The experts of the Forensic expert kollegium carry out vibration diagnostics, which belong to one of the types of non-destructive testing.
One of the objects of vibration diagnostics are rolling bearings, which have a fairly wide scope of application.
Like any mechanism or assembly, rolling bearings have a limited service life. Even the service life of two identical bearings can be different and is determined by many parameters, including operating conditions, maintenance, correct installation, workmanship, etc. The main parameters characterizing the quality of a rolling bearing are:
deviations in geometric dimensions, shape, relative position of bearing surfaces and rotation accuracy;
- hardness, grade of steel (other materials) used in the manufacture of bearing parts;
- non-uniformity in hardness within one bearing ring;
- parameters of the roughness of the bearing surfaces;
- gaps, etc.
As a result of a rolling bearing operation, various types of damage can occur. The main causes of damage are:
- manufacturing defect;
- defect in assembly and operation (improper lubrication, faults during installation, excessively high loads, vibration, wear).
The cause of the destruction (damage) of a rolling bearing can be determined by the nature of the damage. However, as the expert practice shows, in this case it is too late to take any measures. Bearing damage can lead to failure of the entire assembly and, as a result, to the entire machine or equipment failure. To prevent such undesirable situations, it is necessary to periodically check the condition of the rolling bearing.
During the examination of bearings by the experts of the Forensic expert kollegium, the following parameters and defects are subject to control:
- temperature;
- vibration;
- cracks;
- condition of the lubricant;
- noise;
- drips, etc.
The goal of vibration diagnostics is to identify bearing defects at an early stage, which makes it possible to carry out prompt repair or replacement of a defective part. The main advantage of vibration diagnostics as a type of non-destructive testing is that it allows assessing the examined equipment without stopping and disassembling, without disrupting the well-oiled technological process.
The main signs of rolling bearing defects that can be detected during vibration diagnostics are:
- the growth of high-frequency vibration (in the frequency band 800-1800 Hz);
- the vibration amplitude of even harmonics at frequencies that are multiple of f0 - the bearing's own rotational speed is greater than odd ones;
- the vibration amplitudes of the higher harmonics rapidly decrease with the growth of their serial number (kf0, where k = 1, 2, 3 ...);
- the vibration amplitudes of higher harmonics decrease slightly with increasing k, the highest vibration is at the natural frequency f0.
The above, as well as some other signs, signal the presence of defects. Based on the results of vibration diagnostics of rolling bearings, it is possible to determine the type of defect, as well as the degree of its development. Comparing the results obtained with the current standards, one can answer the question: "Is it expedient to continue using the equipment or does it need to be repaired?"
You can order vibration diagnostics at the Forensic expert kollegium at: Minsk, Zhukovskogo st., 11 A, 4th floor
or by phone +375 (17) 317 04 71; +375 (17) 317 04 72; +375 (17) 317 04 73; +375 (17) 317 04 74; +375 (17) 317 04 76; +375 (44) 588 60 11, +375 (29) 109 60 11
