Research On The Design Method Of The Spherical Hinge For Side Three Supports Multi-Crawler Unit

In recent years, multi-crawler unit are widely used in the process industry. The length of the pedrail is very long and the pedrail under enormous weight. When the crawler work surface is not flat, each group of tracks may be located in different planes. The spherical hinges allow the upper structure of relative rotation.Then the crawler can overcome uneven ground. So in multi-crawler unit, spherical hinge is an important component which connects the pedrail and rack. The reliability of spherical hinge determines the safety and economy of the production. Therefore, this paper based on understanding of the traditional design method of spherical joints; research the method of the spherical hinge by the finite element. The main research work and achievements of this paper are as following:1. Through searched and read literature of multi-crawler unit and spherical hinge, kept abreast of current development in technology at home and abroad, then understand that multi-crawler unit is widely used in industry, and the usefulness,composition and research of spherical hinge in multi-crawler unit. Learn the relevant knowledge of the finite element method, and understand the basic idea and characteristic of the finite element method. Through study the finite element analysis ANSYS, to further deepen the understanding of the finite element method. Then the direction of this paper is determined.2. When the crawler device is stationary or linear motion, the supporting force of the upper structure is the main force of spherical hinge. But when the crawler device turn, the lateral force from the track is a force to spherical hinge. The impact of the lateral force is needed to consider in the design calculation. This paper used experience formula to calculate the crawler vehicle resistance. According to the role of spherical hinge, a variety of design requirements need to be considered in the design. In engineering design, the design of spherical hinge reference to the sliding bearing design method, but there are some differences between the design of spherical hinge and the sliding bearing.3. Starting from the elastic contact problem, the contact stress and contact radius formulas are derived through the Hertz formula. Then establish the finite element model of the spherical joints without lining and no solid support within by ANSYS Parametric Design Language (APDL) for the ANSYS contact analysis. Then compare the results of ANSYS contact analysis calculation with the results of Hertz formula calculation, to verify the accuracy of ANSYS contact analysis calculation. Then, calculate spherical joint model of different hollow degrees, consider the effect of hollow degrees upon strength and stiffness of spherical joint. Choose a better structure through analysis and comparison. Finally, establish ANSYS three-dimensional model of spherical joints under lateral force load or without lateral force load, analyze the effect of lateral force load upon strength and stiffness of spherical joint. And deliberate the effect of the liner thickness variety upon analysis calculation results of spherical hinge.4. Finally, the fatigue analysis of spherical joint is progressing. First, introduce the basic concept of fatigue, fatigue damage accumulation theory and analysis of general fatigue in this paper, and then simply descriptive the fatigue module in ANSYS-Workbench. Established spherical hinge model by ANSYS-Workbench, set of contacts, define material properties, applied constraints and loads, set the solution parameters, then to carry out fatigue analysis. After the calculation completed, analyze the fatigue results of spherical hinge to determine the location which is subject to damage, provide basis for the design optimization of spherical hinge.In summary, spherical hinge in multi-crawler unit is the research object in this paper. Then analyze calculate spherical hinge by ANSYS, including contact analysis and fatigue analysis. This study research leads the design of spherical hinge. This paper has supports practical significance and practical value to support the design of spherical hinge in the future.