What is the Lifespan of a Belleville Washer?

  • Thread starter Thread starter Ranger Mike
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the lifespan and performance characteristics of Belleville washers, particularly in applications involving air bearings and aluminum components. Participants explore factors affecting longevity, such as temperature, material interactions, and dynamic loading conditions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants inquire about the expected lifespan of Belleville washers and under what conditions they might lose tension or relax over time.
  • One participant notes that in specific applications, such as slip-clutches, Belleville washers can last indefinitely if not overheated.
  • Another participant discusses a machine tool application involving air bearings and suggests that the washers may relax over time, potentially increasing the air gap due to aluminum expansion.
  • A different viewpoint suggests that material creep is unlikely unless operating at high temperatures, and emphasizes that fatigue could lead to gradual material failure rather than immediate shape change.
  • Concerns are raised about wear between the steel washers and aluminum components, which could lead to loosening over time.
  • One participant mentions observing stacks of Belleville washers "flip" direction when overstressed, prompting curiosity from others.
  • Another participant questions whether the application is dynamic, as advised against by washer manufacturers, and seeks validation of this concern.

Areas of Agreement / Disagreement

Participants express differing views on the factors affecting the lifespan of Belleville washers, particularly regarding temperature effects, material interactions, and the implications of dynamic loading. No consensus is reached on the expected lifespan or the validity of concerns regarding dynamic applications.

Contextual Notes

Discussion includes assumptions about material behavior under stress, potential fatigue mechanisms, and the specific conditions of use that may affect washer performance. Limitations in understanding the exact operational environment and material properties are acknowledged.

Ranger Mike
Science Advisor
Messages
2,461
Reaction score
446
A Belleville washer, also known as a coned-disc spring, conical spring washer, disc spring, Belleville spring or cupped spring washer, is a type of spring shaped like a washer. It has a frusto-conical shape which gives the washer a spring characteristic.

Belleville washers are typically used as springs, or to apply a pre-load or flexible quality to a bolted joint or bearing.

They may also be used as locking devices, but only in applications with low dynamic loads.



what is the expected life of the typical belleville washer?
how long until it will loose tension? loosen up?
 

Attachments

  • Belleville_washer.jpg
    Belleville_washer.jpg
    3.8 KB · Views: 609
Engineering news on Phys.org
How long do you need it to last? I've seen them used in slip-clutches before and typically if they do not overheat they last indefinately.
 
Thanks for the input..the machine tool application is to locate air bearings on an aluminum guide way. the machine has movement in X , Y and Z direction. It seems to me that over time the washer would relax and the air gap would increase. Aluminum expands with temperature and the washers prevent galling of the aluminum i guess...
 
Hi Mike,
I don't think there will be any creep in the material unless it's operating at very high temperature, but since it's mated with aluminum, it doesn't sound like your temperature will be that high. Steel (and virtually any material) can be subject to fatigue which is the gradual development of cracks in material due to cyclic stresses and you've indicated that may be the case here. But fatigue generally doesn't cause the material to change dimensions until the crack grows to the point of breaking, at which point you have a catastrophic failure. What may be an issue in this case is movement between the steel belleville washer and the aluminum. When you have movement between two parts, regardless of material type, there's often some kind of wear between the two. One or both parts begins losing material, so the joint would loosen up over time. So I think to answer your question, you shouldn't expect the washer to change shape over time unless you have stresses so high you get yielding or failure, and belleville washers are generally designed to go flat without yielding.
 
When overstressed, I have seen stacks of Bellevilles 'flip' direction.
 
enigma said:
When overstressed, I have seen stacks of Bellevilles 'flip' direction.
Really? That would be pretty wild.
 
The application in this scenario is similar to the attached pic. The air bearings are gliding over the precision surface..in the illustration a 2 micron air gap is used when GRANITE ways are used..the air gap goes to .0254mm (.001") or even 0.003" inch when aluminum is used..hence the belleville washer is used...but is this not a DYNAMIC application...exactly whet the washer manufacturer advises against?

hey..it might be nit pickling but is concern not valid in this case?
 

Attachments

  • BEARINGS.JPG
    BEARINGS.JPG
    42.5 KB · Views: 578

Similar threads

Physics What do most do with a M.S. in Medical Physics?
  • · Replies 7 ·
Replies
7
Views
5K
Could New Materials Propel China's Industry to Bill Gates-Level Success?
  • · Replies 4 ·
Replies
4
Views
10K
Investigation of hydrogen-on-demand systems (HODS)
  • · Replies 4 ·
Replies
4
Views
32K