致中心膜厚和最大温升增大,而最小膜厚和摩擦系数减小。
There is zero-entrainment velocity contact between adjacent balls of ball screw,which is worse than common pure rolling or rolling-sliding contact,and the contact between adjacent balls under periodic load is more complicated.A numerical calculation model for thermal elastohydrodynamic lubrication between adjacent balls of ball screw under sine wave load is established under zero-entrainment condition,the pressure is solved by multigrid method,the elastic deformation is evaluated using multigrid integration method,the temperature field is calculated by column-by-column scanning technique,and the numerical simulation of thermal elastohydrodynamic lubrication for linear contact is realized.Taking R100-25Y2 ball screw as research object,the oil film characteristics and influence of load amplitude and surface waviness on oil film characteristics are analyzed.The results show that during loading process,due to enhanced squeezing effect,the"temperature-viscosity wedge"effect enhances,the oil film depression depth and central film thickness increase,the minimum film thickness decreases,the maximum temperature rise in contact area increases,the friction coefficient decreases,and there are opposite during unloading process.Due to time-varying effect brought by load variation,the oil film variation reflects a certain hysteresis compared with load variation,and the increase of load fluctuation amplitude further increases the hysteresis;the presence of surface waviness leads to fluctuations in curves of pressure and thickness of oil film,and a specific length of waviness can cause an increase in central film thickness and maximum temperature rise,while the minimum film thickness and friction coefficient decrease.
作者
杜恒瑞
王静
王新庆
DU Hengrui;WANG Jing;WANG Xinqing(College of Mechanical Engineering,Donghua University,Shanghai 201620,China)
出处
《轴承》
北大核心
2024年第5期63-70,共8页
Bearing
关键词
滚珠丝杠
线接触
润滑
油膜
压力
表面波纹度
摩擦系数
ball screw
line contact
lubrication
oil film
pressure
surface waviness
friction coefficient
