pulleys and sheaves

   / pulleys and sheaves #1  

wowbw7

Bronze Member
Joined
Feb 10, 2008
Messages
51
2 questions I hope someone can help me with:

1) almost all the v-belt pulleys or sheaves I find are listed as "fractional horsepower" rated. to me that sounds like you can only use on equipment with less than 1 horsepower, but I know that can't be true. what does the fractional horsepower rating mean?

2) i have had to remove pulleys from shafts many times where space behind the pulley is tight and using a puller is sometimes quite difficult or impossible to use. my question is: is it a good or bad idea to coat a shaft with anti-seize before installing the pulley to ease in removal?
thanks for any help
 
   / pulleys and sheaves #2  
I cant answer #1 but in reply to anti seizing a shaft, this is something i've always done with no ill effects. Either anti seize or white lithium grease. somewhere down the road you or someone else will surely be thankful.
 
   / pulleys and sheaves #3  
A fractional horsepower motor (FHP) is an electric motor with a rated output power of 746 Watts or less.

....according to Wikipedia anyway.
 
   / pulleys and sheaves #4  
.

Sizing info:

McMaster-Carr

Also check pages 1036-1039


At different speeds they can handle various HP ratings. Strangely enough, running them faster gives them a higher rating. Also you can gang them for higher HP too.

This chart is for multi rib belts (like current fan belts in cars) but it illustrates the point:



Also, yes, use a high temp wheel bearing grease.

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   / pulleys and sheaves #5  
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some more info:



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   / pulleys and sheaves #6  
the use of never sieze is a must when dealing with such things
 
   / pulleys and sheaves #7  
Since HP is calculated in the time it takes to do work, it isn't a surprise to find speed ratings on the hp requirements on sheaves.
David from jax
 
   / pulleys and sheaves #8  
I do not know where you are looking but any good PT house will have what you need.
 
 
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