Design Of Rotary Motor And Performance Research On Safety Valve

The requirement of hydraulic excavator for both the quality and the performance has become increasing higher with the development of our economic construction. At present, the domestic excavator components basically all depend on import, that undoubtedly increases the cost of an excavator and reduces the competitiveness of domestic excavator. Therefore, it is urgent to develop hydraulic components for domestic excavator with reliable performance. In this thesis, we aim at the rotary motor and safety valve of 20t excavator as the research object and mainly achieve the study as follow:(1) The design of the core parts of rotary motor used for 20t excavator is performed according to the axial piston motor design principle. Through theoretical analysis and MATLAB simulation, the structure size of piston, slipper, port plate, backhaul plate and cylinder is definite, as well as, kinematics and kinetics of piston and slipper are analyzed, and strength checking of slipper is carried out with ANSYS software.(2) The performance of common hydrostatic bearing slipper is analyzed, at the basis of that, a kind of structure, named slant slipper is presented using the hydrodynamic lubrication of slant slider. The result shows that the bearing performance of the slant slipper has certain improvement through simulation analysis. The dynamic equation of common one is set up and the paper also analyze the response of slipper in the case of abrupt changes of external load.(3) The operating principle of safety valve for the rotary motor is analyzed and the dynamic mathematical model of safety valve is established. The effect of the main structural parameters on the dynamic characteristics of the safety valve is discussed by the dynamic response curve, using SIMULINK toolbox of MATLAB to build the simulation block diagram.Through the design and analysis, a reference of the development of rotary motor is provided, at the same time, the principle of hydrostatic bearing is used in the slipper design, by which the slipper designed is compared with the one by the redundant squeezing force method. This thesis also makes research on the dynamic characteristics of a safety valve, offering a basis to further design or improvement of it.