Influence of bearing structure on vibration and noise

Falling body rolling sound, the noise in general, mostly in low speed and bear radial load of large bearings. When the bearing in radial load operation, bearing load area and non-load area, if the bearing has a certain radial clearance, non-load area of the rolling body and the inner raceway does not contact, but because of the role of centrifugal force may contact with the outer ring, in low speed, when the centrifugal force is less than the weight of the rolling body, the rolling body will fall and collision with the inner raceway or cage and stimulate the inherent vibration and noise of the bearing.

And have the following characteristics: for only the role of radial load and radial clearance is also easy to produce. In a particular range will also produce and different size of the bearing its speed range is also different. Easy to produce when grease lubrication, oil lubrication is not easy to produce. When using poor quality grease is more likely to produce. It may be continuous or intermittent sound. It often occurs in winter.

The forced vibration often excites the second-order and third-order bending inherent vibration of the outer ring, thus emitting the noise. Through the use of pre-load method can effectively reduce the noise, reduce the radial clearance of the bearing work after installation, the use of good lubricant can also be improved, some foreign companies use light rolling body, such as ceramic rollers or hollow rollers and other technical measures to prevent this noise generation. Rolling body through vibration, when the bearing in the radial load under the role of operation, its internal only if the dry rolling body to bear the load, due to the elastic contact with the collar constitutes the spring support so that the rolling body in the radial load through the line of action produced a periodic vibration, and the center of the shaft will therefore move up and down vertically or do horizontal movement, while triggering noise. This kind of vibration is called rolling body through the vibration, especially in low speed operation performance is more obvious. The amplitude is related to the bearing type, radial load, radial clearance and the number of rolling elements. Usually the amplitude is small, if the amplitude is large when the formation of harm, for this often use to reduce the radial clearance or apply the appropriate preload to reduce. Acoustic sound is between the metal sliding friction produces quite violent squeal, although this bearing temperature rise is not high, bearing life and grease life is not much impact, but also does not affect the rotation, but unpleasant sound is disturbing, especially bearing radial load of large short cylindrical roller bearings often have this noise.

Cage sound, in the bearing rotation process cage free vibration and it and rolling body or collision will issue this noise. It may appear in all kinds of bearings, but its sound pressure level is not too high and is low frequency. Its characteristics are: whether it is thin oil or grease lubrication will appear. Stamping cage and plastic cage can be produced. It is easy to appear when the radial clearance is large. It is easy to occur when the outer ring is subjected to bending moment.

Because keep frame pocket hole clearance and keep frame and ring clearance in the finished bearing inevitably to exist, so want to eliminate the keep frame sound is very difficult, but can reduce assembly errors, preferential selection of reasonable clearance and keep frame runout amount to improve. Another kind of cage special sound is due to the cage and other bearing parts guide surface friction between the cage triggered by self-excited vibration and occurrence of the clamor sound. Deep groove ball bearing stamping cage is thin, in the radial and axial plane of the bending stiffness is low, the overall stability is poor, bearing high-speed rotation will be due to bending deformation and self-excited vibration, causing a beeping sound.

When the bearing under radial load and poor grease performance, the initial operation will be heard click, click noise, which is mainly due to the rolling body in the load area after leaving, the rolling body suddenly accelerated and collision with the cage and noise, this impact sound inevitable but with the operation of a period of time will disappear. Prevent cage noise measures are as follows: bearing high speed rotation, pocket hole clearance large bearing cage vibration amplitude is much larger than the pocket hole clearance small cage vibration amplitude, so the pocket hole clearance value is particularly important. In order to make the cage rotation movement stable, should try to use the collar guide and pay attention to give the guide surface of sufficient lubrication, the high-speed conditions of the tapered roller bearing structure to improve, the roller guide L type cage to the collar retaining edge guide Z type cage.

To pay attention to minimize the radial clearance. Try to improve the manufacturing accuracy of the cage, improve the surface quality of the cage, help to reduce the rolling body and cage collision or friction noise. Actively use advanced cleaning technology to effectively clean the spare parts and the products after closing the sleeve to improve the cleanliness of the bearings.