摘要：The top relief surfaces of an hourglass worm gear hob are ground manually in the traditional manufacturing process,which cannot ensure the width of the land surfaces of the ***,each geometric feature of the hob has been produced through different manufacturing techniques and machine tools,which results in low *** solve this problem,we propose a semi-automatic computer aided design(CAD)method for *** point clouds of each feature surface of a hob are calculated by combing mathematical equations of the top relief surfaces built by the proposed method with other existing equations of hob *** to the point clouds,the method can achieve the automatic modeling for the hob in three-dimensional(3D)software by classifying and extracting the parameter information of the feature-hierarchical knowledge of the *** on the generated 3D model,the entire surfaces of the hob can be manufactured on a four-axis computer numerical control(CNC)milling machine through only twice *** of the width of the land surface of the hob manufactured by semi-automatic CAD method on a measuring projector proved the precision of the designed width can be *** edge of the contact area on the worm wheel in a meshing experiment is clear and distinct,which means the worm gear drive is meshed well and the hob manufactured by the proposed method has improved *** method simplifies the processing technique,and improves the design efficiency and production accuracy.

摘要：多头环面蜗轮滚刀通常采用螺旋槽,以降低刀齿负前角的绝对值、并均衡每个刀齿左右两侧的前角,从而提高滚刀的切削性能。由于环面蜗轮滚刀螺旋线上各处的螺旋升角不同,所以各个刀齿左右两侧的前角均衡问题更为复杂,鲜有螺旋槽前刀面的精确成形方法的研究。基于环面蜗杆专用数控机床,提出采用双锥砂轮磨削螺旋槽环面蜗轮滚刀前刀面的方法,根据齿轮啮合理论,建立由双锥产形面展成平面二次包络环面蜗轮滚刀螺旋槽前刀面的数学模型,给出每个刀齿两侧在分度环面螺旋线上的前角计算公式。算例计算结果表明:如果采用直槽滚刀,对应的前角在-19. 530 3°～19. 530 4°;通过合理的参数选择,可使得螺旋槽滚刀对应的前角在-8. 1°～7. 3°,有效减小了刀齿负前角的绝对值。对环面蜗轮滚刀螺旋槽进行仿真加工,并且在仿真软件中对前角进行测量,测量结果与计算结果相吻合,证明本文方法的正确性。

摘要：环面蜗轮滚刀刃带面的刃带宽需控制在一定的范围内以保持刃口的强度和锋利性,圆周定位误差的存在使刃带宽发生变化。为了磨削出满足需要的刃带面,研究了周向定位误差对刃带宽的影响规律。根据微分几何和齿轮啮合原理,建立了求解含有周向定位误差的刃带宽的数学模型。研究了存在周向定位误差时,刃带宽沿环面蜗轮滚刀的轴向和齿高方向的变化规律。同时,在VERICUT中建立虚拟的四轴联动环面蜗杆磨床,对周向定位误差的影响进行仿真验证。研究结果表明:周向定位误差对环面蜗轮滚刀边齿齿顶处刃带宽的影响最大;刃带宽与周向定位误差具有很强的相关性,呈线性变化关系;对于特定的算例,当给定的刃带宽e=1. 0 mm在±10%范围内变化时,周向定位误差允许的调整范围为-0. 122°~0. 054°。