Vibration and temperature measurement based indicator of journal bearing malfunction

Abstract

This paper aims to present the development and implementation of the new malfunction indicator in journal bearings, based on vibrational and thermal records, called DFJB-Defect Factor Journal Bearing. Briefly, the indicator contains the specifically processed information about the bearing vibrations and temperature, on the basis of which the DFJB is calculated using fuzzy logic, and thus the state of the journal bearing may be determined. It should be pointed out that the DFJB is developed in a manner that besides the temperature and the total number of absolute vibrations, it may also integrate following parameters of monitoring: the parameters of rotating vibrations, vibrations spectrum, the thickness of oil film in the journal bearing, the intensity of the ultrasound emission of the bearing etc. These parameters may in certain cases offer more reliable malfunction identification. Experimental investigations conducted in this work, on real machine equipment and in real exploitation conditions, have shown this method to be reliable in the identification of malfunctions in journal bearings. As a result of implementation of DFJB, the time necessary to collect measuring data is significantly shortened, whereas the diagnosis procedure for journal bearings is highly simplified. This is particularly important in complex technical systems with a vast number of measuring points, which often result in the overload of the operator.