The Miba SJB® supports the rotating shaft on a hydrodynamic oil film rather than through rolling elements. This load distribution significantly reduces peak contact pressures and avoids common rolling bearing failure mechanisms such as spalling, false brinelling, and white etching cracks.

In addition, the simplified bearing architecture contains significantly fewer components, reducing system complexity and associated failure risk.

The Miba SJB^® combines the proven advantages of hydrodynamic bearings with a segmented architecture specifically developed for wind turbine main shafts.

Key benefits include:

• Simplified design with fewer components
• Accommodation of shaft bending and misalignment without dedicated alignment mechanisms
• Drop-in compatibility with established bearing design spaces
• High power density, enabling turbine uprating and future scalability
• Reliable performance at very low operating speeds
• Service-friendly segmented design for easier maintenance and repair

• Bearing Seizure: The SJB^® incorporates sump lubrication ensuring the oil-film and temperature monitoring mitigates the risk of critical damage.
• Bearing Seizure after long standstill and restart (Stop-Start) : The patented design and lubrication concept are developed to overcome this condition.  

Continued operation after bearing damage is generally not recommended.

However, the segmented design allows quick inspection and replacement of affected segments, which can significantly reduce maintenance time compared to replacing a complete bearing assembly.

The patented SJB^® geometry generates a hydrodynamic lubrication effect even at very low sliding speeds.

Stable lubrication can be established from sliding speeds of approximately 0.05 m/s onward (around 1 rpm), supporting reliable operation during idling and low-wind conditions.

SJB^® has fixed geometry, in which transient load events are generally less critical as proven in other applications. This is the main differentiator from other journal bearing solution.

The segment geometry can be tailored to different drivetrain architectures and load spectra. Multiple design variants have already been validated for dynamic operating conditions representative of wind turbine applications.

The SJB^® geometry can be tailored to meet the specific drivetrain requirements.

This allows shaft runout and displacement characteristics to be matched to the requirements of connected components, including the gearbox, without compromising overall system functionality.

The SJB^® incorporates a sump lubrication concept that ensures lubricant availability across all operating conditions.

Integrated oil reservoirs within the rotating segments distribute lubricant throughout the bearing, supporting continuous oil supply without the need for a dedicated external oil pump.  

Following inspection, individual damaged segments can typically be replaced.

If significant wear or damage is observed across multiple segments, replacement of the complete segment set may be recommended.

Damage to the outer ring is generally unlikely because it is significantly harder than the bearing coating material.

Minor damage can be repaired up-tower. Such in-situ repair approaches are established in marine applications. However, more severe damage may require drivetrain disassembly.