Early examples of gears date from the 4th century BC in China (Zhan Guo times – Late East Zhou dynasty), which have been preserved at the Luoyang Museum of Henan Province, China. The earliest preserved gears … 查看更多內容

The definite ratio that teeth give gears provides an advantage over other drives (such as traction drives and V-belts) in precision … 查看更多內容

General
Rotational frequency, n Measured in rotation over time, such as revolutions per minute (RPM or rpm). Angular frequency, ω Measured in radians/second. 1 RPM = 2π rad/minute = π/30 rad/second. Number of teeth, N How … 查看更多內容

In some machines (e.g., automobiles) it is necessary to alter the gear ratio to suit the task, a process known as gear shifting or changing gear. There are several ways of shifting gears, … 查看更多內容

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 from writing a book to dressing meat". In this … 查看更多內容

External versus internal gears
An external gear is one with the teeth formed on the outer surface of a cylinder or cone. Conversely, an internal gear is one with the teeth formed on the inner surface of a cylinder or cone. For bevel gears, … 查看更多內容

Backlash is the error in motion that occurs when gears change direction. It exists because there is always some gap between the trailing face of the driving tooth and the leading face of the tooth behind it on the driven gear, and that gap must be closed … 查看更多內容