Material

ZX-100K as replacement of PTFE

Description of the application

The threaded nut described here is used in the drive of cross tables (XY positioning system). The up-to-now  used material was PTFE and its hub is 25 mm. The polished and hardened threaded rod (60 HRC) is driven  from a step motor.

Load

Fa = 30 N
n = 790 min -1

Problem

Stick-Slip-free, dry-running, highly accurate positioning and in addition, because of the machine is driven by a  stepper motor, also a high damping were required.

Problem-solving

A threaded nut TR 12 x 3 made of ZX-100K is used, which in comparison to the previously used PTFE is much shorter.

Working life

It reaches a minimum working life of 10 years.

Advantages

Unlike a ball screw spindle, the pair trapezoidal threaded rod and the made of ZX-100K threaded nut, has got  an excellent damping. The highest accuracy is achieved. Through a thin-wall zone, in which the threaded nut  has got no thread, it can be easily preloaded, whereby a positioning accuracy of 1 micron can be achieved.  The backlash (lost motion) is reduced to 0.