Glossary · Automation fundamentals, platforms and components
Ball screw
Also known as: Recirculating ball screw, Ball screw drive
German: Kugelumlaufspindel
In mechanical engineering, a ball screw (recirculating ball screw) is a linear actuator element that converts rotary motion into linear motion with low friction: balls roll between the threaded shaft and the nut and are returned through a recirculation channel.
- Automation components
In one sentence
A ball screw converts rotary into linear motion with low friction, using balls that roll between screw and nut and recirculate.
Example
The Y axis of the milling machine is driven by a servo motor through a preloaded ball screw with a 10 mm lead.
How it applies
- Engineering: Ball screws offer high efficiency and positioning accuracy. Lead, preload, critical speed and load rating determine the design. Because friction is low, many ball screws are not self-locking, so vertical axes need a brake to hold the load.
- Maintenance: Lubrication, contamination and wear change backlash and accuracy. Schedule lubrication and backlash checks as part of Preventive maintenance.
- Documentation: Maintenance manuals state lubricant, intervals and how to check backlash. Safety instructions must warn that a vertical axis can drop when the brake is released or the motor is disconnected.
Ball screw vs. lead screw
A lead (trapezoidal) screw slides nut on thread, has higher friction and is often self-locking. A ball screw rolls, is more efficient and precise, and usually needs a brake for vertical loads.