Dynamic Seal And Durability Research Of MR Damper For Railway Vehicle Suspension System

The vibration of railway vehicle reduces the service life of the vehicle parts, causes the failure of vehicle, reduces the passengers’ comfort, also destroys stability of vehicles running, influences the running quality of vehicle seriously. So it is very important to control vibration of railway vehicle.The damper is the core component of railway vehicle vibration control. In all kinds of damper, the magnetorheological(MR) damper has dual advantages of both active control and passive control, is ideal semi-active damper, and it has a broad prospect of application in railway vehicle. In order to speed up application process of the MR damper in the railway vehicle, this paper faces use requirement of railway vehicle suspension system, for the mechanical properties,sealing performance, response speed and fatigue performance of the MR damper to carry out researches as follows:Firstly, this paper analyses theoretically the influence of temperature rise on speed characteristic, response time, adjustable coefficient of traditional MR damper, and researches experimentally the mechanical properties of damper in the temperature rise, and find that, as the temperature rises, the damping force of damper decreases at the same conditions, the response time reduces, the adjustable coefficient increases, and the experimental results agree with the theoretical analysis very well. The data show, when the current is zero, the temperature has a big impact on damping force, and as the current increases, effect of the temperature on damping force weakens.Secondly, in view of the leaking problem of damper, this paper puts forward a kind of dynamic seal structure, and expounds working principle of dynamic seal, designs and manufactures a MR damper, completes its assembly process. The Dynamic seal combines the principle of magnetic seal with the principle of corrugated pipe seal, it is composed of three seal structure, reduces the wear and tear of seal ring, improves the reliability of seal, has good durability,is suitable for high frequency vibration and long-term vibration conditions of railway vehicle.Thirdly, this paper calculates and analyses the proof pressure of dynamic seal structure designed, also calculates the sealing ability of first grade and energy loss of carrier fluid in the wear resistant unit relying on the Bernoulli equation, uses the pressure formulation of dynamic airtight container to calculate the proof pressure of secondary seal, uses the pressure formulation ofmagnetic sealing to calculate the proof pressure of secondary seal, and checks the sealing ability of damper.The results show that dynamic seal can satisfy the requirement of damper seal.Finally, this paper uses the finite element software ANSYS to simulate and research fatigue life of damper piston rod and corrugated pipe of damper. This paper researches experimentally mechanical properties of damper Under variable temperature and leaking and durability under normal temperature, and compares the experimental data with data of conventional MR damper and analyses data of those, results show the seal properties of new damper is better than old damper, its mechanical properties is more stable and its vibration damping performance is more reliable in the long vibration.