弧齿锥齿轮摩擦系数与啮合效率研究

Friction Coefficient and Mesh Efficiency in Spiral Bevel Gears

综合考虑接触几何、接触载荷、速度矢量、卷吸夹角、表面粗糙度、流变特性等因素,研究了不同啮合位置以及不同转速下弧齿锥齿轮的摩擦系数与啮合效率.结果表明:一对啮合副从啮入到啮出过程中,摩擦系数先增大后减小,与相对滑动速度变化趋势相反;一个啮合周期内,弧齿锥齿轮啮合效率与摩擦系数变化规律相似,但在啮出点附近,由于下一对啮合副进入啮合,啮合效率开始增大;随着转速增大,摩擦系数减小,啮合效率增大.采用文献中已有摩擦系数计算方法分析了弧齿锥齿轮摩擦系数和啮合效率,并与本文中的计算结果进行对比.结果表明:在节点啮合时,采用经验公式与简化算法的摩擦系数预测结果误差较大,而啮合效率计算误差较小;混合润滑和全膜润滑状态下,基于摩擦系数简化算法的弧齿锥齿轮效率计算结果与本文中的计算结果相近.

The friction coefficient and mesh efficiency were investigated under different contact positions and speeds considering the contact geometry, contact load, velocity vector, entraining angle, surface roughness, rheological characteristic. The results indicate that the friction coefficient increased firstly and then decreased which gave a reverse trend compared with the variation of relative sliding velocity during a meshing cycle. Besides. from the engaging-in position to engaging-out position, the mesh efficiency appeared a similar trend as friction; however, the efficiency increased again around engaging-out position due to the start of another meshing pair. The larger gear rotational speed,the smaller friction coefficient and the higher efficiency were. The friction coefficient and meshing efficiency were also analyzed using the friction computational methods in literature, and the results were compared with the present study.The analysis reveals that the error of friction was relatively large nearby the pith point whilst the error of efficiency was negligible. The efficiency obtained by simplified method seemed to be closed to the present study under mixed lubrication and full-film lubrication regimes.