Optimal Linear Actuation for Friction and Wear Measurement

[jrebollo]

I am looking for industry best practices on how to measure friction under load.
I have a semi-circular bearing loaded onto a steel shaft and need to know what the best way(s) is/are to measure the friction force between the two. What are the best set-ups for doing this type of measurement? I know this is a very broad and general question so if you need clarification please let me know. Thanks for your help.

Regards,

JRebollo

 

[Jboggs]

Homework?

 

[jrebollo]

I know it looks academic but I've been tasked with questioning our current test set-up and finding out what the optimal set-up would be and why. Any thoughts would be appreciated. Thanks for your help.

Regards,

JRebollo

 

[CastMetal]

ASTM standards would be a good place to look.

http://www.astm.org/Standards/G115.htm

, bring your wallet.

Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations

 

[Zinov]

Hi Robello,

There is the 'calott test' a sort of rotating sphere at low speed and load for a certain time. After the test, look under microscope for the surface of the worn zone and do some calculation to extract your coefficient. This is used by some German tool makers to test their coating wear resistance.

Many other standard setups exist and are ready for use,but generally at low speeds and low loads. Some say that friction coefficient depends on the speed (there is a critical speed value after which the effect of speed is obvious). So if you are at high speeds, take care.
The applied load and should be considered. it will affect the coefficient of friction, there are some critical loads. Existing standard setups use ,generally, low loads. So if you are at high loads, take care.
Initial surface conditions of your shaft surface will have an influence : grounded surface, Electropolished, coated and if coated what kind of coating.
Regards,
Zinov