Design of light weight Hydraulic Connecting Rod for Agricultural Tractor 2019-28-0016
Hydraulic power train assembly of an agricultural tractor is meant to controls the position and draft of the implement depending upon the type of crop, farming stage, implement type and soil conditions. These variations induce extreme range of loads on the hydraulic system, thus making it challenging to design these components. Hydraulic connecting rod is critical component of hydraulic power train assembly. Standards like IS12224, IS4468 governs the design of hydraulic power train components which regulates the test method for hydraulic power and lift capacity of the tractor.
In this paper, a virtual simulation process has been established to design a hydraulic connecting rod to meet the requirements. The hydraulic connecting rod basically functions as a short column, which is subjected to the operating hydraulic pressure of the hydraulic lifting mechanism. The current circular connecting rod is higher in weight and cost. So, there is scope for optimizing the design of connecting rod. Virtual simulation has been done by performing (i) Multi body dynamics analysis (MBD) approach is used to predict the loads on Tractor Hydraulic Lift arm and (ii) Static structural analysis for the durability. In the initial stage of analysis, topology optimization study has been performed to get the feasible shape. From the results of Optimization approach, parametric analysis was performed and finalized the design. Optimized design with Cross Ribbed structure is having uniform strength in all directions and meets the Design criteria. The final Optimized model achieved 30% weight saving over current design. Optimum Design of hydraulic connecting rod was patented. The cross ribbed connecting rod has been successfully implemented on farm tractor.
Keywords: Hydraulic powertrain assembly, Connecting rod, Multibody dynamics (MBD), Topology Optimization, Virtual simulation and Static analysis