Abstract: In terms of the issues of bogie hunting instability alarm and car body low-frequency sway for a high speed train in the operation period, a new wheel profile named type LMB_10 is designed based on the characteristics of wheel-rail contact between the wheel profile of type S1002CN and the actual measured rail profiles before and after grinding. During the design procedure, the wheel profile is divided into three sections, namely the wheel root area, working area and end area. With respect to the wheel profile of type S1002CN, the designed profile in the working area remains unchanged, while the root area is reduced in order to have a larger wheel-rail clearance. This helps to reduce the possibility of bogie hunting instability alarm due to high wheel-rail equivalent conicity. For the end area, the slope of the wheel tread is increased so that the risk of carbody low-frequency sway is reduced. The results of simulation and field test show that the contact between profile of type LMB_10 and rail profile of type CN60 has a low equivalent conicity of 0.105, and a large wheel-real clearance. It also has a good adaptability when matching with the rail profiles before and after grinding, and the hunting stability, ride comfort and curving performance of the vehicle system have been improved. In the actual operation assessment, the profile of type LMB_10 has a quite long running mileage up to 390,000 km before wheel tread reprofiling, and the vehicle system has always maintained good dynamic performance in the whole service period.

Key words: equivalent conicity, vehicle stability, wheel tread design, wheel-rail contact relationship