Idler Friction Factor Test Procedure

Saviz - Bidec, Iran
(not verified)
Posted in: , on 9. Jan. 2011 - 15:24


We are Consultancy company and planning to find manufacturer in order to manufacture Idlers for us.

Also, for our design input we need to know, the idler friction factor fairly accuractly.

Thus, I am seeking testing procedure (to provide to idler manufacturer) for test and find the friction factor of idler for different load? Unfortuently I could not find such a standard in any standards organization.

Is there any suggestion for that? Or could somebody provide test procedure for that.

Thanks and Regards


Idler Drag Testing Criteria - What Sizes Are Relevant?

Posted on 9. Jan. 2011 - 03:19

You need to be comprehensive if you wish to be accurate. Here is a start with 11 items to consider:

1. Bearing size, type, and manufacturing location - not all bearings are created equal.

2. Grease type and quantity

3. Bearing seal type and if contact type run-in specifications - sufficient run-in to mimic 3 months of service that polishes any contact members

4. How to apply load that does not influence the test with additional drag conditions that mask the test results.

5. Bearing rotation and its influence with sealing and drag

6. Speed

7. Temperature

8. Application of grease drag as advanced by majjor bearing suppliers: SKF, FAG, NTN, KOYO, ......

9. Statistical regime to obtain representative variance and mean -- what accuracy is desired?

10. Measurements on assembly balance and run-out tolerances (TIR) - testing and specification acceptances.

11. Test environment including dust, moisture, and all of the above.

I suggest you look at what major academic institutions have done. Typically, they are more advanced than idler suppliers. Prof. Craig Wheeler at University of Newcastle, Australia has a respected test facility that is based on his thesis work. He continues to update the procedures, as larger bearings are applied. Prof. Manfred Hager's (retired) work at Univ. of Hanover, Germany has performed many tests and has a respected test facility, based on the interests of Rheinbraun and major German system and component suppliers. FMC manufacturing in USA and China have a good testing and QA procedures. They attempt to be reasonably accurate. SME papers of the past which published measurements. Precismeca, manufacturing in Germany for Rheinbraun, et al.

Why do you wish to re-invent? It would be more helpful if you stated more specifically what you goal was with some details. What is your affiliation? Why didn't you complete the forum form on your details? We like to know who, what, why, ....... to encourage sharing and knowing who we are helping. This question has been asked before and answered by many before.

Lawrence Nordell Conveyor Dynamics, Inc. website, email & phone contacts: phone: USA 360-671-2200 fax: USA 360-671-8450

Re: Idler Friction Factor Test Procedure

Posted on 9. Jan. 2011 - 03:23

Item 5 refers to shaft deflection. Once the shaft rotation exceeds the bearing limiting criteria, the life will be reduced.

Also you should become familiar with ratings and failure criteria in order to properly assess the selection process.

Lawrence Nordell Conveyor Dynamics, Inc. website, email & phone contacts: phone: USA 360-671-2200 fax: USA 360-671-8450
Saviz - Bidec, Iran
(not verified)

Idler Friction Factor Test

Posted on 10. Jan. 2011 - 07:06

Hi Larry,

Thanks for you comprehensive reply. Seems I need to collect complete information to go further.

Lets put my question in other word. I have (manufactured )idler and I want to know what is its friction factor is? for example 0.03 And we want to build test equipment for that.

Unfortuently I have not access to the people and universities as you mentioned in your reply at the moment.

I did know Craig Wheeler before when I worked in Autsralia and studied there. But at the moment I am working in Iran and have not access to these univeristy, so it is better for us to build the test equipment for ourselves.

Is there any procedure for this kind of testing? I read in Rulmica catalogue that, they could provide us friction factor for different loading, thats what I need. (For example 0.023 for F= 5KN dynamic load)

My profile on folrum is complete and have all of my information, not sure why you mentioned it is not complete.

I am Mechanical Engineer and our company mainly working in Steel and some times Iron ore, copper, and we are designer.

Also, I have some test procedure from Kobe Steel, but It did not satisfy me, I think it does not provide accurate test result to me.(I would be able to send it to you, if you like)

Still, Should I collect these 11 itmes to mentioned again, in order to test the idler.

If I have test

Hope I could transfer enough information and my goal. or clear as mud?

Thanks for your time,

Best Regards