一般螺纹的中径部处于螺纹牙型之内,而滚珠丝杠螺纹按其螺纹特有形式,它的中径是在螺杆牙型之外,即螺杆与螺母中间之滚珠中心连线上,因此滚珠丝杠的螺旋升角按滚珠丝杠公称直径来计算,冷轧滚珠丝杠的坯径就不能以公称直径来考虑。必须到螺杆牙型某一点去找,又因滚珠丝杠牙槽是圆弧形而其牙顶又是近似梯形,牙槽、牙峰分界处极不明显,必须用计算方法求出冷轧坯径。 The average diameter of the thread is within the thread form, while the ball screw thread according to its unique form of thread, and its diameter is outside the screw type, that is, the middle of the screw and nut ball connection center, so the ball Spiral angle screw ball screw according to the nominal diameter to calculate the diameter of cold-rolled ball screw can not be nominal diameter to consider. Must be to a certain point of the screw teeth to find, but also because of ball screw groove is arc-shaped and its top is approximately trapezoidal, alveolus, teeth peak boundaries is not obvious, you must calculate the method to obtain cold-rolled blank path.