我厂于1997年加工装配了一批特殊电机(如图1所示),电机转子轴有一段长300mm的三角螺纹。螺纹对轴的同轴度要求较高。由于生产、存放、装运过程不慎,造成轴外侧的螺纹受到损伤,而内侧的螺纹却是完好的,验收时经环规检测不合格。为了挽回损失,要求立即反修。开始我们采用板牙重新加工的方法,自外向里切削,结果板牙偏向螺纹损伤的一侧,不能正确导向,使完整侧的螺纹重新被切削,加工完后牙形变小, I plant in 1997 assembled a number of special motor processing (Figure 1), the rotor shaft has a long 300mm triangular thread. The coaxiality of the thread on the axis is higher. Due to the production, storage, shipping process inadvertently, resulting in damage to the thread outside the shaft, while the inside of the thread is intact, the acceptance of the ring test unqualified. In order to restore the loss, require immediate anti-revisionism. Began to use the method of reworking the die from outside to inside cutting, the results of the side of the tooth flanking the thread damage, can not be properly oriented, so that the entire side of the thread to be re-cut, tooth shape after processing is small,