changing pulley sizes

10 years 4 months ago #640 by RDK
changing pulley sizes was created by RDK
I want to slow down my compressor motor. The original motor was a 1740 rpm 1 1/2 hp and I replaced it with a 3450 rpm 1 1/2 hp motor. I used the motor pulley from the original motor and it runs to fast. The pump pulley is a 10" and the motor pulley is a 2". I think I need to either reduce the pump pulley size or increase the motor pulley size. Which do you recommend? The pulleys are a 6 groove type. The shaft size on the motor is 5/8" o/d and the shaft size on the pump is 3/4" o/d.

Please Log in or Create an account to join the conversation.

10 years 4 months ago #644 by MTR-Admin
Replied by MTR-Admin on topic changing pulley sizes
It's certainly recommended to replace the Motor Pulley instead of the Pump Flywheel...after all you may not find another Flywheel that will bolt on to the pump you have.

Typically Pumps run around 800 to 1,000 RPM or so at the shaft, so if you reduce the Pulley size on the motor you will get a slower RPM on the pump.

However, if you're using a 3,450 RPM Motor with a 10" Flywheel and a 2" Motor Pulley, your pump should only be spinning at 690 RPM. That should be WELL within the RPM range...

You can reference the calculation chart on this site for your reference:
gadi.agric.za/software/renting/pulley_calc.php

- MTR

Please Log in or Create an account to join the conversation.

Moderators: MTR-Admin
Time to create page: 0.044 seconds