Centrifugal Compressor

What kind of compressor and what size?

Remember the tip clearance is at the exit, not the inlet. it should be the distance from the impeller tip and the shroud. This can't be measured, it needs to be calculated.

On the centrifugal comperssors I built, I would place the impeller into the shroud and measure from the back plate of the impeller to the shoud mounting point. Then from the same impeller location to the impeller mounting point. (where the impeller mounts to the shaft. Then you need to measuer on the diffuser, from the should mounting point to the shaft when the shaft is pulled as far forward as i can go. (the shaft should have between .010" and .014" float.) Note, there should be a spacer in the shaft, be sure it's there when you take the measurments.

Sound confusing? It is. But you can do it. Now the tuff part. Subrtact the reading from the impeller to the shroud, from the diffuser mounting location to the spacer on the shaft.

Take that result and subtract the measurment of the back of the impeller to the impeller seat. What remains is the shim thinkness you need.

Not so fast.. now subtract the designed clearance, which, depending the size of the impeller, could be between .020 and .011". you really need to get that number from the OEM.

Good luck

Laby

Bull Gear Float,

Sorry it's not adjustable... the bull gear should have somewhere between .008 to .020" float. The bigger the rotor the harder to check, but if your bearings don't show any wear, I wouldn't worry about it. If your bearings are showing wear, replace them.

Laby