The application principle of ball screw in CNC machine tools

The application principle of ball screw in CNC machine tools
The performance of ball screw nuts: Ball screw nuts have excellent performance, mainly including high transmission reliability, reverse clearance, low wear, and long-term trouble free operation; Sensitive transmission, high operating accuracy, and less prone to crawling; High transmission efficiency and smooth operation; Easy to use, lubricate and maintain, reliable; After applying pre tightening force, axial clearance can be eliminated, and there is no empty stroke when reversing; Reversible transmission; The disadvantage is that it cannot self lock and requires a balancing device for vertical installation.
The characteristics of ball screw nuts: The transmission form of ball screw nuts can be divided into screw rotation and nut rotation.
Screw rotation transmission refers to: the screw rotates and the nut is fixed on the workbench. The screw rotates to push the nut, and the nut drives the worktable to perform reciprocating motion. We usually use this type of installation method.
Nut rotation transmission refers to: the screw is fixed, the nut is fixed on the worktable through bearings, the servo motor drives the nut to rotate, the nut moves axially along the screw, and then drives the worktable to move. This transmission method is generally used on machine tools with long screw rods to prevent vibration and deformation of the screw rods due to insufficient rigidity.
According to the structure of ball screw nut, it can be divided into two types: internal circulation and external circulation.
The ball screw nut with external circulation mode consists of a screw, ball, ball return system, and nut. The main difference from the internal circulation method is that the two ends of the nut spiral groove are connected by ball return pipes, allowing the ball to return from one end to the other, forming a closed circulation loop.
The key to the structure of the ball screw nut with internal circulation is the installation of a cylindrical cam type reverser in the side hole of the nut. The reverser is milled with an S-shaped bead groove to connect adjacent threaded raceways. The ball enters the reversing device from the threaded raceway, and is forced to pass over the top of the screw thread into the adjacent raceway by the reversing device, achieving circulation.
The working principle of the ball screw nut: Here we only briefly describe the working principle of the external circulation ball screw nut, and the working principle of the internal circulation ball screw nut is similar to it.