1. The external thread of one nut is used to adjust the relative axial position of the two nuts through the round nut to realize the pre tightening.

2、在兩個螺母的凸緣上分別切出齒數差為1的齒輪，兩個齒輪分別與兩端相應的內齒圈相嚙合，內齒圈用螺釘緊固在螺母座上。

2. The gears with tooth number difference of 1 are cut out on the flanges of the two nuts. The two gears are meshed with the corresponding inner gear rings at both ends, and the inner gear rings are fastened on the nut seat with screws.

通過轉動其中一個螺母，使兩螺母的相互位置發生變化，以調整間隙和施加預緊力。此種方法機構簡單可靠。剛性好，應用為廣泛。在雙螺母間加墊片的形式可有生產廠根據用戶要求事先調整好預緊力，使用時裝卸非常方便。

By turning one of the nuts, the mutual position of the two nuts is changed to adjust the clearance and apply the preload. This method is simple and reliable. It has good rigidity and is widely used. In the form of adding gasket between the double nuts, the manufacturer can adjust the preload in advance according to the user's requirements, so it is very convenient to unload when using.

4、將螺母的內螺紋滾道在中部的一圈上產生一個導程突變量，從而使左右端的滾珠在裝配后產生軸向錯位實現預緊。滾珠絲桿螺母副軸向間隙的目的：增加預緊減少反向時的空行程，出現無反向死區，同時提高了傳動剛度和傳動精度。

4. The internal thread raceway of the nut produces a lead mutation on the middle circle, so that the left and right end balls produce axial dislocation after assembly to realize preloading. The purpose of eliminating the axial clearance of the ball screw nut pair is to increase the preload, reduce the empty stroke in the reverse direction, so that there is no reverse dead zone, and improve the transmission stiffness and transmission accuracy.