IP ratings applied to shaft seals

[Tmoose]

The appropriate electrical enclosure "IP" ratings are readily available.

However, the sealing required at the shaft to achieve comparable Ingress Protection is much harder to find.
The best I have found was in a 1989 Publication WL 01 200 EA from FAG, the bearing folks. The info in a chart is in the attachmemt.

Is there another source of shaft sealing requirements?

thanks

Dan T

 

[LionelHutz]

Wouldn't you just figure out what you have to seal against and then pick a seal or a bearing with the correct seals.

I would say in that enclosure IP ratings either don't apply or were never meant to apply to a bearing or shaft seal. So, I can understand why you didn't find any info on IP ratings of shaft seals. I would say shaft seals is a more complex application that is outside the scope of the enclosure IP ratings.

Typically, a shaft seal is protecting a bearing of or trying to contain a lubricant of some sort. Performing that task means that achieving something like the equivalent of an IP54 rating on the opposite side of the seal is fairly easy. Now, meeting the equivalent of IP56, IP57 or IP58 could take some further considerations.

 

[Tmoose]

My dilemma is we have several dozen motors in outdoor service shaft mounted horizontally, but feet mounted ~ vertically as part of a package provided by others.

Well, we have had our first motor bearing "failure" a few weeks ago. Looks pretty rusty in there, (as well as not very much grease) but the other end was fairing much better.

I asked the motor manufacturer directly about the SHAFT sealing provided on these motors, and got the reply " IP 55. " Seems like that >>should<< be immune to water jets from any direction or even temporary flooding.

I'm awaiting details of the actual seal geometry and hardware.

More aggressive re-lube schedule would likely help, but there are other seal features implied in the motor manual that make me think we well may have a farm pond forming adjacent to each drive end bearing.

 

[waross]

Looks like LOL, lack of lubrication.
How long have these been in service? I would expect any motor bearing to lsat at least one year without service, and expect most applications to last two years.
Is this a belt drive application? Running the belts too tight may cause the bearing to run hot and cook out the grease.
Give us a little more information such as HP, time in service, type of drive (belt or direct) type of machine and environmental conditions.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[sreid]

Bearing Isolators?

http://www.inpro-seal.com/

 

[Skogsgurra]

Does "shaft mounted horizontally, but feet mounted ~ vertically" mean that shaft still is horizontal?

If shaft is vertical and the motors weren't designed for that, you will - of course - have problem with water entering the motor. In a recent case, I had motors that were designed to run vertically. The problem was that they had been mounted with the sealed end pointing down. So bearings failed quickly. Have to check everything.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[waross]

Hi gunnar.
I took that to mean mounted on a vertical surface with the shaft parallel to the ground. That is the motor body rotated 90 deg about the axis of the shaft. Normally the greasing and grease drain holes are oriented vertically with the grease fitting on top and the drain fitting on the bottom. This orientation would put the grease holes horizontally across the axis of the shaft so that complete gravity drainage of the bottom half of the bearing would not be possible.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[LionelHutz]

I don't think you got the right answer. IP55 would be referring to the motor housing.

I would agree with what Bill posted, it could be an issue if the motor is rotated 90 degrees from it's intended mounting position.

 

[electricpete]

Some of the weapons at your disposal:

Bearing seals (installed on the bearings themeslves) If your D*N permits it.

Isolators (like Inrpo) as sreid mentioned. Most manufacturers provide these in their lines of severe duty IEEE841 motors (although I don't see it mentioned in IEEE841).

As you know, the bearing needs grease as a vital part of the moisture exclusion for the bearing. With no visible grease found (is that what you had?), I'd suspect an assembly screwup. Unless your thinking the grease washed out?... should be able to see external evidence of that I'd think.

=====================================
(2B)+(2B)' ?

