DESIGN-OUT MAINTENANCE ON FREQUENT FAILURE OF MOTOR BALL BEARINGS

Availability of mechanical equipment is a function of its reliability and maintainability. Reliability of equipment, at any instant of time signifies the probability of its survival. Classically, the reliability is an equipment design attribute. It is, however, experienced that reliability of equipment is also dependent on how well the equipment has been shaped-up in the chain of processes from design to commissioning. A case study on design out maintenance on frequently failing bearings of a pump-motor set, which showed poor reliability, is discussed. A step wise analysis is detailed in this paper. The analysis showed that improper inspection post-manufacturing or lack of emphasis on the manufacturing drawings issued by the design department can lead to low equipment reliability and can create field problems for maintenance personnel. It is suggested that an analytical approach to maintenance culminates into design out maintenance, thereby increasing reliability and availability. The design out maintenance approach applied to the case study increased the mean time to failure of bearings from 37 days to 2066 days. This shows that DOM is capable of significantly reducing operation costs of an organization.