Discriminant NTN angular contact ball bearing fault damage to adjust the preload method

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 zhangs gauge ( Frequency profiler, etc. ) Can measure the size of the vibration, through frequency points cannot deduce the abnormal condition in detail. Due to the measured values of bearing or sensor installation position and different using conditions, and thus needs prior to the measurement value of each machine stop after certain discriminant analysis compare specifications. Due to injuries such as NTN bearing even with slight detachment, also an exception and irregular, and thus with the sound of the measuring device can stop, tell the sound device, the size of angular contact ball bearing rolling noise in operation and timbre to stop inspection, have the effect of early prevention. If used oil hole can directly measure temperature of bearing outer ring, is more appropriate. General situation, NTN bearing temperature, average according to the bearing of the outdoor temperature can fathom. If smooth, device is appropriate, bearing temperature will rise sharply, can present abnormal high temperature, then must stop and take the necessary precautions. Usually, the temperature of the bearing with running start gradually rise, 1 - Two hours later to reach steady state. Angular contact ball bearing of the normal temperature for machine heat capacity, heat dissipating capacity, rotational speed and load. At any time when necessary, the use of thermal device can monitor the working temperature of bearing, and completes the temperature value beyond rules automatic alarm or stop to avoid burning shaft accident attack. NTN bearing assembly is a fundamental operation in 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 process, is the assurance of quality of bearing assembly work. NTN bearing clearance refers to the situation in a ring is fixed and another 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, can form at the same time accept the load to reduce the number of roller, a single roller load increase, thereby reducing the rotating precision of bearing, reduce the use of life; Clearance is too small, can make the friction force increases, the heat generated by the increased, aggravate wear, also can reduce the use of the bearing life. Therefore, when bearing assembly must be strict control and adjust the clearance. When is preloaded bearing assembly, for inner ring and outer ring an axial force, as its bearing clearance, and make contact with the inner and outer ring roller early deformations. Preloaded can you improve bearing in the working status of the stiffness and rotation accuracy, accept load is bigger, rotating request high precision bearings, mostly in the absence of clearance to have a small amount of work under the interference of the state, this situation needs to stop bearing pre-tightening during assembly. Adjustment of clearance and preload is usually through inner ring make appropriate axial circle of foreign relative displacement method. It is not hard to see from the above technology concept, through the diagonal contact ball bearing clearance adjustment, to progress the bearing ability and rotating precision of bearing, progress the using life of bearing. But at the same time can make the NTN bearing friction intensified, calorific value increases, so the clearance or preload adjustment when necessary to ensure smooth and heat dissipation. If improper adjustment or smooth, can in turn exacerbated bearing wear, reduce the service life. Properly stop adjustment and preloaded bearing clearance, and also pay attention to the following questions.