当计算轴承期望寿命时，  一个主要假定是轴承将得到良好润滑。这意味着，将正确的润滑剂按照正确的量在正确的时间送达轴承。所有轴承部要求充分润滑以保证可靠操作．润滑剂在滚动接触区和滑动接触区将滚动体、保持架和滚道三者分离。没有有效的润滑，滚动体和滚道以及其他接触面之间会出现金属间接触，导致损坏这些表面。
When calculating the life expectancy of bearings, one of the main assumptions is that the bearings will be well lubricated. This means that the correct lubricants are delivered to the bearings at the right time in the correct time. All bearing parts require adequate lubrication to ensure reliable operation. Lubricants separate the rolling body, cage and raceway between the three parts in the rolling contact area and the sliding contact area. Without effective lubrication, intermetallic contact occurs between the rolling body and the raceway and other contact surfaces, resulting in damage to these surfaces.
通常采用润滑剂失效”这个术语来表示轴承中没有润滑油或润滑脂。当出现这种情况时，轴承损坏分析通常并不那么简单。许多损坏情况是因为应用中使用的润滑剂粘度不足、粘度过大、润滑过度、润滑剂量不足、润滑剂受到污染或润滑剂错误造成的。因此，在进行任何润滑损坏分析时，都要彻底检查润滑剂特性、作用至轴承的润滑剂量和工作条件。
The term "lubricant failure" is usually used to indicate that there is no lubricating oil or grease in the bearing. When this is the case, the analysis of the bearing damage is usually not so simple. A lot of damage is due to the lack of lubricants, excessive viscosity, excessive lubrication, inadequate lubricant, lubricant contamination or lubricant errors. Therefore, when any analysis of the lubrication damage is carried out, the lubricant characteristics, the lubricant quantity and the working condition of the bearing must be thoroughly examined.
当润滑无效时，将导致表面疲劳形式的损坏．这种损坏可能发展迅速，常常难以与材料疲劳或剥落产生的失效区分开来．剥落出现，常会破坏无效润滑证据。然而，如果发现得很早，将可以看到指向真正损坏原因的标志。
When the lubrication is invalid, the surface fatigue will be damaged. This damage may develop rapidly, and is often difficult to distinguish from the failure caused by fatigue or peeling. The appearance of spalling often destroys the invalid lubrication evidence. However, if it is found very early, a sign that points to the cause of the real damage will be seen.
润滑不足导致的损坏阶段。第一个可见的故障指示通常是表面上很细的粗化条纹或波纹。之后，产生细裂纹，接着是剥落。
The damage stage (surface damage) caused by insufficient lubrication is shown below. The first visible fault indication is usually fine roughing or rippling on the surface. After that, a fine crack is produced and then peeled.