Since some friction does exist, esp

Since some friction does exist, especially between the rolling elements and their separator (轴承座) , the lubricant also must remove the heat caused by this sliding action. As a result, although there is minimal friction present, a lubricant is still absolutely essentialFatigue. which is the cause of failure (失数) of a properly lubricated antifriction bearing, is a stress-reversal phenomenon (应力反向现象) that takes place on the contacting surfaces of the raceways and rolling elements Hence the life of an antifriction bearing is measured by the number of shaf revolutions (轴承转数) that occur prior to fatigue failure. The greater the bearing load, the shorter will be the life of the bearing. Also. the greater the shaft speed, the shorter will be the bearing life. Since fatigue is a statistical occurrence, the percent probability of failure also must be considered.