建立六轴数控圆柱齿轮蜗杆砂轮磨齿机磨削面齿轮的理论模型。提出以初始设计蜗杆砂轮轴截面齿形为基本参数,并考虑齿廓抛物线修形来设计金刚滚轮,再用于修整椭球式蜗杆砂轮的方法。利用双参数啮合方程建立了面齿轮磨齿加工的齿面方程。齿面磨削仿真及轮齿接触分析表明,直接以蜗杆砂轮轴截面齿形作为金刚滚轮齿廓来修整砂轮,所磨削得到的面齿轮齿面压力角偏小,且传动误差为不连续的上凹形曲线。当给滚轮以抛物线修形设计之后,所磨削的面齿轮齿面偏差基本为负值,传动误差曲线为良好的连续上凸式抛物线形。承载接触分析表明新的设计可以减轻齿顶边缘接触,减小冲击振动。数值算例表明,采用该方法磨削加工的面齿轮可以获得较高的精度和良好的啮合性能,并给出了试验验证。
A physical model for grinding face gears with six-axis CNC cylindrical gear grinding worm wheel machine tool is developed. A new method is proposed, which takes the initial design shaft section of the worm wheel as the basic parameters and designs the diamond dressing wheel for dressing worm wheel considering parabolic tooth profile modification. The surface equations of face gear machined by grinding worm are established by two-parameter meshing equations. Tooth grinding and tooth contact analysis shows that, if a diamond wheel which directly takes the worm wheel shaft section as the tooth profile is used for dressing the worm wheel, the pressure angle of the face gear will be smaller and the transmission error curve will be discontinuous and concave. When the dressing wheel is designed with parabolic-shaped modification, the grinding surface deviation of face gear is basically negative, and the transmission error curve is continuous convex parabolic type. The loaded tooth contact analysis indicates the new design can reduce edge contact at tip of tooth and vibration. Numerical examples prove that face gears machined by this method can get higher precision and good meshing performance. An experiment is performed to verify the method.