Tribological failure analysis of a magnetic drive pump

The failures of a magnetic drive pump are investigated to determine the root cause. The journal bearing design was verified and compared to a similar application that has experienced no operating problems. Also, an investigation of the materials and the product used for lubrication were performed. The root cause was found to be an insufficient fluid film thickness being developed for hydrodynamic lubrication. This occurs as a result of low viscosity of the product and high dynamic loads. It is suggested that care should be taken with bearing selection and design for specific magnetic drive pump applications as inadequate design can lead to catastrophic failures.