Shock Absorber Selection for Pneumatic Cylinder End Stops
How to review cylinder-driven stops where thrust force continues during absorber compression.
Direct answer
For pneumatic cylinder end stops, calculate the moving mass energy and add the work done by cylinder thrust over the absorber stroke. The absorber must handle both the impact energy and the continuing drive force while staying within hourly duty and force limits.
Questions this page answers
- How do I select a shock absorber for a pneumatic cylinder?
- Should cylinder thrust force be included in shock absorber sizing?
- Why does a cylinder end stop need more than mass and velocity?
Required inputs
Formula logic
Cylinder thrust work
F is cylinder thrust and s is absorber stroke in meters. Add this when pressure continues pushing during the stop.
W = F x sUnit: N m
Review steps
- 1
Identify the actual impact speed
Use the speed at the end of travel, not only the nominal cylinder speed from the catalog or valve setting.
- 2
Add cylinder thrust contribution
If air pressure remains applied during deceleration, include the force acting across the absorber stroke.
- 3
Review alignment and return behavior
Cylinder stops often fail from side load, poor alignment or insufficient reset time rather than energy alone.
Common mistakes
- Sizing the absorber as if the moving load were free motion while the cylinder is still pushing.
- Ignoring pressure variation between commissioning and production settings.
- Mounting the absorber off-axis and creating side load on the piston rod.
Technical notes
- Cylinder-driven applications should be treated as powered motion when thrust continues during deceleration.
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Use the sizing tool when you have the inputs, or send the application data for engineering review.