The sound of running the bearing correctly
If the bearing is in a good continuous rotation condition, it will emit a low whining or humming sound; Sharp hisses, squeaks and other irregular sounds often indicate that the bearing is in a poor rotation condition. A sharp squeaking noise can be caused by improper lubrication. Improper bearing clearance can also cause metallic noise.
Dents in the outer ring tracks of the bearing cause vibrations and create a smooth and crisp sound. If there is intermittent noise, it means that the rolling part may be damaged. This sound occurs when the damaged surface is run over, and the presence of contaminants in the bearing often causes a hissing sound. Severe bearing damage can produce irregular and loud noise; Noise can also be generated if it is due to knock marks caused during mounting, which varies with the bearing speed.

Big metallic noise

Abnormal load: correct the fit, study the bearing clearance, adjust the load, and correct the position of the shell shoulder.

Poor installation: the machining accuracy of the shaft and shell, improve the installation accuracy and installation method.

Insufficient or unsuitable lubricant: relubrication, choose the appropriate lubricant.

Rotating parts have contact: modify the contact part of the curved seal.

Regular noise
Indentation, rust or scarring of rolling surfaces due to foreign objects: replacement of bearings, cleaning of relevant parts, improvement of seals, use of clean lubricants.

Surface deformation (after steel carburizing): replace the bearing and pay attention to its use.

Raceway surface stripping: Replace the bearing.

Irregular noise
Excessive clearance: study the fit and bearing clearance, and modify the preload.

Foreign body intrusion: study of replacing bearings, cleaning relevant parts, improving sealing devices, using clean lubricants.
Spherical wounds, peeling: Replace bearings.

Detection method for abnormal bearing noise

Noise detection method
It is a direct measurement method for abnormal sound by using a high-quality microphone to extract the bearing sound pressure signal at a certain distance and direction in a sound suppression environment where the basic noise is less than 20dB, and extracting the abnormal sound components 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, the qualitative detection method is divided into monitoring abnormal sound method and observing vibration waveform method; The quantitative parameter detection method refers to the use of measured parameter values related to abnormal sound in the vibration signal of the bearing under test, such as: the peak of vibration and the crest factor to evaluate the abnormal sound of the bearing.

Correct storage of bearings.
Keep the original packaging, do not open arbitrarily, if the packaging is found to be damaged, it must be opened and carefully cleaned, and the oiled packaging must be re-oiled.

The relative humidity of the storage room should not exceed 60%, the temperature difference should not be too large, and the bearings placed in the original packaging can be stored for several years. Sealed bearings or bearings with shields may have reduced the lubricating properties of the grease filled in the bearings after prolonged storage.

The storage room should also be resistant to vibration and shaking. Bearings not stored in the original packaging should be properly kept, and bearings are strictly prohibited from being placed together with corrosive things to prevent corrosion and contamination.

Large rolling bearings can only be stored flat, and the sides of the inner and outer rings are preferably fully supported. If stored upright, permanent deformation may occur due to the heavier inner and outer rings and rolling elements, while the inner and outer ring walls are relatively thin.