| With the acceleration of urbanization process and the improvement of people’s consciousness of environmental protection and the demand of comfort and convenience of travelport,modern tram has regained more attention and application.Modern tram includes steel tram and rubber-tired tram which using rubber wheel drive and guided only by one central rail and its weight is carried by the running rubber tire.Therefor,rubber-tired tram’s requirements for the force of the rail subgrade is much lower compared with steel tram which greatly reduced the line’s construction cycle and cost.However,due to the application and study and the development history of rubber-tired tram is a bit less,people’s research on the relationship between wheel and rail of this type of tram is not yet thorough,so that there is no mature theory of wheel and rail relationship at present.The basic requirement of the safe running of the rubber-tired tram is keep the guide wheels on the guide rails and the performance of the guide mechanism directly determines the straight line stability and curve passing performance of the tram.In order to improve the guiding performance of the guide mechanism,it is necessary to carry out theoretical research on the wheel-rail relationship of the rubber-tired tram,and because the experimental research is also an important technical means to promote the theoretical research,so it is of great value to study the design technology of the test-rig of the rubber-tired tram.Based on the analysis of the characteristics and the guiding principle of the rubber-tired tram and the guiding characteristic of the the power running gear and the contact form of the guide wheel and the guide rail,this paper determined the dynamic simulation project of the power running gear according to the technical characteristics of the rubber-tired tram and the structural characteristics of the power running gear.The first part of the dynamic simulation project is replace guide rail with railroad wheel which could simulate the change of the velocity and the angle and the track irregularity and the steering angle between the guide wheel and the guide rail by controling the state of the track wheel,and meantime simulate the the power running gear’s load by controling hydraulic cylinder.The second part of the dynamic simulation project is determined study and test method of the rubber-tired tram’s wheel-rail relationship according to the research on derailment mechanism of traditional rail vehicle which is clear the speed,load,angle of attack,steering angle’s influence on wheel-rail relationship by measuring the lateral force of the guide wheel,the vertical force,the relative displacement between the guide wheel and the track wheel and other parameters.Completed the first test-rig of the power running gear of the rubber-tired tram in China compared with the factory,and power running gear of rubber-tired tram was studied and tested.More attention was paid to the straight line stability and curve passability of the power running gear.We can get a conclusion that the derailment criterion of the traditional rail vehicle is not applicable to the rubber-tired tram and the steering angle of the power running gear should be less than 16 degree and when the angle of attack is greater than 2 degree,the wear of the guide wheel becomes severe and harsh noise occurs.The experiment’s results showed that the test-rig can test the key parameters of the wheel-rail relationship of the rubber-tired tram,and meet the requirements of the test.It provides a test platform for the futre theoretical research on the dynamics and the wheel-rail relationship of the rubber-tired tram. |
