• Backlash-free metal bellows couplings with inner conical hubs
  • For shaft diameters from 10 – 90mm
  • Torque range: 18 – 5000Nm
  • High torsional stiffness, good compensation of shaft misalignment, low restoring forces
  • Compact design with high clamping forces


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...MORE on Bellows Couplings


KBK metal Bellows couplings - because of their extremely high torsional stiffness and both angular and axial flexibility - are installed wherever powers, up to the highest levels, have to be transmitted between shafts, highly efficiently and absolutely backlash-free. This means that they effectively compensate for manufacturing variations in drive or support shaft bearings, both for angular and axial misalignment, with only very low restoring forces; thereby extending bearing life considerably.

In today's ever increasing drive systems demands, KBK metal Bellows couplings prove an indispensable connection component. Their wide range of different shaft fixing versions; whether

  • by bore & keyway, with two locking set-screws, 1 over the key, the other at 120° onto the shaft, or
  • by 'key-less' bore only, with part axial-split & radial-cut hubs 'all-round clamping' via single socket-head screw
  • mounted in drilled, tapped & counter bored hole along a chord line across the split in the hub, or
  • via protruding expanding mandrel into hollow shafts, or
  • by the 'key-less' bore only, 'clamping' compression imposed, from tightening multiple-screws axially, across conical
  • mating ring/tapered surface hubs, or
  • by simple flange bolting connection,
  • the installation options are enormous.

On the one hand, there are large, extremely robust designs, withstanding the harshest environmental conditions and loads (=KB4-7; caters for shafts from 10 to 100mm, with torque capacities from18 to 5,000Nm); on the other hand, there are space-saving, very short installed length metal Bellows couplings for small diameter shafts - the MINI-Couplings - (=KB1-3; for shafts from 1 to 24mm & torques from 0.1 to 10Nm) in the range.

The coupling principle offers the advantage of very simple & easy handling and operation.

In most variations it comprises of only a single component.

With the key-less, split-/clamping- hub designs, drive shafts suffer no damage, with the elimination of any possibility of rubbed 'flats' from abrasion appearing in any form, on dismantling or even during operation. The torque to be transmitted is more evenly distributed, around the whole shaft surface, as opposed to only one side of the keyway. There is no possibility of fretting corrosion. Life span is substantially improved and it is maintenance-free.

The bellows part of the coupling is made from stainless steel, whilst hubs made from aluminium alloy are 'Loctite' glued to each end. However, with the larger hub sizes (from KB4/60 upwards) material changes to steel and they are soldered, or welded to each end of the bellows.

Combining all these positive qualities makes the bellows coupling one of the most popular and proven shaft connectors found, particularly, in the industrial sectors of NC machines, Servo Drives, Packaging Machines, Linear Devices, Machine Tools, Pulse Generators (encoders, etc.) and Robot Control Drives and also in practically every other area of the dynamics, even under the most difficult environmental conditions.

Specific 'KBK' Feature:

A particular feature of the KBK metal Bellows Couplings arises from their meticulous manufacturing process, where guaranteed high concentricity of assembled components is assured, because every single coupling is 'centred' at the jointing assembly, on a mandrel. The rotational concentricity is then measured (for high accuracy) again at the final inspection stage.

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