Abstract:  Aiming at the problems that the axle box bearing of multiple units was prone to fatigue damage, the elastic composite cylindrical roller bearing was selected as the transmission support component for multiple units wheel sets, and the theoretical derivation, simulation calculation and experimental analysis of the bearing capacity were conducted for the elastic composite cylindrical roller bearing applied to wheel sets. Firstly, the mechanical model of multiple unit‘’s bogie was developed with the vertical loads, transverse loads and longitudinal loads by axle box bearing under track irregularity condition. In addition, considering the structural characteristics of the elastic composite cylindrical roller bearing, the optimized filling degree of the elastic composite cylindrical roller bearing was determined under the two working conditions, abnormal load and conventional load, for the wheel sets, the bearing characteristics of the elastic composite cylindrical roller bearing and ordinary cylindrical roller bearing were compared and analyzed with the above working conditions. Finally, the contact stress was tested on the bearing test bench to verify the accuracy of the EMU wheel set bearing simulation model and the superiority of the elastic composite cylindrical roller bearing. The results show that the maximum equivalent stress of the elastic composite cylindrical roller bearing is 19.82% and 27.92% lower than that of ordinary cylindrical roller bearing under abnormal load and conventional load conditions, respectively. The analysis results might provide theoretical references for the design and optimization of wheel sets transmission system of multiple units.

Key words: multiple units wheel set; elastic composite cylindrical roller bearing; carrying capacity; fatigue damage ;filling degree; equivalent effective stress