Metal bellows couplings – torsionally stiff and precise

Metal bellows couplings are used in high precision applications where positional accuracy is of greatest importance. Some application areas include medical technology, test benches, wind turbines, and servo drives in machine tools.

Metal bellows couplings are especially suitable for highly dynamic direct drive applications. The stainless-steel bellows compensates for lateral, axial, and angular shaft misalignment with very low restoring forces and accelerates with a low moment of inertia.

Blind Mate Metal Bellows Coupling

Our BK5 bellows coupling is particularly suitable for complex, hard-to-reach assembly situations, featuring a two-piece pluggable design. This does away with the need for tedious access holes to be drilled into housings and rotating the coupling into the correctly aligned position for turning the clamping screws. This coupling can simply be pulled apart axially without concern for shaft clamping.

We offer several hub connections as standard designs, with single clamping screws in accordance with DIN 4762, as well as a conical clamping ring hub that can be mounted axially with very high compression force on the shaft. Additional hub designs can also be selected from our standard product offering and used with this two-piece coupling.

Backlash-free, Torsionally Stiff, and Highly Precise

Recently, we encountered a customer application with some challenges. The standard metal bellows designs were insufficient to meet the specific system requirements. A difficult assembly and disassembly process repeatedly damaged the bellows. During the assembly process, severe buckling pushed the bellows beyond its capabilities, while disassembly resulted in the bellows being stretched out and pulled too far apart.

This is where our technical team created a custom solution to address the difficult assembly situation. A special construction with interior bump stops was created to prevent this kind of damage. Using three spacer bolts that are attached via drill holes in the hubs, the metal bellows is prevented from being distorted beyond its capabilities, avoiding damage during installation and removal.

Technical data of the coupling

  • Coupling model: BK5/750/139/XX
  • Nominal torque: 750 Nm
  • Max. torque: 1,100 Nm

Lateral misalignment: 0.3 mm