Study Various Defects of Ball Bearings through Different Vibration Techniques
The main objective of this study is to evaluate ball bearing defects under different operation conditions through vibration measurements. There are several tests conducted for healthy and defective bearing under variable speeds and load conditions. Experimental tests are conducted for six sets of ball bearings. Initially, a good bearing is fastened in the test rig and vibration signals are measured using the FFT analyzer to show the base-line performance of a healthy bearing. Then, the good bearing is exchanged by defective bearing and vibration signals are measured for each case separately under the same operation condition. Frequency domain, time domain and root-mean-square are used to describe various bearing defects. The experimental results are showed that each one of these methods is useful to identify the bearing problems. Also, the results proved that the significant variation in the root-mean-square at different rotational speed.
Harvey J. Finison (Equipment Laboratory, Wright Field, Dayton, Ohio): One of the greatest problems in brush wear testing has been the selection of test conditions representative of service conditions. Selection of test conditions considerably more severe than actual operating conditions may result in elimination of brushes capable of giving excellent service performance, in fact, superior to those which may be selected on the basis of more severe tests.