Bearing in operation, except for some of the inherent and functional parts requested by the campaigns, all other deviations from the ideal location of movement are referred to as bearing vibration. When the vibration of the bearing to radiation surface, crossing the vibration energy into pressure, spread by air and then went out for sound radiation. Part 20~20 000 Hz, acceptable to the ear to acoustic radiation, that is, for bearing noise. Bearing noise measurements should be carried out in special silencers indoor. Anechoic room background noise is low, can distinguish between bearing noise and ambient noise, but its high construction costs, and cannot test at the scene. Bearing vibration, is the main source of noise, and noise performance is a strong feature, so replace measurement of noise with vibration measurement in General.
(1) bearing Raceway Raceway is sound and its control method when the bearing operation, rolling it across the Raceway surface and make a slippery continuous sound, is the basic sound of all rolling bearings will be unique. General bearing Raceway acoustic sound that is combined with other sounds. Ball bearing roller is irregular, above 1000Hz frequency, frequency of rate changes with the speed, but the overall sound pressure level increases with accelerating speed of. Roller bearing raceways for its acoustic sound pressure level diminishes with the increase of viscosity while small bearing Raceway, its sound pressure level in the viscosity increases to about 20mm2/s above, by reduction to increased. Greater the rigid housings, roller lower the overall sound pressure level of sound. Radial clearance is too small, and Raceway total sound pressure level and frequency will increase sharply as the reduction in radial internal clearance. Method of controlling the rolling sound: Optional low noise bearings bearing corrugated-small, carefully choose the conditions of use. Acoustic noise affecting the whole machinery of the Raceway, Raceway reduction can reduce the noise of machinery as a whole.
(2) impact sound and its control method for a larger model of the rolling ball bearings or cylindrical roller bearings under purely radial load at low speed operation, due to the centrifugal force of the rolling small load-free area in the rolling elements roll cage will shock or road noise. But as the speed increases, this noise will disappear. Rolling control method for impact sound: appropriate reduction of radial clearance, reasonable structure and material compliance cage bearings.
(3) the creak of the bearing and its controlling method creak is a cylindrical roller bearing has seized all the harsh metal sound that may occur, mostly in the larger models of grease lubrication bearings, and deterioration of the base oil in lubricating grease more easily, almost does not happen when the oil lubrication. In addition, the more vulnerable in the winter, when under purely radial load, the radial clearance is prone to big occasions, and with models of different sizes, within a certain range of specific speeds likely to occur, both continuous and intermittent.
Many factors affect bearing vibration, such as load, speed, quality of lubrication and bearing Raceway, analysis of vibration of bearing defects. And primarily analysis of bearing parts machining precision and quality of Raceway on vibration effects (apart from other factors), it is measured in the same axial loads (30N), the same constant speed (1800 r/min), without grease (just add two drops of spindle oil to protect the roller to avoid friction). This targeted to identify major causes of bearing vibration (such as roundness, inside and outside the ring groove waviness, roughness, contour, channel defects, defects in ball, and so on) so that bearings correspond to the part taken in the course of processing or assembling of technological measures, ultimately improving the quality of bearing vibration.


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