Why does the shaft journal of a liquid-ring vacuum pump experience wear, and what is the most appropriate way to address it?

BOKE VAC

Following a thorough inspection by qualified technicians at Shandong Bokexing Vacuum Technology Co., Ltd., it was determined that the axial journal wear observed in the liquid-ring vacuum pump is primarily caused by the loosening and detachment of the axial lock nut, which allows axial movement of the bearing and results in wear on the bearing seat. When the pump’s journal wears, it often manifests as a rapid temperature rise during operation accompanied by abnormal noises.

　　 Liquid-ring vacuum pump When first introduced, water-ring vacuum pumps were primarily used as self-priming pumps; over time, they have been increasingly adopted across numerous industrial sectors, including petroleum, chemical processing, machinery, mining, light industry, pharmaceuticals, and food production. As more and more enterprises begin using water-ring vacuum pumps, the number of operational issues has also grown. For example, under the influence of high temperatures, high pressures, severe corrosion, and cavitation, bearing journal wear and corrosion are common problems. So why does bearing journal wear occur in water-ring vacuum pumps, and what is the most appropriate approach to address it?

　　Following a thorough inspection by qualified technicians at Shandong Bokexing Vacuum Technology Co., Ltd., it was determined that the primary cause of journal wear in water-ring vacuum pumps is the loosening and detachment of the axial lock nut, which allows axial movement of the bearing and consequently leads to wear on the bearing seat. When journal wear occurs in a water-ring vacuum pump, it is often accompanied by a rapid temperature rise during operation and abnormal noise.

　　 Conventional repair methods for journal wear in liquid-ring vacuum pumps:

　　Conventional repair‑welding machining methods readily cause material damage, leading to part deformation or fracture and thus exhibiting significant limitations. Brush plating and spray‑plating rework typically require outsourcing, which not only results in long repair cycles and high costs but also fails to address the root causes of wear, as the repaired materials are metallic—materials that offer poor impact resistance and limited ductility.

Liquid-ring vacuum pump

　　 On-site repair method for journal wear in liquid-ring vacuum pumps:

　　On-site repair is a equipment maintenance approach that has emerged in recent years. Its principle lies in using Sorel carbon‑nanoparticle polymer material technology to address equipment malfunctions without the need for machining. This material is high‑temperature resistant, highly corrosion‑resistant, and machinable; it exhibits excellent adhesion and mechanical properties, effectively cushioning and withstanding the combined mechanical stresses encountered during operation. Moreover, it can be applied directly during the repair process, ensuring 100% surface‑to‑surface compatibility of the repaired components. Its inherent lack of creep also enables it to absorb impact loads effectively. By leveraging the front and rear shafts as reference dimensions, the repair process maintains dimensional accuracy, thereby guaranteeing optimal performance after restoration.

　　 On-site repair procedure for journal wear in liquid-ring vacuum pumps:

　　(1) Perform surface oil‑burning treatment using oxygen–acetylene.

　　(2) Use a tool to grind the surface and remove high spots.

　　(3) Measure the shaft diameter and ensure that the shaft’s bearing surface is free from wear.

　　(4) Conduct a dry run of the tooling to ensure it fits perfectly.

　　(5) Anhydrous ethanol may be used for surface cleaning to ensure the surface is dry and clean.

　　(6) Spray SD7000 release agent onto the inner surface of the mold.

　　(7) Mix and apply the carbon nanopolymer material;

　　(8) Clamp the dedicated fixture and heat the shaft end to accelerate material curing;

　　(9) Dismantle the tooling, remove excess materials, and complete the repair work.