Falling body rolling sound, the noise in general, mostly in the 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 be in contact with the outer ring, in low speed, when the centrifugal force is less than the rolling body self-weight, 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 sizes of bearings and its speed range is different. When grease lubrication is easy to produce, 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. It often occurs in winter.

The forced vibration often excites the second 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 after the installation of the bearing work, the choice of good lubricant can also be improved, some foreign enterprises use light rolling body, such as ceramic roller or hollow roller and other technical measures to prevent this noise. Rolling body through vibration, when the bearing in the radial load under the role of operation, its internal only if dry a rolling body to bear the load, due to the elastic contact with the collar constitutes the spring support so that the rolling body in through the radial load line of action produced a periodic vibration, and the centre of the shaft will therefore move up and down vertically or do horizontal direction, 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 reason is often used to reduce the radial clearance or the application of appropriate preload to reduce. Acoustic sound is between the metal sliding friction generated quite violent scream, although this bearing temperature rise is not high, bearing life and grease life is not much influence, 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.

Keep frame sound, in the bearing rotation process keep frame 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. Stamped cage and plastic cage can be produced. Radial clearance is easy to occur when large. It is most likely to occur when the outer ring is subjected to bending moments.

Because keep frame pocket hole clearance and keep frame and ring clearance in the finished bearing inevitably to exist, so completely eliminate keep frame sound is very difficult, but can reduce the assembly error, preferential selection of reasonable clearance and keep frame runout to improve. Another kind of keep frame special sound is due to keep frame and other bearing parts guide surface between the friction triggered by the keep frame of self-excited vibration and occurrence of the clamor sound. Deep groove ball bearing stamping keep frame is thin, in the radial and axial plane of bending stiffness is low, the overall stability is poor, bearing high-speed rotation will be due to bending deformation and self-excited vibration, causing 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 away, the rolling body suddenly accelerated and collision with the keep frame 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 its cage vibration amplitude is much larger than the pocket hole clearance small cage vibration amplitude, so pocket hole clearance to take the value is particularly important. In order to make the cage rotation movement stable, should try to use the collar guide way and pay attention to give guide surface of sufficient lubrication, to 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 keep price, improve the surface quality of the keep frame, is conducive to reducing the rolling body and keep frame collision or friction generated noise. Actively use advanced cleaning technology, effective and thorough cleaning of spare parts and products after fitting, to improve the cleanliness of the bearings.