Failure analysis of idler roller bearings in belt conveyors

This paper analyses failures of one hundred idler roller bearings of a belt conveyor. It indicates possible causes of damage and proposes measures to eliminate them or at least minimize them. The bearings were collected for 6 months when idlers were disassembled for service. The bearings were carefully studied and each identified damage was classified in accordance with the ISO 15243:2017 standard photographed and described in terms of its manifestations and causes. The research has shown that the most dominant types of damage are plastic deformation in the form of gaps (42.3%) and corrosive wear (30.7%). Consequences of roller bearing damage are described and illustrated with photographs. The paper also examines impacts of the idler installation position (lateral or horizontal) on bearing damage. Possible main causes of roller bearing damage are represented by a fault tree analysis (FTA) diagram. The created fault tree can be a useful tool for engineers in defining requirements for purchase of new idlers.