Analysis And Optimization Of The Spiral Lifting Mechanism Of Multi-function Crane In CRH Bogie Check And Maintain Lines

Multi-function crane is the main transportation equipment of CRH bogie checking and maintenance limes which is used for the auxiliary bogie maintenance work.Spiral lifting mechanism of Multi-function crane is used to lift bogie in high frequency and worked intensively.Nut bears serious wear and tear and bolt bears periodical alternating load which is prone to fatigue damage.To solve these problems,it's necessary to study the statics load distribution and dynamic meshing characteristics of screw transmission mechanism of the Multi-function crane.The spiral lifting mechanism of Multi-function crane is studied in this paper which is based on the finite element static theory,contact mechanics theory,dynamic theory and fatigue theory.The main research contents are as follow:(1)Established the axisymmetric finite element model and the solid finite element model of the screw transmission in use of the softwares Solidworks,Hyperworks and Ansys.Analyzed load distribution in different thread section of a screw pair and verified results of the two finite element models with SOPWITH and YAMATOTO method.Assessed the load distribution of the screw transmission in variety of tooth shape parameters.The optimization screw transmission mechanism is put forward(2)Carried out dynamic meshing simulation of screw transmission mechanism under the maximum load condition.Verified element grid independence of the nut tooth surface contact stress.Analyzed the load distribution of tooth surface and the bending stress distribution of the tooth.Analyzed the speed,load and offset load on the effect of dynamic meshing characteristics of screw transmission.Optimized the screw transmission structure based on the analytical results.After the optimization,the surface load distribution of the screw pair tooth is more uniform.(3)Analyzed the original and optimized screw transmission mechanism.Compiled the load spectrum based on the dynamic meshing simulation and analyzed the fatigue life of bolt of the spiral lifting mechanism of Multi-function crane.Compared the fatigue life of optimized bolt modal with advanced bolt modal.It turns out that the fatigue life of bolt is doubled and is higher than the required non-failure operation time of Multi-function crane.