Hi, engineers around the world! We are going to introduce you to a new series, one that will discuss engineering breakthroughs over the years that transformed society at that time. By hard work and inspiration, these engineers foresaw the use of a particular invention, and it was upgraded to become the backbone of local development. So, starting right from the ancient world, there are some inventions that helped people and boosted the economy like baskets and hunting tools. But, one particular engineering assembly stands out from the rest as it continues to be used today in every moving machine. The invention is wheel and axle, and it is perhaps the greatest invention of all times as further machines would not have been impossible without it.
The oldest wheel and axle dates back 5400 years ago according to Radiocarbon dating techniques. The remains were found in excavations in Slovenia and no word regarding its inventor has so far been unearthed. It was a simple wooden assembly with an ash wheel and an oak axle. Numerous other discoveries from other areas prove that is indeed an ancient invention, and it is possible to have been developed parallelly in different parts of the world. So, nobody gets credit for the invention of wheel and axle, but further individuals are credited with coming up with new versions and utilizations for it.
The wheel and axle were first used for driving carts and carriages, but it was not until the Golden Age of Greek Science and Technology that they were used in machines. It was Hero of Alexandria who identified the use of wheel and axle for lifting weights and increasing the mechanical advantage. He also incorporated the invention into a pioneering water wheel that was used to power a music organ. Not many uses were developed for the wheel in the latter millennium except for some design changes. The next significant thing in the development of this technology was the use of ball bearings by Leonardo Da Vinci. However, these ball bearings were only begun to be used in wheel and axle assembly by the start of the 19th century when locomotives with steel rims and shafts were made.
The design of the wheel itself has gone through radical changes over the years. The early ones were just a circular piece of wood attached to a crude wooden axle. 2000 CE saw the first use of the spoked wheel that had rims attached to the center of the wheel with spokes. The same design was incorporated to make iron rims by the Celtics, whose wheels became so popular that they remained unchanged for the next three thousand years. The use of metal wheels continued until the development of pneumatic wheels and wire based spokes. Now the outside of the tyre was all rubber, and it took away most of the maintenance requirements for automobiles. Locomotive wheels continued to be made with steel as they were to be run on metal rails.
From 1950 onwards steel disk wheels with pneumatic tyres were used followed by alloy rims that had much more favorable properties. Despite the simple nature of the assembly, it is still undergoing further advancements for modular functions. There are Mecanum wheels for robots that allow movement in any direction. There are also hubless wheels, air bearing wheels and active wheels having suspension and motor inside the hub itself.
So, the developments in wheel are showing no signs of stopping. I wonder what else we will see in the coming years!