Direct Comparison
Both systems convert rotary motion into linear motion, but differ fundamentally in their design—with clear implications for force, size, and maintenance:
| Criterion | Linear actuator | Screw jack |
|---|---|---|
| Max. lifting force | bis ca. 100 kN | 500 kN and higher |
| Stroke height | 100–1,000 mm (open spindle up to 3,000 mm) | 100–5,000 mm |
| Stroke speed | 5–50 mm/s (typical, depending on the manufacturer) | 10–200 mm/s and higher (typical, depending on the manufacturer) |
| Synchronization | Difficult, electronic-only | Mechanical drive via shafts/belts |
| Maintenance requirements | Low | Medium to high |
Selection Criteria
Six questions lead to a decision:
- Required lifting force: over 100 kN (economic threshold starting at approx. 150 kN) → screw jack.
- Is synchronization of multiple strokes required? Yes → Screw jack with mechanical coupling.
- Space constraints: limited installation space → linear actuator.
- Required stroke height: over 1 m → A screw jack is more cost-effective.
- Commissioning time: must be short → linear actuator as a catalog solution.
- Budget: small, moderate requirements → linear actuator; large budget, high requirements → screw jack.
Mnemonic
Application Scenarios
Linear actuator: Medical technology (blood analyzers, treatment units), laboratory automation (pipetting robots, samplers), and lightweight assembly applications under 50 kN with stroke lengths up to 500 mm.
Screw jacks: Heavy-duty applications (presses and stamping tools), synchronized multi-axis strokes (printing presses, automated storage systems), and long, variable strokes ranging from 2 to 6 meters.
Knowledge check
Answer all three questions, then click "Check". From 2 of 3 correct answers, the unit counts as completed. You can retry at any time.
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