Influence Of Parameter Change Of Wheel/Rail Contact Pair On Contact Performance Of BMU

With the development of special-shaped wall buildings,BMU,as a kind of high-altitude mechatronics aerial work equipment,have been regularly maintained and cleaned for the construction of curtain walls in high-rise buildings and skyscrapers,which has become an important aerial work tool.Large BMU with arm lengths over 30 m have been rapidly developed.In order to expand the scope of BMU and meet higher operating requirements,telescopic arm roof track BMU have become the mainstream model in the industry.In the actual erection and work of the window cleaner,there will be expansion joints when the track is erected.In actual laying,the track is not completely on a flat surface,and there will be a certain slope.If the changes in the overall mass and center of gravity of the machine are seriously offset,It will have some adverse effects on the walking mechanism of the window cleaner,directly affecting the overall performance and safety of the machine.The load-bearing wheels and tracks in the window cleaning machine travel mechanism are particularly important when changing stations.This article first takes the CWGS250 window cleaner as an example,uses Solid Works to build a full-scale three-dimensional model of the window cleaner,and imports the model into the dynamics simulation software ADAMS to establish a virtual prototype original scale model of the window cleaner.In order to obtain the dynamic contact characteristics and dynamic parameters of the walking mechanism when the window cleaner is running,the window cleaner model is subjected to a complete station conversion process,which prepares for the finite element analysis of the structure of the window cleaner's weighing wheel and track and provides certain The data.The Hertzian contact theory and the finite element elastic contact analysis method are used to perform the elastic contact analysis of the point contact and the line contact state of the load bearing wheel and the track.The finite element elastic contact analysis method in the two theoretical models is more in line with the actual contact state.Compared with the theoretical calculation method,the finite element elastic contact analysis method has fewer limitations and is more accurate.The results of finite element elastoplastic contact analysis and elastic contact analysis of load-bearing wheels and tracks are compared,and the results show that the maximum contact stress of the load-bearing wheels has reached the material's yield limit,but the deformation is small and it has a good load carrying capacity.Introduce the slope track,and change the slope of the track at the joints and the slope of the straight track to create a reference slope limit range that is reasonable to limit the basic standard in actual construction.Based on the workebench parametric modeling,the finite element model of the window-wiper wheel-rail contact was completed in ANSYS,and the mechanical simulation and analysis were performed to obtain the parameters that have the greatest impact on the contact analysis,and then optimized toobtain the contact analysis.Valid results provide a reference.Finally,the size of the load-bearing wheels is optimized,the work-bench optimization module is used to study the load-bearing wheels,and the optimization scheme is designed with a Six Sigma failure rate to verify the rationality of the optimization results,Improvements were made on the original H-shaped track to provide a new design direction for the design of the track.In summary,the optimal characteristic parameters and track structure parameters of the contact area obtained in this paper have certain engineering application value for improving the bearing capacity and life of the track by analyzing the contact between the load-bearing wheel and the track.