Under the circumstance of high-speed operation, as the rotation speed of rotor is too high, the bearing that supporting the rotor will be heated. Usually the overheating of vacuum pump bearing has the following reasons:
1. Cracking of Valve Block
When a valve block cracks, the pressure on both sides of the impeller will be unbalanced, and the axial force will act on the rotor, which will intensify the bearing load. The long-term operation will increase the bearing temperature. So, in this case, the valve plate should be replaced in time.
2. Shaft End Seal Failure
When the shaft end seal packing is damaged or the seal water hole is blocked, air will be drawn into the pump body from these damaged cracks, which will affect the suction and exhaust performance of the pump. If any side of the seal fails, the pressure on both sides of the impeller will be unbalanced, and the axial force will act on the rotor, which causes the bearing temperature increases.
3. Pre-Tightening Force of Bearing is Too Large
This situation will promote the reduction of bearing clearance or no bearing clearance, leading to increasing of bearing temperature.
4. Sensational Effect
When the vibration of pump body or bearing is too large, the bearing temperature will be high. Please check the pump to find out the cause of sensation and eliminate it.
5. Smooth Appearance
The amount of grease is too small or too many, or grease type does not meet requirement, long service life or grease is contaminated can make bearing heated. At this time, please check the type of smooth grease, ask the manufacturer for the appropriate use amount, and adjust the smooth grease to recover the bearing temperature.
6. Bearing Damage
Damage of bearing roll body and bearing cage will be accompanied by the bearing overheating. Please replace the new bearing timely.