Using a Gearbox to Amplify Air-Blower Speed

This is a lousy picture, but see if you can get a similar fan curve from the internet. It implicitly tells you how the CFM's, RPM's and BHP are related.

CFM = cubic feet per minute

RPM = revolutions per minute

BHP = brake horsepower

I would recommend a belt driven application.

Removed by myself.

Just a word of warning, be careful in over driving fans as this may cause catastrophic failure if run above their maximum rated speed.

Also be wary of the exponential importance of both static and dynamic balance with speed. A slight "shiver" at 1470 will be a catastrophic throwing at even 2000. If you are talking about a squirrel-cage blower, the shaft stress goes up exponentially, also. /bearings, shaft mountings of the wheel, blade bending resistance goes down dramatically, It would be far safer to buy a larger if possible, or properly designed blower, possibly multi-stage if needed, and in the fairly near term, cheaper.

RichH

What is the reason for desiring to use hydraulic in your application? Is the centrifugal blower a low pressure air compressor (that operates at a few PSI) or is it an air mover (that operates are a few inches of water) or something else? Of coarse there are plenty of mechanical drive arrangements out there that could be used like gears, hydraulic pump/motor combinations, belts, silly string (just kidding). Like the others on the post, make sure the blower is designed to operate in the speed, volume, pressure range you plan on using. If I understand right this is in the 2000 HP range.

I had forgot to sign in. Thats me on post #7.

DaveB

What is the pupose of the gear box if you are single staging?

Dear sir, I understand that you want speed up a blower up to 5500rpm, and you want to use a 200hp/1475rpm motor. It seems you have an old blower that you want to "upgrade" increasing speed and power only. What are the original working conditions of this blower? (Power/speed/flow/pressure) If the difference is notable, the changes will be "not able" Each blower it has been ballanced for certain rpm. The dynamic load will change dramatically with a small increment in speed as well as vibrations and, therefore, all mechanical elements (supports, bearings, blades, anchorages, antivibration pads, etc..) and noise, must be reconsidered carefully. If the results of this investigation means dynamic re-ballance of the impeller (or maybe change it) change bearings and suports, reinforce structure... etc... consider to buy a new one. Also keep an eye on electricity bill. Maybe this will lead you to the right decision. BR Abel

Please check here: http://www.denysschen.com/CurvePlot/CPcurveVIV.asp Hope you find it useful. BR Abel

Several contributors have graciously offered help but no answers have been posted to pertinent questions. Whats up?

The size of hydraulics and the mounting of a transmission/gearbox for the power you need, and the cost of same, both would be prohibitive. Cheaper to buy a new unit, sized fight.

Rich