三爪自定心卡盘的卡爪牙与平面螺纹的结合,无论接强度或耐磨以及承受突然动力,在设计上总是要求其接触面越大越好。亦即卡爪牙的弧形完全符合於平面螺纹的弧形。但是事实不可能如此,因为平面螺纹为阿基米德曲线,其各点的半径随着其转角而有增减;但卡爪要求在平面螺纹内作径向进 Three claw self-centering chuck claw teeth and the combination of flat thread, regardless of pick strength or wear-resistant and withstand sudden power, the design is always required to contact the larger the better. That is, the arc of the claw tooth completely matches the arc of the plane thread. However, this can not be the case, because the plane thread is the Archimedes curve, the radius of each point increases or decreases with the corner; but the jaws require radial in the plane thread