DEPENDENCE OF AIR SPRING PARAMETERS ON THROTTLE RESISTANCE

• Main Authors: O. H. Reidemeister, A. V. Kivisheva
• Format: Article
• Language: English
• Published: Dnipro National University of Railway Transport named after Academician V. Lazaryan 2016-04-01
• Series: Nauka ta progres transportu
• Subjects: spring suspension; air spring; viscosity coefficient; stiffness coefficient
• Online Access: http://stp.diit.edu.ua/article/view/67339/66718

Purpose. In this paper it is necessary to conduct: 1) research and analyse the influence of throttle element pneumatic resistance on elastic and damping parameters of air spring; 2) to obtain the dependence of air spring parameters on throttle element pneumatic resistance value. Methodology. The work presents the elaborated model of the air spring as a dynamic system with three phase coordinates (cylinder pressure, auxiliary reservoir pressure, cylinder air mass). Stiffness and viscosity coefficients were determined on the basis of system response to harmonic kinematic disturbance. The data for the analysis are obtained by changing the capacity of the connecting element and the law of pressure variation between the reservoir and the cylinder. The viscosity coefficient is regarded as the viscosity ratio of the hydraulic damper, which for one oscillation cycle consumes the same energy as the air spring. The process of air condition change inside the cylinder (reservoir) is considered to be adiabatic; the mass air flow through the connecting element depends on the pressure difference. Findings. We obtained the curves for spring viscosity and stiffness coefficients dependence on the throttle resistance at three different laws, linking airflow through the cylinder with the pressure difference in cylinder and reservoir. At both maximum and minimum limiting resistance values the spring viscosity tends to zero, reaching its peak in the mean resistance values. Stiffness increases monotonically with increasing resistance, tends to the limit corresponding to the absence of an auxiliary reservoir (at high resistance) and the increase in cylinder volume by the reservoir volume (at low resistance). Originality.The designed scheme allows determining the optimal parameters of elastic and damping properties of the pneumatic system as function of the throttle element air resistance. Practical value.The ability to predict the parameters of elastic and damping properties of the pneumatic system as function of the throttle element air resistance will improve the running performance of carriages, the comfort of passenger transportation and reduce the wear of the rolling stock and the track caused by interaction of carriage and rails.