Imagine 2,000HP motor connected to a gearbox through a grid coupling and running at 1780 RPM. This is a horizontal machine. The question is: for this application what bearings, journal or antifriction, are better and why? Which bearing can deal with misalignment better? Why?

Thanks

Journal is my preference. Maintain oil level, keep the oil clean, sample routinely and align to tolerance and these bearings have a very long life. Typically antifriction bearings do not last as long.

As for dealing with misalignment, that should not be an option. What will prevent proper alignment? How much misalignment?

Don,

as you I would prefer a journal bearing in this application. Unfortunately an antifriction bearing is fitted. Do not ask me why.....Alignment - nothing prevents from aligning the motor. So it should not be a problem.

My question was more general: can journal bearing take more misalignment than antifriction one? Is it more tolerant to this condition?

Thanks

Siemens article on sleeve vs rolling bearings for electric motors:
http://www2.sea.siemens.com/NR/rdonlyres/52B96844-134E-...heoptimalbearing.pdf

Journal bearing is generally less tolerant of various types of misalignment than roller beairng. UNLESS, the bearing is provided with spherical seat between bearing and housing - allows bearing to swivel (self-aligning for angle misalignment of the bearing).

Within the category rolling beairngs. Cylindrical roller beairngs very intolerant of angle misalignment of the beairng. Ball bearings are more tolerant. Spherical roller bearings even more so.

Pete,

thank you for link. I totally forgot about Bill....