磨削面齿轮粗糙表面最小润滑膜厚分析

Minimum lubricant film thickness of rough surface in grinding face-gear

根据齿轮啮合原理,推导传动接触轨迹点的方程。利用微分几何原理求出啮合点处两齿轮的主曲率。结合有限元分析方法,求得啮合过程中齿面的法向接触力。由齿面相对运动原理,计算正交面齿轮传动中的齿面卷吸速度。运用点接触Dowson-Higginson最小膜厚公式计算出光滑齿面啮合过程中的最小油膜厚度。基于磨削齿面形貌的分析,引入最小油膜厚度修正因子,计算出齿面不同形貌润滑状态下最小油膜厚度。研究结果表明:面齿轮从进入啮合到脱离啮合过程中,最小油膜厚度逐渐增大,单齿啮合与双齿啮合交界处出现拐点,其最大值出现在靠近齿根的啮合点处。在计算的粗糙度范围内,增大粗糙度使最小油膜厚度增大。磨削齿面在靠近齿根处的啮合点有最大表面方向参数,且使该点在不同粗糙度下最小油膜厚度的变化最小。本研究为面齿轮设计及其润滑失效分析提供重要依据。

Based on the face-gear generation process, the tooth surface curvature of face-gear was obtained, and the equation of the contact points on the face gear was deduced. According to differential geometry theory, the principal curvatures of the contact points on the pinion and the face gear were calculated. Using ABAQUS, the simulation results of normal contact force were got. The tooth surface relative velocity of orthogonal face-gear drive was achieved. Based on Dowson-Higginson equation, Minimum film thickness of smooth tooth surface in meshing process was obtained. According to the effect of grinding method to surface topography, the minimum film thickness correction factor is recommended, and minimum film thickness of lubrication in the tooth surfaces considering diverse rough surface was analyzed. From the beginning of meshing process to its disengagement, the minimum film thickness increases gradually. Its inflection point appears between the double teeth-meshing area and the single teeth-meshing area, and its maximum appears when the contact point is closes to the root of face gear. In the range of computing roughness, the minimum film thickness increases while surface roughness increases. The contact point near root in grinding wheel has maximum surface pattern parameter, and the minimum film thickness of this point has the least variation. This study provides important basis for the design and the lubricant deficiency analysis of face gear.