When using bearings, rational use is the main method to extend life. The most important thing for reasonable use of bearings is to do good bearing lubrication. In order to maximize the lubrication effect of the bearing, the choice of grease is very important.
The selection of motor bearing grease must consider multiple factors such as the working environment of the motor, the light and heavy condition of the load, the length of operation time, and the level of speed. In the long-term practice of motor repair, the author has realized the choice of motor bearing grease, which mainly depends on the degree of moisture in the working environment of the motor and the operating temperature of the bearing. If these two conditions are not met, grease may be lost, hydrolyzed, damaged bearings, and affect production. There are many types of grease used in motor rolling bearings.
The maximum amount of grease filled in sealed rolling bearings should not exceed about 50% of the internal space, and the best for ball bearings is 20%~30%.
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.
Of course, in order to determine the optimal grease filling level, other factors can also be considered. For example, an open bearing that works in an environment full of dust or moisture and exposed to steam can also be filled with a large amount of grease to protect the bearing from dust and moisture.
