A Research To Running Mechanism Of New Medium-Low Speed Maglev Train With Its Speed Being 140km/h

This paper conducts a research to running mechanism of new medium-low speed maglev train with its speed being 140km/h from four perspectives:introduction to characteristics of running mechanism and comparative analysis of advantages of levitation chassis in terms of mechanical structure; introduction to stress states and constraining conditions of running mechanism travelling in a curve and analysis of decoupling capability of running mechanism travelling in a curve in terms of travelling in a geometrical curve; establishment of finite element model of levitation chassis and analysis of reliability of levitation chassis in terms of statics; and establishment of dynamical model of maglev train and analysis of its good dynamic performance in terms of dynamics. The conclusions are made as follows:1.Running mechanism of new medium-low speed maglev train is largely different from bogie of traditional railway vehicle. The mechanism includes five major systems, namely, levitation chassis module, suspension control system, traction system, brake system and support system. Compared with running mechanism of HSST medium-low speed maglev train, the running mechanism of new medium-low speed maglev train has six differences in structure, namely, centering of large pneumatic spring, long and large linear motor, centering of single anti-rolling sill, linear bearing of middle module, modules independent to each other, smooth decoupling without adoption of forced steering mechanism, all of which reflects characteri-stics of running mechanism of new medium-low speed maglev train.2. When electromagnet module of new medium-low speed maglev train travels in a curve, the location of the electromagnet module passing through any radius curves in a balanced state is determined. Train body will be subjected to lateral displacement in relative to suspension modules, that is, the maximum sliding quantity on sliding table should reach± 78.3mm. To avoid interference when maglev train travels in a curve, clearance between two modules must exceed 0.08m, and 500m vehicle coupler is required with enough surplus length reserved. Modules on left and right sides will suffer from misalignment, with misalignment quantity reaching up to 106mm.3.Strength of each part on levitation chassis can meet requirements. Relatively large stress will occur in a concentrated way at joint of bracket and girder, stiffener of bracket, hole of braking clamp at the middle of pole plate outside, and corner of supporting seat of vertical slider, with the maximum stress being 142MPa. Overall deformation of levitation chassis is very small with the maximum deformation quantity being 0.33mm. Since the height of pole plate of electromagnet module is increased to 132mm from 118mm, deformation of pole plates inside and outside is thus very small, being about 0.3mm.4.Damping value of pneumatic spring and coupling stiffness of draw bar have a large influence on stability of vehicle running. Proper selection of these values can make running stability index of vehicle be satisfactory. Maglev train designed can run at a maximum speed of 140km/h. When the train is under full load, it still can pass through a R50m raised curve at a speed of 30km/h, showing good dynamic performance and meeting design requirements.