Selection Of Ball Screw Nut Models
Types of Nuts Ball screw nuts can be divided into: elbow type, circulator type, and end cap type according to the circulation method of the steel ball. The features of these three circulation methods are shown below. In addition, ball screws can be classified not only by the circulation method, but also by the preload method.
[Classified according to the steel ball circulation method]
①Bend type
(Types SBN, BNF, BNT, BNFN, BIF, and BTK) Circulating Guide Vane Type (Type HBN) These models are the most typical nuts that use elbows to circulate the steel balls. After the steel ball is scooped from the groove of the screw shaft into the elbow, it returns to the groove and performs an infinite circular motion.
②Circulator type
(DK, DKN, DIK, JPF and DIR types) These models are the smallest nut, change the direction of travel of the steel ball through the circulator, and return to the original position across the outer diameter of the screw shaft, making an infinite circular motion.
③End cap type: Large lead nut
(Types SBK, BLK, WGF, BLW, WTF, CNF and BLR) These models are the most suitable nuts for high-speed feed. The steel ball is taken from the groove of the screw shaft into the through hole of the nut by using the end cover, and returns to the groove through the through hole to make an infinite circular motion.
【Classification according to the preloading method】
①Positioning and preloading method:
The double nut method (BNFN, DKN and BLW type) is a method in which a preload is applied by inserting a tab between two nuts.
②Dislocation preloading method
(SBN, BIF, DIK, SBK and DIR type) Compared with the double nut type, the volume is smaller, and the preload is applied by changing the pitch of the thread groove in the middle of the nut without using an adjusting plate.
③Constant pressure and pre-pressure method
(JPF type) A spring structure is set at almost the middle of the nut, and the preload is applied by changing the pitch of the central thread groove of the nut.