Kitchen exhaust blower rattling


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Old 01-05-19, 03:11 PM
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Kitchen exhaust blower rattling

Iíve got a 10 year old dcs range hood with some sort of German blower unit that is rattling like crazy. I took it apart and cleaned it, put some wd40 in the 2 bearings and put her back together.

Itís worse on low speed and seems ok at highest speed only. Som of it sounds like the rotor scraping the inside of the stationary part and some of it sounds like vibration,

Do I have to replace the bearings or is there some sort of balancing of electric blower motors I need to learn?
 
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Old 01-05-19, 04:12 PM
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Unfortunately most motors have sealed bearings where oiling doesn't help. WD-40 would not be considered a bearing lubricant anyway. Sometimes you can get lucky spraying or dripping oil into the end of the motor shaft but it's usually a temporary repair. You can replace the bearings in most motors if you have the patience to get the motor apart. Balancing or repairing a bent squirrel cage blower wheel is pretty hard to do.

It's usually pretty easy to tell if the problem is bearings or a bent blower wheel.
You can run the motor/blower out of the hood to see it's a balance problem.
 
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Old 01-05-19, 05:22 PM
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Thanks for the reply! Iíve already taken it all apart I think - or at least there are no screws left to take out. Hopefully I can just pop the bearings out with a screwdriver or do I need a gear puller or something?

How do I know if itís a bent wheel vs bearings?
 
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Old 01-05-19, 05:56 PM
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If you run the blower/motor outside of the housing...... you can watch it when it spins under power or set the motor on something so that the blower wheel turns very close to something. Turn the wheel by hand and watch the gap between the wheel and what you have it sitting next to.

Sometimes the bearings will slide easily off the shaft.
I have several pulley/gear pullers that I use to pull bearings off.
 
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Old 01-05-19, 06:54 PM
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Iíve got some gear pullers for flywheels etc. but these bearings are real small. Curious if you have pullers for small motor bearings. I have to get calipers in there but I think itís 3/8 ID....
 
 

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