Precision Threaded Spindle Drives

Trapezoidal-thread spindles usually have an efficiency of less than 50 %. They are therefore only suitable for converting a rotary motion into a longitudinal motion. Our standard spindles mated with our standard nuts are therefore generally selflocking unless there are vibrations etc. The „precision-rolled design with optimized lead and concentricity accuracy and wear-resistant surface“ which we have chosen for our stock programme is intended for the general mechanical engineering sector. This design as well as the tolerances chosen make the finished product a favourably priced solution. The range of application of our trapezoidalthread spindles is furthermore considerably enlarged as it is possible to choose among nuts of red brass, grey cast iron and steel; steel nuts, however, are not intended for motion screws.
Trapezoidal-thread spindles of stainless steel are suitable for even more applications e.g. in the food industry, see "stainless driving elements".

When used as motion screws, it is important to ensure adequate lubrication, see lubrication systems. 

Ball-screw spindles are right-hand threaded spindles featuring a ball connection between nut and spindle. Thus, rolling friction is provided in contrast to the sliding friction of the trapezoidalthread spindles.

This offers a variety of advantages:

• Efficieny of more than 90 % (trapezoidal-thread spindles only 20 – 40 %)
• Minimum of wear, therefore long life
• Starting torque only 1/3 of conventional threaded spindles
  (no stick-slip, but also no self-locking capacity)
• Longitudianl motion convertible into rotary motion
• Minimal lubrication – similar to ball bearings

Ball-screw spindles are very favourably priced and yet sufficiently accurate to justify their employment in many types of application. The hardened thread profile is a rolled pointed-cone profile. The balls mesh under load at approx. 45°.
We are glad to rework the tips of our standard ex-stock spindles on request.
Spindles and nuts are always supplied separately (spindle and nut detached). A sleeve provided in the bore of the nut prevents the balls from getting lost and serves as mounting aid at the same time. Lubrication is effected directly into the nut via a threaded hole. Only in cases where lubrication is not possible in this way, grease or oil can be applied directly onto the spindle. Please note that our standard ball-screw nuts are provided with dirt-repellent wipers on both sides since contamination results in increased wear. We recommend our lubrication systeme.