determining belt speed

andyzinct. · Aug 22, 2009

If you have a 3" belt pulley driving a 9" pulley what is the reduction in speed? Is it a ratio of the circumferences? Thanks

Anonymous-0 · Aug 22, 2009

It will operate at a speed 3 times slower

greenbeanman in Kansas · Aug 22, 2009

Figures out the same way whether you use circumference or diameters. 33.333333%

Anonymous-0 · Aug 22, 2009

Using the outside diameters or the circumference is about right, but to be perfectly correct you need to use the pitch diameters which tend to be about 0.2" smaller than the outside diameter but that also depends on the V belt width. So 9 becomes 8.8 and 3 becomes 2.8 and the ratio is 3.14 instead of 3. If its that critical that can be important. If not you are good either way.

Gerald J.

teddy52food · Aug 22, 2009

Speed x diameter of one = speed x diameter of the other.

John B. · Aug 22, 2009

Yes like the first person said it will reduce the speed 3 times.

The 3" pulley will have to turn 3 revolutions for one revolution of the 9" pulley.

MPK · Aug 22, 2009

Speed of drive pulley X dia of drive pulley divided by dia of driven pulley gives you driven shaft speed.

JOB · Aug 23, 2009

Revolutions of Driven = Diameter of driver X revolutions of driver, divided by the diameter of driven

Nebraska Kirk · Aug 23, 2009

(quoted from post at 16:51:48 08/22/09) It will operate at a speed 3 times slower

Correct terminology would be to say that the 9" driven pulley will operate at one third the speed of the 3" driving pulley.

determining belt speed

andyzinct.

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Anonymous-0

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greenbeanman in Kansas

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Anonymous-0

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teddy52food

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