Bearings are one of the core components of a wind turbine and face the challenge of demanding operational requirements. Huge and complex loads, difficult maintenance and high maintenance costs require that the wind turbine spindle bearings have excellent reliability and durability while providing excellent overall load carrying capacity.

 Early small-megawatt fan spindles generally adopted a single spherical roller bearing solution (three-point support). With the increase in the installed capacity and complexity of the fan, this spindle solution is gradually being adopted by other solutions, such as double-aligned roller bearings (four-point support), double-row tapered roller bearings plus cylindrical roller bearings, and oversized doubles. Column tapered roller bearings and two single row tapered roller bearings, which are becoming more common in large megawatt fans, have been replaced. The tracking of the performance of the three-point-supported spherical roller bearing installed in the wind field also shows that the solution is inherently under the load conditions, the lubrication condition is the worst. The bearing surface of the spindle bearing roller and the raceway is inherent. Sliding friction exacerbates surface wear, forms micro-flaking, and eventually accumulates into bearing peeling damage. This micro-flaking is very difficult to avoid, but the impact on bearing life is significant. The performance statistics and damage performance of the three-point bearing main bearing in multiple wind turbines in multiple wind farms also verified this problem.

This damage mechanism makes the application advantages of tapered roller bearings at this position even more prominent. At the spindle end, Timken® double inner ring tapered roller bearings maintain pure rolling motion between roller raceways under complex wind conditions, reducing friction and improving bearing performance under demanding lubrication conditions. At the same time, the spindle tapered roller bearing with axial preload can greatly reduce the axial deformation and turbulence of the main shaft, thereby reducing the impact of the variable wind load on the gear box, improving the working condition of the gear box bearing and improving the use life.

In general, for a three-point supported spindle, a pre-tightened tapered roller bearing can be used to directly replace the original spherical roller bearing without changing other components. From the inherent motion mechanism of the bearing, the performance analysis and the prototype test results show that the tapered roller bearing as an upgrade scheme can solve the main bearing performance problem of the current in-service unit well, and provides a new idea for the technical transformation of the in-service unit.

Reprinted from the network