The Design Of Rotary Motor And The Research On The Piston Friction Pair

Recent years, the Mini-excavator market has grown rapidly and developed vigorously. With the continuous development of science and technology, the requirements of its performance has become higher and higher. The excavator need to complete walking and rotary motion during the working process, and its environment is harsh. As the executive element of excavator's hydraulic systems, its technology level, to a large extent, decides the performance of excavator's rotary system. At present, the technology of rotary motor for excavator aboard is very mature, while in domestic is still in the developing stage and mostly depend on the import, so it's urgent to research on them.This paper takes the rotary motor of 6T excavator as the research object and mainly achieved study as follow. Firstly, analyzed the kinematics and dynamics of swashplate-type axial piston motor, and established the mathematic model. Secondly, calculated the dimension parameters of piston and shaft in accordance with relevant mechanical design manual, finished the preliminary design, then established mathematic model of cylinder based on the reasonable simplification of its structure, use the optimization tool box of MATLAB and relevant mathematic theories,hydraulic theories to optimize the key dimension parameters. Also, the same method is used in the brake design, and the unlock simulation was done. Thirdly, analyzed the stress of piston-cylinder friction pair by using a new calculating method, compare its results with traditional method's, analyzed the difference between them and try to find the reason caused it, then studied the main dimension parameters' effect on the stress of piston. Finally, the leakage and temperature rise of the piston-cylinder friction pair was researched.Through the design and analysis in this paper, the foundation of rotary motor design is discussed, and a reference is provided.