Screw Jack, Worm Gear Screw Jacks - JACTON Industry

Anti-Backlash Screw Jacks Screw jacks are used for positioning loads in numerous applications, however when the load direction alternates between tension and compression within the operating cycle and a high position accuracy must be maintained then a specific type of screw jack is required. The Anti Backlash Machine Screw Jacks is recommended for such applications, as it is able to reduce the axial backlash between the lead screw and the trapezoidal screw thread in the gear to a practical minimum. Axial backlash exists in standard screw jacks as the "gap" or "play" between the flanks of the lead screw thread and the internal thread on the worm gear nut. This gap or play is due not only to normal manufacturing tolerances, but to the fact that there must be some clearances to prevent binding and galling when the screw jack is operating under load. In most applications either the load direction is constant so axial backlash does not occur or the position error