 

[desertfox]

Hi Tmoose

I find this article:-

http://www.macroseal.com/pdf/Parker ProTech SG.pdf

desertfox

 

[desertfox]

IP rating for fridge motors

http://www.google.co.uk/webhp?sourc...gc.r_pw.&fp=85be7de52198e892&biw=1024&bih=589

 

[Pumpsonly]

It is call IM B6 or IM B7 mounting. Nothing unusual.

http://www.servorecambios.com/ABB/dispomont.pdf

It is clearly a LOL case judging on the color or the failed bearing.

The IP rating of the motor include the bearings also.

 

[macmckim]

ElectricPete

IEEE-841 (2009) mentioned it in section 4.5 ( shaft seals are used, shall be non-contact, rotating type). Bearing isolators are another term. Number of brands used - ImproSeal, ProTech, Garlock and others.

 

[electricpete]

4.5 Enclosures
Enclosures shall be TEFC or totally enclosed non-ventilated (TENV) and shall have a degree of protection of IP 55. If replaceable shaft seals are used to achieve this degree of protection[/B], they shall be the noncontact or noncontacting-while-rotating type with a minimum expected seal life of 5 years under usual service conditions. Degrees of protection are defined in NEMA MG 1-2006, Part 5.3

I would submit this does not strictly require bearing isolators because:
#1 - note the word "if"
#2 - there are a lot of "non-contacting while rotating seals" that are a lot cheaper than an inpro. For example Forsheda V ring.

I agree most OEM's provide it with their IEEE841 motors as stated above. It must be one of 2 reasons:
1 - they must have determined it's a worthwhile feature to package into their their "severe duty" motor offerings based on marketing considerations.
...OR...
2 - They couldn't pass the required IP55 tests without it.

==========

Earlier in this thread there was a discussion whether shaft seal was a part of ingress protection. Based on the quote above, it certainly is included (as stated by PumpsOnly). The IP tests as I understand it requires the motor to survive various types of water spray (one digit is for water spray and the other for dust). But is there a disassembly afterwards to inspect to see if water got into the windings or bearings? I don't know for sure but I don't think so.

=====================================
(2B)+(2B)' ?

 

[Pumpsonly]

I believe the IP rating of motor is only certified by proto-type testing and verification of the design and production QC/QA process.
It make no sense to perform a spray test on each and every motor, open it to inspect and reassemble it.

 

[electricpete]

I believe the IP rating of motor is only certified by proto-type testing and verification of the design and production QC/QA process.
It make no sense to perform a spray test on each and every motor, open it to inspect and reassemble it.

Agreed 100%. Who said anything different? I asked if the spray test [when done] involves disassembly afterwards to determine whether water got in.

=====================================
(2B)+(2B)' ?

 

[LionelHutz]

Obviously in this case the fact the motor has an IP55 is useless since the IP55 rated motor is appearing to be inadequately protected for the enviroment it's operating in. So, you need to go to a bearing supplier and ask them what they'd recommend for that application or you need to figure out how to protect the bearing better, which is likely the real reason why you posted here.

I think you first need to determine what the motor is exposed to, as in what direction and how much water is coming at the end of the motor. For example, water running over the end of the motor could be diverted with a simple drip shield. However, the end of the motor being submerged in water would require a more elaborate solution.

 

[Tmoose]

Outdoor southern USA installation. Due to other "issues" with these devices, slurry spray, or water washdown to clean up the slurry spray realistically may occur.

Motor shop reports a v-ring was fitted. I'm waiting for more details about labyrinths, etc.

According to FAG guideline (my original post) a Forsheda/V-ring/axial seal by itself might reach IP54 if bearing against a smooth housing. I can not help but note that in the FAG drawing a secondary lip/shoulder on the shaft is provided to assure axial location of the V-ring. If the v-ring is retained by hope and friction, and relying upon proper initialinstallation location, I am not very confident it will remain forever thus.

 

[Tmoose]

actual installation - coupling cover has 1 or 2 inch gap to motor.

 

[LionelHutz]

Are you also recommending they rotate the end bells of the motor 90 degrees to fix the grease points?