Belt Pulley Speed

Right Compressor RPM / Available motor RPM = Motor Pully Diameter/ Compressor Pully Diameter.

Belt Speed = ∏.( Motor Pully Diameter). (Motor Pully RPM) / 60 m/s

Optimum belt speed must be (as I remember) around 20m/s

That's not enough information. I'd think the supplier of the compresser would help you. He's getting paid, isn't he?

Make sure and use pitch diameter to work out the ratio and not sheave OD. Although these two are close, the pitch diameter represents the diameter the v-belt actually drives the sheave at.

As has been implied, there is a little more to it than just getting the correct resulting RPM. Allowable belt load, how many grooves, belt velocity, etc.

Totally agree regarding get input from supplier. Also- definitely use at least 2 belts, and perhaps 3 (each sized for full HP load) for reliability and stretch resistance.

If the compressor will be starting-stopping frequently, I strongly also recommend a "soft start" controller to minimize wear on belts.

You find the RPM of compressor it should operate from the supplier. If you select bigger Dia. of motor pulley compressor may rotate more RPM than specified RPM. So the life of compressor will come down. Bearing and oil seal may worn out quickly.

If you select smaller dia motor pulley compressor may rotate low RPM. You may get proper performance/output from the compressor. So compressor should rotate in the correct RPM. which will be given by the supplier.

To find the motor pulley Dia come back to me after getting compressor RPM from supplier.

Hi RAMBLER3-TOO,

This may help.

I searched for the ratio of the drive pulley to the motor speed.

1. Pulley And Belt Information CalculatorThe ratio is the driver pulley size diameter divided by the driven pulley size diameter. ... (usually known from the motor speed) while the output RPM is the speed of the driven pulley. ... Drive Pulley Ratio, Variable. Belt Information ...
   www.csgnetwork.com/pulleybeltcalc.html - Cached - Similar -
2. JSS GEAR RATIO CALCULATION: Student Handout 6Motor Speed, wm, 8300 rpm, (revolutions per minute) under load .... For a Pulley System we might select a drive pulley of 6 cm in diameter. ...
   eagle.csd49.org/middle/jss/Course_GearCalc.htm - Cached - Similar -

Hope it helps. If not get in touch.

Rambler,

Nice question but i think you should get a professional engineer on the job

Anthony@ALNO

http://www.alnoproductservices.com.au