Engineering Failure Analysis Methodology & Influence of Spline Cutting Method in Torsional Life Improvement in Tractor Axle Application 2023-28-1318

The Tractors are inevitable in the world due to its remarkable contribution majorly in farming process and other applications. the farming equipment needs to perform multiple applications to enhance the productivity and increased horsepower demands all-wheel drive (Refer fig. 1) or four-wheel drive option in the tractor. So, it is becoming a mandatory feature. The main objective of this study is, improving the torsional fatigue life in front axle spindle shaft by modifying the spline design and optimizing induction hardening heat treatment process in such a way that the other part of the system will have a minor or no design change. It helps us to reduce the part count variability, lower manufacturing cost and development time.

The spindle shaft with undercut design and profile modified design were subjected to tortional fatigue test with same loading conditions to understand the fatigue life cycle difference between two designs at the load of 700kgm as per DVP, the current spline design covered 2.51L, 2.05L cycles whereas modified spline design samples withstood 5.58L, 3.70L cycles. A remarkable improvement in fatigue life cycles were noticed. As a result, it is evident that the under-cut in spline design acts as a low strength member in the whole shaft which initiated crack and subsequently failed. On the other hand, modified spline end allows the carrying higher load and smooth load transfer which helps to withstand comparatively a greater number of cycles. This paper is having detailed information about the failure history, metallurgical failure analysis, manufacturing limitations, design modifications, heat treatment and validation.