海水润滑UHMWPE轴承不同加减速形式润滑分析  

Lubrication Analysis of Seawater Lubricated UHMWPE Bearings with Different Acceleration and Deceleration Modes

作　　者：谢奕浓 王优强 宋晓萍 赵晶晶 XIE Yinong;WANG Youqiang;SONG Xiaoping;ZHAO Jingjing(School of Mechanical and Automotive Engineering,Qingdao University of Technology,Qingdao Shandong 266520,China)

机构地区：[1]青岛理工大学机械与汽车工程学院

出　　处：《润滑与密封》2019年第9期77-82,共6页Lubrication Engineering

基　　金：国家自然科学基金项目(51575289;51705270);山东省自然科学基金培养基金项目(2016ZRB01AJX)

摘　　要：为探究不同加减速形式对UHMWPE轴承加减速过程的弹流润滑机制的影响,建立海水润滑UHMWPE轴承的弹流润滑模型,基于考虑时变效应的Reynolds方程,数值模拟不同加减速工况下UHMWPE轴承的润滑情况。结果表明:加速阶段,采用余弦加速度形式最有利于润滑,膜厚在加速初期受挤压效应的影响而减小最少,使得膜厚不至于过小甚至破裂,在同一时刻内,压力最小、膜厚最大、摩擦因数最小,进入稳态时过渡最为平滑,对轴和轴承的冲击最小;减速阶段,采用正弦加速度形式进行制动最有利于润滑,在同一时刻内,压力和摩擦因数均为最小值,而膜厚则为最大值,为轴承的制动阶段提供更优的缓冲。由于速度变化过程极短,因此不可忽略时变带来的挤压效应,通过对比启停阶段不同时刻的膜厚发现,挤压效应使得压力和膜厚以及摩擦因数在变速结束后仍有相当时长的变化衰减过程;相比于启动阶段,制动阶段的时变效应体现得更为明显。加速度越大,动态效应越明显,压力在加速过程出现第二次起伏以及制动过程出现第一次起伏的时间越早。To explore the effects of different acceleration and deceleration forms on the elastohydrodynamic lubrication(EHL)mechanism of UHMWPE bearings during the acceleration and deceleration process,the EHL model of seawater-lubricated UHMWPE bearings was established.Based on the Reynolds equation considering time-dependent effect,the lubrication of UHMWPE bearings under different acceleration and deceleration conditions was numerically simulated.The results show that during the accelerating process,the cosine acceleration form is the most beneficial for lubrication in which the film thickness is least affected by the squeezing effect at the initial stage of acceleration,and the film thickness is not too thin or even broken.At the same time,the pressure is the smallest,the film thickness is the largest,the friction coefficient is the smallest,the transition is the smoothest when entering the steady state,and the shock on the shaft and the bearing is the smallest.During the decelerating process,braking in the form of sinusoidal acceleration is most beneficial for lubrication.Since the speed change process is extremely short,the squeezing effect caused by the time-dependent cannot be ignored.By comparing the film thickness at different times during the start-stop phase,the squeeze effect makes the pressure,film thickness and friction coefficient change and decay for a long time after the end of the speed change.The time-dependent of the braking phase is more obvious than the start-up phase.The greater the acceleration,the more obvious the dynamic effect,the sooner the second fluctuation of pressure occurs in the start-up process and the first fluctuation occurs in the braking process.

关 键 词：UHMWPE轴承 海水润滑 时变效应 弹流润滑 

分 类 号：TH117.2[机械工程—机械设计及理论]