Research On Dynamic Performance Of Passenger Car System With Elasto Damper Coupled Wheelset

Since the operation of railway, traditional wheelset has been widely adopted as the general wheel-rail guiding system of railway vehicles all over the world. And due to its outstanding performance of automatic centralization in straight line and curve self-steering ability with characteristics of simple structure and admirable working performance, traditional wheelset with cone-shaped tread has led a long-term period of dominant status in railway industry. While actually there are some disadvantages and shortcomings of traditional wheelset derived from restrictions of further increasing the critical speed influenced by hunting motion caused by cone-shaped tread. Therefore, someone proposed the concept of independently rotating wheels, which means the wheels left and right of traditional wheelset are decoupled and can rotate independently around central axle. Theoretically according to the principles of the kind of independently rotating wheels, there is no longitudinal creep force between wheel and rail, and the critical speed of the vehicle can reach a extreme high values. But followed by the fact of steering ability depends on the contact of flange and rail, it could be worse and disadvantages for long-term operation of independently rotating wheels, due to its characteristics of lacking of longitudinal creep force and its caused of longitudinal creep moment, losing the ability of self-steering in curve line with serious wear may lead to derailment accidents. It is very necessary to develop a new type of wheel-rail guiding system possessed of both the advantages of traditional wheelset and independently rotating wheels to eliminate related defects. And so, a kind of coupled wheelset was born to be a very solution. In details, the wheels left and right of coupled wheelset are connected by a coupler without fully consolidated or relatively independent. And its dynamic performance can be controlled by changing coupling factors. When an appropriate value of coupling factor is selected, the coupled wheelset could have both good abilities of self-steering and automatic centralization. In this paper, it focused to study the dynamic performance of one type of coupled wheelset which called elastic damper coupled wheelsets (EDCW).Firstly, the dynamic equations of multibody vehicle were deduced and the calculation model of a passenger car system with EDCW under the consideration of actual status of EDCW to analyze was established, in which system-stresses and non-linear part in system were considered, and its kinematics differential equations were deduced.In this paper, the dynamic performance of a vehicle with EDCW is further analyzed as well, and the result can be concluded about the influences of coupling stiffness and damper on vehicle dynamic performance, as well as the sensitive interval of coupling factor. The application of EDCW in passenger car system can break the limit of critical speed of traditional wheelset, and also could solve the problem of bad performance about wheel-rail contact and curving issues of independently rotating wheels when in operation. It is important to point out that when an appropriate value of coupling factor is selected, the EDCW could get a total improvement on vehicle critical speed and curving performance. When the coupling factor of EDCW stays a sufficient small value, its dynamic performance can be equaled to the independently rotating wheels. While on contrast, when the coupling factor is big enough, its dynamic performance is more likely the traditional wheelset.Based on the study of the dynamic performance of bogies with the same coupling factor of EDCW in the wheelsets front and rear, this paper has also discussed and studied the dynamic performance of bogie with different types and coupling factor of leading and trailing wheelsets, and finally the optimal coupling modes and coupling factor values of EDCW were got.It is the first time having proposed a deep analysis on the dynamic performance of passenger vehicle system with EDCW in this paper, and the content can really provide a good reference to the practice application of the wheel-rail guiding system with this kind of wheelsets.