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The lubrication of rolling bearings

 

The purpose of lubrication of rolling bearings is to reduce friction and friction inside the bearing, prevent burning, and its lubrication effects are as follows:

 

(1) Reduce friction and friction

In the intercontact parts of the rings, rolling elements and retainers that make up the bearing, metal contact is prevented, and friction and wear are reduced.

 

(2) Extend fatigue life

The rolling fatigue life of the bearing is extended when the rolling contact surface is well lubricated during rotation. Conversely, if the oil viscosity is low and the lubricant film thickness is not good, it will be shortened.

 

(3) Discharge friction heat and cooling

The recirculating oil feeding method can be used to dissipate heat generated by friction or heat from the outside and cool it down. Prevent the bearing from overheating and prevent the lubricating oil from aging itself.

 

(4) Miscellaneous

It also has the effect of preventing foreign matter from penetrating into the inside of the bearing, or preventing rust and corrosion.

 

Lubrication method:

 

The lubrication method of bearings is divided into grease lubrication and oil lubrication. In order to make the bearing function well, first of all, it is necessary to select a lubrication method that is suitable for the conditions and purpose of use.

 

Cleaning of bearings: When disassembling and overhauling the bearings, first record the appearance of the bearings, confirm the residual amount of lubricant, and wash the bearings after sampling the lubricant for inspection. As a cleaning agent, cleaning agent and kerosene are commonly used.

 

The removed bearing is cleaned, divided into coarse cleaning and fine cleaning, and placed in the container respectively, and the metal mesh is placed at the bottom first, so that the bearing does not directly contact the dirt of the container. If the bearing rotates with dirt during rough cleaning, it will damage the rolling surface of the bearing, so it should be careful. In the rough cleaning oil, use a brush to remove grease and stickiness, and after it is roughly clean, move on to fine washing. Fine washing is a careful cleaning of the bearing while rotating it in the cleaning oil. Also, keep the cleaning oil clean at all times.

 

Bearing inspection and judgment: In order to judge whether the disassembled bearing can be used, it is necessary to inspect the bearing after it has been cleaned. Check the condition of the raceway surface, rolling surface, mating surface, the wear of the cage, the increase of bearing clearance, and the damage and abnormality of the unrelated dimensional accuracy.

 

For non-separating small ball bearings, the inner ring is supported horizontally with one hand and the outer ring is rotated to confirm whether it is smooth.

 

For separable bearings such as tapered roller bearings, the raceway surfaces of the rolling elements and outer rings can be inspected separately.

 

Because large bearings cannot be rotated by hand, pay attention to check the appearance of rolling elements, raceway surfaces, cages, flange surfaces, etc., and the higher the importance of bearings, the more careful inspection must be carried out.