tension on pulley

pardal · Feb 26, 2003

It seem to be a basic question.

I need to use a 24 mm diam pulley by 20 mm heigth at 1500 rpm , it will handle about 0.10 HP .

I will use a flat belt with a friction coeficient 0.5 , 0.03" [ 0.762 mm] thick.
The allowed tension at 600 Ft/min is 10 Pd/inch by 1 inch wide .

Here is my question >
Which will be the tension applied at the center of the pulley , it is for size the ball bearings , and the shaft's diameter where the pulley will be located.

My best option is to use the pulley at cantilever after a
61900 bal bearing , on a 9,90 mm shaft diameter.

Pardal

dvd · Feb 26, 2003

For belt drives use

T2/T1=e^(mu*beta)

where

T2 = tight side tension = load + T1
T1 = slack side tension

mu = friction coefficient
beta = wrap angle in radians

solve for T1 and then T2.

If you are transmitting 0.1 Hp at 1500 rpm, then your torque is approximately 4.2 lb-in and your load is around 8.9 lb. I got 11.2 lb for T2 and 2.3 lb for T1 assuming 180° wrap and the 0.5 friction coefficient. So it looks like your belt may be overloaded.

Use vector sum of tensions to get bearing reaction.

This doesn't include the effect of centrifugal force on the belt. It also would be assumed that the other pulley(s) in the system are same diameter and thus have same tension requirements. I would verify the 0.5 friction coefficient, it seems kind of high.

pardal · Feb 27, 2003

Hi DVD , your help is what I needed.
I will change some values to correct the extreme tension on belt .
I can do two thing :increase wraped angle and widen the pulley .
Thanks Pardal

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tension on pulley

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