Maximum force on a linear damper? 1

[MechEng1235]

I am looking at this damper on mcmaster (

http://www.mcmaster.com/#6521k73/=rtyy6p)

which has a maximum force of 100lbs. Does anyone know what this indicates? Does it require 100lbs. to move the rod? I am not sure how to quantify how much resistance the damper will provide. It has all the dimensions I need but it isn't adjustable so I want to make sure I know what I'm getting.

 

[IRstuff]

"maximum" implies that any more than that, something bad will happen.

TTFN
faq731-376

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[MintJulep]

For a proper "damper" the force is proportional to velocity.

So this thing isn't technically a damper.

Most likely it's a gas spring with a (nearly) constant force.

You'll need to find a proper technical data sheet for the thing to really understand what it does.

 

[LittleInch]

The data sheet is a bit vague, but seems to be a simple hydraulic damper. the 100lbs is the maximum load it is designed to resist, which will then equate to a certain speed. As a damper it needs some force to move and will move providing a nearly equal force in the opposite direction as it turns some of that force / energy into heat inside the damper as it moves. A higher force would simply move faster and could either buckle the damper or lead it to fail after a certain number of operations.

an optional extra is a fixed resistance which implies exactly that.



My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[GregLocock]

another otption is that the oil may cavitate at a load of somewhat over 100lb. This is one cause of damper fade.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[dvd]

I think 100 pounds indicates the number of times it may be struck with a hammer to un-jam it.

 

[dgallup]

Right below that one on the catalog page are adjustable dampers.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[3DDave]

There are a few useful characteristics missing from the Catalog page.

1) Static load - minimum force required to overcome static friction
2) Extension force vs Extension speed
3) Retraction force vs Retraction speed
4) Variations in the above characteristics vs Temperature
5) Side load capacity at maximum retraction force
6) Torsion resistance, static and dynamic, for rod turning in cylinder
7) Degrees of swivel of the ball joints
8) An explanation of why the detail ball picture shows left hand threads

If any of the above are important, McMaster-Carr is often willing to give out OEM contact information.