液压缸往复密封圈表面接触应力监测研究

在液压缸中，往复动密封圈表面接触应力是决定其密封有效性的关键，但由于在工作过程中对往复密封表面接触状态进行监测的难度很大，因此对其变化规律仍缺乏深入了解。针对这一问题，以液压缸活塞杆Y形密封圈为对象，通过有限元仿真分析密封圈内唇磨损对密封圈表面接触应力的影响，确定密封圈表面接触应力的最佳监测部位；采用光纤光栅传感器(FBG)进行密封槽表面接触应力监测试验，通过铺设于密封槽的FBG传感器采集应力数据，得出密封圈周向和轴向接触应力均随内唇磨损增加呈现先增大后减小的趋势，与仿真结果一致；接触应力对密封磨损程度变化的响应灵敏度会随密封压力的增加而增大。研究结果为液压缸实际运行过程中往复动密封状态的监测提供了依据。     

Synthetic fluids for automotive gear oil applications: A survey of potential performance

This paper describes studies of transmission lubricants in an axle efficiency test rig. The test lubricants were evaluated over various temperature ranges, for each of five road load speed conditions. This was done for both truck and passenger car. Three synthetic gear oils were evaluated, based on various combinations of synthetic hydrocarbons, esters, and viscosity improvers, and were compared to conventional SAE 80W-90 lubricants. All three oils demonstrated improvements in axle eficiency. Also reported are evaluations of seven test lubricants in a high-temperature, high-torque test, and results of seal compatibility tests.     

基于虚拟制备的大环径比O形金属橡胶密封件结构性能研究

金属橡胶密封件(MRS)作为一种新型轻质弹性金属结构，可以替代传统聚合物材料密封件在极端环境中使用。但由于MRS结构的复杂与制备工艺的繁琐，MRS结构特性与力学性能无法精确设计而影响了工程应用。针对这一不足，基于计算机仿真技术，对大环径比O形MRS的制备工艺流程进行数值模拟，采用虚拟制备构建可以真实反映MRS宏观力学性能及微观复杂结构的模型，并依据实际工况对MRS不同压缩工况下的模型进行静力学仿真分析，分析压缩率对于密封系统摩擦界面的接触特性及其结构响应的影响，结果表明其接触特性受到压缩工况及包覆层塑性失效的共同作用。以静力学仿真输出的细观接触应力为参量，结合间隙流动模型，对密封件泄漏率进行仿真和计算，分析其泄漏率的影响因素，结果表明在密封件不发生塑性失效的前提下，较大的压缩率可以减少泄漏。研究结果对新型宽温域密封件的参数设计、性能研究与推广应用有一定的指导意义。     

Assessment of the Lubricity of Grease-Sealing Rotary Shaft Seals Based on Grease Properties

Grease-lubricated sealing systems have an increased risk of starved lubrication. For this work, the lubricity of 23 greases in a rotary shaft sealing system was evaluated with a new test and evaluation method. The lubricity was then correlated with rheological and other grease properties. These grease properties are either available by the data sheet or can be measured with low effort. The results of the correlation allow a preselection of greases which are expected to lubricate rotary shaft seals well. This can support manufacturers and users in considering the lubrication of the sealing system early in the development process.     

An Empirical Study on the Wear of Reciprocating Hydraulic Rod Seals Using 15 Different Oils

Hydraulic oils differ in their chemical composition and viscosity substantially. Their influence on the wear of rod seals is neither fully understood nor can be predicted precisely. The primary objective of this study was to evaluate the influence of various oils and their wetting properties on the wear of rod seals. In an empirical study, the wear of 30 commercially available polyurethane U-cups was investigated with 15 different oils using a recently built test rig. The wear of rod seals increased with lower viscosity and higher polarity of the oil. Both oil properties are combined in a new parameter which helps to assess the lubricity of oil and the wear of rod seals.