What is an idler gear?
An idler gear in a gear train is defined as the gear placed between the input and output shafts (between the drive gear and the driven gear).
For example, it is used to change the rotational direction of the output shaft, or to fill a large gap between the input and output shafts without affecting the speed ratio.
In the example shown below, Gear2 becomes the idler gear without changing the speed ratio.
Single stage gear mechanism using an idler
It should be noted that the speed ratio of this single stage gear mechanism is as follows.
Speed ratio i = z2/z1 × z3/z2 = z3/z1
相关链接 - 惰轮