As a design alternative to screw-based linear drive systems, the Amacoil (Aston, PA)-Uhing Model RS4 drive nut provides backlash-free linear motion and simplifies changes to linear pitch, according to the company. The linear pitch of an RS4 nut is factory-set at one of five different linear pitch settings, determined by application requirements. The motion provided by RS4 nuts is achieved by specially machined rolling ring bearings which are in constant single-point contact with the drive shaft, even during reversal. This assures that any rotational movement of the shaft is transferred smoothly and without play from shaft to bearings. The bearings convert the rotary motion of the shaft into linear output and anti-backlash solutions such as shims or double enveloping gears are unnecessary.
See more at www.amacoil.com.