Speed Increaser or Decreaser, which is better

[edison123]

Given a speed ratio, which gearbox has better efficiency step up or step down ? For example, of 990/850 RPM or 720/850 RPM, which gear ratio will have lower losses ?

 

[drawoh]

edison123,

I doubt that there is a significant difference in the efficiency of spur or helical gears, or chain or belt drives for that matter. I would be much more interested in the efficiency of your motor. Does it provide the required power more efficiently at 990 or 720 RPM?

JHG