"Stretch Bolt" in place of Belleville Washer? 4

[PhilBW]

I am designing a piece of processing equipment which will include a splined, rotating shaft. Multiple replaceable rotating elements are slid onto the full length of the shaft. A large washer and bolt at the end of the shaft will hold everything in place.

However, the process is high temperature, which causes the replaceable elements to expand at a faster rate than the shaft they are mounted on. Normally I would use a Belleville type spring washer under the bolt to allow the expansion. In this case, the expansion will be 3-4 mm, which requires multiple Belleville washers. There is not physically room for a stack of 4-6 Belleville washers.

Are there other options, such as “stretch bolts” that can be stretched hundreds of times and still return to their original length? Any other suggestions?

 

[MintJulep]

Could you fit your stack of bellvilles inside the diameter of the shaft?

 

[NickE]

How about:

http://www.cloverspring.com

They will also make short runs out of other than stock alloys for a price.

 

[MintJulep]

One of the pictures on the cloverspring site is pretty close to what I was thinking.

Take a look at the "upgrade your valve performance" picture on the slideshow.

Imagine that the ball was threaded, and was constrained so that it would not rotate (and maybe was a disk rather than a ball).

Thread your bolt into that.

 

[Barry1961]

Can you make some room at the other end of the spline shaft?

Barry1961

 

[PhilBW]

Thanks to everyone for some great suggestions. You've given me a couple of options to work with which I hadn't considered before.

Phil

 

[Tmoose]

A "long enough" drawbolt could accomodate 2mm elongation easily.

If the replaceable rotating elements don't have carefully controlled face and bore runout the stack will curl up when the clamp bolt is tightened.

 

[PhilBW]

Thanks Tmoose. I will check in to that as well.