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gear reduction/increaser vs pulley????

gear reduction/increaser vs pulley????

gear reduction/increaser vs pulley????

(OP)
I'm writing this post for some help due to my lack of knowledge. I have been working on a project in my garage  that I am using a 5hp 240v single ph motor at 3250  rpm.   max 15amp continuous.  the issue is that I am running this project through a pulley system in order to get the desired rpm output at the project (which is roughly 1400rpm).  In order for the project to be effective I need to increase the rpm at the output by 300-400 rpm (I can only get to about 1000 without exceeding ampacity).    when I get to that point I exceed the 5hp or under requirements that I am looking for  and ultimately exceed amp limits. I have tried many combinations of pulley sizes and even a gear reduction box which only increased the draw.  my question is:   is it possible to overcome amp to hp ratio with a gear/pulley system  or is it always relative?  for example if I go to a pulley system or gearing reduction/increaser  would this take the load off of the motor and reduce the amp draw?  or is there another way to achieve this?  any help would be appreciated.  

RE: gear reduction/increaser vs pulley????

Uh, 240/15 corresponds to ~4.82HP, with no conversion losses.

You can't get 5HP out of a 4.8HP pipe.

Using a four pole motor at ~1750 rpm and no belts or gears will get rid of the losses external to the motor, so all you need to buy is a 4 pole motor with ~120 pct efficiency.  winky smile

Reduce the motor rpm a little more and use it start a Diesel.

Mike Halloran
Pembroke Pines, FL, USA

RE: gear reduction/increaser vs pulley????

It's all about power.  If you want to drive a load that has the same torque requirements, but at a higher speed, it takes more power (Power = torque x rpm).  No matter what mechanical advantage you use, power in = power out.  You can't create extra energy from nothing.

The upshot is: you need a bigger motor.

Don
Kansas City

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