Monometallic motor-axial bearings of diesel locomotives: replacing bronze with complex aluminium alloy

Introduction. Replacing the material of monometallic motor-axial bearings currently manufactured from bronze to aluminium alloy is advisable to improve traffic safety due to the higher reliability and efficiency of such bearings.Materials and methods. This article studies the materials of monometallic motor-axial bearings, bronze and the proposed complex aluminium-tin alloys. Mechanical properties are determined by standard methods: tensile strength, relative elongation (ductility), Brinell hardness, impact strength. Antifriction properties (abradability, score resistance, wear resistance of the antifriction alloy and the steel associated with it, the heating temperature of the steel surface and the coefficient of friction) were determined according to the methods of the Railway Research Institute approved by JSC Russian Railways on the SMTs-2 friction machine. Bronze and three grades of aluminium alloys were tested with M-14V2 diesel oil, and bronze, B16 babbitt and one grade of aluminium alloy were tested with axial oil.Results. This research shows the possibility of replacing bronze with complex-alloyed aluminium alloys both in terms of economic indicators and antifriction properties. A comparison of mechanical properties is carried out, in most of which aluminium alloys are found superior or not inferior to bronze. The exception is ductility, in terms of which bronze surpasses the proposed alloys.Discussion and conclusion. According to the complex of service characteristics obtained in laboratory studies, it seems expedient to replace bronze with complex aluminium antifriction alloy. The final decision on such a replacement could be made after bench and operational tests of motor-axial bearings on diesel locomotives.