Electric motor hp 2

[Logger_Rob]

Hello. Does the Hp of an electric motor increase with use of a reduction gearbox?
So, say I had a 4hp motor and I put it through a gearbox with a ratio of 20:1, would the output hp be 80? Or am I completely deluded?

 

[BrianPetersen]

Nope. You will lose horsepower by the mechanical efficiency of the gear unit.

You are perhaps confusing the power with the torque.

 

[Logger_Rob]

I see, so a reduction in speed x20, increase in torque x20 and a slight (negligible maybe) drop in hp?

 

[BrianPetersen]

Yes; the efficiency of the gearbox will generally show up as the output torque being less than (input torque)x(gear ratio).

I said "generally", because while gearboxes with physical teeth on the gears leave no choice but for the output speed to be locked to the gear ratio, other types of drives may have opportunities for "slippage" representing loss of speed in addition to the loss of torque.

 

[Logger_Rob]

Very helpful, thank you.

 

[itsmoked]

Torque x speed = horsepower

So by this you can see that you can trade off speed for torque and trade down on torque for more speed but you cannot increase the horsepower without somehow adding more.

Keith Cress
kcress -

http://www.flaminsystems.com