链条套筒与销轴铰链副冲击载荷-往复运动的弹流润滑数值模拟

数值模拟链传动中销轴与套筒之间的定载荷和变载荷弹流润滑接触问题,套筒相对于销轴做纯滑动往复运动。定载荷是假定往复运动过程中载荷恒定不变;变载荷是假定链节在啮入和啮出链轮过程中存在的冲击载荷按正弦函数规律变化。比较在定载荷和变载荷加载条件下线接触往复运动工况的弹性润滑油膜变化情况,分析在动载荷加载条件下不同行程长度对弹性流体动力润滑特性的影响。研究发现,动载荷对油膜的压力、膜厚影响较大:随着动载荷的增加,油膜中压力急剧增大,膜厚减小;但加载方式对摩擦因数的影响不大;在相同的加载方式下,随着行程长度的增加,油膜压力减小,中心膜厚和最小膜厚显著增加。

Numerical Simulation of Reciprocating EHL with Impulse Load for Chain Bush and Pin Hinge Pair

The elastohydrodynamic lubrication(EHL) contact with fixed and varying loads between the pin and the bush in the chain drive was analyzed by numerical simulation,and the bush does reciprocating motion relative to the pin. The load was assumed to be constant or time-varying over the motion during the process of meshing in and out of the chain wheel. The characteristics of EHL oil film in line contact in reciprocating motion with a constant load condition and time- varying load condition were compared. The influence of different stroke length on the characteristics of EHL under varying load was analyzed. The results show that the varying load has a great influence on the pressure and thickness distributions of the oil film. The oil film pressure is increased sharply and the film thickness is decreased with the increase of the varying load,but the effect of loading mode is trivial on the friction coefficient. Under the same loading mode,with the increase of stroke length,the oil film pressure is decreased,the center film thickness and the minimum film thickness are increased obviously.