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IMO Slew Drives And Slew Rings

Neilson Hydraulics and our sister company VHS Hydraulic Components are the UK distributor for IMO, a specialist in turning and slewing solutions, which provides a wide range of slew drives and slewing rings that can be used in a variety of applications.

Since 1988, IMO has been consistently delivering high-quality slewing rings and swivel drives, made in Germany to their satisfied customers. As a result, IMO is now one of the leading manufacturers of large roller bearings and ready-to-install gear system assemblies today. 

What is a slew drive?

A Slew Drive is a fully assembled unit, comprising of a ball or roller slewing ring, designed to handle the simultaneous transfer of axial and radial forces, as well as tilting moments with hydraulic or electric drives in a completely enclosed housing.

  • Spur gear unit or worm drive
  • Max. torques of up to 450 kNm
  • Max. tilting moment load of up to 1,200 kNm
  • Raceway diameter of up to approx. 1,000 mm
  • Unlimited slewing range
  • Fast installation
  • Smooth, jolt-free movement - no stick/slip effect
  • Maximum safety through full encapsulation
  • Cost-efficient, proven technology
  • Compact, space-saving, heavy duty


For Slew Drives, some attachments such as the brake, planetary gear, motor, and rotary encoder can be delivered on demand.


Standard product or individual solution?

Whether you seek a standard product or a personalised solution, IMO Slew Drives offer a wide range of standard series to choose from. Should our standard options not meet your specific application requirements, our skilled application engineers can collaborate with you to create a custom-made slew drive. We can accommodate versions for continuous operation and extreme temperatures, as well as utilising special materials if required. Furthermore, the mounting structure such as valve blocks, hydraulic connections, adapter plates, and sensors can also be taken into account in the design.


IMO Slew Drives can be used in a variety of applications

IMO Slew Drives are designed for a long lifetime with low maintenance efforts. They require a small amount of installation space, but can take top loads, hence they are the top slewing solution for many applications. IMO Slew Drives are used in a wide range of industries, including forestry, agriculture, mining, numerous maritime applications, and machine construction and plant engineering.




The IMO Slew Drive WD Series features:

  • High rotational speed
  • High gear ratio
  • Rotational speed 1-3 rpm


IMO Slew Drive WD-L features:

  • Raceway diameter 156 mm to 713 mm
  • Maximum tilting moment 9 kNm to 1,095 kNm


IMO Slew Drive WD-H features:

  • Raceway diameter 280 mm to 725 mm
  • Maximum tilting moment 94 kNm to 1,052 kNm


The IMO Slew Drive SP Series features:

  • Higher rotational speeds
  • Higher duty


IMO Slew Drive SP-I features:

  • Raceway diameter 229 mm to 1091 mm
  • Maximum tilting moment 22 kNm to 353 kNm

IMO Slew Drive SP-H features:

  • Raceway diameter 455 mm to 955 mm
  • Maximum tilting moment 153 kNm to 562 kNm




What is a Slewing Ring?

Slewing Rings, are also known as large diameter antifriction bearings for the simultaneous transmission of axial and radial forces, as well as tilting moments. They serve as replacements for traditional solutions with fixed and floating bearings, as well as king pin bearings. Often, this results in bearings with axial/radial bearing combinations with one bearing point. This can streamline the design of the mounting structure and the installation of the bearings considerably, which in turn reduces effort and the associated costs.



Tried-and-tested and highly cost-effective, IMO antifriction bearings are available as:

  • Ball slewing rings, roller slewing rings, and ball-roller combination slewing rings
  • Four-point bearings, double four-point bearings/eight-point bearings, flange bearings, wire race bearings, cross roller bearings
  • Segmented slewing rings
  • Gear rims
  • External gearing, internal gearing, or without gearing
  • Diameter ranging from 100 mm to 6000 mm
  • With cages (steel, brass, or plastic) or spacers (brass or plastic) 
  • With standard seals or specially produced special seals
  • Optionally with induction-hardened raceways
  • Different corrosion protection coatings possible


IMO Slewing Rings have mounting holes and a sealed raceway system with grease lubrication. They can be combined with motors, pinions, and planetary gears. Functions and parts of the mounting structure, including attached bearing rings can be integrated.


IMO Slewing Rings can be used in a variety of applications

IMO Slewing Rings are used in various applications as machine elements that can simultaneously transmit axial and radial forces, as well as tilting moments. The application spectrum ranges from large triple-row roller slewing rings for tunnel construction to small ball slewing rings for medical technology. However, IMO slewing rings are used in the bottling and filling industry, opencast mining, bulk handling, and transport engineering. In the field of renewable energies, IMO blade bearings, yaw bearings, and main bearings are used in wind turbines or as rotor blade bearings in tidal stream systems. Below, you can find out about product details for your application.




The IMO Ball Slewing Rings feature:

  • Single or double row
  • Four-point raceway geometry
  • Enables robust constructions for harsh operating conditions


Ball diameter
12 to 80 mm


The IMO Roller Slewing Rings feature:

  • Single-row, double-row, or triple-row
  • Top load with really small installation space
  • Top requirements for even load distribution.


Roller diameter
10 to 100 mm


The IMO Ball-Roller Combination Slewing Rings feature:

  • Combination of roller and ball slewing rings
  • Used for dominant axial force and low radial loads/tilting moments


Ball diameter
25 to 80 mm
Roller diameter
to 100 mm




Enquire about IMO Slew Drives and Slewing Rings at Neilson Hydraulics

To enquire about IMO Slew Drives and IMO Slewing Rings, please contact Neilson Hydraulics on: 01709 821 002 / E: sales@neilson-hydraulics.co.uk or visit our website at:   https://www.neilson-hydraulics.co.uk/collections/imo