The frequency of rolling bearing failure may be the discrete frequency of a certain part, or it may appear in the form of a sideband, and the sideband may be the frequency of a bearing component, the rotor speed frequency, the sum or difference frequency of each component, the sum and difference frequency of each frequency of each component. Although in practice, as long as the bearing failure is confirmed, the effective identification of the bearing failure frequency can not only help to determine whether it is a bearing failure, but also probably determine whether the bearing needs to be replaced immediately (Suggestion: if the bearing component is determined to be faulty, it should be replaced in time).

1, the bearing failure frequency is a non-integer multiple of the speed frequency;

2, bearing early failure may not occur at discrete fault frequency, but there will be a high-frequency peak group centered on the outer ring natural frequency;

3, when the rolling element is defective, 2xBSF is usually generated, and sometimes the 1xBSF May be the sum frequency of the inner and outer ring failure frequency

4, the inner and outer ring failure frequency sum frequency = bearing roller through frequency;

5. The more harmonics or sideband generated by rolling bearing defects, the more serious the defects are;

6, only the outer raceway frequency 1X, generally caused by a grain, if there is no change trend, can be used for a long time;

7, bearing inner ring failure frequency is often accompanied by 1X speed frequency sideband;

8. The failure frequency of the bearing outer ring is BPFO and its higher harmonics. When the inner ring is fixed and the outer ring rotates, it will be accompanied by 1X speed frequency side band;

9. Poor bearing lubrication will also cause direct contact between the cage and the rolling body, resulting in cage defect frequency.

10, the frequency of poor bearing lubrication is about 900 to 1600Hz, there are 3 or 4 spikes, and the difference frequency between spikes is 80 to 130Hz;

11, only the inner raceway defects, and the defects are small, the BPFI amplitude is small, and may disappear and appear (sometimes not in the bearing area);

12. When a variety of bearing faults are combined, they may not occur at the frequency of each component, but at the sum or difference between the frequencies of each component (such cases are less);

13. The amplitude of the bearing outer ring fault frequency is generally higher than the amplitude of the bearing inner ring fault frequency due to the transmission path;

14, when multiple rolling elements or rolling elements have multiple defects, it is often manifested as broadband noise;

15, bearing failure generally in the development of rolling body and cage failure before the first is the inner ring or outer ring failure frequency;

16, bearing cage failure frequency is usually not in its fundamental frequency, but as the frequency of other parts of the bearing or speed frequency side band;

17, when the rolling element itself fails, it often produces not only the rolling element failure frequency (BSF), but also the cage failure frequency (FTF);

18. When the cage breaks, the rolling element rotation failure frequency may occur, and FTF appears as a sideband;

19, no matter what form the cage frequency appears, it indicates the generation of problems, should be paid enough attention to.

20. When the outer ring is fixed, if the contact Angle increases, FTF, BPFO and BSF increase, and BPFI will decrease; If the contact Angle decreases, vice versa;

21, when the bearing is spalling, with the increase of the defect and the increase of friction, it will produce a "firewood pile" spectrum peak.