Study On Design Technology Of Thin Walled Four Point Contact Ball Bearings Used For Industrial Robots

Thin walled four point contact ball bearings used for industrial robots are key elements for industrial robots. They play a crucial role in robots main engine performances of action accuracy, running stability, running flexibility, life, and reliability. In order to solve the problems of lacking mature design and analysis methods for such bearings in domestic at present and meet the matching need of industrial robots host, it is necessary to study the design theory and method for thin walled four point contact ball bearings used for industrial robots, establish the optimization design and analysis methods for such bearings, and provide the theory support and design basis for the development of such bearings in domestic.For above-mentioned reasons, the paper, taking the thin walled four point contact ball bearings used for industrial robots as the research object and according to the structural characteristics, working conditions and requirements of such bearings, has studied the main parameters optimization design method for such bearings from the aspects of the selection of the objective function, the determination of the constraint conditions and the solution of the multi-objective optimization design, established the mathematical model of main parameters optimization design and the solving algorithm of such bearings, and written the optimization design program at the first. Then, the paper has studied the key structure parameters design for such bearings from the aspects of groove curvature radius coefficient, groove position, rib height, clearance and performances, etc, presented the design methods of key structure parameters for such bearings. After this, the paper, aiming at the typical model thin walled four point contact ball bearing FPXU408-2RZ used for industrial robot, has established whole finite element simulation analysis model of hollow shaft, bearing FPXU408-2RZ and housing and applied loads and boundary conditions based on real working conditions by using finite element analysis software ANSYS, and carried out the whole finite element analysis on this bearing, and solved load distribution of the flexible supporting bearing. Finally, the paper accurately calculate the life of bearing FPXU408-2RZ with the calculation method of bearing life based on the bearing actual load distribution on the basis of Lundberg-Palmgren rolling bearing life theory.By the research, the paper has established the optimization design methods of main parameters and structure parameters for thin walled four point contact ball bearings used for industrial robots, made up the shortage of lacking design methods for such bearings in domestic, and solved the accurate solution problems of load distribution and life of the flexible supporting bearing. The finite element analysis indicates that the axle-system elastic deformation has great influence on bearing load distribution and life. The classical method has been responsible for a great error in the solution of load distribution and life for the flexible supporting bearing. But the finite element method can solve this issue perfectly. The research results can supply some design basis and theory support for product design and theory analysis of thin walled four point contact ball bearings used for industrial robots, and can improve the level and reliability of product design and analysis.