Research On Steps Of Adjustable Width Escalators

With the development of economy,the application of escalator is more and more widespread,such as shopping malls,subway stations and other public places.The ladder is one of the basic parts of the escalator structure,which is usually cast by mold.At present,escalator enterprises generally choose three specific widths,that is 600 mm,800mm and1000 mm,as common models for ladder production in order to facilitate production.Compared with the width adjustment range allowed by national standard(580-1100mm),the selection range of cascade width is greatly reduced.In some applications where the size of the escalator is limited,such as natural scenic spots,outdoor amusement places and so on,the escalator of specific width cannot be applied.For the steps of these special occasions,the mold has to be opened again,which greatly increases the production cost.Aiming at the above problems,this paper designs an escalator step with adjustable width to adapt to different installation width requirements.First of all,the realization forms needed for the adjustable width of the cascade are defined,and the structure composition of the adjustable width of the cascade is determined.Then according to the national standard in the range of change to determine the width of the cascade size,design and calculate the width of the adjustment of the width of themechanism,at the same time to design the selection of other components,and the design of the selected parts for a comprehensive check.Then,the static analysis of the adjustable width ladder is carried out,and the stress distribution and maximum deformation of the ladder are obtained.Because the step width of this design is adjustable,but its mechanical properties are different under different width conditions,it is necessary to test the force and deformation of the step under different adjustment width.The minimum adjustment width of the step can be achieved is 580 mm,the gap between this width and the commonly used600 mm width is small,so the 580 step is omitted in the study,and the three commonly used width and the adjustment maximum width step are analyzed.Firstly,the 600 mm and 800 mm widths of the steps are analyzed respectively.The results show that the steps meet the national standard requirements when expanding the above widths.However,the stress and strain increase significantly when the expansion width is large.In order to prevent the failure of the cascade under large width,the strengthening design of the cascade structure is carried out when the adjustment width is large.The results show that the statics performance of the improved1000 mm and 1100 mm steps meet the national standard.By comparing the four groups of data,the 600 mm and 800 mm steps without strengthening the structure were obtained,and the maximum stress and maximum deformation increased significantly with the increase of width.The maximum stress position occurs in the component outside the main body of the step.The maximum deformation occurred at the middle step edge.After strengthening the structure 1000 mm and 1100 mm steps,the maximum stress growth range is small.The maximum deformation values differ little.The maximum deformation position is still located at the middle step edge.When the ladder is adjusted to the maximum width of 1100 mm,the safety margin is small,and the number of reinforcing bars can be increased correspondingly in practical application.Finally,the dynamic analysis of the designed adjustable width ladder is carried out.First,the sixth order modal analysis is carried out.The results show that the first natural frequency of the four kinds of steps decreases with the increase of the width of the step.The first natural frequency with a width of 600 mm is the largest,and the difference between the first natural frequency with a width of 1000 mm and that with a width of 1100 mm is small.Therefore,the larger the spread width of the ladder is,the more likely the ladder will resonate.Then the obtained modal analysis results are imported into the harmonic response analysis module as pre-processed data for harmonic response analysis.The results of harmonic response analysis show that the dynamic performance meets the requirement.By comparing the four sets of data,it is concluded that the deformation values of the three commonly used width steps under dynamic load also increase in turn with the increase in width,and themaximum adjusted width value of 1100 mm is close to that of 1000 mm steps.