Ok, so there's an annular groove cut mid-way along the length of the shaft. That might well be for retention of lubricant. You'll have to forgive my assumptions about low RPM operation - I took these to be the typical 'Muffin' type fans, that run about 600 RPM.
This is a long-shot, but does the groove in the shaft communicate with a passage in the bearing, by any chance? Just wondering if there's a wicking type oiling system in the design, as seen in larger electric motors. If there's no passage for lube, then I'd stick with the suggestion to use a light-bodied grease like Phil's and make sure to pack the groove full of it. But again, there's no harm in using a medium-body motor oil, like 30W or 10W-40. It's not as if it's going to be in 24/7/365 service, eh? What's the diameter of the shaft, btw? 1/4" or less? Got any pics of the parts? On Sun, Apr 17, 2016 at 8:43 PM, Noel Chiappa <[email protected]> wrote: > > From: drlegendre > > > If they use sleeve bearings, take a close look at the material.. does > > it have the sintered look of oil-impregnated bronze (Oilite)? > > It looks like copper, actually; it's quite reddish. (The central pin seems > to > be steel of some sort.) But I'm not familiar with Oilite, so I can't say > for > sure. > > > Are there channels in the bearing to allow the distribution or > > retention of grease? > > There's a section of reduced diameter in the center of the pin; the ends > are > full diameter, with no grooves of any kind. The sleeve is a plain cylinder. > > > Those fans tend to run at pretty low RPM > > Not these. They are doing very high RPM indeed. > > Noel >
