• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>39th aerospace mechanisms symposium >Measuring the EHD Film Thickness in a Rotating Ball Bearing
【24h】

Measuring the EHD Film Thickness in a Rotating Ball Bearing

机译：在旋转球轴承中测量EHD膜厚度

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper presents two independent ways to directly measure the change in axial deflection of a bearing that is proportional to the magnitude of the total elastohydrodynamic (EHD) film developed. The first uses multiple capacitance displacement gages as a direct measurement of axial displacement and the second method uses the change in operating preload force to calculate the axial change in the test fixture and bearing stack. Convergence of the results from two independent techniques adds confidence to the experimental process. Either method can provide accurate EHD film thickness over extended time for a complete bearing under varying load, speed and lubrication conditions. Additionally, the methods are equally applicable to non-metallic materials, such as Si_3N_4 balls, which preclude the use of other techniques. The method has some advantages to the practicing engineer over the classical ball on a flat quartz plate because the full range of bearing design parameters and kinematic interactions are operating.rnThe EHD film thicknesses of two oils and one grease were measured in an operating 304 sized angular contact bearing for up to 600 hours of running time at 6000 rpm. EHD film thickness was determined by simultaneously measuring the resultant displacement and axial force change of the outer rings due to collapse of the EHD film when the bearing pair was brought from full speed to rest. Because each measurement of axial displacement was completed within 2 seconds, the results are not affected by a contribution due to thermal expansion. We compared a common synthetic hydrocarbon base oil (Pennzane) with a common mineral oil (Coray). We found the synthetic oil film thickness to be approximately one half that of the mineral oil. We also compared film thickness with both large and small amounts of grease. We found that the large grease amount produced a prolonged run-in transient film that was thicker than the base oil steady state film. However, with a smaller amount of grease, the thickness fell to a value that was comparable to the base oil. Initial assessment indicates that the degree of lubricant starvation is greater than can be accounted for with conventional EHD theory.
机译：本文提出了两种独立的方法来直接测量轴承轴向挠度的变化，该变化与所开发的总弹性流体力学（EHD）膜的大小成比例。第一种方法使用多个电容位移计直接测量轴向位移，第二种方法使用工作预紧力的变化来计算测试夹具和轴承组的轴向变化。来自两种独立技术的结果的融合为实验过程增添了信心。两种方法都可以在变化的载荷，速度和润滑条件下，在延长的时间内提供准确的EHD膜厚，从而形成完整的轴承。另外，这些方法同样适用于非金属材料，例如Si_3N_4球，从而排除了其他技术的使用。与常规的平面石英板上的球相比，该方法相对于传统球具有一些优势，因为该轴承的所有设计参数和运动学相互作用都在起作用。接触轴承，以6000 rpm的转速运行600小时。通过同时测量轴承对从全速运动到静止时由于EHD膜破裂而导致的外圈位移和轴向力变化来确定EHD膜厚度。因为每次轴向位移的测量都在2秒内完成，所以结果不受热膨胀影响的影响。我们将普通的合成烃基础油（Pennzane）与普通的矿物油（Coray）进行了比较。我们发现合成油膜的厚度约为矿物油的一半。我们还比较了膜厚与油脂量的情况。我们发现，大量的润滑脂会产生延长的磨合过渡膜，该过渡膜比基础油稳态膜要厚。但是，使用较少量的润滑脂，厚度下降到可与基础油相当的值。初步评估表明，润滑剂的饥饿程度要大于传统EHD理论所能解释的程度。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号