ZL50 Wheel Loader Overrunning Clutch Failure Analysis And Improvements

ZL50 wheel loader has been the flagship model in Chinese wheel loader market since the last 80's. In combination with hydraulic torque convertor, as one of the most popular assembly in wheel loader,Overrunning clutch leads to higher vehicle trafficability,automatic infinitely variable speed drive and overload protection for engine.This paper gives a background knowledge introduction on overrunning clutch and wheel loader, including ZL50 drivetrain and overrunning clutch operating principle.Ideal Uniform stress analysis as common assumed condition that taken during design and analysis actually almost never happened in real work condition.It showed up that different stress conditions among all the rollers cause particular stress, overstress and surface crack origin.This paper gives a brief introduction on Finite element analysis, Ansys and Ansys Workbench.To verify the above concept on software view,FEA,finite element analysis, ansys workbench is used in this paper,based on rated power input against overrunning clutch.Typical failure parts of overrunning clutch are pictured in this paper to make a visible representation and show the real failure situation.Both the FEA analysis and the failure parts evidenced the different stress of diffent rollers.Based on the FEA analysis and the failure parts,several countermeasures and improvements were recommended or implemented on view of component mechanical design,component material composition and technology development.The failure rate of overrunning clutch dropped down dramatically from 4%-5% to 1% or less than 0.5% after the improvements.And with the achievement of stabilization of engineering process,the quality and performance of overrunning clutch meet all the related requirements of ISO 9000 standard.