schroefspindels

Schroefspindels, often seen as lead screws, are threaded rods used in machines to convert rotary motion into linear movement. They provide precise positioning along an axis, typically in conjunction with a nut or half-nut that travels along the screw as it is turned. Schroefspindels are common in manual and some CNC machine tools, where they move components such as carriages, cross-slides, or tailstocks. They can also be found in jacks, clamps en stage-mechanics where controlled linear travel is required.

A schroefspindel consists of a screw with a helical thread and a mating nut that rides on the thread. The screw is supported by bearings at each end and guided by the machine’s structure to minimize lateral play. Thread forms used for leadscrews are usually trapezoidal or Acme-like profiles, chosen for strength and wear resistance. The lead of the screw—the linear distance traveled per full rotation—depends on the thread pitch and the number of starts. A single-start screw has a smaller lead and finer resolution, while a multi-start screw increases the lead for faster travel but typically reduces self-locking and may require stricter backlash compensation.

In practice, leadscrews offer high load capacity and good rigidity, with the beneficial property of self-locking under favorable friction and pitch conditions, which helps resist backdriving. Drawbacks include relatively high friction, wear over time, and backlash, which can affect precision. Ball screws offer higher efficiency and reduced backlash but are more complex and costly.

Maintenance involves regular lubrication, inspection for wear or damage, and alignment checks. In modern high-precision contexts, leadscrews are often complemented or replaced by ball screws or other linear positioning systems.