Schaeffler further develops hydrodynamic plain bearings for wind turbine gearboxes

Hydrodynamic sliding bearings write a new chapter for the development of fans

Additive manufacturing and finishing of bearing sliding layers paves the way for industrial-scale mass production

Bearing design starts from a comprehensive system concept

Schaeffler has further strengthened its market position in bearing solutions for wind turbine gearboxes with the introduction of a plain bearing arrangement with support for planetary gears. Modern high-performance wind turbine gearboxes are often equipped with multiple planetary gears to handle the ever-increasing torque. At the recent WindEnergy Hamburg, Germany, Schaeffler exhibited advanced hydrodynamic sliding bearings. Plain bearings in this series can even help increase the power density of gearboxes in very small installation spaces. The copper sliding layer of the bearing is only a few millimeters thick and is applied directly to the surface of the planetary gear journal using additive manufacturing technology. The journal and the sliding layer are chemically bonded and have a service life of decades.

Bearings are designed with a comprehensive system concept

On the basis of the finite element method simulation process of the entire bearing system, Schaeffler uses elastohydrodynamic (EHD) simulation tools to design the plain bearings. The design process seeks to achieve the thinnest lubricating film thickness and complete separation of the surfaces. In order to achieve zero-wear conditions, Schaeffler has created a detailed technical design process for customers.

Leading the Trend of Wind Turbine Gearbox Development

To address the increasing torque density inside the gears, one of the ways gear box manufacturers are increasing the number of planetary gears at each stage. In this way, higher torque can be transmitted in the same installation space. However, rolling bearing solutions have space size limitations, and even with the small size of the planetary gears, they are not compatible with applications. The small diameter of the plain bearing solution is a decisive advantage in this regard.

The copper bush and the planetary gear journal are combined into one, representing the latest level of current technological development. The direct integration of the pin into the plain bearing using modern additive manufacturing processes further pushes the technology forward.

Additively manufactured bronze sliding layer hydrodynamic plain bearings: a new chapter in the development of wind turbine gearboxes

Installation example of a Schaeffler bronze sliding layer planetary pin

State of the art of plain bearing arrangements for supporting planetary gears in wind turbines: shrink fit plain bearing bushings