Early detection of bearing failures

Throughout the industry widespread use is made of rotating machines (engines, fans, mechanical transmission systems, etc.). One of the most common types of mechanical parts found on machines of this type is bearings, which are frequently used because they combine satisfactory performance with the ability to bear, at times, heavy loads.

Any abnormalities or incidents with such components may have serious consequences for operators and maintainers, for example train failures, physical injuries or the extra maintenance costs of replacing the damaged parts.

Against this backdrop, inspection of bearings and their condition is one of the vital facets of all preventive maintenance policies.One of the phenomena that needs to be watched in operating mode is vibrations. Vibration analysis is a major factor, especially since scientific instruments are available on the market to enable malfunctions to be identified in time, thus pre-empting potential difficulties by enabling quick and efficient replacement of the parts concerned (rings, races, balls), provided that users have sufficient skills in the use of these instruments.

With its experience in the field of vibration diagnostics, the Test and Measurement Laboratory (LEM) at RATP is able to propose a variety of services to maintainers and operators throughout the various product lifecycle phases from definition of requirements through to expert analysis of incidents via periodical inspections in the course of maintenance operations.

The LEM recently played a part in drafting the texts of procedures for inspections conducted using vibration measurements to be applied by the maintenance units (choice of measurement points, indicators, relevant frequency bands, warning thresholds, etc.).

Similarly, the LEM is also happy to assist its clients in choosing measuring equipment by making critical assessments of the performance standards promised by the manufacturers and testing the convenience and practicality of devices ultimately to be used by large
numbers of maintenance technicians.

To identify the condition of bearings fitted on railway vehicles or in public transport infrastructure, the LEM boasts a wide range of skills and capabilities in addition to vibration measurements and can therefore offer a complete package of services in detecting potential bearing wear problems. Its approach is set out below:.