Maintenance and lubrication of anti-friction bearings in NSK bearings

The proper lubrication of anti-friction bearings in NSK bearings is crucial to their successful operation. For ordinary or sleeve type bearings, there are different principles in different practices. In order to make the maintenance of the party anti-friction bearing, we must understand and use these principles.

After fully understanding these principles, you should have a key consideration. We quote from NSK Bearing Industry's "Guidelines for Improved Bearing Lubrication": "The characteristics of lubricants, especially the characteristics of greases, cannot be determined only on the basis of specifications." The specification only generalizes one product to the physics and may also include a chemical description. The utility can best explain the problem, but the specifications are almost unrelated to the practicality.

The anti-friction bearings in all NSK bearings basically contain two hardened steel rings, multiple hardened balls or rollers, and a separator or cage that separates the rollers or rollers. These types are divided into many categories in use. Some types, such as needle-shaped column bearings, may not have an inner ring, and the rollers move directly on the hardened shaft.

Type of anti-friction bearings in NSK bearings:

Anti-friction bearings are divided into two main types. They are ball bearings and roller bearings. At the same time, we also need to know that due to the different specific uses of manufacturers and bearings, according to these basic structures and evolved many different types.

Lubrication function:

Anti-friction lubricants have the following main functions 1. Lubricate the sliding contact between the retainer and the rest of the bearing.

2. Lubricate any contact between the seat ring and the roller that is not actually rolling.

3. Lubricate the sliding contact between the roller and the guide in the roller bearing.

4. Lubricate all really rolling contacts in the bearing.

The secondary functions are:

5. Protect highly delicate surfaces from corrosion.

6. Assist the seal hood against foreign substances. Grease has a magnetic function.

7. Provide a thermal (cold) means.

Oil lubrication The resistance to deformation that exists in oil-lubricated NSK bearings consists of the following factors: bearing design and load; oil viscosity, amount, and bearing speed.

The friction torque is minimal when the amount of oil is just enough to form a thin film on the contact surface. However, if there is too much oil, the friction will increase when the viscosity of the oil is too high. However, the desire to pay less attention to friction losses to maintain safe lubrication is usually dominated by the majority. This means that more oil, usually a heavier oil, will be used to reduce losses due to evaporation or leakage.

However, it should generally be borne in mind that heavy-duty bearings and low-speed bearings usually require heavy oil. Lighter and higher speed bearings require lighter oils.

Lubrication with grease When applying grease to anti-friction bearings, high pressure theory may not be required unless it is used with great care. High pressure can damage the bearings and waste grease. Excessive grease causes danger due to high temperatures and creates an invisible environment around the bearings. In most applications, ball or roller bearings can be fully lubricated if the grease level accounts for one-third to one-half of the bearing capacity. Excess volume will usually be wasted by the seal case.

In practice it is necessary to use more than the recommended amount of grease. When the required torque is low, only a very small amount of grease is required to complete the lubrication of the bearing. When the speed is very low and NSK bearings are exposed to dust or moisture, the bearings may almost fill up. Bearings often require more frequent lubrication than normal under high speed and high temperature conditions.

Store grease in a clean container. Grease the bearing with a clean short slurry or grease gun. Keep the grease container capped. The grease on the bearing should not be overfilled. Lubricants will emerge from overfilled bearing cartridges, absorbing dirt and causing trouble. Too much lubricant can also cause the bearing to overheat. This phenomenon is particularly likely to occur on high-speed shafts - the overturning of the lubricant causes overheating.