How does the main bearing contribute to the reliability and efficiency of wind turbines?

Wind energy is a cornerstone of the global energy transition and at the same time, one of the most demanding engineering disciplines in renewables.

As turbines scale up to deliver higher output and lower levelized cost of energy (LCoE), every drivetrain component is pushed closer to its operational limits.

At the center of this load path lies one critical component: the wind turbine main bearing. It supports enormous rotor forces and bending moments, transfers torque to the gearbox with minimal losses and must operate reliably for decades, even under violent gusts, sudden storms and frequent start-stop events.

When traditional bearings in wind turbines reach their limits

Today's roller element bearings have limited load-carrying capacity and show high failure rates.

They account for less than 1% of a turbine's total cost — yet their failure can lead to losses of up to 100% of the turbine's value.

After all, downtime increases the levelized cost of electricity (LCoE). Reliability ensures the profitability of your wind power plant. 

Miba Segmented Journal Bearing (SJB^®) – The alternative for main bearings in wind turbines

Miba's bearings have been operating reliably under extreme loads and harsh conditions across many applications: from hydropower and turbomachinery to wind gearboxes.

The Miba SJB^® transfers this proven principle to the wind turbine main shaft. It is conceived for compactness, high power density and crane-less service.

Gain creators & pain relievers

For main bearings in wind turbines, the Miba Segemented Journal Bearing^® offers many economic advantages

• Low OpEx due to improved availability
• Future-ready — enabling power density increase and compact drivetrains
• Longer lifetime due to simple, robust design
• Low downtime through crane-less serviceability
• Easy and full recyclability for a low CO₂ footprint
• Lower system and service costs
• Significant improvement in reliability; lowering failures across useful life
• Easy handling and local supply of spare parts

Your development partner for main bearings in wind turbines

Miba is your development partner for main bearings in wind turbines, offering unique testing and simulation expertise as well as application knowledge. With around 100 years of bearing expertise, the Miba Bearing Group has grown into a reliable and global partner for functionally critical components.

We work closely with leading OEMs and gearbox manufacturers, combining application expertise with engineering know-how across the entire product lifecycle:

• In-house design, simulation, and testing including FMEA and full-scale drivetrain validation
• Holistic system perspective: from material science to application engineering
• Industrialized precision: functionally important geometries produced with the highest repeatability
• Field engineering support — turning operational insights into design action
• Local-to-local supply strategy backed by a global footprint
• Financial independence ensuring long-term supply security