Applications for Urethane Flexible Couplings

Less Maintenance, Better Performance & Easy Installation

In their simplest form, couplings connect two shafts together at their ends, prevent the shafts from disconnecting during operation, and transmit power between the two. Their main goal is to join two pieces of rotating equipment, all while permitting movement despite some misalignment.

Couplings can be either flexible or rigid (elastomeric or metallic). There are many types of coupling designs including jaw couplings, donut couplings, pin and bush couplings, grid couplings, gear couplings, chain couplings, tire couplings, and more. Here, we’ll provide more insight into flexible couplings and in particular, flexible urethane couplings.

What Is A Flexible Coupling?

Flexible couplings are an essential part for equipment that functions under harsh environments. They are specially designed to transmit torque from one shaft to another when two shafts are misaligned.

In general, they help to dampen shock loads and vibration, prevent metal on metal contact, and lead to clean, quiet machine performance. Some, however, can be sensitive to chemicals and high temperatures, and they are not torsionally stiff enough for positive displacement.

Within the flexible coupling world, couplings can be further broken down into three major types: compression loaded, shear loaded, and torsional.

With compression type elastomeric couplings, the driving and driven hubs rotate in the same plane. Parts of the driving hub push parts of the driven hub through elastomeric elements that act as cushions between them. These cushions are not attached to either hub. As torque is transmitted, the coupling is compressed.

Compression type couplings have a higher load capacity in compression than shear, and can transmit higher torque and tolerate greater overload.

With shear type elastomeric couplings, the driving and driven hubs rotate in different planes. The driving hub pulls the driven hub through an elastomeric element, which is attached to both hubs. As torque is transmitted, the elastomeric element absorbs some of the torque by being stretched through twisting.

Shear type couplings can account for more parallel and angular offset than compression type couplings, plus they offer a greater degree of torsional softness.

Torsional elastomeric couplings dampen torsional vibrations. They are most commonly used in mechanical power transmission systems, and more commonly in diesel engine applications. They “tune” the system above or below its natural frequencies.

Where Are Urethane Flexible Couplings Utilized?

Flexible urethane couplings are used in many industrial equipment applications. They’re used to join drive shafts to driven shafts, motors to pumps, gear boxes to driven equipment, motors to gearboxes, and internal combustion engine flywheels to pumps, transmissions, blowers, and more.

Industries that utilize flexible urethane couplings include steel and metal mills, sawmills, pulp and paper, mining, industrial and automotive manufacturers, and automation.

Popular Flexible Coupling Material

Coupling designs and compositions vary greatly in order to satisfy different application criteria.

Urethane is an elastomeric coupling material with resilience, elasticity and has the best damping capabilities.  Urethane is the optimal elastomeric choice for applications that require high torque in confined spaces, or those that require resistance to atmospheric elements like ozone, sunlight, and hydrolysis. They are impact, oil, chemical, and abrasion resistant. The teeth of a urethane coupling flex to account for misalignment, yet are rigid enough to perform in almost any application.

Call PSI For Your Flexible Urethane Coupling Needs

There are many types, styles, and material compositions in the world of flexible couplings. When selecting the coupling that meets the needs of your equipment, you’ll want to consider the conditions under which the coupling will be used, including the torsional stiffness, horsepower, shaft misalignment, backlash, and rotational velocity error. Also, what degree of lateral, axial, or torsional flexibility does your application require?

Call one of our experienced urethane professionals at (800) 888-5156 for design assistance and to get help selecting the right flexible coupling for your equipment. You can also conveniently request a quote for any size project online, at any time.

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