Ball screw bearings not only have the characteristics of high precision, reversibility, and high efficiency, but also have the advantage of low friction resistance, which makes them widely used in various industrial equipment and precision instruments. An important operation to ensure low friction resistance of ball screw bearings is lubrication. So, what lubrication is used for ball screw bearings? What are the common lubrication methods? What advantages do they have? Let's take a look together.
grease
1. Advantages of grease lubrication
(1) Low liquidity. The fluidity of grease lubrication is small, and it is not easy to leak. The formed oil film has good strength, which is more conducive to the sealing use of rolling bearings. Nowadays, bearings in equipment not only require long-term operation, but also friction between each other. Whether it is up and down movement, or left and right movement, there are requirements for bearing grease. Therefore, this grease can ensure vertical but not loss, Can provide better lubrication.
(2) Easy maintenance. The use of grease lubrication in rolling bearings can also extend the lubrication maintenance time, making bearing maintenance simpler. Very good load-bearing capacity, especially for bearings with high loads, and also has good load-bearing performance, so it can withstand the load capacity of current bearings. In addition, lubricating grease also has a very low evaporation rate, so it can exert such performance during high-speed and high-temperature operation, and can obtain long-term lubrication. This way, there is no need to spend too much effort on maintenance.
(3) Low dosage. Nowadays, when using bearing grease, it may be found that the amount of grease used is relatively small, especially when a small amount is needed on the lubricating surface. Therefore, it can reduce the amount of grease used and also reduce the cost of the enterprise.
Disadvantages of grease lubrication
(1) High friction torque. The friction torque of grease lubrication is relatively large, and its applicability is low for rolling bearings that require high-speed operation; If the bearing needs to operate at high speed, for safety reasons, it is not recommended to use lubricating grease for lubrication.
(2) Poor cooling performance. The cooling performance of the grease lubrication method is poor. If too much grease is added to the rolling bearing, it can also cause overheating of the rolling bearing due to stirring the lubricant. Overheating of bearings can to some extent reduce the service life of bearings and affect their normal use.
Oil lubrication
1. Advantages of oil lubrication
(1) Good cooling effect. Due to the heat carried away by lubricating oil in circulation, it can achieve good cooling and cooling effects, thus enabling bearings to achieve relatively high rotational speeds. Especially suitable for rolling bearings with high operating temperatures.
(2) The viscosity is optional. Viscosity is an important characteristic of lubricating oil, and its magnitude directly affects the fluidity of the lubricating oil and the thickness of the oil film formed between the friction surfaces. The viscosity of the lubricating oil can be selected according to the situation. The viscosity of lubricating oil at bearing operating temperature is generally 12-15cst. The higher the rotational speed, the lower the viscosity should be chosen, while the heavier the load, the higher the viscosity should be chosen.
2. Disadvantages of oil lubrication
(1) High sealing requirements. The sealing requirements of lubricating oil for bearing devices are relatively high, because in general, if the sealing is not good, the lubricating oil is easily contaminated by impurities, which increases the rotational friction force of the bearing. In addition, due to the relatively high fluidity, if the sealing is not good. This will cause lubricating oil leakage. Therefore, oil lubrication requires bearings to maintain good sealing conditions.
(2) Inconvenient operation. Oil lubrication requires a relatively complex oil supply device, which is not as convenient to operate and use as lubricating grease because the density of lubricating oil is generally not as high as that of lubricating grease. Therefore, it is necessary to control its fluidity during use, which increases the maintenance workload of rolling bearings.