Research On Scale Optimization Method Of New TBM Propulsion Mechanism Based On Transfer Characteristics

As one of many TBM subsystems,the propulsion mechanism is the key equipment for tunneling.The working environment of the mechanism is very complex,and the geology varies from soft to hard.At the same time,it needs to bear the heavy load,large mutation load and strong vibration load from the working environment.If the force transfer performance is not good,it will lead to three problems: the propulsion power transfer can not adapt to the serious change of the working environment of the driving face,the driving resistance transfer can not adapt to the serious change of the working environment of the supporting face,or the working mode can not adapt to the change of the working state,which will bring all kinds of adverse effects to the tunnel construction.For example,instantaneous joint force is too large will cause tool wear and even fracture,more serious will appear tool deformation,propulsion cylinder fracture,tool head disintegration and other accidents.Therefore,how to improve its topological configuration,optimize its mechanism scale and improve its force transfer performance from the perspective of mechanical design will be the main problem of this paper.The following research work is carried out in this paper.1.The research background and significance of this paper are described,and the research status of TBM hard rock boring machine at home and abroad,TBM propulsion mechanism research status and parallel mechanism scale optimization status are summarized.This paper summarizes the research work of other scholars and puts forward the main research contents of this paper in view of the problems faced by TBM propulsion mechanism.2.In TBM advance new institutions as the research object,analyzes its degrees of freedom,that complete with 6 degrees of freedom,on the basis of the principle of coordinate transformation kinematics analysis was carried out on the agency to get the kinematics equation and the velocity jacobian matrix,and based on the agency’s equation and velocity jacobin matrix of linear drivage and curve of excavating trajectory planning.Finally,the stiffness of single propulsion cylinder is analyzed,and the stiffness of moving platform in each direction is studied based on this.3.The force of the driving mechanism in the tunneling process was analyzed,and it was concluded that TBM was subjected to five tunneling resistance and two resistance moments in the working process,respectively: The friction between the shield shell and surrounding soil,the friction between the shield tail and the segment,the friction between the supporting platform and the track,the front resistance of the cutter head,the cutting resistance of cutting rock,the horizontal resistance moment,the longitudinal resistance moment.Based on this,a mechanical model of the propulsion mechanism was established.The expression of joint force is deduced,and the relationship between joint force and motion parameters and structural parameters is analyzed.It is concluded that the radius of moving platform and the radius of fixed platform are the main factors affecting joint force.4.According to the analysis of common mechanical faults of TBM,the force transfer performance index was established,and the optimization function was established based on the index,and the structural parameters were optimized by genetic algorithm.In order to verify the correctness of the optimization results,a load compliance index was introduced,and the mechanism was also optimized based on this index.Comparing the results of the two optimization methods,it is concluded that the force transfer performance index is effective.