Requirements for sliding bearings of Canned Motor Pumps

The quality of sliding bearings in Canned Motor Pumps has a significant impact on the smooth operation, reliability, and service life of the pump. Therefore, before determining the bearing structure of the pump, careful analysis and understanding of the working conditions of the bearings are necessary. For example, the lubricity, cleanliness, thermal conductivity, and corrosiveness of the conveyed medium, environmental conditions during pump operation, bearing loads, service life, and maintenance conditions must all be comprehensively considered to correctly determine the structural form and geometric parameters of the bearings.

In general, the following requirements should be proposed for the bearings in Canned Motor Pumps:

1. It should have high operational economy, meaning that the bearing should have minimal wear even when the amount of lubricating and cooling liquid flowing out of the pump’s discharge chamber is at its minimum.
2. Within the allowable wear range of the bearing, it should ensure the specified service life and not compromise the operational stability of the Canned Motor Pump.
3. The pump should be able to run under specified conditions, effectively lubricated and cooled by the conveyed liquid, while ensuring the continuous and stable operation of the bearings.
4. Ensure that the sliding bearings have good thermal conductivity structurally and in terms of materials, to ensure that frictional heat in the bearing friction zone is effectively dissipated.
5. Select a reasonable PV value.
6. The material of the bushing should undergo wear-resistant and anti-corrosion treatments, typically using processes such as chrome plating, spray coating with hard alloys, and currently, ceramic materials treated with plasma spraying technology are also used for bushings.
7. The component structure should have good maintainability, allowing for simple replacement of faulty parts when bearing failures occur.
8. The pump should operate and be stored under permissible vibration and impact environments, or even when the rotor operates in reverse, without affecting the bearing’s operational capacity.
9. It should have low sensitivity to changes in pump operating conditions and moderate damage generated during pump operation.

To meet the above requirements for the sliding bearings of Canned Motor Pumps, careful selection and design of bearing components should be carried out, ensuring the smooth flow of the lubricating and cooling liquid through the bearing fluid passages conveyed by the pump, to avoid insufficiency or interruption of the lubricating medium for the sliding bearings. Additionally, to improve the operational reliability of the bearing friction pairs, materials with low friction coefficients and high thermal conductivity should be used.