Load distribution and contact of axle box bearings in electric multiple units

Abstract

The rolling bearing, as the key part of the moving component of an electric multiple unit (EMU), its mechanical behaviour has become an active area of research in the development of high-speed EMUs. To provide a reliable basis for evaluating service life span and operational reliability of double-row tapered roller bearings, the load distribution of axle box bearings and the contact stress of bearings were investigated in this study. The methods of numerical analysis and actual load measurement were performed to calculate the internal load distribution. After obtaining the internal roller load distribution relation, a model of a single roller contacting the inner and outer raceways was established to calculate the contact stress state using Abaqus software and the Hertz theory. Results show that the contact load of each roller in the bearing decreases with the increase of the azimuth angle until the roller is outside the load-bearing area. The contact half width and the contact stress distribution of the simulation and the theoretical computation results are consistent. This study can provide a basis for the design and service life evaluation of this type of bearing.