Belleville Springs 1

[Dougt115]

I am looking for a spring(s). That have a 0.5 inch travel and a 0.10 minimum height.

Total load is >500lbs

I can locate these around a shaft for stability. Spring ID is >0.375, OD may be <0.75 inches.

I am thinking of the mentioned Belleville Springs but I worry about the snapping. I know I can stack these alternating front to back to get the travel but the higher the h/t ratio the more the snap.

Ideally the springs would have the lowest height when unloaded but this may not be possible, opposite of the Belleville Springs.

Anyone have an opinion or suggestion?

 

[BrianPetersen]

Sure about your dimensions? Your travel is more than the minimum height, and that doesn't make sense for the type of spring that you are talking about.

 

[drawoh]

Dougt115,

I have been using medium service die springs for adjustable optical fixtures. These are very stiff, and they have a solid height about half of their free height. I have worked out usable travel versus working height, and these outperform rubber springs, and stacks of belleville washers.

Search Associated Spring Raymond. Several other vendors make them. These springs are colour rated, and typically, are painted blue.

--
JHG

 

[MikeHalloran]

Only volute springs can compress that far, but you don't have enough volume available to support 500 lbs with such a spring.

You have painted yourself into a corner.
There is no magical spring material that can get you out of it.

Start the redesign of whatever the spring goes into by selecting an appropriate stock spring, then design your assembly around it.



Mike Halloran
Pembroke Pines, FL, USA

 

[Dougt115]

I am looking for a free length to solid height of >4. That is why I am looking at a stack of Belleville spring washers.

 

[Lou Scannon]

I am looking for a free length to solid height of >4. That is why I am looking at a stack of Belleville spring washers.

I haven't dealt with springs that much in my walk of life but that sounds like a pretty remarkable specification for a Belleville spring, to me. Maybe a telescoping conical spring could manage that, but like Mike Halloran, I'm dubious about the force to volume ratio, and I agree with his advice on how to proceed.

"Schiefgehen will, was schiefgehen kann" - das Murphygesetz

 

[MintJulep]

Maybe, just maybe a rubber block, possibly open-cell foam.

 

[3DDave]

Belleville Springs are highly non-linear and unpredictable. That is, tiny variations in material thickness cause large variations (20% and up) in spring rate. They are also hard to stack alternating because they are dished, though if you are only concerned with their performance when flat its OK. Because they are very hard and the travel for the springs at the one end of a stack is tiny, they can carve a notch in whatever guide structure there is and can shift and engage that notch, preventing it from working OK. The pre-load/rest height also tends to drop a lot the first few times the springs are flattened.

There are a lot of good things about Belleville Springs, but the catalogs didn't previously mention the above pitfalls.

If the numbers you had are correct, you are looking at 6:1 free-height to compressed height. This and 4:1 are far beyond what a Belleville Spring can do. Waver-springs might, but they will be a larger diameter than what you have mentioned.