The earliest surviving gears date from the 4th century BC in China (Zhan Guo times – Late East Zhou dynasty), … See more

The word gear is probably from Old Norse gørvi (plural gørvar) 'apparel, gear,' related to gøra, gørva 'to make, construct, build; set in order, prepare,' a common verb in Old Norse, "used in a wide range of situations fr… See more

The gears of the Antikythera mechanism are made of bronze, and the earliest surviving Chinese gears are made of iron, These metals, as well as tin, have been generally used for clocks and similar mechanism… See more

The most common techniques for gear manufacturing are dies, sand, and investment casting; injection molding; powder metallurgy; blanking; and gear cutting.
As of 2014, an estimated 80% of all gearing produced w… See more

Besides gear trains, other alternative methods of transmitting torque between non-coaxial parts include link chains driven by sprockets, friction drives, belts and pulleys, hydraulic couplings, and timing belts. … See more