Research on the Influence of Characteristics of Secondary Suspension on Vehicle Vertical Vibration in High-Speed Maglev Vehicle

Abstract Aiming at the phenomenon that the vertical vibration acceleration amplitude of the vehicle body of a certain type of EMS high-speed maglev train increased significantly after being put into operation for a long time, theoretically analysis and numeral calculation were carried out about the influencing factors of the vertical vibration characteristics of the vehicle body in this type of high-speed maglev train, determining that the secondary suspension device in the form of symmetrical closed-chain six-linkage this type of vehicle had obvious influence on the vertical vibration characteristics of the vehicle body. Then with the vehicle system dynamics model considering the dynamic characteristics of the symmetrical closed-chain six-bar linkage mechanism in the secondary suspension, the influence of the slewing resistance in the rotating pair of the mechanism on the vertical vibration of the vehicle body was deeply studied. The research results show that: the operating speed of the vehicle and the vertical stiffness of the primary suspension have little influence on the vertical vibration of the vehicle body; the vertical stiffness of the air spring in the secondary suspension and the slewing resistance at the rotating pair of the symmetrical closed-chain six-link mechanism both affect the vertical vibration characteristics of the vehicle body, but the latter has a more obvious impact, whose influence on the vertical acceleration amplitude of the vehicle body is up to more than 50%, compared with the test results; in order to improve the vertical dynamic performance of this type of maglev train, it is suggested to keep the slewing resistance at each rotating pair of the symmetrical closed-chain six-link mechanism in the secondary suspension at a low level during daily operation and maintenance of the vehicle.