Type Synthesis of 3-translation Parallel Mechanism Based on Graphical Approach

doi:10.3901/JME.2021.23.034

Abstract

Abstract: The 3T(3-translation) parallel mechanism has been widely used in the fields of industrial manufacturing, medical treatment and military industry. With the development of the logistics industry, a 3T parallel mechanism with high stiffness, simple control and low maintenance cost is urgently needed to replace manpower for cargo sorting. Therefore, a 3T parallel mechanism type synthesis method based on the graphical approach is proposed. A large number of equivalent DOF pattern of branches are developed by using the graph equivalence principle in the graphical approach, which provided a foundation for innovative configuration of branches. A large number of new branch chains is also provided a variety of possibilities for subsequent assembly of parallel mechanisms. According to the number of branch chains and the number of constraints contained in the branch chains, the branch selection schemes are divided into seven types. The first four schemes are able to synthesise more than 1 041³ novel 3T parallel mechanisms with a branch number of 3, and the last three schemes are able to synthesise more than 1 041² novel 3T parallel mechanisms with a branch number of 4. Scheme 1, Scheme 5 and Scheme 6 are selected as examples to integrate four new 3T parallel mechanisms, and then K-G formula is used to calculate the DOF and screw theory is used to verify the kinematic characteristics, which verifies the correctness of this new method. The new method synthesizes a large number of new mechanisms, which include decoupled or semi-decoupled mechanisms and are easy to calculate and control, so it has an important application prospect.

Key words: graphical approach, 3-translation, parallel mechanism, type synthesis

CLC Number:

TH112

LI Yongquan, JIANG Hongsheng, ZHENG Tianyu, JING Han, ZHANG Lijie. Type Synthesis of 3-translation Parallel Mechanism Based on Graphical Approach[J]. Journal of Mechanical Engineering, 2021, 57(23): 34-46.

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