What is a center distance ?
For a pair of gears in mesh, the distance between the centers of the two gears (the minimum distance) is the center distance.
As shown below with the equation and the diagram, the center distance of the meshing gears, a, is the sum of the pitch diameters (d1 and d2) divided by 2.
a = (d1 + d2) / 2
For example, if
d1=40
d2=80
then a = (40 + 80)/2
and the center distance is 60.
Also, if there is a limitation on the center distance, due for example to machine design considerations, the center distance may be adjusted by shifting gears. (For more details, please see a separate page.)
相关链接 - 中心距