High Speed Bearing Lubrication

- Apr 11, 2018 -

Needle Roller bearings

Under normal circumstances, the viscosity of the bearing lubricating oil decreases as the temperature rises. 

In order to avoid bearing burn out, you must add the right volume of lubricant. However, the increase in the volume of oil also increases the resistance of the stirring, and increases the dynamic friction loss, thereby requiring an increase in the driving force of the electric spindle. 

If you use a small amount of grease lubrication, not only can not achieve the purpose of low friction, but also with the heat of the bearing.

Related Tags: Trace Lubrication High Speed Bearing Lubrication

Needle Roller bearings


The temperature rise of the high-speed rotating electric spindle is very important. The temperature rise of the spindle comes from the bearing on the one hand. The method to reduce the temperature rise of the bearing is:

(1) Reduce the dynamic friction loss of the bearing;

(2) improve the cooling conditions of the bearing;

There are several methods for the lubrication of commonly used spindle bearings:

1. grease lubrication

Under normal circumstances, the viscosity of the bearing lubricating oil decreases as the temperature rises. In order to avoid bearing burn out, you must add the right amount of lubricant. However, the increase in the amount of oil also increases the resistance of the stirring, and increases the dynamic friction loss, thereby requiring an increase in the driving force of the electric spindle. If you use a small amount of grease lubrication, not only can not achieve the purpose of low friction, but also not with the heat of the bearing. The high-speed rotation of the high-speed motor spindles accelerates the deterioration of the grease and reduces the service life of the grease. Grease is mostly used under low speed or heavy load conditions. The speed should not exceed 8000rpm/min.

2. oil mist lubrication

At present, the lubrication of electric spindle bearings in high-speed grinding of numerically controlled grinding machines mostly uses oil mist lubrication, and the lubrication of oil mists is also a kind of minor lubrication, which reduces the frictional rolling and the temperature of bearings and improves the use time of electric spindles. Another advantage is that the internal spindle has a certain air pressure when it is lubricated by the oil mist of the electric spindle, which prevents the abrasive particles from entering the shaft shell of the electric spindle and causes damage to the electric spindle. However, oil mist lubrication has the problem of environmental pollution and inaccurate oil control.

3. oil and gas lubrication

Oil and gas lubrication has the following characteristics:

(1) A very small amount of lubricating oil can be continuously and stably supplied to the bearing.

(2) The environmental pollution is small. After the air-lubricated electric spindle is continuously operated in the propylene box for about 2 hours, the air pollution in the measurement box is about 0.03 mg/m3. Pollution is less lubricated than oil mist. The reason is that oil and gas lubrication is less oil than oil mist. Lubricating oil and compressed air flow into the bearing in gas-liquid two-phase.

(3) Dust or moisture and cutting fluid are difficult to enter into the spindle, and the compressed air maintains a positive pressure inside the spindle bearing.

(4) Compressed air can take away the heat generated inside the motor spindle, effectively preventing the bearing from thermal deformation.

Needle Roller bearings

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