Tapered roller bearings are rolling element bearings that can support axial forces (i.e., they are good thrust bearings) as well as radial forces. Description The inner and outer ring raceways are segments of cones and the rollers are tapered so that the conical surfaces of the raceways, and the roller axes, if projected, would all meet at a common point on the main axis of the bearing. This geometry makes the motion of the cones remain coaxial, with no sliding motion between the raceways and the outside diameter of the rollers. This conical geometry creates a linear contact patch which permits greater loads to be carried than with spherical (ball) bearings, which have point contact. The geometry means that the tangential speeds of the surfaces of each of the rollers are the same as their raceways along the whole length of the contact patch and no differential scrubbing occurs. The rollers are stabilized and restrained by a flange on the inner ring, against which their large end slides, which stops the rollers from popping out due to the "pumpkin seed effect" of their conical shape. The larger the half angles of these cones the larger the axial force that the bearing can sustain. Tapered roller bearings are separable into a cone assembly and a cup. The non-separable cone assembly consists of the inner ring, the rollers, and a cage that retains and evenly spaces the rollers. The cup is simply the outer ring. Internal clearance is established during mounting by the axial position of the cone relative to the cup, although preloaded installations without clearance are common. Metric tapered roller bearings follow the designation system defined by ISO 355. History On March 23, 1895, John Lincoln Scott, a farmer and carpenter from Wilmot, Indiana applied for a patent from the United States Patent Office for his invention of a roller bearing that fit on "the axle-skeins and hubs of wagons, buggies, or other wheeled vehicles". The bearing was composed of two sets of cylindrical rollers, one set larger in diameter than the other, that fit on flats machined on the tapered axle-skein. In 1898, Henry Timken was awarded a patent for the tapered roller bearing which used conical rollers. At the time, Timken was a carriage-maker in St. Louis and held three patents for carriage springs. However, it was his patent for tapered roller bearings that allowed his company to