Experimental Investigation of Shaft Radial Load Effect on Bearing Fault Signatures Detection

This paper investigates the influence of external radial load applied to the shaft on bearing fault detection based on vibration or current in induction motors operating under different conditions. This paper details the results of a laboratory trial comprising different test sets on the condition monitoring and fault diagnostic of a six-poles induction motor using a design of experiment (DOE) approach. The dedicated test setup comprises a custom-made fixture that allows us to dynamically vary the radial load applied to the output shaft. The aim is to investigate the effects of radial load on the fault diagnosis of shaft bearings and the interactions between other operating parameters, such as output torque. Specific scalar parameters have been proposed for the condition monitoring of the test motor from vibration and current data. The correct choice of the significant parameters is proven by the strong dependence on the damage returned by DOE results.