Torque Limiters with Bush Bearings

KBK-C Series

Torque Limiters, with Integrated friction-bush freewheel for mounting Pulleys, Sprockets, etc.

The safety couplings for direct drives are a combination of our long term proven and optimized torque limiting systems and a coupling element which can compensate misalignment between the driving and the driven shaft.

Within a wide range users can choose different versions with metal – bellows or servo-inserts (spiders).

For the safety and overload protection of indirect drives we do offer a wide range of torque limiters with integrated ball bearing or bush bearings. Pulleys, sprockets, pinions or customized parts can be assembled directly on the coupling flanges with a high accuracy.

Available in this range:


CI – with Compact INNER Shaft fix Collet

  • Backlash – Free Safety Coupling
  • Compact inner conical hub, high clamping forces
  • For mounting pulleys, sprockets, …
  • Torque range: 3-500 Nm

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CA – with High clamp force OUTER Shaft fix Collet

  • Backlash – Free Safety Coupling
  • Self – centering and self – releasing outer conical hub, very high clamping forces
  • For mounting pulleys, sprockets, …
  • Torque range: 3-500 Nm

CK – with fast assembly ‘Clamp-Lok’ Shaft fix Hub

  • Backlash – Free Safety Coupling
  • Fast assembly with clamp hub
  • For mounting pulleys, sprockets, …
  • Torque range: 0.2-500 Nm

CP – with Simple assembly Shaft fix Hub & Keyway

  • Backlash – Free Safety Coupling
  • Easy assembly with keyway
  • For mounting pulleys, sprockets, …
  • Torque range: 3-500 Nm
...MORE on Overload/Safety Couplings


'KBK' Overload Protection Clutch- or, Safety- Coupling Combination Connection Units present a product, which is continually increasing in importance in today's era of advancing automation. Compared to alternative Overload Protection possibilities, such as an electronic 'cut-off' device, or the classic Friction-Clutch hub, these Combination Units offer a number of advantages. The distinguishing feature is their extremely short re-action times, within milli-seconds, which represents an almost immediate 'cut-off' of the torque transmission and, thus, protection for man and machine in a collision course situation.

Indeed, personal injury and extensive 'break-down' times, with their corresponding machine repair costs, can be avoided by installing these Combination Units.

Furthermore, these Units are unaffected by environmental influences, such as temperature changes, or being in contact with oils and greases, which have an especially negative effect on the function of friction-clutch hubs.

By means of definitive pre-tensioning across disc springs with digressive spring characteristics, every overload torque can be preset precisely, to a very high function-accuracy. Upon reaching this overload torque setting, the coupling disengages at the clutch and the torque transmission is interrupted, immediately. In addition, this disengaging clutch-plate movement process can be coupled to a mechanical or, electronic switch, which brings the drive to a halt.

After dropping below the overload torque setting, further rotation of the coupling Unit (at low speed) returns the sprung clutch multiple hardened & polished 'caged' steel balls into their corresponding V-groove detents to re-engage automatically and take up the torque transmission again. Rotation may be in either direction. 'Asymmetrically' arranged balls/cage bores & detents options only allow re-engagement after a full 360 ° rotation, whereas the 'symmetric' arrangement options offer multiple re-engagement positions. There are two overload torque setting ranges offered for each clutch-coupling size, ranging from 1 to a maximum 1,600Nm

To the overload protection function benefit arising from these clutch-coupling types, each according to requirement and execution, the positive characteristic features of a conventional metal bellows- or, flexible 'spider'- coupling is added, namely shaft misalignment compensation, as well as enormously high torsional rigidity, minimal reaction forces and backlash-free torque transmission.

With the flexible 'spider' variation, accommodation of shocks and vibrations, as well as electrical isolation, is achieved, in addition.

Alternatively, a single or, double support bearing design for direct Pulley, Gear or Flange mounting is also offered in the range.

The simple construction, with only few and single-part components - thereby ensuring minimal dimensions and moments of inertia - facilitates a problem-free integration into every drive line, as well as an uncomplicated installation and dismantling, without leaving any marks on the components to be connected.

Application areas for Overload Protection Safety Clutch-Couplings are found wherever there is a danger of a 'crash' or, of an overload generally; e.g., in high dynamic drives, Machine Tools, Textile- and CNC- controlled Machines, Servo Drives and many other areas in the dynamics.

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