Affiliations: Universidade de São Paulo, Escola Politécnica,
Depto. de Engenharia Mecânica, Brasil
Note: [] Corresponding author: Rui Gomes Teixeira de Almeida, Av. Prof.
Mello Moraes, 2231, CEP 05508-900, Butantã, São Paulo, SP, Brasil.
Tel.: +11 3091 5590 r. 231; E-mai: [email protected]
Abstract: In the last years new technologies and methodologies have been
developed for increasing the reliability of fault diagnosis in mechanical
equipment, mainly in rotating machinery. Global vibration indexes as RMS,
Kurtosis, etc., are widespread known in industry and in addition, are
recommended by international norms. Despite that, these parameters do not allow
reaching reliable equipment condition diagnosis. They are attractive for their
apparent simplicity of interpretation. This work presents a discussion about
the diagnosis possibilities based on these traditional parameters. The database
used comprises rolling bearings vibration signals taking into account different
fault conditions, several shaft speeds and loading. The obtained results show
that these global vibration parameters are limited regarding correct fault
diagnosis, especially in initial faults condition. As an alternative method a
new technique is proposed. This technique seeks to obtain a global parameter
that makes better characterization of fault condition. This methodology, named
Residual Energy, uses integration of the difference between the power spectrum
density of the fault condition and the normal one. The results obtained with
this technique are compared with the traditional RMS and Kurtosis.
Keywords: RMS, kurtosis, vibration, rolling bearings, condition monitoring
