Research On Remanufacturing Process And Performance Of Locomotive Bearing

The connecting rod bearing is one of the important parts of the diesel locomotive engine,which plays a very important role in the correct operation of the diesel locomotive.The movement efficiency of the engine are also closely related to the performance of the connecting rod bearing.In order to make full use of resources and reduce the harm to the environment,remanufacturing method is now widely used for the complex and diverse failure forms of the bearing bush.This article employed the characteristics of remanufacturing technology by uses air spray technology to repair and strengthen the surface of the bearing bush.The composite material was selected as the remanufactured coating,and the remanufacturing process of the bearing bush was studied.The mechanical,modal and temperature characteristics of the remanufactured bearing bush were simulated by finite element simulation used ABAQUS/Standard.Moreover,the remanufactured coating material was prepared,and the friction and mechanical properties of the coating were studied.The air spraying machine was used to spray the samples under different process conditions,and the optimal process parameters of the remanufactured bearing air spray technology were obtained.The results of the repaired bearing bush were evaluated,which further confirmed the usefulness of the air spray technology to the bearing bush remanufaturing.The feasibility of remanufacturing repair is detailed as follows.A remanufactured coating was prepared by In-situ synthesis of nano-SiO₂ modified graphene oxide?GO?as a filler to reinforce polyimide?TPI?,which shows excellent friction properties.GO/SiO₂ demonstrate a very obvious effective effect on the improvement of TPI friction performance.Under the same conditions,the wear of pure polyimide is 5.28×10^-7mm³N^-1m^-1,while that of GO/SiO₂/TPI is 5×10^-8 mm³N^-1m^-1,which is an order of magnitude lower.The coating was also rubbed with lubricating oil under the same pressure conditions.As a result,in the case of oil-lubricated friction,no wear marks were seen on the surface of the coating during the same friction time,and the coefficient of friction was orders of magnitude lower than that without oil-lubricated friction.According to the experimental research results,the friction performance of the coating has been significantly improved after the addition of GO/SiO₂ filler.When the filler content is 0.8%,the coating has a significantly lower friction coefficient and wear,which shows significant effect on the friction performance of the coating.It can be seen from the comparison of the compressive mechanical properties of different filler materials and composite materials filled with different contents of filler GO/SiO₂ that the mechanical properties of the coating are optimal when the filler GO/SiO₂ content is 0.8%.The thermal decomposition of GO/SiO₂/TPI composite material shows that the maximum temperature resistance of the remanufactured coating can reach 453?,which can meet the normal working requirements of the bearing bush.The process parameters of GO/SiO₂/TPI air spray remanufacturing are air pressure at 0.7-0.8MPa and the addition amount of filler GO/SiO₂ at 0.8%.Under this process parameter,a remanufactured coating with excellent performance can be produced,.Through the finite element analysis software ABAQUS,the remanufactured bushes prepared under the remanufacturing process conditions were subjected to mechanical,modal and temperature field analysis.Regardless of the tooling or load,the stress and strain of the remanufactured bushes are higher than those of the original bushes.Remanufactured bush coating contributes to force dispersion and high strength,and the first three-order natural frequency of remanufactured bearing bush is 10%stronger than that of the original bearing bush in modal analysis under damping,but the gap between the two increases with the increase of the analysis step.In the analysis of the temperature field,the maximum temperature of the remanufactured bearing bush is lower than the original bearing bush,and the temperature difference is also smaller than the original bearing bush,which may mainly due to the remanufactured coating leat to better the heat dissipation performance and the overall heat dissipation.It can be seen that the choice of GO/SiO₂/TPI composite material as the remanufacturing coating can provide new ideas for improving the friction and mechanical properties of the bearing bush and provide reference data for the remanufacturing of the bearing bush.