为了解转向架的曲线通过过程,根据蠕滑理论推导出轮对曲线通过方程,发现制约转向架曲线通过性能提高的主要因素是传统转向架一系定位刚度较大,限制轮对相对于构架的摇头自由度,影响轮对自导向能力的发挥.动力学仿真发现相对于锥形踏面,磨耗型踏面可以提供轮对通过半径为300 m曲线所需的轮径差.传统三轴转向架由于一系定位刚度较大,导向轮对在曲线半径1 100m以下均发生轮缘接触,而后端轮对具有较好的导向性能,具有较小冲角.径向转向架通过耦合轮对摇头运动保证转向架的稳定性,同时通过径向机构,轮对实现牵引和导向功能的分离.采用较小的定位刚度和反相耦合端轴轮对摇头运动,可以互相促进轮对导向,减小轮对冲角.径向转向架能够实现无轮缘接触通过半径为450m以上曲线.
To better understand the process of bogie curve negotiation, according to the creep theory, dynamic equation is deduced. It is found that the main factor that restricts the bogie curve negotiation performance is a larger positioning stiffness in the traditional bogie, which limits the yaw motion and the self-steering ability of wheelset. Relative to the conical tread, the wheel diameter difference can be provided by wear tread when wheelset negotiates 300 m radius curve. Because the traditional three axle bogie has a larger positioning stiffness. When the bogie negotiates less than 1 100 m radius curve, flange contact occurs on the lead wheelset outer side and rear wheelset has a better performance with smaller angle of attack. The wheelset yaw motion is coupled to ensure the stability in the radial bogie. By the radial mechanism, the function of transmitting traction force and steering of the wheelset is separated. The using of smaller positioning stiffness and antiphase coupling yaw motion of end axle wheelset can promote each other wheelset curve negotiation performance and decrease the angle of attack. The radial bogie can negotiate over 450 m radius curve without flange contact.