Miniature bearing scream noise characteristics

1) easy to produce large bearing radial clearance; 2 usually appeared in the grease lubrication, oil lubrication is relatively rare; (3) and decreases with the bearings' す and often appear within a certain speed fan (4) the winter often appear; 5 it is random and unpredictable, and fill in the amount of fat and fat, the performance of bearing installation operation condition. 3. Caused by scar and the inclusion of the noise is mainly caused by not civilization production, card or bruised because of fatigue residual fall, rust spot and inclusion into the bearing face. ( 1) Scar noise when rolling surface has crack, bruised, pit and rusty spot, will generate a cyclical vibration and noise, when turning speed must be its cycle remains the same, with the loss of the rotational speed, the cycle will be longer. If there is damage of raceway, I will send out the voice of the continuous; If there is damage, rolling element will be issued if if no voice, but the sound is cyclical out now, its cycles related to the bearing specifications, rotational speed and damage location. The class has the characteristics of energy spectrum width and big noise, it is easy to use FFT ( Fast Fourier transform method) On-line monitoring technology, so far for the more thorough research. In recent years, wavelet transform technology ( 小波变换) Is widely applied to the vibration frequency spectrum analysis of the work, the center is concentrated information, to extract the weak signal from the large amount of information, early diagnostic. Wavelet transform technology enhances the the periodic damage of noise vibration monitoring and CARDS don't ability. ( 2) Friction friction noise refers to the abnormal noise on the ball bearing, usually appear on the larger bearings, especially the grease lubricated bearing, when bad lubrication performance are more likely to happen. Besides bearings in bear radial load only and radial clearance and compare the big and easy to produce. The happening of the grating is not stable, sometimes occurs in a row, sometimes intermittent hair, and along with the change of rotating speed are different. And the noise occurs only at a certain speed range, and the speed range varies with bearing model. Experimental research shows that the rolling bearing friction sound produced not only have direct relationship with lubricating oil properties and external bearing raceway machining quality also have relations. Cause mechanical vibration and noise of rolling bearings in addition to the above analysis of several cases, also with the bearing rings geometry, waviness, eccentricity, the pendulum of raceway and rolling body of roundness and factors such as geometric shapes. When the rolling bearing raceway surface or burr defects such as scar, rusty spot on roller, bearing in operation will produce stress changes, leading to high frequency vibration. These defects if appears on the rolling path, the noise is often continuous; As happened in the rolling element, sometimes no noise is cyclical. In the rolling bearing such as falling into impurities and granular dust ash, also may make the instability of a noise. Bearing radial clearance is also caused by noise factors. Practice shows that Europe starts to emit tones between high noise, clearance is too large will produce larger noise. For high speed rotating shaft bearing, keep slimming ambient air had a greater influence on the disturbance of noise, when the design should consider mainly.