The bearing is easy to produce when the radial clearance is large. It is also easy to produce when only radial load is applied and the radial clearance is large. The higher the viscosity of the lubricant, the lower the sound pressure level, but for grease lubrication, the viscosity and the shape of the soap fiber can affect the noise value. No matter how the speed changes, the main noise frequency Almost unchanged but the sound pressure level increases with the increase in speed; d. e. It may be continuous or intermittent. The speed range of bearings of different sizes is also different in a certain range. Vibration frequency is above. It usually appears in grease lubrication, but oil lubrication is rare.

This is mainly due to the sudden acceleration of the rolling elements and the phase of the cage after the rolling elements leave the load zone. f. c. Some foreign companies use light rolling elements, such as ceramic rollers or hollow rollers. Because of the elastic contact between the ring and the rolling element, a nonlinear vibration system is formed. b. Raceway sound Raceway sound is a kind of smooth and continuous noise caused by rolling elements rolling in the raceway when the bearing rotates. This noise can be prevented by reducing the radial clearance of the bearing and adopting a shallow outer ring raceway structure.

The stamped cage of deep groove ball bearings is thin, has low bending stiffness in the radial and axial planes, and has poor overall stability. When the bearing is running under radial load, the load zone and the non-load zone in the bearing, if the bearing has a certain radial clearance, the rolling elements in the non-load zone do not contact the inner raceway, but due to centrifugal force, it may contact the outside For this reason, at low speeds, when the centrifugal force is less than the weight of the rolling elements, the rolling elements will fall and collide with the inner raceway or the cage and stimulate the natural vibration and noise of the bearing, and have the following characteristics: a.. For example, under normal conditions, the high-quality 6203 bearing raceway sound is 25 ~ 27dB. Decrease as the bearing size increases, and it often appears in a certain speed range. 　　

The source of the raceway sound is the natural vibration of the ring after being loaded. b. The squealing sound is a rather violent squeal sound caused by sliding friction between metals. Its appearance is irregular and unpredictable, and is related to the amount and performance of grease filling, and installation and operating conditions. Both stamping cages and plastic cages can be produced. d. This forced vibration often excites the second-order and third-order bending natural vibrations of the outer ring, thereby emitting the noise.

Noise and vibration are random;  It may appear in all kinds of bearings, but its sound pressure level is not too high and low frequency. It often appears in winter. It is easier to produce when using inferior grease. Its characteristics are: a. d. e. Its characteristics are: a. When the bearing is under radial load and the grease performance is poor, the noise of 'click, click' will be heard at the beginning of operation. The rigidity of the bearing seat increases, the lower the total sound pressure level, even if the speed increases , The total sound pressure level does not increase much; f. Because the cage pocket gap and cage and ring gap are unavoidable in the finished bearing, it is very difficult to completely eliminate the cage sound, but it can be improved by reducing the assembly error and optimizing the reasonable clearance and cage movement. To prevent this kind of noise. 　　

Another kind of special noise of the cage is the noise caused by the self-excited vibration of the cage caused by the friction between the cage and the guide surface of other bearing parts. c. It is most likely to occur when the outer ring is subjected to bending moment. It often happens in winter. Falling body rolling sound The noise generally occurs in large bearings that are subjected to radial loads at low speeds. When the radial clearance increases, the sound pressure level increases sharply; e. Although the temperature rise of the bearing is not high at this time, it has little effect on bearing life and grease life, and does not affect the rotation, but the unpleasant sound makes People are disturbed, especially large short cylindrical roller bearings bearing radial load often have this noise. It is easy to appear when the radial clearance is large. It can also be improved by using good lubricants. In fact, the sound energy excited by the raceway sound is limited.

Although it is unavoidable, high-precision machining of the working surface of the parts can be used, the correct selection of bearings and the precise use of bearings to reduce noise and vibration. This kind of noise is most typical of single row deep groove ball bearings bearing radial load. When the bearing rotates at a high speed, it will produce self-excited vibration due to bending deformation, Mechanical roller bearing causing 'buzzing' . 3. The preload method can effectively reduce the noise and reduce the radial clearance of the bearing after installation. It only attracts people's attention when its sound pressure level or tone is extremely high. Grease lubrication Easy to produce, not easy to produce when oil lubricated.

Either thin oil or grease lubrication will appear. As we all know, even if the most advanced manufacturing technology is used to process bearing parts, there will always be small geometric errors of varying degrees on the working surface, so that small fluctuations between the raceway and the rolling elements will excite the natural vibration of the vibration system. When the lubrication or machining accuracy is not high, it will excite the natural vibration related to this elastic characteristic, and it will become noise when it is transmitted to the air.