Ball Screw in machine applications

Positioning or Transport in Ball Screw applications?

Planning

Contents

1. Positioning vs. Transport in Ball Screw applications

Selecting the right ball screw depends primarily on the specific application. The key question is: Is the ball screw used for the precise positioning of a component, or is it mainly intended for transporting heavy loads over longer distances?

2. Difference between Positioning and Transport

Positioning means moving an object or tool to a defined position with extremely high accuracy and repeatability. Typical characteristics include:

  1. Short travel distances (often only a few millimeters to centimeters)
  2. Low speeds
  3. High requirements for stiffness and minimal axial backlash
  4. High dynamics during short movements (e.g., short cycle times)

Transport refers to moving loads over longer distances where extreme accuracy is less important. Instead, the focus is on robust, low-wear motion. Typical characteristics include:

  1. Longer travel distances (up to several meters)
  2. Higher speeds and frequent movements
  3. Higher loads with a focus on service life
  4. Acceptable axial backlash and lower precision requirements
Ball Screws in a Powder Pressing Machine

Positioning in Powder Pressing Machines: High-Precision Ball Screws in Action

3. Application examples for Positioning

In these applications, tools and workpieces must be moved and positioned with extreme precision, often with accuracy in the micrometer range. The ball screw is part of the drive system for the axes (X, Y, Z), enabling precise and highly repeatable movements.

Technical challenge: Minimal axial backlash is essential, as any play can cause positioning errors that affect workpiece quality and dimensional accuracy.

Equipment used for optical or tactile measurements requires precise and repeatable positioning of measuring sensors or test specimens. The movements are often very small but require high dynamics and excellent repeatability.

In semiconductor production, wafers with extremely small structures must be positioned with exceptional accuracy. These applications require ultra-high positioning precision as well as smooth, low-vibration motion. Preloaded ball screws are commonly used as a standard solution in this field.

Precise travel movements combined with high stiffness are required to achieve safe and accurate positioning. Ball screws ensure reliable and controlled motion in these demanding applications.

4. Application examples for Transport

In storage and conveyor systems, ball screws are used, for example, to move lifting tables, transfer carriages, or sorting modules. The focus is on long travel distances and high loads.

Technical challenge: Extreme precision is less critical in these applications. Instead, high load capacity, robustness, and long service life are the main requirements.

In these applications, ball screws are used to adjust tools, press jaws, or other heavy machine components. Travel distances are often longer, while positioning accuracy at the micrometer level is usually not required.

Ball screws are used in lifting systems for positioning and moving components in automated production environments. The main requirements are reliable operation, high load capacity, and durability during frequent movements.

Ball screws are used for adjustments and movements that must be robust, reliable, and low-maintenance. These applications require solutions that can withstand demanding operating conditions and provide long-term performance.

5. Key criteria for selecting the right Ball Screw

Positioning

Transport

Criteria

Accuracy requirement

Very high (μm range to 1/10 mm)
Moderate (mm range sufficient)

Axial backlash

As little backlash as possible (preload)
Backlash acceptable for reduced friction

Travel distance

Short to medium
Medium to long

Load

Usually low to medium
Medium to high

Wear

Higher due to preload
Lower due to backlash

Positioning

Transport

6. Conclusion

The distinction between positioning and transport applications is the key foundation for selecting the right ball screw. Positioning applications require precise, preloaded ball screws with minimal axial backlash, while transport applications with higher loads and longer travel distances are better suited for ball screws with backlash. The application examples clearly demonstrate why this differentiation is technically and economically beneficial.

What are your experiences on this topic?

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High-Precision Ball Screws

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