Bearings in diesel generators 1

[MS0000]

Hi!

I am choosing bearings for 8000HP 750 RPM generator, used directly coupled(flange mounted machine) to diesel engine.

Normally flanged sliding bearings are used in this type of machines. Do any of you have any experience about antifriction bearings in these applications? Special arrangements? Is it possible to make antifriction bearings a feasible solution - by spring preloading them?

All the comments are appreaciated.

 

[catserveng]

My personal experience with generators using rolling element bearing behind medium speed engines has not been good. Both Ideal and EM used ball bearings in generators behind CAT 3600 series engines, while the engines using distilate fuel seemed to not have too many problems, the engines using HFO had numerous DE bearing problems and most of those machines get retrofitted to sleeve bearings.

Had similar experience with larger gas engine prime mover machines. Natrual gas fired engines with minimal combustion problems seemd to have few bearing problems, bio-fueled engines, especially on landfill gas had several issues and we stopped installing generators with rolling element bearings, using mostly sleeve bearings by Dodge or Renk. Never really got a good explanation from the generator manufacturers, but since the units that were more torsionally active had more problems I'd guess it had something to do with that. So depending on number of cylinders, long term engine condition and type of torsional coupling used you may or may not have reasonable service life.

While most of my experience is with CAT prime movers, found some similar issues with Mak, MWM and Wartsila based units.

Hope that helps, Mike L.