Why Does Your Bearing Grease Harden?
July 12, 2022
I believe that many friends have encountered the phenomenon that the bearing grease becomes dry and hard during operation. After the grease becomes hard, it will cause blockage, resulting in poor system lubrication, increasing the frictional resistance of mechanical parts, and increasing the consumption of mechanical power, etc. . So, why does bearing grease harden? Typically, grease hardening is caused by the separation of the Base Oil from the thickener, creating a lumpy mass. In fact, under normal circumstances, part of the base oil in the grease will also be precipitated from the grease over time. As the amount of base oil precipitation increases, the grease will gradually harden. When the amount of precipitation reaches half , the grease needs to be replaced immediately.
Therefore, card friends must regularly lubricate and maintain the hub bearings. Generally, the life cycle of grease is about 6 months to 1 year. Excessive grease filling in the bearing, overheating caused by mechanical conditions (improper installation, excessive load, etc.), and insufficient lubrication can all cause overheating problems in operation. Among them, too much grease filling is a common cause. If the mechanical temperature of the vehicle is too high during operation and the dropping point of the grease is reached, the base oil will start to separate out, causing the grease to start to dry and harden.
Therefore, card friends do not think that the more grease is added, the better, and the right amount is the best when carrying out bearing lubrication and maintenance. Bearings with large radii and high speeds generate high centrifugal forces and can also separate the grease, causing the grease to harden.
Choice of Grease When selecting bearing grease, it should be determined according to the bearing speed, operating temperature, noise reduction, load and other working conditions. The best lubricating effect can be achieved only by choosing the right grease. Select Bearing Grease Considerations 1. When the bearing load is large and the speed is low, the grease with a small cone penetration should be selected, otherwise, a large cone penetration should be selected. High-speed bearings use grease with a smaller taper and better mechanical stability. Special attention is paid to the lower viscosity of the base oil of the grease. 2. The dropping point of the selected grease is generally 20-30°C higher than the working temperature. In the case of continuous operation at high temperature, be careful not to exceed the allowable operating temperature range of the grease. 3. When the sliding bearing works in a water-drenched or humid environment, calcium-based, aluminum-based or lithium-based grease with good water resistance should be selected. 4. Use grease with good adhesion. In a humid environment, at a temperature of 75-120 °C, calcium-sodium base grease should be considered. In a humid environment, the working temperature is below 75 °C, and there is no No. 3 calcium-based grease, but aluminum-based grease can also be used. When the working temperature is 110-120℃, lithium-based grease or barium-based grease can be used. For concentrated lubrication, the consistency is smaller. The above are the suggestions and precautions on how to choose bearing grease. In addition, when choosing bearing grease, the type and brand of grease should also be considered. Their performance and characteristics are also different, and the applicable occasions are also different. Not the same.
