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 due to the role of the centrifugal force may be in contact with the outer ring, in the 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 of the bearing and noise.

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

The forced vibration often excites the second-order and third-order bending intrinsic 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 loading, the selection of good lubricants can also be improved, some foreign enterprises use light rolling body, such as ceramic rollers or hollow rollers and other technological measures to prevent the generation of this noise. Rolling body through vibration, when the bearing in radial load operation, its internal only if the dry rolling body to bear the load, due to the elastic contact with the ring constitutes the spring support so that the rolling body in the radial load through the line of action of the cyclic vibration, and the center of the spindle will be up and down on the vertical movement or to do the horizontal direction of the movement, and at the same time to trigger the noise. This type of vibration is called the rolling body through the vibration, especially in low-speed operation is more obvious. The amplitude is related to the type of bearing, 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, often used to reduce the radial clearance or apply the appropriate preload to reduce. Sharp sound is the sliding friction between the metal produces quite violent screaming, although the bearing temperature rise is not high, the bearing life and grease life is not much effect, also does not affect the rotation, but unpleasant sound disturbing, especially bear radial load of large short cylindrical roller bearings often have this noise.

Keep frame sound, in the bearing rotation process keep frame free vibration and it and rolling body or collar impact will send out this noise. It may appear in all kinds of bearings, but its sound pressure level is not too high and low frequency. It is characterized by the presence of both thin oil and grease lubrication. Stamping cages and plastic cages can be produced. Easily occurs when the radial clearance is large. Easy to occur when the outer ring is subjected to bending moments.

As the cage pocket hole clearance and cage and ring clearance in the finished bearing inevitably have to exist, so want to eliminate the cage sound is very difficult, but can be reduced through the assembly error, preferably reasonable clearance and cage tampering to improve the amount. Another kind of cage special sound is due to the cage and other bearing parts guide surface friction triggered by the cage of the self-excited vibration and the noise. 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, caused by beeping sound.

When the bearing in the radial load and grease performance is poor, the operation of the initial period will hear 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 the noise, this impact sound is unavoidable 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 bearing its 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 rotational movement stability, should try to use the collar to guide the way and pay attention to give the guide surface of the full lubrication, the high-speed conditions of the tapered roller bearing structure to improve the roller to guide the L-type cage into the collar edge-guided Z-type cage.

Pay attention to minimize radial clearance. Try to improve the manufacturing precision of the cage, improve the surface quality of the cage, which is conducive to reducing the rolling body and cage collision or friction noise. Actively use advanced cleaning technology to effectively clean the spare parts and the products after combining sets to improve the cleanliness of the bearings.