Monday, January 28, 2008
Lubricating sealed bearings
have devised a pretty slick way (pun intended) of lubricating sealed bearings. It is so simple and non destructive. The bearings are placed in a container just big enough to hold them. In this case, a little plastic cup. Oil is poured over them until they are completely submerged. Normally I use 90W gear oil. Then the cup is placed under the bell jar on the vacuum table, and a vacuum pulled which extracts the air. As you watch you can see the air being pulled out of the bearings and bubbling up through the oil. After a moment or so release the vacuum and oil will be sucked into the bearings to replace the missing air.
I've lubricated lots of bearings this way. Usually they get over filled so they leak a bit until the excess drains out, but that is ok. I've re-lubricated electric motor bearings that sounded like they were wore out. The bearings in my 50 plus year old table saw sounded like a grist mill until I lubed them. Now they are quiet as new ones. One time I ran onto some new-old stock bearings that had set on the shelf so long the grease had hardened rendering them useless. Some fresh oil to soften the grease and and they are ready to roll again.
Not every shop is equipped with a vacuum table and a bell jar, but something as simple as a 1/2 pint canning jar with a hose fitting soldered to the lid would work fine. There are lots of sources for vacuum, some people could even hook it up to their head. A vacuum cleaner would probably not draw enough. You need at least 15 inches. Those hand pumps that are used to bleed hydraulic brakes would work, there are aspirators available. Even condensing of steam in a closed chamber.
Play a little, you will have fun with it.