Research On A Gauge-changeable Bogie With Traditional Wheelset Structure

There are many different track gauge systems in the world railway,which cause great obstacles to the development of regional economy and international railway transportation.The emergence of automatic gauge-changing technology solves the obstacles to railway intermodal transportation caused by different gauge systems.The research on automatic gauge-changing technology started earlier in foreign countries,and the patent layout and technology monopoly have been completed in this field.It brings challenges and opportunities for the research and development of gauge-changing technology in China.It is of great significance to develop automatic gauge-changing technology with completely independent intellectual property rights by studying advanced foreign technologies.The key to the automatic gauge-changing technology lies in the design of gauge-changeable bogies and the ground devices.This thesis studies the existing domestic and international gauge-changing technologies and analyses the principles and characteristics in different technologies.In this thesis,traditional wheelset structure is adopted as the technical route to achieve automatic gauge-changing.By analyzing the principle of the gauge-changeable bogie,a solution based on traditional wheelset and suitable for high speed and urban rail vehicles is given.On this basis,the main researches are as follows:(1)This thesis studies the existing domestic and international gauge-changing technologies and analyses the principles,advantages and disadvantages in different gauge-changeable bogies.Adopting traditional wheelset structure as the technical route to achieve automatic gauge-changing.Based on analyzing the principle of the gauge-changeable bogie,a solution suitable for high speed and urban rail vehicles is given in this thesis.(2)This thesis analyzes the structure and kinematics of the locking device,which is the key technical difficulty in the scheme of gauge-changeable bogie.On the basis of analyzing and referring to the existing data,combined with the specific structure of the gauge-changeable bogie wheelset and axle box device,the preliminary structural scheme of the locking device is given.Through the analysis of the motion of the locking device,it is found that the circular motion of the rotating arm will cause the horizontal displacement of the locking rod,increase the friction between the positioning surface parts,and affect the movement flexibility and positioning accuracy of the locking device.Therefore,an optimization scheme is proposed to replace the direct connection between the swivel arm and the locking rod by setting the cam structure on the swivel arm.Through the cooperation of the cam structure and the roller of the locking rod,the circular movement of the swivel arm is transformed into the vertical linear movement of the locking rod.(3)Based on the actual operation of standard and variable gauge trains,the operation load condition and abnormal load condition of locking device and axle box are established,and the strength analysis of relevant components is completed.The calculation results show that the maximum Von-Mises equivalent stress value of each component is less than the material yield strength,and the safety factor is more than 1.5 times,which meets the static strength design requirements.Under the operation condition,the stress cycles of the nodes to be measured after the projection of the maximum principal stress fall within the Goodman fatigue limit diagram,which meets the design requirements of the fatigue strength.(4)The strength analysis of the axle,wheel and roller spline structure in the gauge-changeable bogie shows that the dangerous position of the axle is located in the transition position between the outer sleeve seat and the outer end shaft body.The maximum equivalent stress value is 68.76 MPa,far less than the allowable stress of the material,and the safety margin is sufficient.The maximum equivalent stress of the wheel is 161.07 MPa,and the maximum dynamic stress is 267.84 MPa,meeting the design requirements of static strength and fatigue strength of wheel.The maximum equivalent stress of roller spline is58.33 MPa,matching the application requirements.