Research And Development Of Hydrostatic Transmission System Of Warehouse Logistics Equipment

Hydrostatic transmission has such many advantages as stable starting under full load,infinitely variable speed,easily converting driving direction forwards and backwards and high transmitting power, it has been applied widely on all kinds of mobile machinery in the developed countries, but in our country, the foreign grown products of hydrostatic transmission have only been applied and popularized, without systematic and deep research for hydrostatic transmission system.The traditional driving method of warehouse logistics equipment is mechanical transmission. The mechanical transmission needs the expensive electric governor system. But the electric governor system is imported from the developed countries. Besides, mechanical transmission has such many disadvantages as big starting pulsation,starting difficultly under full load and converting driving direction difficultly. So it can not satisfy the working requests of warehouse logistics equipment. From the point, This thesis is based on the RS 16 Electrical forklift of Zhejiang Noblelift Equipment Joint Stock Co.,Ltd. The hydrostatic transmission of warehouse logistics equipment is researched systematically.Main contents of the thesis are listed as follows:1. The property of mechanical transmission,hydraulic mechanical transmission and hydrostatic transmission is analyzed. the principle drawing of hydrostatic transmission system of warehouse logistics equipment is built.2. The key parts of hydrostatic transmission system is designed. The heat of hydrostatic transmission system is researched. The result shows that the influence of the pressure loss of relief valve and throttle valve to the power loss of system is the biggest.3. The key component of hydrostatic transmission system-axial piston variable displacement pump is researched. Kinematics and dynamics of piston and slipper are analyzed. The analysis shows that the tilt angle of swash plate,piston diameter and cylinder speed has the bigger influence to the force of piston. The basis of theory is provided for the research and development of axial piston variable displacement pump.4. The dynamic characteristics of the hydrostatic transmission system is researched, the mathematical models of the hydrostatic transmission system are deduced, the dynamic characteristics of hydrostatic transmission system is simulated by the toolbox-SIMULINK of MATLAB. Then the dynamic response of system pressure, inlet flow of motor and motor torque is obtained. The simulation analysis shows that the system is steady and the hydrostatic transmission system can well satisfy the working requests of warehouse logistics equipment.5. The experiment researches of hydrostatic transmission system are operated. The result shows that the system has small vibration,low noise,no leakage,normal temperature, can satisfy the working requests of warehouse logistics equipment.