‘Slew On the Safe side’

IMO Slew Drives & Slewing Rings for Forestry and Agriculture



IMO is a specialist in turning and slewing solutions. Since 1988, IMO has been developing and producing IMO Slewing Rings and IMO Slew Drives for the most varied of application areas, including Forestry and Agriculture.


Prime examples of equipment in the Forestry and Agriculture industry incorporating the IMO technology are:


  • Mowing machines
  • Wood choppers
  • Combine harvesters
  • Trailers
  • Logging equipment
  • Forage harvesters
  • Felling devices
  • Slurry transporters
  • Municipal vehicles


For more than 30 years, IMO antifriction bearing solutions have been impressing customers throughout the world with their excellent technology, high quality, and the customer proximity of the company. However, the slewing ring specialist focuses on custom bearing solutions. In close collaboration with the customer, we develop tailored slew drives and slewing rings to fully exploit the potential of the applications at hand.


IMO Slew Drives


IMO Slew Drives ensure the most efficient possible transmission of high power and torque inside a compact, closed unit.

  • Easy motor assembly
  • Fully encapsulated

IMO WD-L Series Slew Drive

The IMO WD-L Series Slew Drive. 8 sizes, torque from 3.2 to 42.8KNm


But what exactly is a Slew Drive?

A Slew Drive is a ready-to-install unit consisting of a ball or roller slewing ring for 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.
  • torques of up to 450 kNm.
  • 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.
  • Screw it on, connect it up and you’re ready to go.


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


Standard product or individual solution

IMO Slew Drives are available as a large selection of standard series. If none of IMO’s standard solutions are suitable for your application, our application engineers can work with you to develop a custom slew drive. Versions for continuous operation and extreme temperatures are possible, as are special materials. 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, that is why they are the top slewing solution for a lot of applications. IMO Slew Drives are used in forestry and agriculture, but also in mining, manlift platforms, numerous maritime applications, machine construction and plant engineering.


Example of an IMO WD-L Series Slew Drive at work:



To be able to adjust the mowing head flexibly (above) and to keep the motor block sitting vertically on slopping terrain (below).




The below IMO Slew Drives are currently in use in wood choppers and in combination forestry vehicles:


IMO Slew Drive with integrated driving pinions:

  • maximum torque 6.8 kNm
  • maximum tilting moment 120 kNm
  • with electric or hydraulic motors
  • with or without brake

IMO SP-I Slew Drive


SP-I 0641


IMO Slew Drive with worm drive:

  • maximum torque 42.8 kNm
  • maximum tilting moment 300 kNm
  • with electric or hydraulic motors
  • with or without brake

IMO WD-L Slew Drive

WD-L 0625








Forage Harvester


IMO Slewing Rings


Single and double-row ball slewing rings.



  • Long service life.
  • Exceptional operating safety.
  • Reduced costs over the product’s lifetimes.


Available in a wide range of standard seizes or as customised special solutions, optimized for the agricultural and forestry sector.


Example of IMO Slewing Rings and Slew Drives in action:




The felling head and the swivelling driver cabin for the swivel arm’s axle.


But what exactly is an IMO Slewing Ring?

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


Cost-effective and tried-and-tested, 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 – such as attached bearing rings – can be integrated.


IMO Slewing Rings can be used in a variety of applications

IMO Slewing Rings are used in numerous 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.


Neilson Hydraulics is proud to be an official IMO UK distributor. We have a highly experienced technical team available to help and discuss your requirements and provide you with solutions. Please view and for further information but also contact Neilson Hydraulics on: 01709 821002 / E:


IMO Logo




Neilson Hydraulics supplies IMO Slew Drives, including IMO Slew Drives WD Series (WD-L & WD-H) and IMO Slew Drives SP Series (SP-I & SP-H), as well as IMO Slewing Rings, including IMO Ball Slewing Rings, IMO Roller Slewing Rings and IMO Ball-roller Combination Slewing Rings. We also team up with our sister company VHS Hydraulic Components to provide technical help






Leave a Comment