Effects Of Surface Crack To Freight Train Beating’s Performance

Rolling bearing is the important part of axle box device, not only under the weight from freight train spring directly, but also bear transverse and longitudinal rush from rail effects on wheels, so the load role in the axle box bearing is great, it’s performance can affects the operation of entire freight train directly.Load effect on the bearing can only form a small contact area between roller and raceway, therefore, the stress on the contact surface between roller and raceway is very high. Long in this state, the contact surface is very easy to cause fatigue damageFatigue、poor installation or improper maintenance can produce crackle on bearing surface, this will accelerate the damage of bearings, affect the service life of bearing directly. In order to study the influence of defects on the bearing, the main work of this paper is as follows:1. Study on the theory of rolling bearing. The main study is rolling bearing’s load distribution、stress and strain; From the perspective of the fracture mechanics, analysis the crack propagation, and the stress condition at front of the crack, provides a theoretical basis for finite element analysis for bearing2. Create the bearing model in ANSYS. Compute stress intensity of the bearing, analysis the stress and strain of the roller, compared with the results of theoretical. The results show that by the increase of the load, the edge effect become more and more apparent.3. At the end of roller’s contact surface set up the bearing models with1mm、2mm、3mm crack, compute strength of the bearing, analysis stress and stress intensity factor of the bearing.4.Compared stress of bearing found that the existence of crack in the bearing makes stress more concentrate; Through analysis the stress intensity factor, the results show that the crack has a deep extended trend; As the length of crack growth, the stress intensity factor of the innermost crack increase.5.At the end of the article, calculator the size of critical crack, the result show that when crack existing in bearing, with increase of the load the size of critical crack decreases rapidly.