Judge NTN angular contact ball bearing failure damage to adjust the knowledge - bearing pre-tightening methods

From spalling, indentation, rust, crack and wear will be reflected in the bearing vibration measurement, NTN bearing vibration of bearing damage is very sensitive, so the angular contact ball bearing through the use of special bearing vibration measuring device ( Frequency analyzer, etc. ) Can measure the size of the vibration, through frequency points cannot deduce the abnormal situation. Due to the measured values of bearing or sensor installation position and different using conditions, thus requiring prior to each machine is analyzed by the measured value of the determined after judgment standard. As NTN bearing even with slight stripping damage, also an exception and irregular, and therefore with the sound of the measuring device can distinguish, USES the sound device, angular contact ball bearing in operation to check the size of the rolling sound and quality, have the effect of prevention in advance. If using the oil hole can directly measure temperature of bearing outer ring, is more appropriate. In general, NTN bearing temperature, average according to the bearing on the surface of the outdoor temperature can be predicted. If the appropriate lubrication, installation department, the bearing temperature will rise sharply, appear unusually high temperature, must stop at this moment, take the necessary precautions. Usually, the temperature of the bearing with operation began to slowly rise, 1 - After 2 hours to reach steady state. Angular contact ball bearing of the normal temperature for machine heat capacity, heat dissipating capacity, rotational speed and load. When necessary, the use of thermal device can monitor the working temperature of bearing, and implement e. automatic alarm when the temperature is more than the household or stop to prevent the shaft accidents. NTN bearing assembly is the basic operation of benchwork assembly and repair work, and the adjustment of the clearance and preload is an important part of the rolling bearing assembly work. Accurately grasp the clearance adjustment and pre-tightening technology concept, and in the assembly work correctly using this technique, is the assurance of quality of bearing assembly work. NTN bearing clearance refers to a fixed in a ring, a ring along the radial or axial made the biggest activity, so the clearance is divided into radial clearance and axial clearance. Angular contact ball bearing assembly, clearance cannot too big, also not too small. Clearance is too large, will cause the load at the same time reduce the number of roller, a single roller load increase, thereby reducing the rotating precision of bearing, reduce the service life; Clearance is too small, can make the friction force increases, the heat generated by the increased, aggravate wear, also can reduce the service life of bearing. Therefore, bearing in the assembly to strictly control and adjust the clearance. When is preloaded bearing assembly, for inner ring and outer ring an axial force, to remove the bearing clearance, and make contact with the inner and outer ring roller early deformations. Preloaded can improve bearing in the working status of the stiffness and rotation accuracy and load is larger, higher bearing rotating accuracy requirement is mostly in the absence of clearance there is even a small amount of work under the interference of the state, in this case you need in the assembly of bearing preload. Adjustment of clearance and preload is usually by inner ring external circle for appropriate axial relative displacement method. It is not hard to see from the above technology concept, through the diagonal contact ball bearing clearance adjustment, can improve the bearing capacity of bearing and rotating accuracy, improve the service life of bearing. But at the same time can make the NTN bearing friction intensified, calorific value increases, so adjust the clearance or preload must guarantee good lubrication and cooling. If improper or poor lubrication, you will in turn exacerbated bearing wear, reduce the service life. Correctly for the adjustment of the bearing clearance and preload, also note the following problem.