What are your thoughts on greasing sealed ball bearings running 3000 rpm in 100* F temps, super dusty farming operation ? We have tried 1 pump/50 hrs, daily grease 1 pump, and 1 pump seasonally (200 hrs) . We see little difference ,but more grease seems to shorten the life slightly.
I guess that would depend upon if the bearing was originally packed with clay based grease. Those absolutely do not like to be cross contaminated. It will get sticky and generate heat. Those are typically sealed with viton clad side seals. The ones with plain old tin sides, they should be greased regularly, the mfrs have moved away from that practice saying that the excess grease will draw in dirt. If it is flooded with lube, I fail to see how it will be drawn in. I still believe in daily grease. Grease to purge, wipe off excess, let her rip. With all that said, no one will even wipe off a zerk before lubing, let alone wipe off excess. NO MOLY GREASE IN A HIGH SPEED ROLLER, EVER!
We do clean the zerks before greasing and try not to pop the seal on bearings ( 1 pump) Moly was going to be another question.... Why not in bearings if it is so slick ?
If you leave the rubber seals on and use a grease gun... one pump or not it can still shove the seal into the bearing. If you're gonna grease them anyways get a pick and pick the seal off the side that will receive the grease... the other side seal will get pushed off anyways As for the moly in roller bearings it can cause the rollers to not roll... instead they slip or skid... however supposedly if the moly is 5 percent or less it is supposed to be ok....
Sealed bearings don't take grease. Generally if they need grease the bearing will have a seal on only one side. High speed bearings that run in sealed cases, like high pressure water pumps, just take a couple of pumps every couple of hundred hours and the excess gets extruded. You can't pump them full or they will overheat. The manufacturer will usually be the arbiter of what type of grease and how often to do it.
Except that every head and tail pulley you come across will have a sealed Dodge bearing or pillow block of some sort with a tin sided roller bearing. Those must be greased , the frequency depends on the builder.
I have bad luck with the Dodge bearings because they have plastic cages instead of steel. 2 much grease in those and the cages break,... bearing failure coming soon