Research On The Structure Design Of Shield Machine’s Fuse Shaft

With the rapid development of national economy and technology, underground transportation system brings great convenient for people’s life. Shield machine is developed quickly as the important engineering machinery in building underground transportation system, and fuse shaft as the core component of shield machine not only has the ability to transfer power, but also has overload protection function. However, fuse shaft is often cracked before providing overload protection in practical project, which seriously hinders the construction schedule and reduces efficiency of construction.There are many reasons for fuse shaft’s breakage. Unreasonable design is one of those reasons. This paper analyses and researches the structure of fuse shaft. First this paper analyses the force form from the apart of fuse shaft’s function, construct, transmission of power and relevant parts, gets its force form is torsion, then discusses its working principle bases on circular shaft’s torsion and stress concentration theory. Second, this paper brings in and introduces the relevant knowledge and theory of optimal structure designing, and establishes the optimization math model with optimal design method, then to introduce the knowledge of optional structure designing based on ANSYS. ANSYS can be used to build parametric finite optimization model as a fuse shaft optimal structure designing tool. And structure optimization design of groove is completed based on this model. At last, this paper processes optimal design for U and V type grooves structure in the above method, and gets the rationality and feasibility of two structures.The optimal result indicates that shear stress is greater than material torsional strength in the security load of existing arc structure size of fuse shaft, explaining that unreasonable design is the main reason for fuse shaft breakage. After size optimization, maximum shear stress is close to material shear strength and maximum shear stress fits for the function requirement on the influence of its position and size of the arc. The result also indicates that U type groove structure is not good and V type structure can be used to fuse shaft. This paper can get determined size through the method of optimization.This paper provides some valuable theory for shield machine’s fuse shaft designing. It has important instructive significance for solving practical problem and improving existing structure, and it can effectively reduces the possibility of fuse shaft’s early breakage.