Dynamic Simulation Of Escalator Step Chain With Analysis And Optimization Of Key Components

Escalator is an indispensable means of transportation in modern society.Its appearance and popularization have facilitated people’s travel and life.At present,escalator technology mainly includes the development trend of ensuring smooth operation and reducing energy consumption.The current development trend of escalator technology is mainly to ensure smooth operation and reduce energy consumption.As the core drive device of escalator,step chain drive system carries passengers up or down through chain drive during the operation of escalator.Its dynamic performance and component operating state determine the smooth operation and safety of escalator.It is of great significance to study the smoothness of step chain drive,the working condition of components and to optimize the weight reduction of step chain components during the operation of escalator.In this paper,dynamic performance,force,deformation and stress distribution of step roller and chain plate during operation of automatic escalator step chain drive system under different conditions are studied by means of dynamic simulation and finite element analysis,and lightweight design of step chain plate components is carried out.The content and conclusions of the thesis are as follows:(1)Dynamic simulation model of escalator chain drive system was established by ADAMS.The influence of operating speed and initial tension on the operation stability of escalator was studied.It was found that the fluctuation of chain speed would increase with the increase of speed.The influence of initial tension on velocity fluctuation of escalator is studied,and it is found that proper initial tension can improve operation stability of escalator.The influence of different operating speeds and passenger loads on force of chain drive components is studied.It is found that the force of roller and chain plate of step chain components does not change much at different operating speeds.The load of step roller and chain plate under different passenger loads is obtained,which provides load data for finite element analysis of step chain components below.(2)Based on the force data of the step roller obtained by dynamic simulation,the meshing and rolling contact of the step roller components during operation are analyzed through ABAQUS to study the operation condition of the step roller under two conditions.1)In the research of meshing contact,it is found that the maximum internal stress of the roller is concentrated in the area of the inner ring of the roller,and the internal stress distribution decreases from the inner ring and the middle area of the roller to the surrounding area.When the width of the tooth profile is optimized,the deformation and internal stress values during the engagement of the roller with the tooth profile are significantly reduced,and the stress value in the inner ring area of the roller decreases rapidly,resulting in a more uniform internal stress distribution.2)Rolling contact research shows that the running speed has no obvious influence on the contact between the roller and the guide rail.When the friction coefficient between the roller and the guide rail increases during operation,it helps to improve the contact state between the roller and the guide rail,but at the same time,the contact area between the roller and guide rail will also decrease,and the contact stress between the roller surface and the guide rail will increase.The contact condition between the roller and the guide rail in a worn state drops rapidly.As the wear of the roller increases,the contact stress of the roller also increases.(3)Based on the load data of the step chain plate obtained by dynamic simulation and the load analysis of the step chain plate by ABAQUS,the paper studied the stress distribution and structural deformation of chain plate structure under different passenger loads,which reveals that many materials in the middle area of the step chain plate under load are not fully used.The ATOM topology optimization module is used to optimize the chain structure,and the redesigned step chain reduces the volume by 35%.In addition,static strain tests under different tension loads have been carried out on the front and rear step chain plates before and after optimization.Stress distributions in the middle of the chain plate and at the shaft holes have also been measured.These not only verify the reliability of the previous static finite element model of the chain plate,but also prove that the stress value of the optimized chain plate structure is within the safety range.