| Rail transportation is an important means of transportation for trade exchanges between China and its neighboring countries on the land.With the introduction of the strategies of the "one Belt and one Road" and the "Going Outward",economic and cultural exchanges between China and the countries along the "one Belt and one Road" will become increasingly frequently.However,due to various reasons,the railway gauges of different countries are not uniform,which has caused great difficulties for international intermodal transportation.Gaugechangeable trains can run on different railway gauges,which is the best solution to the problem of international intermodal transportation.The transmission means of wheel-axle of gaugechangeable bogies is different from the interference fit transmission of traditional bogies wheel-axle,so the wheelset structure needs to be redesigned and analyzed.First of all,the main structure of gauge-changeable bogies in Spain and other countries was introduced,and the gauge changing principle of different gauge-changeable bogies and the transmission means of wheel-axle torque was briefly analyzed in this thesis.Based on the wheel-axle structure of a high-speed “Electric Multiple Units”(EMU)bogie in China and the successful design experience of foreign gauge-changeable bogies,three kinds of transmission schemes for the wheel-axle structure of high-speed gauge-changeable EMU bogies suitable for 1435/1520 mm railway gauge were put forward in this thesis,which are roller spline transmission scheme,spline shaft transmission scheme and sleeve spline transmission scheme.Secondly,referring to the Mechanical Design Manual and the GB/T 17855-2007 Calculation Method of Spline Bearing Capacity,the theoretical strength of the involute spline was analyzed.The calculation found that the splined pair of the splined shaft transmission scheme did not meet the requirements of long-term wear-free work,while the splined pair of the sleeved transmission scheme met the strength check indicators.After analyzing and comparing the advantages and disadvantages of the three wheel-axle transmission schemes of gauge-changeable bogies,it was found that the advantages of the sleeve-type spline transmission scheme were more prominent.Thirdly,the finite element model of driving involute spline was established by using Hyper Mesh software,and the ANSYS software was used to calculate structure strength.The influence of gauge change and structure interference change on its FEM strength were analyzed.The calculation results show that the gauge change has little effect on the overall strength of the spline;the spline strength is mainly affected by the amount of structural interference.Subsequently,static strength and fatigue strength analysis were performed on the two gauge-changeable bogie wheels.From the results of the local static strength check of the wheels,the maximum stress of the spokes varies greatly with the change of the load loading section;from the overall static strength check results of the wheels,the static strength check results of both types of wheels meet the requirements;from the fatigue strength check results of the wheel spoke area and the non-spoke hole area,the results of the checked area nodes’ s fatigue strength safety coefficients are greater than 1,so the fatigue strength of both wheels meets the requirements.Finally,according to the European standard EN 13104 Design Methods for Wheelsets and Bogie Power Axles for Railway Applications,the stress conditions of two gaugechangeable bogie axles were analyzed,and the stress of the dangerous section of the axle were calculated at different gauges and operating conditions.The calculation results show that the strength safety factor of the cross section of the two axles is greater than 1,both of which meet the standard requirements. |
PDF Full Text Request