Anybody have any confirmed technical data on the type of greases that are best suited for the bearings known as "shaker" bearings? These are bearings that support large vibrating conveyors like used in foundries.

Hi Max
"Shaker" Bearings can easily damage the metal soap complex greases, lithium Aluminium,

Polyureas use a different thickening system and tend handle this type of shear stress a lot better as the polyurea thickner is arranged as a "polar" type thickner and as the stress is removed the grease will return to it's original NLGI value,

Exxon, old witco, greases tend to very good as the EP is passive CaCO3 additive so no ativation of the boundary additive due to heat or water, check out the base oil requirements for the bearing and purchase to grease for the spec, most grease types have a degree of compatibility with polyurea so you should be able to over grease and purge as much as possible for the first couple of weeks until you see the colour change to new grease then set up the grease flow by microscope and allow the grease to burn a bit before it is flushed through to get maximum life from grease as the grease will be more expensive,
Note if you decide to do this check out grease compatibility issues with supplier,
Regards Rob S