Falling rolling noise. In general, the noise mostly appears in large bearings under low speed and bearing radial load. When the bearing operates under radial load, load zone and non-load zone in the bearing. If the bearing has a certain radial clearance, the rolling body in the non-load zone does not contact the inner raceway, but it may contact the outer ring due to the centrifugal force. At low speed, when the centrifugal force is less than the dead weight of the rolling body, The roller will fall and collide with the inner raceway or cage and stimulate the natural vibration and noise of the bearing. And has the following characteristics: for only the radial load and radial clearance is also easy to produce. Bearings of different sizes are also produced in a specific range and their speed ranges are different. Fat lubrication is easy to produce, oil lubrication is not easy to produce. It is easier to produce when using inferior grease. It could be continuous or intermittent. Winter often occurs.

The forced vibration often excites the second and third order flexural natural vibration of the outer ring, thus generating the noise. By using the preload method can effectively reduce the noise, reduce the radial clearance of the bearing after installation, the selection of good lubricants can also be improved, some foreign enterprises use light rolling body, such as ceramic roller or hollow roller and other technical measures to prevent the generation of this noise. Rolling body through vibration, when the bearing runs under radial load, its internal only if dry rolling body bear load, because of the spring support formed by the elastic contact with the ring, the rolling body produces periodic vibration through the radial load line, and the center of the rotating shaft therefore moves vertically or horizontally up and down, and causes noise at the same time. This type of vibration is called rolling through vibration, especially at low speeds. The amplitude is related to bearing type, radial load, radial clearance and number of rolling elements. Usually, the amplitude is small. If the amplitude is large, the harm is formed. For this reason, the radial clearance is often reduced or the appropriate preload is applied to reduce it. Shrill sound is a rather violent scream caused by the sliding friction between metals, although the bearing temperature rise is not high at this time, the bearing life and grease life is not much influence, also does not affect rotation, but the unpleasant sound is disturbing, especially the large short cylindrical roller bearing bearing radial load often this noise.

Cage sound, free vibration of the cage in the process of bearing rotation and its impact with the roller or ring will give off 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 thin oil or grease lubrication will appear. Stamping cages and plastic cages can be produced. It is easy to appear when the radial clearance is large. It is most likely to occur when the outer ring is subjected to bending moments. Because cage pocket hole clearance and cage and ring clearance inevitably exist in bearing finished products, it is very difficult to completely eliminate cage sound, but it can be improved by reducing assembly error, optimizing reasonable clearance and cage movement. Another cage special sound 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. The stamping cage of deep groove ball bearing is thin, the bending stiffness in the radial and axial plane is low, and the overall stability is poor. When the bearing is rotating at high speed, it will produce self-excited vibration due to bending deformation, causing the buzzer.

When the bearing is under radial load and the grease performance is poor, the clicking noise will be heard at the early stage of operation, which is mainly due to the noise caused by the sudden acceleration of the rolling body and the collision with the cage after the rolling body leaves the load area. This collision sound is inevitable but will disappear with the operation for a period of time. Cage noise prevention measures are as follows: When bearings rotate at high speed, the cage vibration amplitude of bearings with large pocket hole clearance is much greater than that of those with small pocket hole clearance, so the value of pocket hole clearance is particularly important. In order to make the cage stable in revolution, it is necessary to adopt the ring guiding mode as far as possible and pay attention to the sufficient lubrication of the guiding surface. The structure of tapered roller bearing under high speed conditions should be improved. The L-shaped cage guided by the roller should be changed to Z-shaped cage guided by the ring guard.

Care should be taken to minimize radial clearance. To improve the manufacturing precision of holding price and the surface quality of cage, it is beneficial to reduce the noise caused by collision or friction between rolling body and cage. Actively adopt advanced cleaning technology to effectively and thoroughly clean the products after the parts and assemblies, and improve the cleanliness of bearings.