# Gear reduction

1. Jun 12, 2014

### cbp5029

I have a 3hp motor, with a torque of 110.85 lb*in. a gear box with a max torque of 6286 lb*in.

gear box ratio is 57.64:1

I have gears attached to the gearbox shaft with a gear reduction of 3.375:1.

My new gear ratio should be 194.53:1 right?....

which would make my output torque approx. 21,500 lb*in...?

just checking

2. Jun 12, 2014

### Travis_King

Are you sure about your motor's torque? I ask because you list the gearbox's max torque (is that it's rated torque) at a value that is lower than the motor torque*reduction.

Also, understand that AC motors (if that's what you are using) are not constant torque machines. They have torque curves, and starting/peak torque can be upwards of 200% (in some cases much higher) of rated torque.

I'd verify you've got the right parts for the application.

As per your question, yes, if you have a gearbox with a 57.64:1 ratio and the output of that is subjected to another 3.375:1 reduction, you will have a 194.53:1 reduction and theoretical torque of 21,500 in*lb (depending on efficiency of the powertrain).