8 Types of Shaft Couplings & Their Uses
Shaft couplings are mechanical elements that join two shafts together and help in accommodating the misalignment of torque from one end to another. These mechanical devices are used for connecting rotating shafts and absorbing misalignments between them. Depending on the alignment precision of the torque and system requirements, couplings can be flexible or rigid.
Some of the most common applications of shaft couplings are for torque and power transmission between rotating shafts, like in compressors, generators, and motors. There are many types of couplings that one may procure as well. Let us have a look at the most common types of shaft couplings.
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
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
, 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.
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.
Posted on April 6, 2022