From shaft couplings for accurate torque transfer to jaw, gear, and motor couplings ensuring reliable connections, our range guarantees optimal performance. These couplings provide the backbone for various applications, from machinery to industrial setups. They form an integral part of rotational mechanisms used to between rotating shafts in compressors, generators, pumps and motors. There are many types of couplings designed to suit your mechanical needs. Here at Cromwell, we stock a wide range of couplings from leading brands such as, Dunlop BTL, KTR, Rexnord and Medway.

What are couplings?

Couplings are simple mechanical devices that are used to make a permanent or semi-permanent attachment between two shafts, which allows power to be transmitted from one shaft (a driven shaft) to the other shaft (driven shaft component).

When are couplings used?

Couplings are widely used in all types of machines mechanisms and applications from industrial, engineering, electrical, packaging, manufacturing, food and beverage to energy sectors.
Couplings are used to:
Connection  -   Used to connect two shafts to hold alignment and transmit power.
Correct misalignment  -   The coupling absorbs compensation to correct a positioning error
Transmit shock  -   Couplings are able to absorb vibrations to improve accuracy, avoid damage to motors and internal machine parts.
Protect from heat transfer  -    A coupling can prevent the transfer of heat from one shaft to the other.

Considerations when choosing a coupling

Coupling type  -   There are two main coupling types: Rigid couplings and flexible couplings rigid and adjustable:
Rigid couplings  -   The simplest coupling type. Used to align two shaft that already are perfectly aligned. Ensure no movement. Rigid type couplings are compression, sleeve and flange couplings.
Adjustable couplings  -   also known as flexible couplings are engineered to be able to tolerate slight misalignment to correct alignments, they ensure precision, absorb shock loads and protect from vibration. Types of adjustable couplings are universal joints, gear and oldham couplings.

Application  -   Not all couplings are the same and have a many of variations and features that a specifically used for different reasons. It is important to know the intended use of the coupling prior to selection.
Maximum Torque  -   It is vital to know the torque maximum level your application can cope with. The value of the torque is dependent on whether the coupling is being used for power transmissions or motion control.
Environment  -   It is important to know the environment that the coupling is to be used in.
Material  -   Consideration to the material of the coupling is vital on selection. Couplings can be made from stainless steel, steel, or plastics.

Couplings jargon buster

We want to make it easy for you, so here are some key terms that will help you understand the terminology a little better

Let's break it down..
RPM  -   All types of couplings have a maximum RPM (maximum rotational speed) that they are able to perform to.
Coupling flange  -   This is a driving coupling that sits between rotating shafts. It consists of two flanges, one of which is fixed at the end of each of the shafts. Then the two flanges are bolted together with a ring set of bolts completes the drive.
Shaft  -   Rotating machine element, often circular in cross section that is used to transmit power to other parts.
Driveshaft  -   This is a rotating shaft which transmits torque in an engine.
Torque  -   This is the force measurement that can cause an object to rotate on axis.


Where are flexible coupling used?
Adjustable couplings, also known couplings are predominantly used in stationary machinery, vehicles, machine tools and automotive drives.

What causes couplings to fail?
There are many reasons that can cause a coupling to fail, but the main reasons are due to excessive misalignment, lubrication (inadequate or insufficient), wrong operating environment or incorrect loads and speed used.