Lubrication of Pump Lineshaft Bearings

[GaTechTheron]

In a vertical turbine pump (VS1), I'm trying to calculate the minimum speed that we can operate the pump. Is there a way I can calculate the minimum speed required to properly lubricate the lineshaft bearings? Is this a function of fluid speed in column, or some sort of pressure drop?

I appreciate the help!

Thanks,
Theron

 

[GaTechTheron]

Nevermind: The pump manufacturer said there are spiral grooves machined into the bearings such that they lubricate themselves. All I have to do is ensure bearings see fluid.