文档介绍：1 EXTENDING BEARING LIFE Abstract : Nature works hard to destroy bearings, but their chances of survival can be improved by following a few simple guidelines. Extreme neglect ina bearing leads to overheating and possibly seizure or, at worst, an explosion. But even a failed bearing leaves clues as to what went wrong. After a little detective work, action can be taken to avoid a repeat performance. Keywords: bearings failures life Bearings fail for a number of reasons ,but the mon are misapplication , contamination , improper lubricant , shipping or handling damage , and misalignment. The problem is often not difficult to diagnose because a failed bearing usually leaves telltale signs about what went wrong . However , while a postmortem yields good information , it is better to avoid the process altogether by specifying the bearing correctly in The first place . Todo this , it is useful to review the manufacturers sizing guidelines and operating characteristics for the selected bearing. Equally critical isa study of requirements for noise, torque, and runout, as well as possible exposure to contaminants, hostile liquids, and temperature extremes. This can provide further clues as to whether a bearing is right for a job. 1 Why bearings fail About 40% of ball bearing failures are caused by contamination from dust, dirt, shavings, and corrosion. Contamination also causes torque and noise problems, and is often the result of improper handling or the application environment . Fortunately, a bearing failure caused by environment or handling contamination is preventable , and a simple visual examination can easily identify the cause . Conducting a postmortem il1ustrates what to look for ona failed or failing bearing . Then , understanding the mechanism behind the failure, such as brinelling or fatigue, helps eliminate the source of the problem. Brinelling isone type of bearing failure easily avoided by proper handing and assembly. It is characterized by indentations in the