Slewing bearings: a superlative test of strength

Eight wind turbines on a green field and clouds in the background

Sustainability and climate protection | 

Huge components - built to withstand extreme forces: Learn more about the design of slewing bearings and the forces they are subjected to in wind turbines.

We encounter large-diameter bearings in many applications, such as wind turbines, cranes, streetcars, articulated buses and even in medical technology. Without slewing bearings, the world would literally stand still. At thyssenkrupp rothe erde, slewing bearings are manufactured that have to withstand enormous forces.

Close up of a slewing bearing
Large-diameter slewing bearings for wind turbines in today’s standard sizes with a diameter of 6 meters, for example for rotor bearings, are a challenge to transport across the plant premises. Powerful overhead cranes are used to move the components weigh over 40 tons, within the halls.

3,500 households and 70 passenger cars – test of strength in the rotor bearing

To illustrate the forces acting on slewing bearings in wind turbines, let’s take a look at the rotor bearings at the base of the rotor blades.

An onshore turbine with three rotor blades, each 63 meters long and weighing 20 tons, generates an energy output of 6.1 megawatts per hour at a wind speed of 14 meters per second. That’s quite a lot, because 6.1 megawatts can theoretically supply around 3,500 households with electricity for an entire year! Under these conditions, axial and radial forces of 1 mega Newton act on the center of a single rotor blade alone. A force equivalent to about 70 passenger cars tugging on a single rotor blade.

To withstand forces of this caliber and ensure smooth movement of the entire turbine, slewing bearings for wind turbines have to meet very specific requirements. That’s why the experts at thyssenkrupp rothe erde have been carrying out intensive research and development work on wind energy for several decades. thyssenkrupp rothe erde offers customers slewing bearings that are optimally adapted to the requirements and locations of the turbines.

In addition to wind energy, slewing bearings are important key components for many other industries. thyssenkrupp supplies customers from all over the world. With diameters of up to 25 meters, transporting the huge components is just as spectacular as their function and performance. rothe erde logistics expert Dirk Saager explains in an interview how the mammoth logistical task and the transport to air, water and asphalt works.

Our experts at thyssenkrupp rothe erde will be pleased to answer any inquiries for information and details about our slewing bearings.