Flexible Coupling: Basic Concepts and Application Insights

Flexible coupling is a widely used sub-category of couplings, offering distinct characteristics and advantages compared to rigid couplings. Common examples of flexible coupling include diaphragm couplings, jaw couplings, spring couplings, and so on. There is a broad range of flexible coupling types available. Therefore, to facilitate a quicker and more convenient selection of the required coupling, engineers can refer to this guide for purchasing.

Definition of flexible coupling

Flexible coupling is a device that transmits torque between two shafts using elastic elements. This design provides the flexible coupling with strong vibration absorption, the ability to compensate for significant misalignments, and effective noise reduction. In situations involving high vibration, heavy impact, or the need for high precision, flexible coupling are often the preferred choice. Hence, flexible coupling is commonly used in motors, pumps, fans, and transmission systems.

Types and applications of flexible coupling

Jaw Coupling

Jaw couplings are widely used and feature a design-oriented appearance. They consist of metal jaws on both sides with an elastomeric element in the middle. This structure enhances torque transmission and centering tolerance. It allows for some degree of misalignment, while also being easy to install and maintain. Jaw couplings are typically well-suited for high-speed rotation and high-precision transmission. However, their ability to handle significant misalignments in the transmission system is somewhat limited.

Fig. 1 Jaw Coupling

Diaphragm Coupling

Diaphragm couplings can be further subdivided into different types, but here we’ll focus on the standard diaphragm coupling. The principle behind diaphragm couplings is the use of the elastic deformation of a metal diaphragm to transmit torque. This design offers high torsional stiffness and low inertia, making it ideal for precision equipment that requires precise alignment.

Fig. 2 Diaphragm Coupling

Spring Coupling

The principle of spring couplings is similar to that of diaphragm couplings, but instead of a diaphragm, a spring is used to improve the ability to compensate for axial movement and to resist vibration and shock. Compared to other flexible coupling, spring couplings are better suited for mechanical systems that experience high deformation, heavy loads, and high pressures.

Fig. 3 Spring Coupling

Gear Coupling

Gear couplings transmit torque through meshing gears, offering high load capacity and durability, making them ideal for heavy-duty and high-torque applications. Their design allows them to accommodate significant axial and angular misalignments, making them widely used in high-power and industrial heavy-duty mechanical systems.

Bellows Coupling

Bellows couplings use the flexibility of bellows to compensate for shaft misalignment and offer excellent resistance to high temperatures, corrosion, and vacuum conditions. They are ideal for applications requiring high-precision alignment and operation in extreme environments, with the ability to accommodate large axial and angular misalignments.

Fig. 4 Bellows Coupling

Features of Elastic Couplings

1. Vibration Damping: Elastic couplings can effectively absorb vibrations and shocks in mechanical systems, reducing wear on components and noise.

2. Misalignment Compensation: They can compensate for axial, radial, and angular misalignments, providing greater installation tolerance and adapting to imperfect alignment conditions.

3. Noise Reduction: The elastic design helps reduce noise and vibration during operation, enhancing the system's stability and comfort.

4. Equipment Protection: By mitigating vibrations and impacts, elastic couplings protect connected equipment from excessive loads and potential damage, thereby extending the equipment's service life.

5. Flexible Connection: They can provide a flexible connection, allowing the mechanical system to operate smoothly even when there are minor movements or misalignments between shafts.

6. Durability and adaptability: Elastic couplings typically use high-performance materials such as rubber, polyurethane, or metal diaphragms. These materials offer excellent wear resistance and chemical stability, making the couplings highly durable and adaptable to a wide range of working environments.

Considerations for Selecting a Flexible Coupling

When selecting a flexible coupling,  it’s important to consider the torque, speed, and accuracy requirements of your equipment.  These factors above will determine the appropriate type and standard of the coupling you choose.

After setting your performance goals, you also need to consider external factors such as temperature, humidity, and corrosiveness in the operating environment. Finally, assess whether the coupling is easy to install and maintain.

If this article helps you better understand, select, or apply flexible coupling, we invite you to stay connected with us at JLCMC. We can offer high-quality, cost-effective mechanical parts procurement and supply services tailored to your needs. There is currently a $9 newcomer no-threshold coupon event to help every customer have a better shopping experience.