Problem with 'O' Ring Tolerance?

In summary, the conversation discusses a homework question regarding the design of a shaft and 'O' ring with specific tolerances. The individual is struggling to find a solution that meets the 5% allowable stretch limit. They mention reaching out to various industries and finally finding one that can provide the desired tolerance.
  • #1
suhagsindur
19
0
It may seems like simple homework question but it is industrial question with actual condition & I am struggling for the answer & also asked this question on other website but not get any reply. So ,please help me

'O' ring Internal Diameter(ID) ID=4 mm with tolerance is + & - 0.15mm. Tolerance as per in most of the standards.
I design shaft of 4.0+0.15=4.15mm for maintaining minimum stretch of 0.00mm in any condition.
If Shaft dia is 4.15mm & minimum 'O' ring ID is 4-0.15=3.85mm then 'O' ring stretch is 4.15-3.85=0.3mm.
'O' ring stretch percentage is 0.3/3.85 * 100=7.79 % > 5% alowable limit.

Please tell me is there any other solution for this OR all the industries make compromise in stretch with small ID 'O' ring.
I not gives any tolerance on shaft. If I will give then Stretch increase more & so intensify the problem.
 
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  • #2
I am not sure where the 5% allowable stretch limit came from, but if you must meet this, I would recommend to talk to the o-ring manufacturer and see if they will deliver a batch with the tolerance you need. There will probably be a price adder as they will have to sort and measure their inventory.
 
  • #3
In Parker 'O' ring handbook, Dichomatik 'O' ring handbook & Eriks 'O' ring handbook Stretch limit given as 5% maximum. However, I tried to contact so many industries from last 3 weeks & finally I find one which gives me desirable tolerance which I required. So, my problem is solved.

Thanks for reply
 

Related to Problem with 'O' Ring Tolerance?

1. What is an "O" ring tolerance and why is it important in problem solving?

An "O" ring tolerance refers to the acceptable range of deviation in size or shape for an "O" ring, which is a rubber seal commonly used in mechanical systems. It is important in problem solving because if the tolerance is too large, the "O" ring may not fit properly and cause leaks or other issues.

2. How do you determine the appropriate "O" ring tolerance for a specific application?

The appropriate "O" ring tolerance for a specific application can be determined through calculations and testing, taking into consideration factors such as the material of the "O" ring, the pressure it will be subjected to, and the temperature range it will be exposed to. It is also important to consult industry standards and guidelines.

3. What are the consequences of having a tolerance that is too small or too large?

If the tolerance is too small, the "O" ring may not fit properly and could cause damage to the seal or the surrounding components. This can result in leaks, malfunctions, and potentially costly repairs. If the tolerance is too large, the "O" ring may not be able to effectively seal the system, leading to leaks and other issues.

4. How can "O" ring tolerances be controlled and maintained during production?

"O" ring tolerances can be controlled and maintained during production through careful monitoring and quality control processes. This includes using precision equipment, conducting regular inspections, and implementing corrective actions when necessary. It is also important to work closely with suppliers and follow strict production protocols.

5. Are there any alternative solutions to using "O" rings with specific tolerances?

Yes, there are alternative solutions to using "O" rings with specific tolerances. Depending on the application, other types of seals such as gaskets, diaphragms, or mechanical seals may be more suitable. It is important to carefully consider the requirements and limitations of the system before selecting an alternative solution.

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