Structural Synthesis And Design Of New Face-shovel Excavator Mechanism

Along with the development of national economy, the requirement of waterconservancy and hydropower project, mining, port construction and municipalinfrastructure project and the corresponding investment are increasing by years, and so asthe large-scale digging and loading equipment. For the features of heavy loading and highworking efficiency, the hydraulic face-shovel excavator is becoming more and morefavorable by builders. The working device of excavator is the primary part to finishexcavating movement, however, the documents and files of studying and designingworking device of face-shovel is still deficient and there is only one mechanism type hasbeen applied for the monopoly of patents. In view of that, this article proposed a newkind of multi-linkage mechanism which is suitable for face-shovel excavator bymechanism innovation, and accomplished the whole analysis, design and evaluatingwork.This article followed the studying procedure of mechanism selection, mathematicalmodeling, dimension design and cylinder matching. Firstly, the atlas database of planar12-link3-DoF topological graph was applied and from which a suitable mechanism wasselected by adding several selection principles built up by the working characteristics offace-shovel excavator. Then kinematics model of the new mechanism was establishedand the inverse and forward kinematics and velocity solution were analyzed.Also design method of the primary dimensions of working device for a certainbucket capacity was introduced, and the primary dimension for a capacity of50m3wasobtained. Regarding the stability during horizontal lifting and level excavating motion asthe optimal objective, the component dimension and joint position were optimized byapplying GADS. Additionally, the axes of cylinder joints were optimized as well.Referred by concept of digging-restriction-force, the mechanics model of newmechanism was established and the digging atlas of it was redefined. On the basis of that,the conception of bearing force atlas of cylinders was proposed. Then according to thebearing force atlas and characteristic of coupling mechanism, the reasonable approach of matching cylinders for excavator was given and parameters of the cylinders are obtainedby the way. Finally, the performance of the new mechanism face-shovel is demonstratedand compared with existing product the advantages that the new mechanism has weretestified.