Sheave axles of mine shaft hoists � difficulties and limitations in assessing their technical condition during in-service tests

The paper discusses the difficulties and limitations in the possibility of assessing the technical condition of sheave axles during in-service tests resulting from the lack of access to many areas of the outer surface of the axle due to built-in bearings and mounted sheaves, as well as from the complex shape of some types of axles. Examples of in-service axle failures are given and the causes are discussed. In addition, information on the legal basis for performing non-destructive testing of sheave axles in service, technical requirements for sheave axles, critical areas found in axles, theoretical basis for ultrasonic testing, and testing techniques including the latest phased array method is presented.