Analysis And Research On Several Key Technical Problems Of Balanced Cranes

Maintaining neutral equilibrium and replacing the lifting nut are difficult problems in electric balanced cranes’ designing and operation. According to the research, deformation of the linkage is one of the most important factors which influence on the neutral balance of balance cranes’parallelogram mechanism. Either improving the structure of the screw nut pair to replace the lifting nut, or designing the lubrication device to improve screw nut lubrication, or prolonging the lifting nut life can solve the problem effectively in replacing the lifting nut.The main research contents of this dissertation are as follows:(1) Based on the theory principle of electric balanced cranes, the existing designing experiences on electric balance cranes were summarized; two key structures’designing of1T electric balance crane were completed, including parallelogram mechanism proportion amplification mechanism and screw-nut mechanism, and3D model of the1T electric balanced crane was built in the SolidWorks.(2) Depending on the theory of multi-body kinematics and dynamics, motion simulation software ADAMS was used to complete a dynamic simulation analysis of1T electric balanced crane. The simulation results show that the designed electric balanced crane satisfy the noninterference moving condition, and acquire the kinematics and dynamics characteristics in the process of movement.(3) Based on the finite element theory, models of different thickness, different cross-section, with or without welded stiffeners of parallelogram mechanism were built,. Using Abaqus for finite element analysis, the minimum deformation and max-stress value of lightest parallelogram rods were obtained. Analysis results show that the proper thickness of rods, choosing variable cross-section, and adding welded stiffeners can effectively improve the strength and stiffness of parallelogram mechanism.(4) Four modifying schemes of screw-nut pair were put forward, and by the analysis and evaluation of the four schemes. And the lowest cost and the most reliable solution is chosen.