Man with safety clothes is moving a slewing bearing, World market leader, Customized design, All-round service package

Slewing bearings from Rothe Erde - Market leader with over 160 years of experience

Your benefits at a glance

  • Market leader

    Thanks to our extensive experience in both slewing bearing design and production, Rothe Erde is the world market leader for large diameter bearings.

  • Low failure rate

    We have developed industry leading calculation procedures and adhere to strict quality requirements in order to provide the highest quality products.

  • Flexible, individual bearing design

    From single piece requirements to volume production demands - customized solutions are developed for every project.

  • Future-oriented product portfolio

    The portfolio is continuously developed and improved so that the product portfolio is always state-of-the-art.

Market leader

Thanks to our extensive experience in both slewing bearing design and production, Rothe Erde is the world market leader for large diameter bearings.

Low failure rate

We have developed industry leading calculation procedures and adhere to strict quality requirements in order to provide the highest quality products.

Flexible, individual bearing design

From single piece requirements to volume production demands - customized solutions are developed for every project.

Future-oriented product portfolio

The portfolio is continuously developed and improved so that the product portfolio is always state-of-the-art.

Each customer is the most important person to our business. In North America we continue to earn their business every day since 1962.

Frank Küpper
VP of Sales & Engineering, thyssenkrupp rothe erde USA Inc.
  • 25,000 mm diameter

    As broad as the areas of application of slewing bearings are, their individual designs are equally diverse. This is clearly evident with their possible size range: Rothe Erde is able to manufacture segmented slewing bearings with a diameter of up to 25,000 mm, and in the non-segmented form with a diameter of up to 9,600 mm.

How does a slewing bearing work?

A slewing bearing, also known as a slewing ring, is a machine element that absorbs all axial and radial forces and the resulting tilting moments, in a single, self-retaining and ready-to-install bearing unit.

The goal is to quickly and easily transfer the forces acting on the slewing bearing to the adjacent structural machine elements. The overall design of the product, including the inner and outer rings, the gear cutting, rolling elements and mounting holes, enables it to transmit the applied loads and allow smooth rotation at the same time while maintaining a compact footprint. Slewing bearings enable and facilitate the rotational motion of wind turbines, excavators, cranes and tunnel boring machines, just to name a few. The slewing bearing offers many advantages compared to other solutions, including taking up significantly less space, weighing less and being more cost-effective in most cases.

The world in motion - where are slewing bearings used?

rothe erde® slewing bearings prove themselves as important mechanical components in very diverse areas of applications. The applications and products are as varied as the slewing bearings themselves: they are individually designed and manufactured for each application. Find out which solutions are available in each industry:

The production process - how a ring is turned into a slewing bearing

The challenge of the production process is to manufacture a product that can withstand the intended operating conditions over the long term. Among others, these are:

  • Installation, also in extreme conditions, e.g. in offshore wind turbines.

  • High axial and radial forces, e.g. in machines used in the construction industry and infrastructure development

  • Tilting moments, e.g. in large crane systems

  • Heavy loads, e.g. in transport and conveying technology

As the leading manufacturer of slewing bearings, our aim is to create solutions and manufacture products that have an above average service life, even while being subjected to harsh operating conditions.

Find out how a rothe erde® slewing bearing is created through processing a rothe erde® ring:

Turning

A large-diameter antifriction bearing in close-up in the turning process

In the first step, the seamless rolled ring is machined.

The ring is placed centrally on a horizontal table of a CNC vertical lathe. After machining one side, it is then turned and machined from the other side.

In this machining step, the program-controlled turning of the contours takes place. These include the surfaces, pilots, steps, seal grooves, chamfers and raceways for the rollers or balls of the bearing.

