考虑界面摩擦效应的齿轮齿面断裂风险预测研究

PREDICTION MODEL OF GEAR TOOTH FLANK FRACTURE CONSIDERING INTERFACIAL FRICTION

在循环载荷作用下,齿轮齿面断裂是裂纹源萌生于次表层位置发生的一种疲劳断裂失效形式,该失效模式与轮齿内部位置点的局部材料强度和局部应力状态密切相关。基于接触理论及弹性力学基础理论,建立含界面摩擦的轮齿内场应力和含硬度梯度的应力强度计算数学模型,开展齿轮齿面断裂风险预测研究。结果表明,计算最大应力风险位置发生在齿面下一定深度位置,与齿面断裂疲劳源表征位置基本一致。随着摩擦因数的增加,轮齿内部安全系数降低,表明界面润滑不良易引起轮齿内部裂纹加速萌生而造成齿面断裂疲劳失效。提出的齿面断裂风险预测模型为抗齿轮齿面断裂设计制造提供基础技术性保障和支撑。

Under the fatigue loading condition,tooth flank fracture,crack source initiated at the subsurface position,is a subsurface fatigue failure.The failure mode is closely related to the local material strength and local stress state at the internal points of teeth.Based on the contact theory and elastic mechanics,a mathematical model for calculating the internal field stress of gear teeth with interfacial friction and the stress intensity with hardness gradient was established,and the risk prediction of gear tooth flank fracture was carried out.The results show that the calculated maximum stress risk position occurs at a certain depth below the tooth surface,which is basically consistent with the representative position of the tooth surface fracture fatigue source.With the increase of the friction coefficient,the internal safety factor of the gear teeth decreases,which indicates that poor interfacial lubrication can easily lead to the accelerated initiation of internal cracks in the gear teeth,resulting in the fracture fatigue failure of the tooth surface.The risk prediction model provides basic technical guarantee and support for the design and manufacture of tooth flank fracture resistance.