Belt drives can support long strokes and dynamic speed changes, while ball screws convert rotation into linear travel through a screw and nut. Compare travel, speed, load, positioning requirements, guidance, environment and maintenance using the maker's sizing data for the application.
Both drive types move a load along a guided path, but the transmission, support requirements and performance tradeoffs differ. Start with the motion profile and sizing data for the specific unit.
Drive comparison
| Factor | Belt drive | Ball screw |
|---|---|---|
| Motion element | Belt looped around pulleys | Rotating screw and nut convert rotation to linear movement |
| Stroke and layout | Often used for longer strokes and flexible layouts | Available travel depends on screw length and support design |
| Speed profile | Can suit high-speed travel and dynamic changes | Performance and durability depend on speed and screw design |
| Factors to size | Belt tension, load, pulley, guidance and environment | Screw lead, load, speed, support, lubrication and guidance |
| Maintenance review | Belt wear, tension and exposure to dust or chemicals | Lubrication, wear, alignment and support requirements |
Thomson’s linear unit selection guide describes belt drives as suited to long strokes and dynamic changes in speed and direction, while noting potential slippage and wear factors. It also describes ball screw tradeoffs at high speeds. Match those general characteristics to the exact product’s data.
Sizing checklist
- Write down travel, load, moving mass and mounting orientation.
- Define speed, acceleration, duty cycle and positioning requirements.
- Check the manufacturer’s force, speed, life and repeatability specifications.
- Include guides, couplings, motor, brake, feedback and controller compatibility.
- Review dust, temperature, chemicals and lubrication access.
- Ask the linear-motion supplier or integrator to validate sizing and support conditions.
The drive does not determine the full machine safety design. Include guarding and access requirements in the engineering review. Compare servo and stepper motors and review PLC selection. Browse linear motion.
Sources
Compare a lead-screw actuator and pneumatic cylinder by utilities, controls and application requirements.
Common questions
Which linear drive is better for a long stroke?
Stroke capability depends on the unit and application. Compare the manufacturer's travel, speed, load and deflection data for the exact model.
Are ball screws more accurate than belt drives?
Positioning performance depends on the drive, feedback, load, guidance and controller. Compare the specified repeatability and accuracy for each model.
What maintenance should I compare?
Review the maker's lubrication, inspection, belt tension, wear and service guidance for the exact linear unit.