Lubrication selection of sliding bearing

The characteristic of lubricated bearing is that the friction is linear contact and the friction coefficient is large. It is generally used in low speed and heavy load machinery.
1、 Selection of lubricant for sliding bearing
The main factors to be considered in selecting the lubricant for sliding bearing are speed, temperature and load, and the viscosity of lubricating oil or the consistency of lubricating grease should be determined accordingly.
When sliding bearing is lubricated, the radius difference (clearance) between spindle and sleeve is the main parameter. The clearance depends on working temperature, load, minimum oil film thickness, friction loss and eccentricity between spindle and sleeve. When choosing lubricant, clearance is also an important parameter. For sliding bearings with small clearance, more attention should be paid to the corresponding relationship between clearance and oil viscosity or grease consistency.
The selection of lubricant for sliding bearing is mainly determined by the operating conditions and lubrication methods. As for whether to use lubricating oil or grease, it is usually determined by the average load factor K of bearing.
Advantages of grease for sliding bearing
(1) In the dusty environment, it is easy to keep the bearing clean and prevent impurities from mixing in;
(2) It is good for sealing but not only for oil leakage;
(3) It will not pollute the environment;
(4) It is convenient to use when it is inconvenient to refuel;
(5) The lubrication system is simple and durable;
2、 Precautions for selecting grease for sliding bearing
(1) When the load of the bearing is large and the rotation speed is low, the consistency of the selected grease should be larger, and the viscosity of the base oil for grease making should also be larger; On the contrary, the products with larger cone penetration should be selected;
(2) Generally, the dropping point of grease should be 20 ~ 30 ° C higher than the working temperature;
(3) The grease should have good adhesion;
(4) If the sliding bearing works in water drenching or humid environment, calcium grease should be selected, while lithium grease should be selected under higher ambient temperature;
(5) Under special operating conditions, such as: railway locomotive axle (high circumferential speed, high load), paper dryer and baking machine, if sliding bearing is used and lubricating grease is used for lubrication, special grease is required.