为揭示重型载货汽车转向前桥轮毂轴承寿命不长的原因,制定了轮毂轴承寿命分析的汽车行驶工况,确定了相应的载荷谱。以Lundberg-Palmgren和Ioannidis-Harris轴承寿命理论为依据,用Romax软件建立了轮毂轴承疲劳寿命分析模型,计算了7.5t转向前桥额定载荷时轮毂轴承的疲劳寿命和损伤率。结果表明,轮毂内轴承满足设计要求,但轮毂外轴承均不满足设计要求。其中寿命最短的右侧轮毂外轴承,内、外圈有明显的错位,滚子承载不均匀,内圈挡肩上轴向载荷的合力方向偏离旋转轴线,产生弯曲力矩,内、外圈存在严重的应力集中。
To reveal the reason for the short life of hub bearings in the front steering axle of a heavy duty truck, the vehicle driving conditions for hub bearing life analysis is worked out with their corresponding load spectra defined. Based on Lundberg-Palmgren and Ioannidis-Harris bearing life theories, a fatigue life analysis model for hub bearings is established with Romax software, and the fatigue life and the damage rate of hub bearings in a 7.5 t front steering axle under rated loading conditions are calculated. The results show that the inner bearing in inner wheel hub meets the design requirements, but the bearings in outer wheel hub don't. Among them the bearing in right outer wheel hub has the shortest life, and there is apparent misalignment between its inner and outer rings with uneven roller loads. Moreover, the direction of resultant force of axial loads acting on inner ring rib deviates from ro- tating axis, generating bending moment and causing severe stress concentration in both inner and outer rings.