Due to the formation of air bubbles during high-speed operation of vacuum pumps, the rapid rotation of the rotors can cause the bearings supporting the rotors to overheat. There are usually several reasons for bearing overheating during the operation of vacuum pumps:

1. Smoothness Issue: Overuse or underuse of lubricant, or an incorrect lubricant type, as well as excessive use time or contamination of the lubricant can cause bearing overheating. At this point, check the lubricant type, consult the manufacturer for the appropriate amount, and adjust the lubricant to restore the bearing temperature.

2. Notable Impact: Excessive bearing temperature occurs when there is significant vibration in the pump housing or bearing. To restore the bearing temperature, investigate the pump housing to identify the cause of the vibration and eliminate it.

When a valve blade cracks, the pressure on both sides of the impeller becomes unbalanced, causing a shaft force on the rotor, which exacerbates the bearing load. Prolonged operation can lead to an increase in bearing temperature. In such cases, the valve blade should be replaced promptly.

4. Excessive bearing preload: This condition can promote the reduction or elimination of bearing clearance, leading to increased bearing temperature.

5. Axial Seal Failure: When the seal ring at the shaft end is damaged or the sealing water passage is blocked, air can be drawn into the pump body through these damaged gaps, leading to the pump's suction and exhaust performance issues. If only one side of the seal fails, it will cause an imbalance in pressure on both sides of the impeller, resulting in an axial force on the rotor that increases the bearing load, thereby raising the bearing temperature.

6. Bearing Damage: Both the rolling elements and retainers of a bearing can exhibit overheating symptoms upon damage. It is necessary to replace the bearing promptly when damage occurs.