30t轴重铁路货车轮对过盈装配设计的可靠性评价与改进

DESIGN RELIABILITY ASSESSMENT AND IMPROVEMENT ON INTERFERENCE FIT SCALES OF THE RAILWAY WAGON WHEELSET WITH 30 TON AXLE WEIGH

从消除轮对装配面上的微动疲劳损伤角度,以在车轮上产生与AAR S660标准相同热机载荷的轮对极限载荷组合为依据,研究30 t轴重货车轮对的设计装配可靠性。采用钢轨片段—车轮—车轴—轴承—承载鞍组成轮对的集成有限元方法计算配合面应力。揭示原设计可以保证轮—轴和轴承—车轴的过盈配合面处于压应力状态,但其中轮—轴过盈配合面局部压应力过小。提出将轮—轴过盈配合调整至0.23 mm(等于孔径的0.01%),计算结果证实已将配合面压应力控制在合理范围。

Design reliability of the interference fits is checked to the railway wagon wheelset with 30 ton axle weigh. Aim focus on eliminating fretting fatigue damage of the wheelset. An extreme load set is applied, which can yields the thermal mechanical loads on the wheel same to the code AAR $660. Integrated wheelset model of finite element method is applied to calculate the stresses on the fit surfaces on a consideration of the physical fit relationship of wheelset, in which the rail pieces, wheels, axle, bearings, and adapters are fitted and analyzed together. Results reveal that the fit surfaces are all in the press stress states, but the stress scales seem smaller on the wheel-axle fit. An improvement suggestion is given to rise the fit scale to 0. 23 mm equal to 0.01 percentage of the wheel hole diameter. Calculation verified that the press stresses on the fit surface has been controlled in a reasonable range.