Study On Hydro-mechanical Transmission System Of 90t Mining Trucks

Hydro-mechanical transmission combines the hydrostatic power flow and mechanical power flow to realize stepless speed variety with high efficiency and large power. It has many advantages in the power drive system of heavy vehicles. At present, the electronic control automatic shift transmission of domestic mining trucks in middle and heavy tonnage must be imported, which increase the cost of vehicle. This paper puts forward a hydro-mechanical transmission system to solve the shortage..1. Referring to the relevant literatures and patents, the technical status and development trend of the traditional transmission systems of mining trucks are summarized and analyzed at home and abroad. The efficiency, economy and technology maturity of five kinds of mining truck transmission forms are compared and analyzed. The results show that the feasibility of hydro-mechanical transmission system is the strongest for domestic 90t mining trucks;2. Aiming to the 90t mining truck,this paper puts forward the double engine hydro-mechanical transmission system, which combined the mechanical transmission system of 55t mining truck with two sides independent hydraulic dirve systems to ensure the driving performances of 90t mining truck. The matching research is done on the proposed transmission system, including the calculation and selection of matching parameters of the engine and hydraulic components. The synchronization problem of the proposed system is studied in emphasis,which includes the start process synchronization and synchronization under outside disturbance. The results show that engine speeds of two power flows should be adjusted together while the displacement of pump keeps unchanged.3. The dynamic performance simulation of the hydro-mechanical transmission system is done under AMEsim environment including full-load starting and no-load starting, the synchronization simulation and hydraulic system dynamic response. the hydraulic power flow shares more load torques when the disturbance load torque increases.The research shows that the proposed double engine hydro-mechanical transmission system has maturing reliable technology and high economy with certain market popularization on the premise of synchronization of mechanical power flow and hydraulic power flow.