a thrust bearing is a particular type of rotary bearing. like other bearings they permit rotation between parts, but they are designed to support a predominantly axial load. thrust bearings come in several varieties. thrust ball bearings, composed of bearing balls supported in a ring, can be used in low thrust applications where there is little .
the ball was painted black and white in hemispheres, . in discussing the spur gear differential, the use of the term annular gear is a convenient way to distinguish the sun gears of the two epicyclic gear trains. the second sun gear serves the same purpose as the annular gear of a simple planetary gear train, but clearly does not have the internal gear mate that is typical of an annular gear .
a ball bearing motor is an unusual electric motor that consists of two ball-bearing-type bearings, with the inner races mounted on a common conductive shaft, and the outer races connected to a high current, low voltage power supply.an alternative construction fits the outer races inside a metal tube, while the inner races are mounted on a shaft with a non-conductive section e.g. two sleeves .
the penny-farthing used a larger wheel than the velocipede, thus giving higher speeds on all but the steepest hills.in addition, the large wheel gave a smoother ride, important before the invention of pneumatic tires. although the high riding position seems daunting to some, mounting can be learned on a lower velocipede.
these mills, made by a variety of manufacturers, featured many blades so that they would turn slowly with considerable torque in moderate winds and be self-regulating in high winds. a tower-top gearbox and crankshaft converted the rotary motion into reciprocating strokes carried downward through a rod to the pump cylinder below. today, rising .