ANALYSIS OF THE INFLUENCE OF RESOURCE-SAVING TECHNOLOGIES AND OPTIMIZATION OF THE TRIBOLOGICAL PAIR "TYRE - BRAKE PAD" ON A LIFE OF WHEEL PAIR BANDS OF A TRACTION ROLLING STOCK
In the paper the analysis of the influence of resource-saving technologies and optimization of the tribological pair "tyre - brake pad" on a life of wheel pair tyres of a traction rolling stock is presented. Resource-saving technologies applied at the Krasnoyarsk railway site over twenty years have allowed increasing the life of tyres of locomotive wheels of freight traffic by 1.5-2.0 times with a sufficiently high investment level. The performance indicators achieved in the last seven to nine years have stabilized, which showed the need for the use of new technologies. As an alternative, it was proposed to pay attention to the work of the tribological pair "tyre - brake pad", in which, in addition to the wear of the consumable part of the pads, the elements of the tyre also wears out. Optimization of the work of the tribological pair "tyre - brake pad" is one of the most important directions for further enhancing the resource of the tyres of the locomotives wheel pairs. To identify the share of wear of tyres by the brake pads, operational tests of the three groups of brake pads were conducted - standard break pads with reduced hardness, standard break pads with increased hardness and experimental break pads (with ferrite-graphite structure) on three locomotives of freight traffic at the Achinsk station. Operational studies have shown that the wear of tyres in absolutely identical conditions depends on both the hardness of the brake pads and their microstructure. With a comparable resource of brake pads, the wear of the tyres of wheel pairs of locomotives by experimental pads having a ferrite-graphite microstructure proved to be two times smaller. The research results allow concluding that the transition to the ferrite-graphite microstructure of cast iron brake pads ensures, due to the removal of internal stress, chill and high content of graphite, a more stable operation of the tribological pair.