A Special Vehicle Hydrostatic Transmission System Design And Simulation Study

The research object of this subject is a special vehicle’s hydrostatic transmission system. The operating device has a great running resistance not only in normal driving but also in working. The design and emulational basic theory and method of hydrostatic transmission system of heat regenerative milling car are analyzed. The main content and results are as following:(1)The hydrostatic transmission program in running and working is obtained, based on its speed regulation method.(2)The model of stress analysis for the whole vehicle is built and power equations of resistance are got. The stress ratios that tools cut the bituminous concrete in different temperature are got by using FEM. Then devices’resistance and power of resistance in different working conditions are also obtained by calculating them.(3)Based on hydrostatic transmission theory, the parameter matching and components selection for engine and devices in driving and working are done. And the selection and computational formula about the efficiency of variable pump, motor and hydrostatic transmission system are checked and analyzed. At last function relationship between control current and running speed can be deduced based on the principle of variable pump and variable motor control and it’s useful for simulation analysis.(4)These two kinds of hydrostatic transmission system can be built by using AMESim: one is working device with load-sensing variable pump, the other one is running device with electron ratio control. Both simulation of working device system modal and dynamic property analysis of running device show the correctness of the parameter matching and selection. The simulation results of climbing performance show that walking system could through the maximum gradient of the road by more than four. The braking time can meet the requirements while there will produce hydraulic shock in the system when braking, so protection measures need to be taken and the opening of engine throttle should be reduced. For avoid the step load cause the wheel slip or the engine flameout when start hydraulic pump, the governor’s time should control more than2s.To ensure the stability of the vehicle starting, the working device cannot work in the initial process, it could work and load the work device’s load after the driving speed stability.