We know linear modules provide reciprocating motion – but how is this precise linear movement achieved? Typically, we use lead screws (also called power screws) which convert rotary motion into linear motion or vice versa. By transforming rolling motion into sliding action with minimal friction resistance and fine thread pitch, these mechanisms enable superior control of linear slides, making them essential for precision industrial applications.
So why do most linear modules use ball screws as their transmission component? Let’s analyze the key reasons, with the most significant being their high precision and load capacity.
1. High Repeat Positioning Accuracy
Ball screws utilize recirculating ball bearings between the nut and screw, creating rolling friction with minimal resistance (ASME research on friction coefficients). This results in negligible difference between static and dynamic friction, enabling micron-level repeatability – perfect for frequently reversing motions.
2. Minimal Wear & Extended Service Life
Rolling contact reduces energy loss through friction (NASA lubrication studies), maintaining accuracy over prolonged operation. The hardened screw/nut combination withstands millions of cycles while requiring minimal lubrication, simplifying maintenance.
3. High Load Capacity & Stable High-Speed Performance
Ball screw systems demonstrate exceptional multi-directional load capacity according to ISO 3408-3 standards, handling radial forces, moments, and overturning loads. Their low friction allows:
- Smaller drive components
- Reduced torque requirements
- Faster speeds without sacrificing stability
4. Micro-Feeding & Rapid Traverse Capability
Through precise thread pitch selection (Thomson Linear whitepaper), ball screws achieve:
- Micron-level incremental movement (with sufficient pulse input)
- High-speed travel (with large-lead screws)
As these characteristics meet critical demands in automation, ball screws have become the preferred choice for linear motion systems. When selecting components, always consult experienced manufacturers like RYK Motion to match specifications with application requirements.
Keywords: linear module, ball screw actuator, ball screw
