Research On The Dynamics Performance Of 32.5t Axle Load Freight Wagon Stering Bogie

Developing big axle load freight bogie above 30t is the next target of China heavy haul, and the transformation to heavy haul on the steering bogie is a feasible path. The research on sub-frame self-steering bogie has been mature in china, but few relevant research results on 32.5 t axle load heavy haul has been developed. Besides from the use of 25t axle steering bogie K7, there are a number of deficiencies. Based on the theory research on the sub-frame steering bogie used cross-anchor to the vehicle dynamics performance, this paper make use of SIMPACK dynamic simulation software to calculate and analysis the feasibility of dynamic performance of steering bogie under 32.5t axle load. Finally aim at some of the problems, the paper offers a few suggestions for the improvement, hoping for providing some useful references for the selection of new big axle load bogie.Via theory analysis, there are two factors of self-steering bogie to improve vehicle curving performance. One factor is that when bogie entering the curve, the steering mechanism would transfer creep torque of the direct wheel-set to the rear wheel-set, which turns it into radial position, and reduce its yaw angle displacement. Another factor is the equivalent shear stiffness of the steering mechanism adding to the bogie, which makes the bogie hunting stability better. At same time, the box suspension stiffness values can be lower than the traditional truck, which is good for curve-passing performance. The additional shear stiffness value from the sub-frame cross-anchor steering mechanism relates to three parameters: stiffness of radial rods, longitudinal and lateral mounting span of steering rods, which have practical significance for the improvement of the steering bogie.Simulation results show that, because of the additional equivalent shear stiffness, self-steering bogie can achieve a higher hunting critical speed and derailed stability compared with the cross supported traditional three pieces bogie both using the flexible suspension. The paper analyses and compares the two bogies differences on the dynamics and wear performance on straight and curve track, and finds that radial truck has some advantages, which proves that steering bogie is feasible for 32.5t axle load.The research on the improvement of the steering mechanism analyses three factors—the selection of radial rods stiffness, the change of geometry parameters of radial rod mount point and the improvement of the mount point hinge, which affect the dynamic performance of the bogie.