CVT Loop Defect Characterization Quantitative Analysis

The roughness,defect,waviness from surface will influence the durability and reliability of the component.Most research about surface now is on roughness,but very less on defect.There is no testing and evaluation standard about defect.Along with technique development,requirement on durability and reliability is increasing.After Bosch transmission technology B.V.improving CVT loop production line,they found the PCP durability increase about 10%.There is no relation between roughness and PCP durability after testing the CVT loop surface from before and present.After research,the defect on loop surface possibly influence CVT belt durability.To further improve the durability by optimize production process,it is necessary to make clear the influence principle.The CVT belt core technology is mostly controlled by Netherlands,Japan and Germany.Only a few domestic relevant CVT surface research has developed.CVT belt surface study at present mainly focuses on roughness and non-metallic material component,No defect research until now.So it is important to build CVT loop surface evaluation standard.The project target is to analyze relation between CVT loop defect characterization and CVT belt durability.The research content is as following:1.Build CVT loop force model,analyze the loads situation in different drive mode.Analyze the force on the whole loop and every single loop.Find the force direction and weakness position.2.Analyze stress concentration and extension theory of surface defect.Based on Loop structure and stress situation,find influence parameters which decides the Pushbelt PCP durability as calculation target.3.Design experiment to make Tumbling and Lem samples.To get the whole 3-D structure of surface,the samples need to be polished and scanned repeatedly.In this project,we choose the white light interferometer and grinding miller.The scanned surface structures are calculation data base for following research.As well,find the error influence parameter and the most adaptable parameters.4.Design image process script and algorithm to calculate(?).The input is image data.The output is(?)after removing dirty point,cutting,rotation,filter and fitting different layers,recognizing defect and calculation.5.Compare(?)distribution of Lem and Turn samples processed by different lines.Compare the calculation result with Pushbelt PCP durability testing result.Analyze the influence rules from defect parameter and get conclusion.