Definition
The Geneva drive, or Maltese cross, is a gear mechanism that translates continuous rotation into intermittent rotary motion.
The rotating drive wheel is usually equipped with a pin that reaches into a slot located in the other wheel (the driven wheel) and advances it by one step at a time. The drive wheel also has an elevated circular blocking disc that "locks" the rotating drive wheel in position between steps. The main difference between Geneva drives and other gears is that Geneva drives have unusual teeth. Unlike other gears, in the Geneva drive, the interaction between the driving and the driven parts is not continuous, and the resultant motion is intermittent.
Animation of the Geneva Mechanism
Construction of the Mechanism
In Geneva drive, there are two wheels: the driving wheel and the driven wheel. The driving wheel has a pin and a little more than a semi-circular disc that is elevated. The driven wheel has 4, 6, or more slots in which the pin of the driving wheel passes and rotates the driven wheel to an angle depending upon the number of slots. If it has 4 slots, it will be rotated 90 degrees in one step, and if it has 6 slots, it will be rotated 60 degrees in one step. The circular elevated disc is used to lock the driven wheel after each step.
Animation of the Mechanism using SOLIDWORKS Motion Analysis
Types
- Internal Geneva Drive
- External Geneva Drive
- Spherical Geneva Drive
Applications
1) The most common application of Geneva Drive is Movie Projectors.
2) Bank Note Counting Machines
3) Automated sampling machines
4) Plotter: Plotter is a computer printer for printing vector graphics.
5) Wrist Watches
Model Files
Edu
