Assessment of mechanism vibration condition based on the intensity of vibration in the wavelet allocated frequency bands

Abstract

Increasing rivalry in the consumer markets requires producers and service providers to in- crease efficiency of their activities. In some cases, this leads to the fact that the intensity of machines and equipment operation increases, so do their work load conditions, and this in turn leads to their rapid depreciation and probability of failures and accidents increases. In such circumstances, the most important task is to develop effective means of monitoring the parameters of an operating equipment technical condition. For rotary type mechanisms (tur- bines, generators, motors, gearboxes, pumps, compressors, fans, etc.), the parameters of vi- bration reflect the functional state of objects well and do not require too much effort on their measurement. The simplest, but used in most cases intensity of vibration control uses its root mean square (RMS) in the frequency band of 10-1000 Hz in terms of vibration velocity. Var- ious vibration parameters obtained from the application of mathematical processing methods (digital filtering, spectrum, cepstrum, envelope etc.) of the original vibration signals are ap- plied to solving complex problems of vibration diagnostics. Condition assessment by RMS vibration velocity is fairly common and is used in solving problems of equipment protection from serious accidents and implementation of vibration diagnostics systems is costly and demands highly qualified personnel. It is proposed to establish a system of technical condi- tion evaluation which would be some middle ground between the two and would have a rela- tively simple implementation. As the parameters characterizing the state of the technical ob- ject, it is proposed to use the intensity of the vibration frequency bands allocated by wavelet function, and divide all the frequency band observed into several sub-band in such a system. The report provides an example to illustrate this approach.