Causes and detection methods of abnormal noise of crossed roller bearings

A crossed roller bearing is a special type of bearing in which the inner ring is divided and the outer ring rotates. Compared with conventional models, the rigidity of crossed roller bearings is increased by 3 to 4 times. At the same time, since the inner ring or outer ring of the crossed roller bearing is divided into two structures, the bearing clearance can be adjusted, and even if a preload is applied, high-precision rotational motion can be obtained.

In our daily life, the bearing will encounter the problem of abnormal bearing noise after three or two years of normal use. The following are several methods for detecting abnormal noise of bearings summarized by crossed roller bearing manufacturers. Let's take a look.

Cause of abnormal noise

There are many kinds of abnormal sounds during the operation of crossed roller bearings, the formation mechanism is relatively complex, and the factors are multi-faceted, and various abnormal sounds are often superimposed together, which is difficult to distinguish. The main reasons are as follows:

(1) There are periodic vibration pulses caused by bumps, scratches or serious defects in the inner and outer raceways of the bearing.

(2) Non-periodic vibration pulses caused by defects such as bumps and scratches on the surface of the rolling element.

(3) Periodic or aperiodic vibration pulses caused by the presence of residual magnetically adsorbed iron powder on raceways or rolling elements.

(4) The pulse of aperiodic vibration caused by impurities or dust entering the running area of the bearing raceway.

(5) Aperiodic vibration pulses caused by violent collisions between rolling elements and cage pockets.

(6) Poor performance of the lubricant, sliding friction between the rolling elements and the cage pockets, and vibration pulses generated by rolling the lubricant when the rolling elements are running.

Abnormal sound detection method

Noise detection method

It is a direct measurement method of abnormal sound by using a high-quality microphone to extract the bearing sound pressure signal at a certain distance and direction in an anechoic environment where the basic noise is less than 20db, and extracting the abnormal sound component by a certain analysis method.

Vibration detection method

It is an indirect detection method for abnormal sound, which can be divided into qualitative detection method and quantitative parameter detection method. Among them, qualitative detection method is divided into monitoring abnormal sound method and observing vibration waveform method. Quantitative parameter detection method refers to the use of measured parameter values related to abnormal sound in the vibration signal of the measured bearing, such as the peak value of vibration and the crest factor to evaluate the abnormal sound of the bearing.

Measuring instrument for measuring abnormal sound of bearings

There are many measuring instruments for measuring abnormal bearing sound. These bearing measuring instruments can measure the effective value of bearing vibration and the peak value, crest factor and pulse number that reflect abnormal bearing sound parameters.

The above is about the reasons for the abnormal noise of the crossed roller bearing and the related detection methods. It is recommended that you use professional testing equipment. After all, the bearings are still used frequently, and the problem must be solved and dealt with.