What will cause repeated bearing failures in a Canned Motor Pump

When experiencing repeated bearing failures, it is important to understand the operating conditions of the Canned Motor Pump. However, in a general sense the most common failure mechanisms for canned motor bearings are:

■ Lack of fluid in the bearings:

If the canned motor is not vented properly prior to start-up or the liquid level drops, then air/gas can enter the bearings. This displaces the fluid and therefor the bearing cannot develop the suitable fluid film required for the bearing to operate.

■ Overloading of the bearings:

The most common example of this would be that the pump is not operating within its design region. This means that the forces being generated by the impeller and reacted at the bearings are larger than designed for.

■Particulate entering bearings:

If particulate enters the bearings, it can score the surfaces and displace the fluid that is designed to be in the bearing. This causes premature wear of the bearings surfaces and can reduce the load capacity of the bearing.

Understanding and addressing these common failure mechanisms are essential for improving the reliability and longevity of canned motor pumps. Proper maintenance, including ensuring adequate fluid levels, operating within design parameters, and implementing effective filtration systems, can mitigate these issues and extend the life of the bearings.