How to choose ultra-high-speed bearing grease? Selection method and joining method
The use of ultra-high-speed grease can effectively reduce friction and wear, play a good role in rust and dust prevention, and extend the fatigue life of the bearing, but the premise is to choose the correct grease, so how about choose ultra-high-speed bearing grease?
Ultra-high-speed bearing grease selection method
1. Look at the consistency grade
Greases are generally classified according to their consistency grades, which are also called cone penetration and needle penetration. Its performance is the degree of softness and hardness of the grease, and the consistency grade needs to be selected according to the requirements of the equipment manufacturer.
2.Grease is thickened lubricating oil
Lubricating grease is also lubricated by oil, and viscosity is an important indicator of lubricating oil. Lubricating oil is divided according to viscosity. Therefore, the viscosity of the base oil should be selected correctly. If the viscosity is too large, It will cause blockage, increased friction, heat generation, etc. If the viscosity is too small, the thickness of the oil film will be insufficient, which will easily cause bearing wear. So choose the correct grade according to the manufacturer’s requirements.
3. Grooving characteristics and dropping point
Generally used for high-speed bearing grease, we must choose grease with good groove forming characteristics, because this kind of grease is not easy to cause blocking effect in use, and can effectively reduce friction and heat generation. The dropping point of the grease should be as high as possible above the upper limit temperature encountered in use.
4. Types of thickener
Different types of thickeners will directly affect the dripping point and oil separation characteristics of the grease. Therefore, a grease with a high dripping point and good oil separation characteristics should be selected. The oil separation characteristics should be viewed from both static oil separation and dynamic oil separation.
How to add high-speed bearing grease
If the amount of high-speed bearing grease added is too large, the friction torque will increase, the temperature will rise, and the grease consumption will increase; if the added amount is too small, reliable lubrication will not be obtained and dry friction will occur. The specific addition amount should be determined according to the size and model of the bearing.
The formula for the amount of grease added is: G=0.005×D×B where G is the amount of grease, in g; D is the outer diameter of the bearing, in mm; B is the width of the bearing, in mm. Therefore, it is necessary to calculate the approximate amount of addition according to the model, outer diameter and width of the high-speed bearing. When injecting grease while the bearing is running, determine whether the added amount is appropriate according to the calculated amount and the temperature of the bearing.
Generally, the amount of lubricant filled in the rolling bearing should be 1/2 to 1/3 of the inner space of the bearing, and it should be reduced to 1/3 at high speed. In addition, the cycle of adding and replacing bearing grease is determined by factors such as operating time, ambient temperature, load conditions, and grease quality. Generally, the grease should be filled once in 5000～10000 hours based on the running record, and the grease should be changed every 10000～20,000 hours.
To sum up, it can be seen that the choice of grease depends on the consistency grade, base oil viscosity, groove formation characteristics and dropping point, the type of thickener, etc., and the amount of grease added is controlled to achieve good rust prevention, dustproof and lubrication etc. functions.
