用于齿面扭曲消减的齿向修形曲线设计方法

针对蜗杆砂轮磨消减齿面扭曲时存在成本高、效率低等问题，探讨在设计阶段消减齿面扭曲的途径。首先，基于蜗杆砂轮磨齿时的接触迹分析，给出了一种齿面扭曲的计算方法，分析了鼓形量及螺旋角对扭曲量的影响；其次，提出一种常用鼓形齿修形曲线的改进设计方法，将修形曲线分成三段，分别计算齿向左右两段各处扭曲量。在满足齿轮设计要求的前提下，通过调整三段曲线的比例因子以及各处的鼓形量，实现齿面扭曲量的消减。计算实例表明，该方法可有效消减齿面扭曲现象，减小齿向修形误差。

Method of designing tooth-trace modification curve for reducing the gear flank distortions

As there are issues such as high cost and low efficiency in reducing the flank distortions with threaded grinding wheel, an approach to improve the issues in design process is explored in this paper. Firstly, according to the contact trace analysis on worm wheel grinding, a novel method to calculate the magnitude of gear flank twist is proposed and the influence of crowning and helix angle on the magnitude of flank twist is analyzed. Secondly, an optimization method of crowning modification curve is proposed, which divides crowning curve into three parts to calculate the lengthwise crowning of the left and the right parts respectively. Then within allowance of gear design requirement, the flank distortions are lessened by adjusting scale factors and flank crowning. At last, an example verifies that the method could eliminate the gear twist and reduce the corrected errors.