Invented (and patented) in 1898, the Tapered Roller Bearing is one of the most important inventions in automotive history. A deceptively simple concept revolutionized (please pardon the pun) cars as we know them.
The basic types of bearings are ball bearings and roller bearings. Simply enough, ball bearings roll on spherical balls which are trapped between raceways. Roller bearings instead use cylindrical rollers which are similarly contained. Both of these bearings have a common problem, however, in that they do not provide any mechanism for bearing load exerted from the side.
Enter Henry Timken, a Carriage maker. In 1898, he developed (and subsequently patented) the tapered roller bearing, which uses a conical shape for the raceways, rather than a cylinder. This transforms a pressing force from the side into an expanding force which in turn presses against the hub, within which the bearing is installed. Thus, the bearing still rolls (rather than sliding) when a sideways force (or thrust load) is exerted.
References:
- Webpage: Henry Timken. inventors.about.com.(http://inventors.about.com/library/inventors/bltimken.htm)