Three types of lubrication methods
1. Oil lubrication
When the bearing works under high temperature and high-speed conditions, it must be lubricated with oil. Commonly used lubricating oils are mechanical oil, high-speed mechanical oil, turbine oil, compressor oil, transformer oil, and cylinder oil. When lubricating with oil, the viscosity of the lubricating oil is the premise of the formation of the lubricating oil film. In order to form a lubricating oil film of sufficient thickness between the contact surfaces, the viscosity of the oil should ensure that it does not lose its minimum viscosity at the working temperature. Therefore, when selecting lubrication, the viscosity of the oil should ensure that it can provide sufficient lubrication for the bearing at operating temperature. Generally speaking, low-viscosity lubricating oil should be used when the bearing speed is high; when the bearing is under heavy load, higher-viscosity lubricating oil should be used. According to oil Depending on the structure of the lubricating system selected for slippage, oil lubrication can be divided into the following categories:
The above lubrication methods are oil lubrication of the bearing. In order to ensure that the lubrication of the bearing is always maintained in a good state, the lubricating oil should be replaced regularly when oil lubrication is used. The replacement cycle varies with the lubrication method. When the oil bath is lubricated, as long as the operating temperature does not exceed 50°C and there is no pollution, it is usually enough to replace it once a year. However, as the temperature increases, the replacement cycle is shortened accordingly. For example, when the operating temperature reaches 100 °C, the oil must be changed every three months. When using circulating oil lubrication, it should be determined by the speed of the oil circulation and whether the oil has been cooled. When lubricating by this method, equipment maintenance and replacement of lubricant are convenient, but the lubricating device is complicated, the sealing is difficult, and the oil is one-time use, so there is no problem of replacement.
2. Grease lubrication
Grease lubrication does not require a special oil supply system and has the advantages of a simple sealing device, low maintenance cost, and low grease cost. It is widely used in bearings operating at low speed, medium speed, and medium temperature. Especially in recent years, the advent and continuous development of anti-wear additives have improved the lubricating properties of grease and made grease lubrication more widely used. The most commonly used greases are calcium-based grease, lithium-based grease, aluminum-based grease, and molybdenum disulfide grease. Different greases have great differences in physical and mechanical properties and adaptable temperature. The appropriate type of grease should be selected according to different working conditions to meet its use requirements. Under normal circumstances, some basic grease is already installed in the bearing when it leaves the factory.
Direct contact for targeted production.
In actual production, the selection of grease should mainly be considered in terms of working temperature, bearing load, and rotational speed.
3. Solid Lubrication
If the use of oil lubrication and grease lubrication cannot meet the lubrication conditions required by the bearing, or cannot meet specific working conditions, solid lubricants can be used, or try to improve the lubrication performance of the bearing itself. Under the conditions of use, a small amount of solid lubricant is added to the grease, such as adding 3-5% molybdenum disulfide to reduce wear and improve compression and heat resistance. For high temperature, high pressure, high vacuum, corrosion resistance, radiation resistance, and special conditions such as extremely low temperature, adding solid lubricant to the copper sleeve can be made into bearing parts with self-lubricating properties, which has a certain effect on reducing friction and wear.