Gear Cutting

A large-diameter antifriction bearing is geared

Gears can be cut either on the outer or inner ring. The gears are cut in several passes by the designated tooling. Gear cutting can be completed using one of the following processes:

  • Gear hobbing

  • Gashing

  • Gear shaping

Hardening

Hardening of a slewing bearing

Hardening increases the wear resistance and thus the service life of the raceways and gearing. Heavily strained surfaces are surfaced hardened by an induction hardening process. These surfaces include the raceways and the gear teeth, if required by the design.

The application area of the product determines the hardening process that is used, such as:

  • Gear hardening

  • Shot hardening

  • Raceway hardening

Full-surface hardening without soft spot is a worldwide unique and patented hardening process developed by Rothe Erde. This process is used for high-speed bearings such as rotor bearings in wind turbines.

Drilling

A large-diameter antifriction bearing is being drilled, close-up photo

First, the drilling takes place. A chamfer is then created at the top and bottom of the entrance. If required, an additional thread can be cut into the bore.

Numerous bores are arranged in rows in the axial direction for mounting the bearing and the load support. Between them are threaded holes for the stop screws in order to lift the bearing by crane.

Raceway Finishing

A slewing bearing in its finishing process

Depending on the design and required tolerances, the finishing of the product is carried out either by hard turning or by grinding. A combination of the two processes is also possible.

For an optimum surface quality, raceways and contact surfaces are machined with a hard ceramic cutting tool prior to the assembly.

Assembly

A slewing bearing with rollers in focus

For the assembly, the rings are positioned on a rotating table. The specified number of balls or rollers are installed into the raceway.

The seals are then fitted between the outer and inner rings on the top and bottom sides, and the gap between the rings is checked for uniformity.

The slewing ring is then lubricated, cleaned and a surface coating is applied.

As a renowned manufacturer of slewing bearings, it is our aim to manufacture products and create solutions that operate reliably over the long term even in extreme environments and have an above-average service life.

Marco Burtchen
Head of Engineering, thyssenkrupp rothe erde Germany GmbH

Quality Assurance and shipping of a slewing bearing

The final inspection of the finished product is carried out internally by the certified quality assurance department or together with the customer and/or a designated 3rd party. During this process, the functionality and geometry are checked in detail. The basis for the inspection is the specifications that were agreed to during the design development or those specified in the contract. The test results are recorded in a written test report and in the QA documentation. The scope of the documentation is defined together with the customer in advance.

After the final inspection, the slewing ring is ready to be properly packaged by our logistics department and readied for shipment. The transport takes place either directly to the construction site on site or initially to a seaport or airport. If the transport cannot be carried out with the standard modes of transport, special trucks, ships and aircrafts are used.

As a reliable slewing bearing manufacturer with production facilities located around the world (Americas, Europe, Asia), Rothe Erde stands for high-quality products and innovative solutions that are designed and manufactured according to all customer requirements, comprehensively and meticulously inspected before delivery and safely shipped to the final destination.

Would you like more information about our bearing types, bearing selection and installation, service and much more? Then download our catalog.

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The world's largest research and development center for slewing bearings

The world's largest research and development center for slewing bearings

Two men in a research center

The functional demands placed on this highly technical product in terms of size, rotational properties, load capacity and service life are constantly changing as a result of dynamic markets. Whether, for example, a tunnel boring machine has to bore ever larger tunnels or wind turbines are getting bigger and bigger - we always find a suitable bearing solution. In the research and development center, which covers an area of 10,700 m², future-oriented developments are tested and all key components and materials are tested to their limits on our 20 test rigs. This allows the use of the components to be simulated under realistic conditions, thus enabling the products to be optimized further and further. In addition, the portfolio is constantly being developed and improved through cooperations with our customers, universities and external research institutes.

Consulting and service - complete product support from a single source

From planning and design to construction and delivery, Rothe Erde is always at your side as a reliable partner. We support you long beyond the warranty period to ensure the slewing bearing reaches its full service life. We offer assistance during installation and commissioning, inspection and maintenance services while the bearing is installed.

Find out more about our services

Reference sites

Find out which large, exciting projects have been implemented over the last 160 years. You can find the most spectacular flagship projects here.