Anti-Backlash Worm Gear Screw Jacks are new products and are used wherever reversible load conditions require precision positioning control.

The unit allows the lash between the drive sleeve and the Work Screw thread(1) to be accurately controlled by the relative position of the upper (2) and lower (3) drive sleeves.

Adjustment of the cover (4), by loosing set Screws (5), changes the relative distance between the sleeves. This change in distance compensate for any slash.
Axial backlash should be minimized but not completely eliminated, the result would be a lock-up of the Jack. When top plate touch the Jack body, the Jack wear is at the limit and Jack shall be revised.

Standard machine screw jacks, machine screw jacks with anti-backlash and ball screw jacks must be considered separately, as the normal backlash will vary due to different constructions.

Ball screw jacks do not have an anti-backlash option similar to the machine screw jacks. Instead for zero or reduced axial play ball screw jacks can be ordered with a pre-loaded ball nut .

If you have need for anti-backlash screw jack,please feel free to contact us.