Helical Spring Lock Washer Stiffness 1

[JakubMech]

Hi all,

Ive tried a few searches but nothing has come up for what im after regarding the stiffness of helical spring lock washers.

Im interested in their force deflection curve (stiffness)for standard metric sizes, much like the readily available full disc spring washers or also known as belleville washers.

Does anyone know of any literature which can help me here?

Jakub

 

[Cockroach]

You are indeed on the right track. The Helical Spring Lock Washer behaves like the Belleville Washer.

Roark does an excellent job on this subject and discusses the stress in relationship to load. In my design work, I have found some literature on the net by simply doing a Google search using "Belleville Springs". Some typically nice "receipe" type solution sets can be found in Spring-Raymond Associates, Lee Springs, Western Spring, etc. Search some of the big boys for their customized engineering approach.

The deflection is nonlinear with load. Belleville Springs have very peculiar properties as you will find out. I find them rather facinating in comparison to helical or torsional spring applications. Increasing in popularity, they are very easy to machine by regular turning practices thus providing ease of manufacturing with economics.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[Screwman]

I have looked for the same data and have not found it. We ended up doing testing to get some numbers. The results were that the initial rate is very low (pretty much like a helical spring) and that comprises about 90% of the travel. For the last 10% of the travel thare is a much higher rate as you rotate the faces of the washer until they a parallel to the bearing surface.
Unfortunately, the data will be hard for me to find, but I remember that for M5 fasteners the maximum load for the first portion of the curve was well under 1000 pounds.

Dick

 

[Cockroach]

Try something along the lines of "

http://www.BellevilleSpring.com"

which is a British website catering to UK consumers. Under the category of "Belleville Washer" you can search for Preload Curve Characteristics and things of that nature.

Hope this helps you get started.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[JakubMech]

OK, but no one has anything purely on these helical spring lock washers?

I'll look at the bellevilles.

thanks

Jakub

 

[israelkk]

JakubMech

Helical washer is basically a "one coil" helical spring made of rectangular wire. You can calculate its properties using the formulations for rectangular wire helical spring.

 

[diamondjim]

More curious why you are using
helical spring washers. They
are of little value in most
applications. Can you use
the belleville type washers?