Design and Test methodology development of Retainer plate in Forward and Reverse mechanism of Tractor Transmission

ABSTRACT: In the Automobile tractor- transmission system plays major role to transfer power from Engine to final drive through gear box enabling Forward/reverse(F/R) movements during field operations and transportation conditions. The F/R retainer plate with idler gear, shaft is located between clutch housing and transmission gear box housing. If the retainer housing plate gets failure, then power will not be able to transfer from engine to transmission gear box main drive. In one of the tractor model Retainer plate failures was observed during field testing. To simulate the failure mode from field to lab condition, the resultant forces and angle were calculated based on the gear torque and gear ratio of the drive line assembly. The resultant loads were applied on Idle gear shaft assembly through servo actuator in cyclic mode at FTL lab. The failure was observed in the Retainer plate and location of failure was matching with Field failure. CAE Virtual simulation was carried out for measured load as per the laboratory boundary conditions and capture the failure mode. To quickly resolve the concern, recommended design iterations were performed in virtual simulation. Optimized designed and virtually cleared retainer plate was then offered to laboratory testing for re-validation. The test result was found to be satisfactory which was then implemented for further field testing. Further failure was not reported from field testing which ensured the robustness of the test methodology and accelerating physical testing. Abbreviations: FTL-Fatigue test lab, CAE-Computer Aided Engineering, F/R- Forward /Reverse Mail Correspondent: V.SARAVANAN@mahindra.com