Why Are Shaft Grounding Rings The Best Choice For Motor Bearing Protection?

In the industrial field, motors are like the "heart" of equipment, providing power to production day and night. However, many engineers and maintenance personnel encounter a headache: even with proper bearing lubrication and correct installation, premature failure still occurs, leading to equipment downtime and significant economic losses. This hidden killer is shaft current.

And one of the most effective weapons to subdue this killer is—the shaft grounding ring.

Let's first discuss where shaft current comes from. Simply put, during the operation of modern variable frequency motors, high-frequency switching generates induced voltage inside the motor. When this voltage accumulates to a certain level, it seeks a release path through the bearings, forming shaft current. Although the current is small, its continuous breakdown of the lubricating oil film on the bearing raceways and balls causes electrolytic corrosion. Over time, pitting and noise will appear on the bearing surface, eventually leading to failure.

So, in which fields do shaft grounding rings play a crucial role? In fact, any motor driven by a frequency converter, especially in medium- and high-voltage, high-power applications, requires a shaft grounding ring.

For example, wind turbine generators, particularly direct-drive and semi-direct-drive permanent magnet turbines, have low generator speeds and high torque, making them high-risk areas for shaft current. Located hundreds of meters in the air, damage to the main bearing or generator bearing due to electrolytic corrosion results in significant replacement and maintenance costs, as well as power generation losses due to downtime.

Furthermore, in process industries such as petrochemicals, metallurgy, and water treatment, large pumps and compressors are core components of production. These devices typically operate 24/7, and a single unexpected shutdown can halt the entire production line. The application of shaft grounding rings effectively prevents sudden bearing failure and significantly extends equipment maintenance cycles.

Why choose Volsun shaft grounding rings to address shaft current?

Traditional ordinary brushes are prone to wear and oxidation, requiring frequent maintenance, and have unstable contact. Their performance deteriorates drastically in humid or dusty environments.

Volsun's professional shaft grounding rings are constructed from conductive fibers and a metal body, featuring lightweight design, low resistance, and physically stable current transmission. Utilizing a cantilever structure design, the soft fiber brush tips conform to the shaft surface, resulting in high conductivity, high wear resistance, and low friction and noise during operation. Currently, Volsun's shaft grounding rings have reached their third generation, achieving a simplified structure and streamlined manufacturing process while maintaining excellent conductivity, thus significantly reducing costs—more than 20% lower than similar products in the industry.

It's worth noting that all shaft grounding rings delivered by Volsun to customers have maintained a "zero quality problem" record, demonstrating their proven reliability and durability.

If you also face challenges related to shaft current corrosion, please contact the Volsun team for professional solutions on shaft grounding rings.