首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 77 毫秒
1.
多点接触乏油弹流润滑模型及试验研究   总被引:1,自引:0,他引:1  
为探讨多点接触乏油弹流润滑机制,基于球与滚道接触区域的排油和补油平衡,建立适用于不同润滑状态的油膜厚度计算模型,可以计算从充分供油、乏油到干涸乏油的中心膜厚以及油膜不平衡时中心膜厚随滚动次数的衰减。利用自制的球-盘接触光干涉弹流试验装置,通过安装双镜筒同时获取相邻球的油膜图像,研究多点接触中相邻球的轨道重合和不重合时前球尾迹对后球油膜图像和中心膜厚的影响。结果表明:乏油润滑条件下,前后球的轨道不重合时轨道之间可相互补油;前后球的轨道重合时,在给定供油条件下,随着滚动线速度增加,入口弯液面逐渐靠近接触区域,中心油膜厚度增加,与相同工况下乏油润滑模型计算的膜厚对比吻合较好,验证了所建乏油润滑模型的正确性。  相似文献   

2.
An ultrasonic pulse striking a thin layer of liquid trapped between solid bodies will be partially reflected. The proportion reflected is a function of the layer stiffness, which in turn depends on the film thickness and its bulk modulus. In this work, measurements of reflection have been used to determine the thickness of oil films in elastohydrodynamic lubricated (EHL) contacts. A very thin liquid layer behaves like a spring when struck by an ultrasonic pulse. A simple quasi-static spring model can be used to determine the proportion of the ultrasonic waves reflected.

Experiments have been performed on a model EHL contact between a ball and a flat surface. A transducer is mounted above the contact such that the ultrasonic wave is focused onto the oil film. The reflected signals are captured and passed to a PC for processing. Fourier analysis gives the reflection spectrum that is then used to determine the stiffness of the liquid layer and hence its thickness. In further testing, an ultrasonic transducer has been mounted in the housing of a deep-groove ball bearing to measure the film generated at the outer raceway as each ball passes. Results from both the ball-flat and ball bearing measurements agree well with steady-state theoretical EHL predictions. The limits of the measuring technique, in terms of the measurable rolling bearing size and operating parameters, have been investigated.  相似文献   

3.
根据角接触球轴承自旋运动特征,同时考虑弹流润滑效应,建立角接触球轴承考虑自旋运动的弹流润滑模型;采用多重网格法求解弹性变形,利用有限差分法迭代求解雷诺方程,得到较为精确的数值解;分析不同赫兹接触压力、滚道表面粗糙度下自旋对角接触球轴承弹流润滑和油膜刚度的影响。结果表明:考虑自旋时随着Hertz接触压力、自旋角速度增大,油膜厚度减小,油膜压力增大,油膜承压区域呈细长状,并向接触中心靠近;随着滚道表面粗糙度幅值增大,油膜压力和膜厚均出现了波动,且考虑自旋运动时,轴承油膜厚度明显减小,油膜局部压力峰值更大;随着卷吸速度、润滑油黏度增大,油膜刚度减小,而考虑自旋运动时油膜刚度值更大;随着自旋角速度增大,油膜刚度逐渐增大。  相似文献   

4.
Under starved conditions the thickness and distribution of the lubricant film in an elastohydrodynamically lubricated (EHL) contact is directly related to the distribution of lubricant on the track in the inlet to the contact. In starved lubricated rolling bearings this lubricant distribution is determined by many effects. The authors have developed a model to predict the oil lost from the track induced by EHL pressure with no replenishment. A complete bearing is modeled with multiple rolling element EHL contacts and with the applied load to the rolling elements varying along the circumference of the bearing. Results of the oil layer thickness on the track are presented for a ball bearing and a spherical roller bearing for different bearing loads and rotational speeds. The predicted layer thickness decay rate for a ball bearing is significantly larger than for a spherical roller bearing and the predicted effect of the bearing load on the decay rate is small compared to the effect of the rotational speed. The predicted decay periods due to the contact pressure effect are small compared to the observed (grease) life of bearings. The results show that a bearing cannot sustain an adequate layer of oil on the running track unless significant replenishment takes place.  相似文献   

