Anyone know how to calc. or approx. v-belt losses?

[ScottAW]

Still on the brainstorming side of a design, thinking about connecting an electric motor to a driveline via pulleys and v-belts. Looking at a 1:1 ratio between the two pulleys (no dia. size picked out yet) running at 3600 RPM at about 10 to 12 kilowatts. Little weary about going this route as I'm concerned about the lack of efficiency in the v-belts - so I'd like to understand what type of loss I'd have to work with. I've read only general notes on v-belt losses with ranges up to 25%, but have not found any good formulas or approximations yet. (may be 2 to 3 v-belts I'm guessing)

Thanks!

 

[EnglishMuffin]

Not sure where you are getting the 25% loss from - I frankly don't believe it. I just picked up "Standard Handbook of Machine Design - Shigley & Mischke" - where they list the following efficiencies : PolyV - 97%, Standard V - 95%, Narrow V - 96%, Connected V - 94%. But for the last word, why not consult one of the manufacturers (eg Gates?). They are always very helpful.

 

[chicopee]

I dont think that you want a 1:1 ratio between driver and driven pulley. Think more in the area of 3:1. Belt and pulley arrangements are very efficient as long as you donot have slippage due to high torquing requirement or loose belting condition the latter of which can be compensated with an idler. At least two belts s/b used for your application. Since you have not provided more specific info. on expected loads and running cycles it is difficult to give you more concrete thoughts.