Although the first early ball bearings are typically attributed to inventors from European antiquity, there is strong evidence to support that roller bearing principles were employed much earlier in other civilizations. Ancient China, for example, is seen to have made use of mechanized armillary spheres between the second and eighth centuries. This would not have been possible without metal bearing technology. Evidence also exists to show that an ecliptically mounted observational armillary using steel bearings was built by I-Hsing and Liang Ling-Tsan in the year 720 AD. In 1088 AD, a clock tower making use of iron bearings was constructed by Su Sung. It is worth mentioning that none of these examples were even state-of-the-art during their time, having been pre-dated by Chang Heng’s bearing use in the making of proto-clocks.
Findings from the 2nd century Hsueh-Chia-Yai village seem to indicate the use of annular bronze objects constructed with internal grooves divided into four or eight compartments by small transverse partitions, each of which contained granular rust. Several objects resembling roller bearings were also found with these bronze objects. If the rust found within the grooves came from the items resembling roller bearings, they would then be considered the oldest ball-bearings known to date.
With such proof being inconclusive, the earliest record would be given to the Romans, who constructed ships between 44 and 54 AD made with bizarre-looking trunnion bearings inside their capstans. Some purists may still not award them with a title, seeing as though they were not true ball-bearings as their spheres could only rotate in one plane.
Although many early examples may have employed rollers in a straight line, true roller-bearings were used in the hubs of Celtic wagons discovered in Denmark around 1883, with each hub showing around 32 transverse grooves. Similar hubs have been found in other European locations dating back as early as the 1st century. Leonardo da Vinci is frequently credited with sketching the first proper roller bearing around 1500 AD, with Agostino Ramelli being first to publish roller and thrust bearing.
Proper ball-bearings were eventually put to use by Cellini in the 16th century. In 1770 the Empress of Russia commanded her engineers to transfer heavy blocks of stone atop cannonballs rolling between bars of iron. It is said this example provided inspiration to Varlo in 1772 to test annular ball-races on road vehicles. It is interesting to note that it took almost 2000 years to develop true ball-bearings from their distant roller-bearing ancestors.
Galileo described the first caged ball bearing in the 17th century, which prevents additional friction caused by ball bearings rubbing against each other. Mounting such bearings into a set did not happen until almost two hundred years later, when the first practical caged-roller bearing was invented by John Harrison for his marine timekeeper. Shortly after this, the first patent for a ball race was issued to Philip Vaughan in 1794.
Around this time bearings began to see frequent use in holding wheels and axles, used to significantly reduce friction over that of simply dragging an object by making the friction act over a shorter distance as the wheel turned. They were made out of a variety of materials ranging from bronze, ceramic, glass, sapphire, steel, and even wood. It is worth nothing that even old materials like wood are still in use today in old water mills so long as the water can provide adequate cooling and lubrication.
Jules Suriray was awarded a patent on ball bearings in August of 1869. His ball bearings were fitted onto a bicycle which ended up winning the world’s first bicycle road race in November 1869. Bearings of this sort are the direct ancestor of those still used in bicycles and other wheel-based applications today.
For more information and examples of present-day applications, please visit the NMB site at http://www.nmbtc.com/bearings/