The pin gear has a number of pins attached to the disk. It is a gear that does not require much precision and is easy to make.
Like bevel gears, you can transmit rotation when the rotation axes of the two gears are tilted.
The same shape can accommodate a certain degree of angular width. (Although it is a little, depending on the design, it is possible to cope with the variability slope.)
As a demerit, backlash (play between gears) increases. Therefore, it is necessary to take measures in the case of a mechanism whose rotation direction changes.
Pin gears can also mesh with spur gears and internal gears. When creating a mechanism that saves space, it is effective to mesh the spur gear and pin gear.