Bearing in good continuous state will emit a low whine or buzzing sound.Sharp hissing, squeaking and other irregular sounds often indicate that the bearing is in poor continuous rotation.The shrill squeaking noise may be due to improper lubrication.Improper bearing clearance can also cause metallic sound.

The indentation in the bearing outer ring track will cause vibration and cause smooth and crisp sound.

If there is intermittent noise, it means that the rolling parts may be damaged.This sound occurs when the damaged surface is rolled, and contaminants in the bearing often cause a hiss sound.Severe bearing damage can produce irregularities and loud noise.

If the knocking scars caused by installation will also produce noise, the noise will vary with the height of the bearing speed.

Reason 1: abnormal load, countermeasures: correct fit, study bearing clearance, adjust and load, and correct the shell shoulder position.

Reason 2: bad installation, countermeasures: machining accuracy of shaft and shell, improve installation accuracy and installation method.

Reason 3: insufficient or unsuitable lubricant, countermeasures: supplement lubricant, choose the appropriate lubricant.

Reason 4: rotating parts have contact, countermeasures: modify the curved circuit seal contact part.

Reason 1: the rolling surface is indentation, rust or scars caused by foreign bodies. Countermeasures: replace bearings, clean the relevant parts, improve the sealing device and use clean lubricant.

Reason 2: (after steel carburizing) surface deformation, countermeasures: replace bearings, pay attention to its use.

Reason 3: raceway surface peeling, countermeasure: replace bearings.

Reason 1: clearance is too large. Countermeasure: study the fit and bearing clearance and modify the preload amount.

Reason 2: foreign body invasion, countermeasures: study the replacement of bearings, clean the relevant parts, improve the sealing device, use clean lubricant.

Reason 3: Spherical injury, peeling, countermeasure: replace bearings.

At present, there are two ways to detect abnormal bearing sound.One is acoustic based noise detection method, and the other is vibration based detection method.

It is a direct method to measure the abnormal sound by using a high-quality microphone to extract the bearing sound pressure signal from a certain distance and direction under the silencer environment with the basic noise less than 20dB, and extracting the abnormal sound components through a certain analysis method.

The indirect detection method of bearing abnormal sound can be divided into qualitative detection method and quantitative parameter detection method.Among them, the qualitative detection method is divided into monitoring abnormal sound method and observing vibration waveform method.Quantitative parameter detection method is to evaluate the abnormal sound of the bearing with the measured parameter values related to the abnormal sound in the vibration signal of the bearing being measured, such as the peak value of vibration and the wave peak factor.

There are many measuring instruments for measuring bearing abnormal sound, and they can be selected for it.

1. Keep the original package and do not open it at will. If it is found that the package is damaged, it must be opened and cleaned carefully and reoiled for packaging.

2, the relative humidity of the storage room can not exceed 60%, the temperature difference can not be too large, the bearing in the original packaging can be stored for several years.Sealed bearings or bearings with dust cover may have lower lubrication characteristics of grease filled in bearings after long-term storage.

3, the storage room should also be shockproof and shaking.The bearings not stored in the original package should be properly stored. It is forbidden to put the bearings together with corrosive things to prevent corrosion and pollution.

4. Large rolling bearings can only be placed flat when stored, and the sides of the inner and outer rings are best supported.If stored upright, permanent deformation may occur due to the heavy inner and outer ring and rolling parts and the relatively thin inner and outer ring walls.

1.Grease has impurities;

2.Insufficient lubrication (oil level is too low, improper storage leads to leakage of oil or grease through the seal);

3.Bearing clearance is too small or too large (manufacturer’s problem);

4.Bearings mixed with sand or carbon particles and other impurities, play the role of abrasive;

5.The bearing is mixed with water, acid or paint and other dirt, which plays a corrosive role;

6.The bearing is clamped flat by the seat hole (the roundness of the seat hole is not good, or the seat hole is distorted and not straight);

7.The bottom surface of the bearing seat cushion iron is uneven (resulting in the deformation of the seat hole and even the crack of the bearing seat);

8.There are debris in the bearing seat hole (residual chips, dust particles, etc.);

9.Eccentric sealing ring (contact with adjacent parts and friction);

10.The bearing is subject to additional load (the bearing is axial compression, or there are two fixed end bearings on a shaft);

11.The bearing and the shaft is too loose (the diameter of the shaft is too small or the set sleeve is not tightened);

12.The clearance of the bearing is too small and it is too tight when rotating (the fastening sleeve is screwed too tight).