Research On The Effect On Dynamics Performance Of High Speed Train By The Suspension Mode Of Traction Motor

The bogie is an important part of high speed train, the design rationality of which can directly influence the speed and quality of running of the vehicle. With the further increase in train speed, its stationarity and safety also receive much concern, which poses a higher request to the performance of bogie. Reducing the unsprung weight and dynamic deformation from motion between the wheeltracks are important principles for the design of bogie of high speed train, the adoption of suspension of traction motor is an effective way to reduce the unsprung weight, which is commonly applied to the bogie of high speed train in China. Due to the different suspension structure and parameters, the suspension mode of traction motor can also be divided into rigid suspension and elastic suspension, thus the research on the effect on dynamics performance of high speed train by different suspension modes is very significant to the design of high speed train and improvement of its dynamics performance.Taking a certain Chinese high speed train as reference, a single-train dynamics simplified model had been built with SIMPACK software, on the basis of comparing the non-linear critical speed of high speed train model of elastic suspension with that of the rigid suspension. Meanwhile these two models were made to run on a straight line set with the same track stimulation with the same speed range, the stationarity of both on straight line had been analyzed, the difference in framework, the vertical and lateral vibrational property of traction motor and lateral wheel rail forces between the two suspension modes had been compared, and the degree of sensitivity of lateral vibrational property of traction motor of both to the change in the transverse stiffness of single stage suspension had been analyzed.Through setting the curved track parameters, these two models of suspension were made to run on a curved line set with the same track stimulation with the same speed range, the curve negotiation performance of the high speed train of elastic suspension and rigid suspension had been compared and analyzed.it was shown by the result that, both of the models were accorded with the safety standard of curve negotiation. When the motor was elastically suspended, its lateral wheel rail force, lateral axle force, rate of wheel load reduction, derail factor and the motor-to-framework transverse acceleration were all lower than that of rigid suspension, thus, the curve negotiation performance of high speed train adopting the elastic suspension was better than that of the one adopting the rigid suspension.Without regard to the effect of lateral damper and lateral stop of traction motor, the rigidity of suspension node of traction motor in the suspension model was changed, how the suspension parameters of model running with different speed grades influence the train body, framework, vibrational property of traction motor and lateral axle force under had been analyzed, the optimal selection range of the lateral and vertical stiffness of the suspension joint was obtained. Finally, how the lateral stop and damper of traction motor influence the lateral dynamics property of this high speed train had been discussed. With only regard to the lateral stop structure, if the lateral rigidity of suspension node of traction motor is less than 0.01kN/mm, the train body, framework and vibrational property of traction motor will be slightly worsened; if the lateral rigidity of suspension node of traction motor is more than 0.01kN/mm, as long as the lateral stop of motor comes into play, the lateral displacement of motor relative to the wheel set can be significantly reduced, and the lateral dynamics performance of the vehicle can be effectively improved with a more significant effect in the case of high speed; while with only regard to the lateral damper structure, the lateral displacement of traction motor relative to the framework can be significantly reduced by the lateral damper of motor, and it can reduce the lateral vibrational acceleration of train body, framework and motor and in turn improve the lateral dynamics performance of the vehicle; as for the elastically suspended high speed train, the range of optimal lateral damping ratio of motor was 0.3～0.5, while if the lateral rigidity of suspension node of traction motor is more than 4kN/mm, the lateral damper of motor needn’t to be used theoretically.