When you hear the word bearing, the first thing that clicks your mind are those ball bearings, right? These are present most commonly in a car’s front wheel or the drive shaft of a bicycle. These typical bearings work when balls are lubricated and isolated in fixed or moving surfaces.
However, as technology is revolutionizing every other day, engineers have found a solution to reduce friction in motion control applications. It has completely transformed the way bearings used to work in the past. Here’s all that you need to know about air bearings.
What are air bearings?
Air bearings use air cushions rather than balls to attain motion. To support the load, a thin film of pressurized air is used, and uniform pressure is ensured throughout the entire bearing area.
Yet, some amount of gas escapes from the bearing area, but pressurized air continuously flows in the bearing to make sure it’s enough to carry the load, rather than collapsing.
The best part about air bearings is that they are non-contact, which means you don’t have to worry about friction. The air bearing is perfect for high-speed applications as well. It’s considered a pioneering solution to friction.
Wondering how the continuous flow of air is achieved in an air bearing? There are large fans that are responsible for blowing air under the hovercraft and an elastic rubber skirt is also used to prevent the air from escaping.
As friction is very low, free rotation of the shaft is experienced. Most applications use simple air but there are other options as well, such as hydrogen, helium, nitrogen, carbon dioxide, and many other gasses, depending on the requirements.
Advantages of Air Bearings
Air bearings come along with numerous benefits, a few of which are listed below;
As mentioned earlier, frictionless motion is one of the top-notch benefits of air bearings and a prominent reason behind their utmost popularity.
With the use of an air bearing in linear applications, you can precisely place the moving carriage within nanometers as there’s also a direct drive motor for it. Air bearings are not only frictionless, but they also provide very high precision.
Even if you are using rotational applications, it’s doable to position the carriage from nanometers to even tenths of arc seconds, making it highly precise. In the manufacturing industry, these bearings are responsible for reducing the hysteresis effect as well.
Maintenance is always a concern in every industry, air bearings not only give a relief from friction but also from excessive maintenance. The mechanical contact between the parts is minimum, there is almost no need for lubrication or inspecting the parts repeatedly to ensure smooth operations.
Moreover, you don’t need to worry about bearing seals which is a common issue when we talk about ball bearings. Performance characteristics are consistent, leading to high productivity.
The issue with mechanical bearings is that they wear repeatedly, which ultimately results in low precision. However, air bearings usually require maintenance regarding moving cables and hoses.
Cleanliness is also a vital goal which is to be achieved by industries. Air bearings don’t possess the risk of generating dirt which could contaminate air. Furthermore, they are also wear-free, so you don’t have to worry about small, tiny pieces lying around in the workplace.
If you are aiming for better cleanliness, you can use air bearings that operate on pure nitrogen.
The efficiency of an air bearing is increased with the increase in speed. It is due to the self-pressurizing effect in air bearings. Many processes require full control over speed in continuous motions. Experiments such as sensor testing require such control.
You can achieve velocity stability even better than 0.01%, which makes the whole procedure super smooth.
Exceptional Rotatory Motion
As rotary air bearings are super stiff, they are ideal to attain precise rotatory motion. In mechanical bearings, there’s always a high risk of wobble error which hampers the smoothness of the process.
As air bearings can rotate up to 100,000 rpm, they are perfect for high-speed applications. It is believed that the risk of wobble error motions in air bearings is 10 times lesser.
The components of air bearings are manufactured with very tight tolerance, leading to better accuracy. You can achieve smooth and silent operations without any unwanted vibrations. Industries prefer these bearings for long-term performance at a high resolution.
As these bearings provide high precision, they are preferred for the manufacturing of optical lenses. Other than that, the aerospace industry also takes full benefit of this exceptional technology.
The unnumbered benefits of air bearing make them suitable for a variety of industries, may it be automotive, aerospace, and many other industries in the world.