8 Types of Shaft Couplings & Their Uses

1. Beam Couplings

           
Beam couplings are available in the market and feature multiple or single helical cuts on the coupling body. Typically, the coupling body includes angular misalignments of up to 7 degrees and parallel misalignments up to 0.025 inches. Beam couplings are majorly used in applications of motion control in which torque is found to be below 100 inch-lbs. Positioning accuracy between driven and driving shafts is ensured with the help of zero-backlash designs.

2. Chain Couplings

           
Suitable for power transmission applications, chain couplings are utilized for transmitting power with a high horsepower range. Parallel and angular misalignment allowances are 0.015 inches and 2 degrees respectively. Generally, this type of coupling uses unique types of double-wide roller chains and sprockets that allow the design to function as a flexible coupling.

3. Bellows Couplings

 
Also suited for places where motion control is needed, bellows couplings possess multiple convolutions of metal that give the high torsional stiffness crucial for positioning applications. The significance of torsional stiffness is high as it reduces the angular and parallel misalignment levels such couplings can accommodate.

4. Gear Couplings

 
Gear couplings transmit high torque and have misalignment capabilities of about 2 degrees in angular and 0.01-0.02 inches in parallel. These are mostly used in pairs with spacer shafts for spanning the distance between the driven and driving equipment. They also require lubricant for proper functioning. However, some designs that are intended for lighter duty utilize lubricant-free nylons and other polymers for the center sleeve.

5. Diaphragm Couplings

 
These couplings are mostly used for taking on high power transmission (as seen in turbomachinery). Diaphragm couplings can have one or more flexible metal convoluted discs. These discs help transmit power to a spacer shaft present inside the assembly before it flows out through a diaphragm stack to the driven machinery. These couplings are equipped to handle high-speed operations and high torque transmissions. The key advantage that diaphragm couplings have over gear couplings is that gear couplings lack lubrication requirements.

6. Jaw Couplings

 
Jaw couplings, both straight and curved, are used for light power transmission and motion control. They have a pair of multi-jawed hubs along with elastomeric spiders. The structure and design of jaw couplings enable backlash-free torque transmission. Parallel misalignment accommodation is usually 0.01 inches and angular misalignment is at about 1 degree. These couplings often operate without lubricant and can transmit torque up to the 1000 inch-lbs. range.

7. Disc Couplings

Disc couplings use single or double stages and single or multiple discs that bolt to the shaft hubs. Primarily used for power transmission, disc couplings can be relied upon because of the flexibility in their thin metal discs that serves for accommodating angular misalignment and transmitting torque.

8. Oldham Couplings

 
Because of their sliding element design, oldham couplings are equipped to handle high degree parallel misalignment. In some modern versions of these couplings, elastomer is used as the center element instead of metal. It is claimed by some manufacturers that oldham couplings have the ability to take on up to 5 degrees of angular misalignment viz-a-viz the use of cylindrical sliders instead of rectangular types.
 
Conclusion
 
There are many channels you can get your shaft couplings from, but if quality is your priority, Aerospace Exchange is just the place for you. Aerospace Exchange is your one-stop destination for all your civil and defense parts needs. Being a part of the ASAP brand, we are an AS9120B, ISO 9001:2015, and FAA 0056B accredited company. So, if you are looking for shaft couplings or other civil and defense-related parts, Aerospace Exchange has all your requirements covered.