High torque flexible couplings: a selection guide

Guide to Choosing High-Torque Flexible Couplings RULAND®:

30/05/2024

Understanding the characteristics of each type of coupling is essential for making the right choice in high-torque applications. Ruland offers a range of high-torque couplings (bellows, disc, and beam) distributed in Italy by Getecno S.r.l., ensuring optimal performance for various application needs.

When selecting the ideal coupling for high-torque applications, it is crucial to consider several factors, including torque and misalignment capacity, speed requirements, and spatial constraints.

Bellows Couplings

Bellows couplings offer the highest torque capacity and torsional rigidity at the expense of misalignment. They consist of two aluminum hubs and a flexible central element called the bellows.

The thin walls of the stainless steel bellows flex while remaining rigid under torsional loads, providing bellows couplings with high torsional rigidity to precisely transmit position in demanding applications. They are the ideal choice for demanding servo applications requiring precise rotation and dynamic movement.

Disc Couplings

Functionally, disc couplings are similar to bellows couplings but have slightly higher misalignment capacities at the expense of torque and rigidity. They are available in single or double disc versions.

Single Disc Couplings
The single disc version consists of two aluminum hubs paired with a flexible stainless steel disc. It is a compact design with equivalent torque and greater rigidity compared to double disc versions.

Designers need to be cautious when using a single disc coupling, as they cannot handle parallel misalignment. Since torque values are the same, the main advantage of using a single disc coupling is space savings.

Double Disc Couplings
Double disc models feature two aluminum hubs, a central spacer, and two sets of flexible discs. This design allows the double disc coupling to function as a double cardanic coupling, with each hub operating independently.

The additional disc elements reduce rigidity while maintaining constant torque compared to the single disc version. Double disc couplings can accommodate all forms of misalignment, making them the preferred choice for designers.

Beam Couplings

Beam couplings are ideal for applications requiring precise positioning and a balance between torque, rigidity, misalignment, and high speed.

This combination of performance characteristics makes them suitable interchangeable elements for couplings such as single disc, which have limitations on misalignment and speed.

Beam couplings are available in both long and short versions: