During the operation of the equipment, the abnormal sound of the bearing may be the quality defect of the bearing itself, or it may be caused by many other reasons.
Today, Sister Bearing to share with you a teacher summed up the "bearing abnormal sound reason", welcome the need for small partners to take their own

01

Bearing noise under different conditions

If the bearing is in good running state, it will make a low buzzing or buzzing sound. If a sharp hissing, squeaking and other irregular sounds are made, it is often indicated that the bearing is in poor condition of connection. The sharp squeak noise may be due to improper lubrication. Improper bearing clearance also causes metal noise.
The dent on the outer ring of the bearing can 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 over, if there are contaminants in the bearing often cause hissing. Serious bearing damage causes irregular and loud noise.

▼The automatic gearbox has abnormal sound. It was broken by the bearing retaining ring.

If the striking marks caused by the installation also produce noise, the noise will vary with the speed of the bearing.

02

Three categories of abnormal noise of bearings

►Large metallic sound

◆ Abnormal load

Solution: study the bearing clearance, adjust the load, and modify the position of the shell and shoulder.

◆ Poor installation

Solution: machining accuracy of shaft and shell, improving installation accuracy and installation method.

◆ Inadequate or unsuitable lubricant.

Solution: add lubricant and choose suitable lubricant.

▲Motor bearings with insufficient lubrication and dry rotation

◆ Contact with rotating parts

Solution: modify the contact part of the curved road seal.

►Regular noise

◆ Because of the foreign body, it causes indentation, rust or scar on the rolling surface.

Solution: replace bearings, clean parts, improve sealing devices, and use clean lubricants.

▲Bearing scar

◆ Surface deformation after steel carburizing

Solution: replace bearings, pay attention to their use.

◆ Stripping of raceway surface

Solution: replace bearings.

►Irregular noise

◆ Excessive clearance

Solution: research coordination and bearing clearance, modify preload.

◆ Foreign body invasion

Solution: replace bearings, clean parts, improve sealing devices, and use clean lubricants.

◆ Spherical damage and peeling

Solution: replace bearings.

03

Specific discrimination of abnormal noise of bearings

►The retainer "sill li..."

Vibration and collision between the retainer and the rolling element may occur regardless of the type of grease. It is more likely to occur when the torque, load or radial clearance is large.

Resolvent:

◆ Improving retainer accuracy

◆ Use small bearings or pre load the bearing.

◆ Reduce torque load and reduce installation error

◆ Selected oils and fats

►The continuous buzz "buzz..."

When the motor runs without load, it makes a sound similar to buzzing, and the motor has an abnormal axial vibration. There is a "buzzing" sound when the motor is turned on or off.

Its specific characteristics are: multiple lubrication state is not good, and in winter, both ends of the motor with ball bearings more, mainly shaft alignment performance is poor, axial vibration under the influence of an unstable vibration.

Resolvent

◆ Grease with good lubricity

◆ Add preload to reduce installation error.

◆ Bearing with small radial clearance

◆ Improving rigidity of motor bearing block

◆ Strengthening the alignment of bearings

△Note: the fifth point plays a fundamental role in improvement.

►Lacquer rust

As the motor bearing casing paint dry, volatile chemical components corrode the end face of the bearing, groove and groove, so that the groove was corroded after the abnormal sound.
Specific features: the rust on the bearing surface after corrosion is more serious than that on the first side.

▲Rusty bearings

Resolvent:

◆ Dry or dry up the rotor or case.

◆ Reduce motor temperature

◆ Selection of suitable paint models

◆ Improving the ambient temperature of motor bearing placement

◆ Less rust is caused by suitable oils and fats, and silicone oil and mineral oil are more likely to cause corrosion.

◆  Vacuum impregnating process

►Impurity sound

An irregular abnormal sound caused by the cleanliness of bearings or grease.
Specific characteristics: sometimes no sound, big and small time, no rules, frequent in high-speed motor.

Resolvent:

◆ Selected oils and fats

◆ Improve cleanliness before grease injection

◆ Strengthening the sealing performance of bearings

◆ Improving cleanliness of installation environment

►High frequency vibration sound "Da Da Da..."

Specific features: Sound frequency varies with the speed of the bearing, the surface corrugation of the parts is the main cause of noise.

Resolvent:

◆ Improve the rolling quality to the surface and reduce the amplitude of corrugation.

◆ Reduce bruises

◆ Correct clearance pre-tightening force and fit, check free-end bearing operation, improve shaft and bearing seat precision installation method

04

Experts say 30 reasons for bearing rings.

1. there are impurities in oils and fats.
2. cage fracture;
3. rusting of bearing raceway;
4. bearing has noise (external vibration source interference);
5. raceway raceway is not qualified (production plant problem);
6. the clearance of bearing is too small or too large.
The diameter of the 7. holes is small (which causes the bearing temperature to be too high).
8. the sealing ring is eccentricity (which is rubbed with adjacent parts).
9. there are sundries in the bearing seat hole (residual chips, dust particles, etc.).
10. bearing has noise (roller end face or steel ball slippage).
The 11. shaft shoulders are too big (touching the bearing seal and rubbing).
12. the gap of labyrinth seal is too small (friction with the shaft).
13. the teeth of the locking washer are bent (touching the bearing and rubbing).
The shoulders of the 14. holes are too big (distorting the seals of the bearings).
15. the position of the oil ring is not suitable (with friction on the flange cap).
16. the bearing is mixed with sand or carbon particles and other impurities, which plays an abrasive role.
17. wear of steel ball and raceway.
The thermal elongation of the 18. axis is too large (the axle is subjected to the static indefinite axial load).
19. the bearing is clamped by the seat hole (the roundness of the seat hole is not good, or the seat hole is not straight).
20. the bearing is mixed with water, acid or paint and other pollutants to play a corrosive role.
21. the bearing and shaft are too loose (the diameter of the shaft is small or the tight sleeve does not tighten).
22. the clearance of the bearing is too small, and the rotation is too tight.
23. there is a pressure pit on the steel ball or roller.
24. the bearing is heated and discolored and deformed.
The 25. axis is too thick to make the actual fit too tight (causing the bearing temperature to be too high or noise).
26. inadequate lubrication (low oil level, improper storage, resulting in leakage of oil or grease through seals).
27. the bottom of the bearing seat is uneven, which causes the deformation of the seat hole and even the crack of the bearing block.
28. the diameter of the bearing seat hole is too large, the actual matching is too loose (the bearing temperature is too high, the outer ring is slippery).
29. the bearing hole is enlarged (the bearing hole of the non-ferrous metal is enlarged or expanded due to thermal expansion).
The 30. axle is subjected to additional load (the shaft is subjected to axial compression or two fixed ends on one shaft).