Drivetrain pressure spike evaluation methodology & optimization: Simulation and Testing Correlation

This paper describes a simulation methodology developed for pressure spike evaluation and optimization of hydraulic system architecture for off-highway applications with hydraulically actuated clutch. This pressure spike leads to a very high torque spike in driveline components during clutch pop-up conditions in puddling operations. These torque spikes lead to potential failure of driveline components i.e. gear, shaft, bearing and torsional damper during sudden engagement events. To assess the hydraulic system performance during clutch pop-up cornering conditions is very challenging and leads to compromise on operator safety in the paddy field. It is essential to develop a simulation methodology in a virtual environment to understand the system behavior during clutch pop-up condition and impact of various hydraulic system parameters. This study adopts a model-based design approach for understanding hydraulic system pressure spike phenomenon and dynamic response. Pressure spike simulation methodology was developed in a 1-D environment with right fidelity modeling approach to capture the transient events. This model includes hydraulic clutch actuation system, clutch Pedal linkages, torsional damper, drivetrain & vehicle inertia. This methodology has been correlated with test data acquired on tractor drivelines during puddling operation in the field. This dynamic simulation model helps to understand and predict the severity of pressure spike early in the product development cycle to assess & optimize hydraulic system design. DOE was conducted to assess the impact of the various hydraulic system components like valves, accumulator on pressure spike and its impact on drivetrain components. This methodology helped in developing new predictive simulation workflows to resolve design issues analytically and effectively within a shorter time with significant reduction of product development time and cost and risk associated with field tests. Keywords: Pressure spike, Simulation Methodology, 1D, Clutch pop-up, Test correlation