Cleaning Old Bearings for Regreasing
Regular cleansing is a very important thing for bearings.So let me tell you how to properly clean it.
Open bearings can easily be washed for re-packing with new grease. Do it before the bearings are (re)mounted in the machine if possible.
The most common way to wash old bearings is to use a clean petroleum based solvent or kerosene for soaking the bearings, preferably overnight. Agitate the container from time to time or use a screw driver in the bore of the bearing and spin the bearing around a few times. Industrial cleaning agitators or ultrasonic cleaners are nice if you have access to one.
If the bearings are large enough for a small brush to get into between the races, then the old grease can washed out while slowly rotating the bearing inside the cleaning fluid. If the bearing is too small for a brush to fit inside, then the races can be revolved by hand with the bearing partly submerged in the solvent.
Drain the solvent and wash the bearing(s) in a second or third container of clean solvent until the bearings are completely clean. When the bearings are clean, they should immediately be protected against corrosion, and the solvent should be removed as it will break down any new grease packed in the bearing.
The clean bearings can be dried by using compressed air, but be *very* careful to hold both rings tight. Blow air into the bearing while holding both rings static. If the bearing is allowed to spin during drying, then the bearing can easily reach extreme speeds and with no oil in the bearing, the races will be damaged very quickly. Also make sure clean, dry air is used.
Another method is to shake most of the solvent from the bearings and then spin it by hand in light oil. The oil will remove the solvent. Wipe off the excess oil from the bearing surfaces, but make sure a thin coat stays for corrosion protection.
Now the bearing is ready for new grease.
Do not give in to the temptation to use way oil or motor oil in bearings. Way oil is intended for for lathe ways and other sliding machine parts especially on metal working machines. As such it has different properties that make it unsuitable for use in bearings sticky, evaporates slowly, not easily washed away by cutting oil, resists drying, low resistance to heat. etc. Motor oil contains detergents to clear and engine of the products of combustion. Not necessary or desirable in an OWWM.
Author：mosbearing 2008-6-17 Source: View(911) Comment(0)