Tangential force 8

[SiggiN]

Hi!

I was wondering where does the "2000" come from in the following formula for tangentail force on spur gear? what is the logic?

This formula also appears in ISO 6336 and DNVGL-CG-0036, but no reason is given

Regards
Siggi

 

[rothers]

r=d/2, I'm sure you can figure what the 1000 is for.

 

[electricpete]

good catch for the factor of 2.

for op, the units are probably given elsewhere as T in N-m and d in mm. I think most people prefer to choose their own units, in which case they should have simply said F = 2*T / d (or better yet F = T/r) and you add any additional conversions based on your own choice of units.



=====================================
(2B)+(2B)' ?

 

[Scuka]

I always wondered why people build conversion factors directly into formulas instead giving me the basic version that works for base SI units and trust me I know how to do the freakin' unit conversion to make the formula work for my particular case.

 

[Denial]

"Hear, hear!" Scuka.[ ] That habit has bugged me since my university days, ie for a helluva long time.

 

[Tmoose]

A principal engineer at work was re-engineering some interference fits on some replacement parts a customer asked us to make.
Transmitted torque and maximum axial thrust were being checked.

He distributed his work for the two calculations in the group for review. The coefficient of (static) friction he used for axial and torque were different. When I asked why, his explanation was "because they are."

I'd bet anything off the (formerly) dollar menu that there were two separate example problems for interference fit torque and axial thrust in one of his reference books, and he copied the "appropriate" formula, with coefficient, for the problem he was working on.

 

[hydtools]

Units of measure should always be given for formulas(formulae) used to prevent confusion.

Ted

 

[rb1957]

check the units ... F may be in lbs and T maybe kip.in (or kip.ft).

Always check the units when working with imperial ... inches, feet, mass, weight, etc

Of course, people should use consistent units ... feet not inches with lbf

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[electricpete]

It's funny how many times we get sidetracked talking about units. But it never gets old...

=====================================
(2B)+(2B)' ?

 

[Tmoose]

Use the units God used in the Bible or I'll kill you.

 

[electricpete]

We must use dimensionless quantities!

https://xkcd.com/670/

=====================================
(2B)+(2B)' ?

 

[IRstuff]

Aside from conversion factors needed because of the selected system of units is inconsistent with that of the equation, it's often the case that empirical fitting coefficients are used, and they are very dependent on the units used.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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