Fatigue life prediction of the axle box bearings for highspeed trains

Abstract

Accurate life prediction of bearings is critical in ensuring the

normal run of high-speed trains. However, due to their high run

ning speed, the bearing load of the high-speed trains is complex

and exposed to hostile conditions; thus, predicting the life of the

bearings by the fixed load using a traditional method is often in

accurate. To solve these problems, the International Organization

for Standardization (ISO) 281:2007 and L–P theory bearing life

calculation methods are applied in this study, combined with the

Miner linear damage theory to propose a bearing life prediction

method based on the measured load. Then, on the basis of axle box

spring and tumbler load testing technology, the railway line of the

motor bogie axle box of CRH380AL high-speed train is measured

to obtain the load time history of the spring and tumbler at the

typical railway line section, as well as the running speed informa

tion of the train. Finally, the predicted life of the axle box bearing

under the actual running condition is calculated using this meth

1. Results are compared with the life calculation results using the

classic Lundberg–Palmgren theory and the ISO standard method.

Results show that the service life calculated by the life prediction

method based on ISO standard is the shortest, which is approxi

mately one eighth of that by the ISO standard method; moreover,

the calculated service life is significantly longer than the actual

overhaul life of the current high-speed train axle box bearing (2.4

million km), indicating that the calculated life is reasonable and

safe. The proposed life prediciton calculation method of the bear

ings can be used to guide the design and the related theoretical

research of high-speed train axle box bearings.