Star gear
A star gear is a step gear in the form of a gear train. It can be used to convert continuous rotary movements into intermittent rotary movements.
In terms of design and kinematics , it is comparable to the Maltese cross gear. In contrast to the Maltese cross gear, however, the number of steps, step angle and pause angle per cycle can be varied within a significantly larger range. In addition, unlike with the Geneva cross gear, the step angles in one cycle do not have to be the same. The same applies to the pause angles. While the speed is always translated in a Maltese cross gear, both a translation and a reduction can be used with a star gearcan be realized in wide areas. The star wheel drive therefore offers clear advantages in its application compared to the Geneva cross drive. However, it is also significantly more complex and expensive to manufacture.
Likelihood of confusion
The output gear of a Geneva cross gear is often referred to as a star gear due to its star-like design . Nevertheless, a star gear is a different form of gear. For example, the gear wheels of a star gear (in contrast to the Geneva cross gear ) have teeth .
A star gear is also often mistaken for a planetary gear . However, these two types of transmission differ fundamentally from each other.
Furthermore, there is a risk of confusion with the spur gears due to the almost identical spelling . The toothing of a star gear can be designed in the form of a spur gear , but this is not absolutely necessary. So there are z. B. also variants with a rack toothing .
Technical application
In the past, star gears were mainly used in the printing and textile industries. Nowadays they have been largely replaced by electronically controlled electric drives.