The oil in the grease in the bearing is separated from the thickener, resulting in a hard mass. Under normal circumstances, a part of the oil will precipitate from the grease over time, and the grease will become significantly harder if the grease quickly precipitates a large amount of oil. In some cases, the grease may become hard after a long period of use. The solution is to shorten the life cycle of the grease, which is generally about 6 months to 1 year.
When half of the base oil of the grease flows out, the grease must be replaced immediately. The high temperature caused by excessive use of the machine and other causes can also harden the grease. Regardless of the reason, the heat will cause excess oil to flow out of the thickener, promote oil oxidation, and harden the grease in the bearing.
Bearings with large radius and high speed generate high centrifugal force, and the grease becomes oil, which hardens the grease. In order to reduce this situation, the bearing should not add too much grease
Grease has good adhesiveness, wear resistance, temperature resistance, rust resistance and lubricity. It can improve high temperature oxidation resistance, delay aging, dissolve carbon, prevent metal wear powder and oil from agglomeration, and improve mechanical wear resistance Resistance, pressure resistance and corrosion resistance.
After knowing the movement process of the grease on the bearing, it is of course concluded that the grease in the bearing should not be too much. The increase in grease is not only wasteful, but also harmful.
The higher the bearing speed, the more harmful. The greater the amount of grease filled, the greater the friction torque. Under the same filling amount, the friction torque of the sealed bearing is greater than that of the open bearing.
When the grease filling amount is equivalent to 60% of the bearing internal space volume, the friction torque will not increase. This is because most of the grease of the open type bearing is squeezed out, and the grease of the sealed type bearing also leaks.
With the increase of the grease filling, the temperature of the bearing rises linearly. Under the same filling amount, the temperature rise of the sealed bearing is higher than that of the open bearing. The grease filling amount of sealed rolling bearings is best to be 20%~30% of ball bearings.
