Grease is very crucial when using bearings. If, using deteriorated grease, not only failed to play its due role, but also to damage the bearings.
Light method
In fine weather, use a screwdriver to lifted the bearing oil to a 45-degree angle to the horizontal. Control sunlight, observe the oil droplets in the light, you can clearly see the bearing grease without debris as well, can continue to function, if excessive wear debris, should be replaced with oil.
2. Oil traces
Take a clean white filter paper, the number of drops of oil dripping on the filter paper, until the oil leakage, if the surface of a black powder, touch with a sense of obstruction, then the lubricant has a lot of impurities inside, a good lubricant No powder, hand dry and smooth, and yellow traces.
3 oil flow observation method
Take two measuring cups, one containing bearing lubricant to be checked, and the other empty on the desktop, the cup full of oil lifted 30-40 cm away from the desktop and tilt, so that the bearing lubricant slowly flowing Empty cup, observe its flow, good quality lubricating oil flow should be slender, uniform, continuous, if there suddenly sudden and sudden oil flow, and sometimes a large stream, then said the oil has deteriorated.
Hand twist method
Twist the bearing lubricant between the thumb and index finger repeatedly grinding, better lubricant feel lubrication, less wear debris, no friction, if you feel between the fingers of the sand like a larger friction, it shows lubrication Oil impurities, can no longer be used, should be replaced with new lubricants.
(A) the role of bearing lubrication Lubrication of the rolling bearing fatigue life and friction, wear, temperature, vibration and other important implications, there is no normal lubrication of the bearings can not work. Analysis of the causes of bearing damage shows that about 40% of the bearing damage are related to poor lubrication. Therefore, the good lubrication of bearings is to reduce bearing friction and wear an effective measure.
(B) Comparison of grease lubrication and oil lubrication Bearing lubrication methods are roughly divided into two kinds of grease lubrication and oil lubrication. In order to give full play to the function of the bearing, it is important to adopt the lubrication method according to the purpose of reduction and use.
(C) grease Grease is a lubricant composed of base oil, thickener and additives. When the choice should be very suitable for the bearing conditions of grease, due to different trademarks, the performance will be very different, so when choosing, we must pay attention.
(D) the choice of grease In accordance with the operating temperature of grease, the main indicators should be dropping point, oxidation stability and low temperature performance, dropping point can generally be used to evaluate the high temperature performance, the actual bearing temperature should be below the dropping point 10-20 ℃. Synthetic grease temperature should be lower than the dropping point 20-30 ℃.
(E) oil lubrication In high-speed, high temperature conditions, grease lubrication has not adapted to use oil lubrication. Through the circulation of oil, you can take away a lot of heat. Viscosity is an important feature of the oil, the viscosity of a direct impact on the size of the fluidity and friction between the oil film formed between the friction surface temperature, bearing the lubricating oil viscosity is generally 12-15cst.
(F) solid lubrication In some special conditions of use, a small amount of solid lubricant added to the grease, such as adding 3 to 5% of the No. 1 molybdenum disulfide can reduce wear and improve the resistance to heat, for high temperature, elegant, High vacuum, corrosion resistance, radiation resistance, and extreme low temperature and other special conditions, the solid lubricant added to the engineering plastics or powder metallurgy materials can be made with self-lubricating bearing parts, such as the adhesive with a solid lubricant stick Results in the raceway, cage and rolling body, forming a lubricating film, to reduce friction and wear have a certain effect.
(F) of the lubricant replacement and replacement a. Grease replenishment interval due to mechanical effects, aging and increased pollution, the bearing configuration filled with lubricating base will gradually lose its lubricating properties. Therefore, the lubrication rank needs to be constantly updated and updated. Lubricant replenishing interval due to the formation of bearings, size and speed of the different, according to the operation time need to replace the approximate intervals of grease.