300HP Elliot - Oil Bath Oil Level

[mswitz]

Hello all,
We have an Elliot Motor (300hp 1949 vintage! - runs like a champ usually) that was recently "rebuilt" and we are running into problems. The bearings are oil bath lubed and the oil is coming out of the bearing race (or whatever it is called) and getting into the motor. My question is: does anyone know what the standard oil level is for these bearings? We apparently are filling it to 1" above the bearing at stand still. Any help would be greatly appreciated! Thanks...

Mike
A2 WTP

 

[electricpete]

"We apparently are filling it to 1" above the bearing at stand still"

That doesn't sound right. Rolling element bearings should never be submerged.

There may be other issues arising during rebuild that can lead to leakage. One I think is poor seating of the standpipe. Is it a vertical motor?

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[electricpete]

There is normally a static fill mark on the motor (vertical motors). That is where you should fill it to while stationary.

=====================================
Eng-tips forums: The best place on the web for engineering discussions.

 

[mswitz]

Yes, it is a vertical motor. It does seem odd that the bearings are being submerged in oil... the company that rebuilt the motor filled the oil to that level. We have an oil indicator tube (external), the pipe runs out from the bearing cavity horizontally and then turns vertical with a fill gauge. Do you think there may be a static fill mark inside the bearing housing?

 

[Mendit]

Many vertical motors when at stand still have the bearing totally submerged. Point to watch, there are 2 or 3 drilled holes (orifices) around the base of the bearing support housing below the lowest point of the bearing, these control the flow of oil to the bearing. If this is 3600rpm, the bearing will pump out all the oil it does not want and throw it over the top of the outer bearing race. There is an oil tube which prevents the oil from going into the motor. This tube can leak and allow oil into the windings. On some old machines the orifice feeding the oil was a small tapered plug on the filler plug when the filler is screwed in the plug was set to control the oil feed to the bearing. Has this stem broken off? this would allow too much oil to flow, and cause overheating and leaking. Note the oil level should not be within 1/2" of the top of the oil tube at standstill.