Solid shaft vertical motor bearings

[Thedroid]

Does NU324 DE and 6222 ODE sound like a proper setup for a vertical mount motor. Motor has large sheave hanging on it, 8 C belts if I remember correctlyl. 1750 rpm 300hp. We had the motor refurbished last year, and after putting it into service there is some strange noises coming out of the DE bearing and the surface temp is higher than historic records. Motor shop says they intalled a 6322, but the nameplate says 6222.

 

[edison123]

The ebaring set-up is fine.

But 6322 in lieu of 6222 ? Impossible, given the size (OD/Width) increase. Ask the motor shop to recheck.

 

[Thedroid]

I thought that it might be a typo. I'll continue to monitor the motor temps, until we can get some vibration analysis done.

 

[electricpete]

Is the lower bearing greased.

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[Feg]

Thedroid

I have seen this bearing set up before on vertical motors, you just need to re-check the bearing fitted as the 63 series is larger than the 62 series. If you are getting higher temps you might check the greasing as the levels of grease and frequency needs to be adjusted to suit, typical greasing of the NU322 is approx 2600 hours but if it was a ball like a 6322 it would be 4000 hours this is based on 50hz. Also 60 grams should be around right. I would recommend you run the motor with grease plate sump plug open to allow any excess grease out and then monitor it. Note: the greasing plate on the motor can sometimes be misleading as it may refer to the std bearing fitted in the factory but the bearings may have been changed by a distributor or agent after leaving the factory. The roller will be taking the radial load applied by the belts while the ball will be for locating.

Hope this helps

 

[Thedroid]

Motor shop called today and said it was a typo, should have been a 6222 up top. Checked temp several times today and it's still kind of high. This motor has historically had surface temps of 100F - 110F around the bearing retainer, and a loaded current of 24A - 26A. Now we're seeing temps of 140F and currents anywhere from 33 up to 38 amps. FLA is 36. Motor is refurbished every year whether it needs it or not, and runs 24/7 all year. It's been in service for about 2 weeks now.

On a different note we got back a similar motor from the shop recently, and we were going to mount it up to it's storage stand today, and noticed that all of the grease fitings, vents, and several bearing plate bolts were hand tight. The grease cavity was dry also. Didn't inspire confidence in the running motor in question.

 

[macmckim]

Applications sounds like a centrifuge motor - IE 8 V-Belts
on the DE. When shop changed the NDE bearing - what was taken out - IE C3 fit bearing or a C4 fit bearing?
C4 fit is has a looser fit between the balls and the race way and can handle more heat when loaded. JMHO.