Slewing rings made to measure for a broad spectrum of applications

Fabricated as a one-off or for your series production requirement - in dimensions ranging from Ø 250 mm to Ø 5000 mm. Customized for your specific use.

Please contact us – we’d be delighted to advise you!

Slewing rings are large-diameter anti-friction bearings which are designed to transmit axial and radial forces and simultaneously absorb the resulting tilting moments. Their high strength makes them eminently suitable for heavy-duty applications.

They are important connecting elements and so they are used in many different ways in a wide and diverse range of machines and plant equipment, such as in the extraction and processing of raw materials, specialised civil engineering, road construction, earthworks, production of construction materials, handling of materials or machine tool manufacture.

Design features of slewing rings

Slewing rings differ from ball bearings or roller bearings in that they are not fitted on a shaft or in a housing like these bearings but are instead axially integrated in the connection assembly by the bolted fitting of the bearing rings. Slewing rings are generally laid in a horizontal position, but they can sometimes be suspended or installed in a vertical position.

Slewing rings consist of an outer ring and one or two inner rings (depending on the design) and, in the majority of cases, a sealed, grease-lubricated raceway system.

The ball and roller races on the rings are made of alloyed tempering steel and are precision-machined and induction-hardened.

The raceway systems are supplied with an initial application of quality lubricant to meet the given performance requirements. The raceway systems have lubrication points (grease nipples) where lubrication (grease) can be reapplied, either manually or, for extra convenience, through the use of central lubrication units.

The seals are made as standard from NBR profiles (nitrile-butadiene rubber) and provide reliable protection for the raceway systems, keeping them free of debris and dirt and shielding them from spray and splashing water. They also perform the important function of keeping  the lubricant in the raceway systems. Special sealing profiles or multiple systems are used to meet certain specifications in heavy-duty environments or in tough conditions involving mechanical stress. Sealing profiles can also be made out of materials with greater heat resistance like FKM/FPM (fluoro rubber / fluorocarbon rubber) for special high-temperature applications.

There are various other applications and cases of operation, however, such as in enclosed drive systems where the sealing is not required on one or both sides and the raceways are supplied with oil or lubricated through the oil circulation system in the equipment.

Slewing rings with toothing mostly come with straight teeth, but inclined teeth and custom toothing designs are also possible.

The toothing is finished to a standard or higher specification depending on the type of slewing ring and the requirements. The teeth can be supplied with a hardened finish to withstand heavy-duty demands and high moments of force.

The toothing quality, tolerance limits, tilting travel, resistance, concentricity, running accuracy and surface protection all depend on the demands placed on the slewing ring.

There are many standard slewing rings but the majority of them are tailored to meet specific requirements and are developed jointly with the customer in any given case.

There are generally three main types of slewing ring:

  • Without teeth
  • With internal teeth
  • With external teeth

These three basic types are taken as a basis for other bearing designs which are optimised for a wide and diverse range of applications and fields of use.

We supply slewing rings in dimensions ranging from Ø 250 mm to Ø 5000 mm. 

  • Single-row axial ball bearing slewing rings without teeth                                   
  • Single-row axial ball bearing slewing rings with internal teeth                             
  • Single-row axial ball bearing slewing rings with external teeth                            
  • Double-row axial ball bearing slewing rings with internal teeth                           
  • Double-row axial ball bearing slewing rings with external teeth                            
  • Single-row axial roller bearing slewing rings with internal teeth                            
  • Single-row axial roller bearing slewing rings with external teeth               
  • Triple-row axial roller bearing slewing rings with internal teeth                           
  • Triple-row axial roller bearing slewing rings with external teeth  

Our technology partner ROTIS

is an internationally recognised and ISO-certified manufacturer of ball bearing and roller bearing slewing rings with a tradition spanning decades. Advances in technology and development have made it possible to make many different types and designs of slewing rings today in dimensions ranging from Ø 250 mm to Ø 5000 mm

ROTIS slewing rings are used in all the many different traditional fields of application as well as in pioneering applications:

  • Crane construction for rotary construction cranes, shipyard cranes, deck cranes, mobile cranes and engine hoists
  • Earth-moving machines, diggers, front-end loaders, rock crushers, bucket-wheel excavators and special deep drilling equipment
  • Wind energy
  • Radar installations, antenna systems, telescopes and periscopes
  • Industrial robots and welding robots
  • Cargo handling and offshore equipment
  • Road and rail vehicles

Our ROTIS slewing rings are all manufactured from high-quality alloyed steel, with seamless rolled rings sourced from respected European manufacturers.

Our slewing rings are manufactured in the EU.

The rings are processed on state-of-the-art CNC machines. Rolling raceways on the rings are induction-hardened or flame-hardened so that they can subsequently be turned or ground to the required accuracy, and the tooth flanks and tooth bases are also hardened depending on the specification.

The quality and dimensions are monitored constantly during and after the process. A final quality inspection is carried out after assembly and is used as a basis for the issue of a test certificate and various accompanying documents.

Other certificates can also be obtained on request, such as Germanischer Lloyd certification, etc.

In addition to manufacturing quality products, we also advise our customers and business partners on applications and designs. The components and parts are designed and optimised with the aid of industry software which has been developed specially for slewing rings.

You are welcome to gather information about our production processes and carry out an audit.

We will be pleased to go through all the procedures with you.