How to diagnose rolling bearing failures using a vibration analyzer?

Thread Content

Generally, when we say a bearing has failed, we use a vibration analyzer for diagnosis at that time. How can a vibration analyzer be used to diagnose faults in rolling bearings? Below, our editor will explain this to you by drawing on the expertise of our company’s technicians: In the process of using vibrations for a simple diagnosis of rolling bearings, it is usual to compare the measured vibration values (such as peak values and RMS values) with certain pre-defined criteria. The vibration analyzer determines whether there is a fault in the bearing by checking whether the actual vibration values exceed the limits set by these criteria, thereby deciding whether further detailed diagnosis is necessary. The criteria used for the simple diagnosis of rolling bearings can be roughly divided into three types: 1. Excellent criteria: These are values used to determine whether the actual vibration level exceeds the allowable limits; 2. Relative criteria: In this approach, vibration measurements are taken regularly at the same location on the bearing, and comparisons are made over time. The vibration level under normal, fault-free conditions serves as the benchmark, and the vibration analyzer uses the ratio of the actual vibration level to this benchmark value to make a diagnosis. 3. Analogical judgment criterion: It is a criterion that involves conducting vibration tests on several bearings of the same model under identical conditions at the same location, and then comparing the vibration values to make a judgment. The criteria for determining excellence are established based on specified testing methods; therefore, it is necessary to pay attention to the applicable frequency range, and vibration testing must be carried out in accordance with the prescribed methods. Excellent, relative, and analogical judgment criteria applicable to all bearings are necessary in order to obtain accurate and reliable diagnostic results.