Characteristics and practical diagnostic technique of double-angle contact ball bearing

In the long-term production status monitoring, we found that the double-column angle contact ball bearing showed strong regularity during its use, and had very good repeatability. When the normal high-quality bearings are used, the vibration and noise are relatively small, but the spectrum is scattered and the amplitude is small, which may be due to some defects in the manufacturing process, such as surface burrs, etc.

After a period of time, the vibration and noise maintain a certain level, the spectrum is very single, only one or two times the frequency. Few appear three times above the power frequency spectrum, the bearing state is very stable, into the stable working period.

After continuing to run, entering the later stage of use, the bearing vibration and noise begin to increase, and sometimes there are abnormal noises, but the change of the vibration increase is slow. At this time, the cliff value of the bearing starts to suddenly reach a certain value. We believe that the bearing is an initial fault.

At this time, it is required to closely monitor the bearing and pay close attention to its changes. Since then, the bearing cliff value began to drop rapidly, and close to the normal value, and vibration and noise began to increase significantly, the increase began to accelerate, when the vibration over vibration standard (such as ISO2372 standard), the bearing cliff value also began to increase rapidly, when both over the vibration standard, and cliff value over normal value (available cliff relative standard), we believe that the bearing has entered the late fault production, need timely maintenance equipment, replace the double angle contact ball bearing.

Bearing shows late failure characteristics to serious failure (generally bearing damage such as shaft, burn, sand rack fracture, rolling way, bead wear, etc.) time is not more than a week, the greater the capacity of the equipment is, the faster the speed, the shorter the interval time. Therefore, in the actual fault diagnosis of the double-column angle contact ball bearing, once the late fault characteristics are found, we should decisively judge the bearing fault, and arrange maintenance as soon as possible.