| High-speed railway transportation has become one of the mainstream transportation modes in the world due to its high speed and large volume.China ’s high-speed railway industry has developed rapidly and formed an independent transportation culture system,which has become a business card for China to enter the world.In order to meet the stability and safety requirements of high-speed train operation,the Ministry of Railways of China determines the development of one hundred meters fixed-scale rail(one hundred meters heavy rail)as an important technical policy of China ’ s railway.The lifting and handling of 100-meter heavy rail is an important part of rail production.The stability and accuracy of the lifting process are of great significance to reduce the deformation and surface damage of the rail and improve the safety of storage,transportation and stacking.The lifting of 100-meter heavy rail is a complex and difficult problem.The current hoisting method of wire rope drum has many disadvantages such as poor Z-axis synchronization and large lateral swing.To solve this problem,a new scheme of single-drive multi-point meshing gear rack transmission is proposed.However,in practice,it is found that the scheme has the problem of gear tooth interference.Therefore,this paper studies this problem.According to the principle of symmetrical arrangement of gears,the scheme of symmetrical meshing of a pair of gears and a single rack is first selected,but the analysis shows that the bearing capacity of the scheme is insufficient,so the scheme of meshing transmission of two pairs of gears and a single rack is replaced.In order to reduce the assembly size,save costs and improve synchronization,the new scheme adopts the transmission mode of a single motor driving the gear through the worm wheel and worm,that is,the single-driven multi-point meshing scheme is used for100 m heavy rail lifting.Single drive multi-point meshing scheme in the model of virtual assembly found the existence of gear interference phenomenon,can not mesh correctly.In order to analyze the interference of gear teeth,the interference of gear teeth is solved through the transmission of gear tooth position relationship,and the solution method of interference of multi-point meshing gear rack transmission gear teeth is obtained.The displacement coefficient method is proposed to solve the problem of gear tooth interference.Based on the magnitude of interference,the reasonable distribution relationship of displacement coefficient is determined by calculation.The modified gear is re-modeled,and the dynamic simulation of the modified model is carried out by using the finite element simulation software.The results show that the gear tooth has no interference,the force is uniform,and the bearing capacity of the mechanism is improved.In this paper,a new scheme of lifting 100-meter heavy rail by using single-drive multi-point meshing gear rack transmission is proposed.The gear tooth interference problem in the scheme is analyzed,and the displacement coefficient method to solve this problem is proposed,so that this scheme can be used for similar occasions such as lifting 100-meter heavy rail. |
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