Study On High-speed Train Axle-bearing Relaxation Mechanism Basic On The Temperature Characteristics

With the vigorous development of high-speed rail, high-speed train has become one of the most important transportation. So the security problem of the high-speed train has become an important issue in the public safety. The locomotive relaxation of the axle-bearing is an important factor affecting the safety of the train. Many scholars at home and abroad have realized the danger of locomotive relaxation. But the study of relaxation is resting on the level of development of monitoring device and avoiding human error. So the process measures targeted inhibit relaxation can’t be got for the locomotive axle-bearing relaxation are not revealed from the mechanism. It will be great significant both in theoretical and practical to study the mechanism of high-speed train axle-bearing relaxation.This paper will study and reveal the mechanism of the high-speed train axle-bearing relaxation from the perspective of temperature and will put forward some preventive measures for relaxation. The main research contents and conclusions are as follows.Thermal expansion coefficient of the key parts of the axle-bearing are determined using Diamond TMA type thermal mechanical analyzer, based on the thermal physical and mechanical properties of the different materials may be on the impact of relaxation. The possibility of relaxation is existed under the action of temperature through the analysis of the thermal expansion coefficient of various materials of the axle-bearing system.The heat source of the bearing is analyzed. The bearing model is established using the finite element analysis software ABAQUS according to the actual working condition of the train axle bearing. It is analyzed in five kinds of working conditions in accordance with the train speed of 380km/h,350km/h,300km/h,250km/h, 200km/h and 120km/h. Temperature field distribution of the different bearing components are summed up. Conclusions are reached that the rolling element has the highest temperature rise, then the outer ring, and the last the inner ring under a certain speed. The temperature of the bearing components are increased with the improvement of train speed. Every increase train speed of 100 km/h, the temperature of the inner ring and outer ring rises about 5℃, and rolling element about 28℃.Expansion amount of the axle and inner ring matching to the temperature are got using ABAQUS simulation within the scope of the bearing temperature distribution got from finite element simulation. Then, test method is taken to determine the expansion amount of the axle and inner ring. And the displacement data is collected in real time using the laser triangulation reflective displacement sensor. Then the expansion amount is calculated. Compared with the finite element analysis and experimental results, the influence rule between the axle-bearing inner ring interference and temperature is summarized. Finally the influence of temperature on axle-bearing relaxation is summed up and preventive measure of relaxation is given.