Help in Sizing and Recommend Components for IC Engine driving a fan

[beaker43]

Hi,

I am fairly ignorant in this area so some expert help would be appreciated.

Application:

25hp internal combustion engine driving a 54" fan.

Engine rpm max is 3600
drive ratio is 2:1
Fan Speed max 1800 rpm

both sheaves will be supported on both sides with pillow blocks on 1" steel shafts.

Engine shaft OD is 1.125"
Would like to use QD bushings if they are adequate

Constantly varying power

Wet environment
Some oil/gas exposure probable

It would be great if you could recommend specific brand/components!

Thanks in advance!

 

[plasgears]

Assume a fan pitch and ducted fan, which leads to mass flow, which leads to power. That's the first step.

Sounds like a neat exam question on the PE.

 

[Tmoose]

These guys put at least a 1 7/16 inch shaft in size 27 and up fans, which are rated at 25+ hp at ~ 1800 rpm.

http://www.nyb.com/catalog/bulletins/051.pdf

 

[beaker43]

It is a 54"/50 pitch propeller, two blade. I have done the calculations for the shafting, and 1" is more than adequate to support the torque. This is actually a thrust prop for a hovercraft.

I guess I am looking for what you would recommend for sheaves and belts in this type of application. I believe that 3V banded belts, and 5VX belts are commonly used. I am interested in keyless bushings since I can eliminate keyways and keys which can vibrate loose and go through the prop causing damage. But I wanted to see what people who work with drive design a lot have to say about the topic.

Thanks!