Hydrostatic transmission model design criteria and hyromechanic transmission comparison in tactical wheeled vehicles

The usability of Hydrostatic Transmission (HST) technology in tactical wheeled vehicles and the selection criteria of the sub-system components were examined. The conditions for the hydrostatic transmission model to work on tactical wheeled vehicles and hydraulic design criteria are specified. Working data of Hydromechanical Transmission (HMT) and Hydrostatic Transmission are compared when equal power and powertrain elements are used. Sub components of HMT and HST transmission systems; By modeling with SimHydraulics and SimMechanics vehicles in the MatLab Simulink package, comparisons are made under the same conditions (Diesel Engine, Vehicle Load, Road Scenario, Acceleration Time etc.). WEICHAI performance report of WEICHAI brand Diesel Engine and Hydromechanical Transmission in the 8x8 Tactical Wheeled Vehicle, whose prototype was completed in 2019 within Roketsan, also provided input for this study. Mechanical simulation was verified with the above mentioned program package using the Diesel Engine and Hydromechanical Transmission provider WEICHAI company catalog data and report output under different road conditions. The same data were used as input to the Hydrostatic Transmission model and a hydrostatic model was created. As a result of the study outputs and results; It has been determined that under the same conditions, both systems can be coupled to the system in terms of efficiency losses at specific speed and load and in which conditions, design criteria and working scenarios of HST instead of HMT. KEYWORDS: Hydrostatic, Hydromechanics, Transmission, Axle Drive, Wheel Drive.