Aerospace bearings: where did it all begin?
According to Report Linker, the aerospace market is expected to grow from USD 9.6 billion in 2021 to USD 17.7 billion by 2026, at a compound annual growth rate (CAGR) of 8.9 per cent. From personal flying vehicles to a greener aerospace, it’s clear the aerospace sector is developing fast — but where did it all begin? Here, Chris Johnson, managing director of SMB Bearings, explores a brief history of bearings in the aerospace sector.
Mankind has always had the desire to fly. In fact, achieving flight has been on our agenda since before the common era. The history of aviation began with the invention of kites, with the origin of the first man-made flying object occurring in 200 BC in China.
Leonardo da Vinci took flight to a whole new level. His plan for a helicopter, most notably known as the Aerial Screw, did not go to plan. Although the helicopter design was ahead of its time, it went down like a lead balloon. It was however, the first recorded use of ball bearings in aerospace design and since then, bearings have played a vital role in this sector.
How have bearings evolved?
Bearings have had a long and complex history. From Agostino Ramelli’s published sketches of modern roller and thrust bearings, to John Harrison’s invention of the H3 marine timekeeper — bearings have evolved.
In fact, inventor and ironmaker, Philip Vaughan, was the first to patent ball bearings, reducing friction and improving efficiency in machinery. The industrial revolution saw further advancement of the ball bearing design. Today, we use bearings for a wide variety of products and applications, from heavy machinery and equipment, to manufacturing, power generation, and aerospace.
There are many exciting innovations happening in the aerospace sector. For instance, a flying car may seem futuristic, but the hybrid car-aircraft Klein Vision AirCar, can fly 1,000 kilometres, at the height of 8,200 ft. It has narrow wings on each side of the vehicle and is equipped with a BMW engine. Beyond the high-profile headline generating innovations, materials science is a key area of research and development in the aerospace sector that has garnered a lot of attention.
Benefits of lightweight composite bearings
Bearings may be small, but the material choice of each individual component counts. They are featured throughout the entire aircraft, including aircraft wing systems, flight control, and aircraft interiors. Design engineers work with precise specifications in aerospace design and the chosen bearings must be lightweight, low-friction and long-lasting.
Bearings in aerospace design must withstand harsh conditions, extreme temperatures, demanding load profiles and high speeds. There are many types of materials that are used in the composition of components for the aerospace sector. Composite bearings are one of them.
One advantage of this material is the weight. A plastic bearing is five times lighter than steel in weight. However, some reinforced composite bearings can deliver the same, or enhanced, technical performance while using less material. Composites are ideal for general interior aircraft use, lowering the total weight while allowing a smoother take-off and journey in the air.
Not only that, but some plastic composites are resistant to heat, UV exposure, and harsh environments. At times, aircrafts must manoeuvre through extreme turbulent winds; therefore, require bearing materials that are resistant to these conditions. Modern reinforced composite bearings will stay intact because they do not absorb any moisture and can cope better in harsh environments than metal. This, therefore, increases the lifespan of the aircraft and avoids costly repairs caused by corrosion.
Much has changed since Leonardo da Vinci’s Aerial Screw, but we cannot deny the powerful impact bearings have had on the aerospace sector. Bearing manufacturers are regularly developing new designs to extend the service life of these components in the aerospace sector, and much of this depends on the research and development in material science. As aerospace innovation continues to advance, the choice of material, even for the smallest mechanical components, will remain important.
Design engineers should team up with the best component suppliers to guarantee lightweight, good quality bearings for an extended service life.