Spring suggestion 1

[Berserk]

Hello,

Could someone please suggest a spring I could use?
Deflection is less than 1/2" and it needs to last ten million cycles.

Now the ten million cycles is what our customer is asking for...But the part we are putting it on just need meet half a million cycles.
The spring is just lifting a fence 1/2" to stop a bin. In case the bin goes on top of the fence, the bin weight + other loads is about 160 lbs

I am checking mcmaster carr and grainger but they do not give information on how many cycles the springs would last.

TIA!

UGNX 11 - Windows 10 64bit
Productive Design Services

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[GregLocock]

You'd have to reverse engineer a given spring design using the wire fatigue charts, which for example are given in the Bosch Automotive Handbook.

A google search on the obvious terms led me to this

http://www.rockfordspring.com/spring-fatigue

Cheers

Greg Locock


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[Jboggs]

Get one or two reputable and well-known spring manufacturers involved. They have application engineers who are experts in how AND HOW NOT to use their products. Generally I would say the less stress/strain involved the longer the life.

Also, have you considered wave springs? Could be the perfect application for that style. I am assuming your spring is loaded in compression not tension.

Either way - use the experience and knowledge of the spring manufacturers' application engineers. That's what they're there for.

 

[TheTick]

You need a bit more design infor yet: available space for diameter and length, and a bit more force data.

You need to be more detailed about load cases--min and max loads art min and max reflections and accompanying spring loads. This is needed to get preload and rate.

Quantity counts. Spring manufacturers typically don't do short runs unless it's protos for a bigger project.

Otherwise, you'll need you shop the catalogs. Not a problem for compression springs. Tension spring availability has fewer options. If you need a torsion spring you're fairly well schtupped.

 

[TheTick]

Also go directly to spring manufacturers' catalogs. Century and Lee provide the springs for McMaster. The catalogs will have all those and thousands more. Plus a more more material and application information.

 

[kjoiner]

I would suggest checking with a spring manufacturer as well. Newcomb Spring has a calculator that will help determine if you are within acceptable stress limits for given spring paramaters.

https://www.newcombspring.com/springulator/compression-spring-calculator

Kyle

 

[IRstuff]

see:

https://onlinelibrary.wiley.com/doi/full/10.1046/j.1460-2695.1999.00183.x

also

https://en.wikipedia.org/wiki/Fatigue_limit

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