Causes Of Discoloration Of Bearing Grease

Grease has oxidation issues. When the grease is left (or run) for a period of time, it will have a lot of contact with oxygen. At the same time, the metal (the bearing itself) acts as a catalyst in this oxidation reaction. Therefore, when calculating the time interval for replenishing grease in bearings, the issue of oxidation must also be considered. During the operation of the bearing itself, the temperature (the bearing itself, or the environment) will change, which causes the base oil in the grease to continuously flow in and out of the thickener. At the same time, every time the base oil goes back, it may not go back completely. If this happens for a long time, the performance of the grease will change and it will no longer be able to lubricate, so lubrication needs to be reapplied. Grease with insufficient base oil may change color. Also, if the temperature is abnormal, the performance of the grease will also change greatly, so there will be discoloration. If the temperature is very high, it will carbonize. The color will become darker. During the operation of the bearing, impurities are mixed into the grease. This kind of impurity may be peeled off by the bearing itself, or it may be entered by the outside world. It may be solid or liquid, which will affect the properties of the grease.