Experimental system for ultrasonic testing of axle sets of diesel-engine trains

The railway network requires safety and reliability of service of all railway vehicles. Suitable technical systems and appropriately adapted working methods, which meet the requirements on safety and good order of traffic, should be maintained. Maintenance of railway vehicles is scheduled in accordance with periodic inspections and regular repairs. Inspections and repairs are prescribed according to the criteria of operational life, limited by the time of operation of a locomotive in traffic or according to the criteria of operational life including the path travelled. This paper deals with testing of axles in wheel and axle sets of diesel-engine trains; attention is devoted to theoretical as well as practical work. A suitable and proven experimental system for the ultrasonic testing of axles of diesel-engine trains was developed. Researchers had at their disposal unserviceable wheel axles and disassembled axle sets in which it was possible to simulate defects at various depths at individual critical points. On the basis of the defects, the applicability of individual ultrasonic probes was assessed. Testing was thus successfully carried out with each of the selected ultrasonic probes at the shorter and longer side of the gear wheel of the driving axle from different fields, and with the apparatus setting at 1.5 and 2.5 m. Each of the variants selected was recorded for subsequent analysis of the results. Finally, based on the procedures selected, geometries of the known types of ultrasonic paths were calculated for a comparison with the results of the experimental work.