5.
利用阻容振荡原理,通过电路参数优化,研制出一台滚动轴承弹流油膜厚度测试仪。仪器的分辨率为3.5Hz/pF,测量范围为0 ̄2.2nF。仪器在全膜弹流润滑时可定量测量弹流膜厚;在部分膜时可根据振荡波形分析非金属时间接触率。利用仪器实测某惯性轮轴承的弹流油膜厚度,并考虑热和乏油的影响,对轴承的弹流油膜厚度进行理论计算,实测结果与理论计算结果基本一致。  相似文献   

6.
The oil film thickness was measured under conditions of minute vibrations using an elastohydrodynamic lubrication (EHL) ball-on-disk test rig. Poly-alpha-olefin (PAO) oil was used as the lubricant under conditions of pure sliding where only the ball specimen was minutely vibrated. It was found that an oil film formed when the amplitude ratio was greater than 1.6. Moreover, when conditions were changed to the maximum vibrating speed, oil viscosity, and maximum contact pressure, the critical amplitude ratio at which the oil film began to form remained at 1.6. Consequently, calculated results showed that the oil film was formed when the amplitude ratio was π/2 (nearly equal to 1.6), which closely agreed with our test results.  相似文献   

7.
Traction drive is a new kind of drive manner in which the power is transmitted by a thin oil film between transmission elements. This paper describes a ball traction drive device. The quasi-dynamics analysis was carried out for the transmission components of the ball traction drive device. The traction coefficients of oils Ub2 and HH-20 were calculated respectively with different rheological models. The elastohydrodynamic lubrication (EHL) film thickness and the traction coefficient between traction drive elements were measured. The results of the calculations are consistent with experiments.  相似文献   

8.
Elastohydrodynamic (EHL) film thicknesses of emulsions have been measured in a rolling point contact using an optical interference method. Both water in oil and oil in water emulsions have been studied.For water in oil emulsions the experimental data suggest that EHL film thickness is almost independent of water concentration and also particle size distribution, although the bulk viscosity of the emulsions is heavily dependent upon these two variables. It is concluded that the EHL properties of such emulsions are determined almost entirely by the EHL properties of the pure oil.For oil in water emulsions, negligible EHL film formation was observed.  相似文献   

9.
刘建平  耿美香  郭峰 《润滑与密封》2007,32(8):60-62,65
在极低速纯滑动的光弹流实验中,采用高粘度聚丁烯润滑剂形成的弹流油膜会在入口区出现凹陷,该反常的入口凹陷与极限剪切应力/界面滑移有关。针对盘纯滑和球纯滑2种不同的运动条件进行了油膜形状的测量,分析了零卷吸预跑合对油膜形状的影响。结果表明,一般地,纯玻璃盘滑动和纯钢球滑动产生的此类反常的油膜形状并不相同;当对弹流接触副采用零卷吸预跑合处理(即钢球和玻璃盘在接触区以大小相同方向相反的速度运动)之后,纯玻璃盘滑动形成的油膜形状有较大变化,油膜厚度增加,入口的楔形斜度下降,此时纯玻璃盘滑动和纯钢球滑动产生的油膜形状差别减小,甚至相同。  相似文献   

10.
王新庆 《润滑与密封》2023,48(12):17-22
假设在一个表面上存在单个粗糙峰或粗糙谷,采用数值分析方法研究大滑滚比下粗糙表面对线接触热弹流润滑接触的影响。研究发现:粗糙峰和粗糙谷造成油膜压力、膜厚和温升曲线的局部波动,其中压力的波动最为明显;在滑滚比较小时,粗糙峰和粗糙谷对压力、膜厚和温升曲线的影响较大, 随着滑滚比的增加,影响逐渐降低; 随着滑滚比的增加,粗糙峰幅值增加对压力、膜厚和温升曲线造成的波动也逐渐减弱。研究结果对于揭示滚珠丝杠或无保持架轴承等的润滑油膜形成和失效有重要意义。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号