AC 1250kW 6000V 3 phases, Vibration 29 mm/s during the starting time (1-2 sec.) at full load 4

[Creator_87]

Hello everyone.

I have a AC motor 1250kW 6000V 3 phases. It has a high horizontal vibration of 21-29 mm/s on a non-drive end bearing during the starting time (1-2 sec) at full load.
Then, the vibration is ok , about 1.9 mm/sec.

According to an operation manual the motor can withstand up to 18mm/sec (1-2 sec) during the starting time at full load.

I don't know what it might be.

Could anyboby tell what reasons might be? Or sources (books, web) where similar broblem was described.

Thank you in advance.

 

[BrianE22]

The tubes bolted to both ends look like they have some mass and springiness. Are you sure it's not the tubes that are shaking?

 

[electricpete]

It looks to me like the orange piping is oil drain piping and the silver-colored hoses are braided flex hoses. I can't say I have every seen a bearing drain configuration before with flex hoses. It makes me wonder the purpose of those flex hoses
[ul]
[li]A - maybe to allow replacement with a motor (or pump) that has drain connections at a different locations?[/li]
[li]OR[/li]
[li]B - Maybe to decouple movement among piping and motor / pump? (if so maybe the designer knows something we don't)[/li]
[/ul]

There are rolling bearings

I can't say that I have ever seen rolling element bearings with external oil supply / drain like that. Typically rolling element bearing generates small enough quantity of heat that the heat can be removed by the bearing housing without the necessity of requiring relying on external oil supply. With the large drains it doesn't look like oil mist lubrication. So overall I'm very confused by the bearing / lubrication arrangement... that's nothing new for me ;-)

I guess the bulge on the outboard end is a fan although I'm not familiar with this type of construction. The only motors I see with fan sticking out the end are TEFC, but this doesn't look like a typical TEFC. I'm not sure I fully understand what's out there on the NDE but I'm wondering whether the accelerometer might be mounted on a flimsy shroud-like part on the NDE. If so that might explain why the NDE is shaking during start and the DE isn't.

Sorry for a lot of rambling.

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

 

[edison123]

That's oil cooled bearings for both the motor and the pump and the inclined big pipe is the inlet feeder with flow control valves for the motor bearings. The flexibles are there there for ease of connection. Similar oil outlets must be on the other side of the motor.

It's a tube ventilated TEFC motor cooled by the NDE shaft driven fan. The DE view will show pipes embedded around the stator periphery.

It's a clean and professional setup and all this 1-2 sec 'high vibration' is a nothingburger imo since the OEM says such high vibrations during cold start are normal.

Muthu

http://www.edison.co.in

 

[Mr_Curious]

Sorry for misunderstanding. The picture above is not the motor i have talked. Its another one with plain bearing. The purpose of the picture is to show the whole unit and supports of the pump.

 

[TugboatEng]

It looks to me like the orange piping is oil drain piping and the silver-colored hoses are braided flex hoses. I can't say I have every seen a bearing drain configuration before with flex hoses. It makes me wonder the purpose of those flex hoses

This is the right way to do it. To add to what Edison said, they even added nice features such as a straight connection on one end to a 90 on the other which makes assembly a breeze. I think there is a lot of tribal knowledge caused by mis-specification of rubber hose. Many operators experienced failure due to rapid deterioration and bad assembly. We will be stuck with that knowledge for decades to come.

Double props if all of the hose assemblies are identical.

 

[edison123]

What stopped you from posting the pic of the motor under discussion?

Muthu

http://www.edison.co.in

 

[TugboatEng]

I can think of a few reasons. Never share information that may allow your competition to know the condition of your operation.