BLOG

Bearing noise of motor – Can replacing bearings solve the problem?

Bearing is the main components of DC brushless motor, DC brushed motor, AC brushless motor, AC brushed motor and cooling fan.

Bearing noise is the most common problem that confuses electrical engineers and users.

Bearing replacement, noise mitigation may be a problem of the bearing itself, but it may not be.While the noise of bearing replacement still exists, the greater probability indicates that the root cause of bearing noise is not necessarily the bearing itself.

How do you understand this?Let me give you a couple of examples.Of course, there are many factors, just to name a few.

First, if the problem is the bearing itself, then replace the bearing with no problem, the noise will be naturally alleviated.The premise is: the replacement of the bearing is no problem bearings.And the replacement method is correct.

Second, if the bearing installation process is wrong, each assembly will cause damage to the bearing, then no matter how to replace the bearing, the noise will always be difficult to eliminate.In addition to the process method, installation should also consider whether the process method is stable.For example, the bearings are also mounted by percussion (cold mounting of small bearings).If the impact damage the bearing, then the possibility of bearing noise greatly increased;When the next bearing is installed, the percussion is relatively light, and the bearing has almost no damage, so the noise of the bearing after assembly is naturally small.If this noise difference is attributed to the bearing itself, the root cause is obviously not found.Over time, such as looming bearing noise problem, can not be fundamentally eliminated.

Third, if there is a problem with bearing housing or shaft component shape and position tolerance, noise may or may not be improved after bearing replacement.First of all, if the bearing seat or shaft has a slight out-of-tolerance of shape and position, after the first bearing is installed, the bearing interior is squeezed and is out of tolerance of shape and position, which is likely to bring noise.At this time, if the bearing is replaced, the first bearing will be removed, then the first bearing to a certain extent to modify the shape and position of the parts of the tooling.If the slight out-of-tolerance is corrected, the replaced bearing will not be abnormal.Secondly, in the case of serious tolerance deviation, the workpiece cannot be adjusted back to the tolerance range even with the “correction” of the fore-sequence bearing.So no matter how you replace the bearing, the noise will still be there.

As can be seen from the above example, if there is a problem with the bearing itself, then the replacement of the bearing is effective.If the problem is not the bearing at all, then replacing the bearing may or may not work.The most perplexing part of this for electrical engineers is that the replacement of bearings is actually effective to some extent, albeit in a very low proportion.Therefore, this confusing phenomenon has led many engineers to believe that replacing bearings is the most direct method with a certain cure rate.