DEVELOPMENT OF A DIAGNOSIS TECHNIQUE FOR FAILURES OF V-BELTS BY A CROSS-SPECTRUM METHOD AND A DISCRIMINANT FUNCTION-APPROACH

This paper describes the development of a failure diagnosis technique for V-belts through vibration monitoring. The V-belt vibration is moni tored at a driven bearing body attached to a power transmission device . Seven basic causes of belt failure and their combinations are consid ered. Power spectra of the vibration data are calculated through noise reduction by a cross-spectrum method. Six parameters characterizing t he vibration data are extracted, and 16 typical combinations of the ba sic causes and a normal belt state are diagnosed successfully by a Bay es' discriminant function approach. Two types of incorrect diagnosis a re examined: Type I leaves a failed belt not repaired, and type II cau ses overmaintenance. A risk ratio for the Bayes' discriminant function is determined to minimize the two types of incorrect diagnosis. Moreo ver, the risk ratio is determined to minimize type I error.