风电行星斜齿轮齿根裂纹对其时变啮合刚度的影响

Influence of Root Crack on time-Varying Meshing Stiffness of Wind Power Planetary Helical Gear

以风电增速斜齿轮行星轮系为研究对象,运用非线性动力学理论和数值分析法计算齿根裂纹故障时斜齿轮副的时变啮合刚度。建立不同程度的齿根裂纹并分析其对斜齿轮时变啮合刚度的影响。经研究斜齿轮齿根裂纹分为贯穿性与非贯穿型,贯穿型裂纹在深度方向上用抛物线形式进行啮合,贯穿整个齿宽;非贯穿型裂纹在深度和齿宽方向上分别用抛物线拟合。共建立二十种不同形状的斜齿轮齿根裂纹。用刚度劣化率定量分析不同程度齿根裂纹对斜齿轮副啮合刚度的影响。分析表明:无裂纹斜齿轮副啮合时,时变啮合刚度是高低循环变化的,在高低变化之间刚度是线性递变。贯穿型裂纹比非贯穿型裂纹啮合刚度劣化更明显,单齿啮合时刚度劣化更为明显。裂纹在深度方向与宽度方向上延长相同百分比时,宽度方向上刚度劣化更明显。

Taking the planetary gear system with wind power increasing speed as the research object,the time-varying meshing stiffness of the helical gear pair with root crack fault is calculated by using nonlinear dynamics theory and numerical analysis method.The influence of root crack on the time-varying meshing rigidity of helical gear pair is analyzed.The root crack of helical gear can be divided into penetrating and non-penetrating types.The penetration cracks engage in parabolic form in depth direction and run through the entire tooth width.The non-penetrating cracks were fitted with parabola in depth and tooth width.Twenty kinds of helical gear root cracks with different shapes were established.The influence of tooth root crack on meshing rigidity of helical gear pair was quantitatively analyzed by stiffness degradation rate.The analysis shows that the time-varying meshing stiffness varies from high to low cyclically and from high to low linearly.The mesh stiffness degradation of the through-crack is more obvious than that of the non-through-crack.When the crack lengthens by the same percentage in the direction of depth and width,the stiffness degradation in the direction of width is more obvious.