Research On Straightening Of Intermediate Axle And Improvement Of Straightening Fault

Shaft with gear is a synthetic mechanical part without bond, and is used widely in machinery, automotive, aerospace, printing, instrumentation and mining industries. Gear shaft have a radial deformation inevitably after heat treatment. Straightening is the most simple, affordable, flexible and effective way to correct the radial deformation. The crack or fracture often occur in the straightening process, because the pressure is not easy to precisely control. The crack or fracture cause to the loss of the waste not only, but also cause to equipment damaged. If the crack is not identified in the straightening process,it will be growth to fracture in the gearbox after be installated. This is a dangerous failure for car. Therefore, reducing straightening cracks and fracture are common issues for the factory.The intermediate shaft of one transmission often occur crack and fracture between D-E site when straightening.This paper research on the intermediate shaft straightening. The analysis of straightening fracture detection shows that the tensile stress in the D-E site generated being more than the tensile strength of the material is the main cause of cracks and fracture.In order to solve the intermediate shaft straightening crack and fracture, this paper studies straightening methods, structural design, straightening process,and so on, and made the following improvements:(1) increase the value of R angle,for reducing the stress concentrated of R position and stress "partial load".(2)adjust the quenching process,for obtaining the appropriate straightening performance.(3)adjust the tempering temperature, for improving the straighten performance intermediate shaft material.(4) straightening when the shaft isheated to tempering temperature.The straightening test verify that the improvement measures are effective,and the cracks and fracture of intermediate shaft when straightening has been solved.Through CAE simulation, it reaches following conclusions:firstly,verify that the tensile stress in the D-E site is the main cause of cracks and fracture. secondly,determine a reasonable straightening stroke, thirdly, verify the effectiveness of improvement measures. The results of CAE simulation are correct because they are consistent with the straightening test, so CAE simulation can well replace straightening test as the tools of straightening performance analysis.