The importance of FAG bearing surface damage failure analysis judgment

FAG bearing conditions required by the increasingly stringent market requirements of equipment and other properties, the performance also increasingly diversified. From a large number of structure, size, select the most appropriate bearings, need a different Angle. Bearing the choice, it is generally believed that as a bearing, the difficulty of installation and removal, bearing, size and bearing of the market, such as space allows, the general decided to bearing structure. In the use of a variety of mechanical design life and comparative study of limit bearing of durable bearing, bearing has to be decided at the same time. In choosing a FAG bearings, bearings are often inclined to think that grease life in aging, the fatigue life of oil, abrasion resistance, low noise, also need to fully research. In addition, according to different purposes, it is a necessary choice for precision, clearance, and keep the frame structure, meet the requirements of the lubricating grease, special design of the bearing. However, choosing bearing no certain order, rules, priority should be given to FAG bearing the required conditions, performance, and related matters, especially the practical. As long as as much as possible in order to keep intact the original performance of bearing, to maintain, maintenance, in the first place, to prevent accidents, ensure the reliability of operation, improve productivity and economy. Corresponding mechanical operation and maintenance standards, on a regular basis, the best conditions. Including monitoring running state, supplement or replace the lubricant, regular check cleared. As the problem of maintenance operation, have bearing rotation, vibration, temperature, lubrication condition, and so on. Repair bearing cleaning: remove the bearing, the appearance of the first record FAG bearing, confirm the amount of residual lubricant, sampling inspection after the use of lubricant, cleaning bearing. As a cleaning agent, general use gasoline, kerosene. Remove the bearing cleaning, washing and fine washing thick, be placed in a container, metal openings at the first, make direct contact with FAG bearing not dirt container. Rough washing, if the bearing rotating dirt, damage to the bearings rolling surface, it should be noted. In the crude oil washing, brush with the brush to remove grease, viscous material, generally clean, wash into the fine. Fine wash wash oil is in the side of the bearing rotation, while carefully cleaned. In addition, cleaning oil must be kept clean. Bearing maintenance and judgment: to determine whether remove bearing can be used to check the bearing after cleaning. Check the raceway, raceway, surface state, cage wear, FAG bearing clearance and to increase the dimension precision, has not damage, abnormal. Non separation of small ball bearings, inner ring, with one hand support level, rotate the outer ring to confirm smoothly. Separation of tapered roller bearings and bearing, rolling your body, the outer ring raceway surface inspection. Large bearings, because they can't rotate with the hand, pay attention to check the raceway of roller and cage, metope, such as appearance, the importance of higher FAG bearings, check more carefully. Through bearing failure and degradation, performance status parameters to judge and predict the performance, reliability, and use bearing on the part of the abnormal situation, cause and degree of risk identification and judgment, decided to repair and improve the method of comprehensive technology. Therefore, bearing fault diagnosis technology is not a simple fault detection ( Or monitoring) Responsible for counting instrumentation of technology, also is not simple. Accurately and quickly and effectively to collect signals, data processing, manual or automatic identification and judgment. In order to confirm the repair cycle science, but also according to the mechanism of all kinds of fault, to fatigue, wear life necessary test and estimate. Fatigue failure cause of fatigue failure is one of the most common failure forms of all kinds of bearing surface, is the metal under the action of alternating load of long-term failure arising from the main performance for fatigue crack initiation and propagation and fracture process. Cracks has two ways: produced from surface crack, namely under the effect of surface contact stress repeatedly, the crack was originally produced in away from the contact surface has a certain depth, and along with the direction of surface at an Angle, to a certain depth from surface, and the more out to the surface, and finally form pitting spalling, left on contact surface pockmark. Quality of smelting materials as mentioned above, pitting corrosion failure and fatigue failure to a great extent, and the merits of the smelting quality materials, surface defects, osteoporosis, and slag is the root cause of pitting corrosion, and fatigue failure of the main parts. Research indicates that non-metallic inclusion influence on bearing life with inclusion type, shape and number of different, inclusions in spherical deformation on the dangers of bearing life is the most serious. On the surface of the surface machining precision parts machining accuracy affect the distribution of contact stress. Surface machining accuracy, surface contact area of load concentration, the greater the contact stress, the more prone to fatigue failure of $surface roughness Ra value is smaller, the stress concentration is small, the high contact fatigue life. Related studies show that the surface roughness by Ra = 0. 4 mm to Ra = 0. 1 mm, the contact fatigue life can be 6 ~ 8 times. The choice of sensors and fixed way according to the structural characteristics of FAG bearings, vibration caused by different using conditions, it may be a frequency of about 1 KHZ under low frequency pulse ( Through the vibration) , also may be the frequency above 1 KHZ, few KHZ and even tens of KHZ high frequency vibration actuator ( Natural vibration) , usually contains both vibration components at the same time. Testing, therefore, FAG bearing vibration velocity and acceleration signal should be covering or covering the above two band, respectively, at the same time the frequency of the filter can be used when necessary to take out the need. Use high-pass filter cutoff frequency of 1 KHZ high-pass filter filter to below 1 KHZ low frequency component, in order to eliminate mechanical interference; Then use signal peak and RMS values or kurtosis coefficient as a parameter to monitor. Many simple bearing monitoring instrument in this way.