As you probably know, couplings are mechanical components that connect two shafts and precisely transmit power from the driving side to the driven side while absorbing axial, radial and angular installation errors. So, what are disc couplings (also called diaphragm couplings or membrane couplings)? A disc coupling is a flexible shaft coupling that transmits torque tangentially from the driving bolt to the driven bolt on a common bolt circle. This torque is transmitted between the bolts via a series of thin stainless steel discs assembled as a group. The flexibility of these couplings comes from the deformation of the material between the bolts. Diaphragm couplings are suitable for high-performance motion control applications and are typically suitable for speeds up to 10,000 rpm.

    The working principle of a diaphragm coupling is to transmit torque via a curved diaphragm disc element. It operates by alternating tension and compression of a chord segment on a common bolt circle bolted between the drive and driven sides. These couplings usually consist of two hubs, two circular diaphragm packs and a center member.

Disc Coupling Styles

There are basically two different types of disc couplings: single disc couplings and double disc couplings.

Diaphragm couplings are typically available in plate packs with 6, 8 or 10 bolt designs. They are used wherever reliable torque transmission is required, even with shaft misalignment which is often unavoidable.

They are universally suitable for temperatures ranging from -50°C (or down to -60°C on request) to +280°C, are torsionally rigid, have no torsional backlash and run quietly at constant angular speeds. They are wear-free, maintenance-free and, if installed correctly, are expected to have an unlimited service life.

‍Optimized plate packs and redesigned component designs allow for higher torque and speed transmission.

Disc couplings (Diaphragm couplings) are widely used around the world

Power generation: air condensers, generators, gas turbines, cooling towers, turbines, boiler feed pumps.

Paper making: waste paper, wet end, dryer, smoothing machine and roller, paper reel, coating machine, filter pan, wastewater purification plant. ‍ ‍ ‍

Cranes: lifting and luffing gear system, slewing gear system, trolley and travel gear system. ‍‍

Ships and shipbuilding: single engine ships, multi-engine ships, dredgers, generator gearboxes, installation ships.

Petrochemical: pumps, fans, compressors, air condensers, jack-up drilling platforms, dryers, agitators, cooling towers, agitators, reactors, installation vessels.

Water and wastewater: pumps, aerators, screw pumps.

Main features of the Disc Couplings

»  No lubrication and coupling maintenance required.

» Inspection of the coupling is possible without disassembly.

»  The condition of the coupling can be checked with a strobe light while the machine is running. (Note: Operating the coupling without a coupling guard is not recommended.)

»  Easy to assess equipment misalignment.

»  Torsionally rigid without any backlash.

»  No wearing parts.

»  Withstands harsh environments.

»  Long life when properly sized and aligned.

»  High power density (higher torque for a given outside diameter).