Wind turbine generator

Electric insulated bearings - protect generators from the effects of stray currents

The main impact of special alumina coating on controlling electrical corrosion

Whenever current passes through the roller bearings, it poses a potential threat to the reliability of the generator. Stray currents can weaken the roller bearings that the generator relies on for smooth operation, leading to generator malfunctions.

When current passes through bearings and passes through rolling elements from one ring to another, a process similar to arc welding occurs, concentrating high-density current on a very small contact surface. This will heat the material to a temperature range suitable for tempering or melting. Over time, thousands of micro pits form, and the rolling contact surface is gradually eroded.  

Not only will the raceway of roller bearings be affected by the passage of current, but lubricants will also be adversely affected. Localized high temperatures can cause lubricant to burn or ignite, and additives may be consumed faster. Finally, the service life of lubricating grease and bearings will be significantly shortened.

These impacts combined can lead to bearing failure, resulting in costly shutdowns and unplanned maintenance. One way to solve this problem is to use insulated bearings.  

Advantages of ESO electrically insulated bearings

Reduce premature bearing failure caused by current

Ready to upgrade existing solutions at any time

Reduce maintenance costs

Extend the normal operation time of the machine and reduce the total cost of ownership

Protect bearings to ensure normal operating time

The characteristic of ESO electrically insulated bearings is that the outer surface of the inner or outer ring is coated with aluminum oxide. The insulation coating formed by a unique plasma spraying process effectively eliminates premature bearing failure caused by stray currents.

Electric insulated bearings combine bearing function and insulation function in one solution, significantly reducing total cost of ownership compared to other insulation methods such as bearing seat or shaft insulation.

The performance parameters of the bearing (such as rated load and operating accuracy) are the same as those of standard non insulated bearings. Electric insulated bearings can be installed using standard methods and tools, and are very sturdy during use, transportation, and handling. Most sizes and models of electrically insulated bearings are available in stock, offering single row deep groove ball bearings and single row cylindrical roller bearings. Special customized series and products can be provided upon request.