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- เผยแพร่เมื่อ 2 ต.ค. 2024
- Changing motor bearings in 40HP motor. This bearing change is same procedure for most any bearings in the hvac industry. Most all your electric motors will be the same for hvac technician.
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Thanks, Alvin and the Chipmunks for this presentation 😆😆😆
Thanks for the video, im about to attempt this on a 75 hp motor in a RMAU. Wish me luck.
thank you guys
How much was labor ?
I love a tasty bearing after it's been cooked!
I have a Baldor with no place for zerk fittings. I'm assuming you just install bearings as they come, leaving the shields on them from the factory? I think they ship with 25 to 30 percent grease in them, which they say is enough for normal light work. Thoughts?
If it does not have a fitting it is very likely a motor with sealed bearings. This would mean that they do not need greasing. If you're installing a set of bearings that are not sealed then you would remove the shields on the side that the grease fitting is on. Typically this will mean the side of the bearing facing away from the rotor is your greasable side that will not have shields.
The VFD is feeling guilty
If that motor is on a speed dive or VFD. That will cause the bearings to go bad it can be corrected by putting a grounding ring on the shaft
Ya I've learned that one the hard way. I recommend it to all customers but many choose not to sadly. Another factor on this one was the belts were overtightened for to long causing axial stress.
back EMF
My dude, your grammar is trash and makes it hard to read what you were trying to type here. Plz proof read before posting.
Good video funny Alvin and the chipmunks sounds voices.
The part where he hits buddy with the hammer
What temperature do you heat the bearing to and for how long?
Thanks
Well done, dudes! Thank you for this, it was very informative!
Could you opt for sealed bearings instead?
Yup
Thats why we only do sealed bearings. No maintenance needed. Plus we had a very stubborn tech who used over constantly over greased, damaging the bearings and effectively making everywhere around motors look like a french frier greese booth..
Looked funny,reminds me of Benny Hill slapping the old bald headed guy on the head.
Wish this would have shown us how to put it all back together, I have questions
Excellent you have just saved me heaps of time👍👍
My Baldor motor has shielded bearings and a grease port as well. Should I install new bearing and remove one side of the shield or just install like OEM (shielded both sides)?
Install new sealed bearings instead, then you dont have to grease. If theres a VFD, then you want to buy bearings with a grounding ring and they will last as long as the motor will (with proper belt maintenance).
Can you just use a heat gun to heat up the bearings? And I’m assuming this is to get the grease all loosened up correct? Very new to this and I’m looking to start doing this. I work for a company where when the bearings go out in a motor they replace the whole thing. I want to learn to fix the bearings so we don’t have to tear a motor out of a AHU that’s high up needing to get all rigged up and what not.
No heat gun would be sufficient. Its to make the inner ring expand larger so it slides over the motor shaft smoothly.
Thanks
My company is going this route on a 50hp! Is there any other factors to look for the reason of the bearing failure? What type of grease used? Thanks for the vid!
The kind of grease depends on the bearing manufacturer. They almost all recomend a poylurea grease (blue). SKF recommends their own LGHP2 I believe, while everybody else (WEG, Baldor, US Motors) recommend Mobil polyrex.
The first factors to look at in early bearing failures is alignment, load, balance/vibration of the load. This accounts for 16% of bearing failures. You need to read and make sure the motor is rated for the use (belt driven equipment, direct coupling, or overhung)
The second factor is lubrication: intervals, amounts, contamination, overheating, seals popped off, etc account for 36% of bearing failures according to SKF. Make sure you do it right.
A third factor to look into is if you have a VFD running the motor. It’s not too much of a concern on Danfoss and ABB drives, but cheaper drives are known to kill bearings. The motor needs a shaft grounding brush (Aegis is a good no maintenance option that motor manufacturers put into their higher end motors). The wires have to be run in such a way that they don’t induce a current through the ground wire, and you need to make sure you don’t have common mode currents going through. You can clamp around all three phases at once, if this doesn’t read 0 amps then you have current going somewhere, likely arcing through the bearings and killing them. You would need a common mode choke to get rid of this. VFDs can also cause premature failure if you are using them to overspeed the motor (above 60Hz is overspeed). Although all good motors nowadays are rated for 90Hz to account for this.
The thing I don't like about the grounding brush is if maintenance over greases, they're insulating the brush and it becomes useless. I always install the external shaft grounding kit. Also, no grease is better than too much grease.
@@BelleTheBoston8weeks yet another reason to buy sealed bearings
What temp did you heat the bearings to?
To be honest im not sure what temp it gets them to. I set the heater to 350F then wait about 10 minutes and its good. Not enough to cause grease to smoke