Internal Geneva Mechanism

Geneva mechanism is used in various applications such as in film movie projectors and movie cameras, automated sampling devices, banknot counting machines etc. There are mainly two types of Geneva mechanism as follows

Fig.: Internal Geneva mechanism Fig.: External Geneva mechanism

Internal Geneva mechanism:

Internal Geneva mechanism is a gear mechanism that translates a continuous rotational motion into intermittent rotary motion. The rotating drive wheel is usually equipped with a pin that reaches into a slot located in the driven wheel that advances it by one step at a time. An Internal Geneva Mechanism is the variant of Simple Geneva mechanism.

Internal Geneva mechanism consist of a driven wheel and a driver wheel. The driven wheel has the slots made internally due to which it gets called Internal Geneva mechanism. The driver wheel of the mechanism rotates continuously and this continues rotation is gets converted into intermediate motion by the driven wheel. The pin of driver wheel gets inserted into slot of the driven wheel every 90° rotation of the driven wheel. The driven wheel rotates by 90° for every 360° rotation of driver wheel.

Fig.: Assembly of Internal Geneva mechanism

The plots obtained from studying the Internal Geneva mechanism are shown below

1. Contact forces between driver wheel and driven wheel at 120 fps without precise contact

2. Contact forces between driver wheel and driven wheel at 120 fps with precise contact

3. Contact forces between driver wheel and driven wheel at 60 fps without precise contact

4. Contact forces between driver wheel and driven wheel at 60 fps with precise contact

5. Angular dispacement at 120 fps

6. Angular dispacement at 60 fps

7. Angular Velocity

Link to the video of Internal Geneva mehanism : https://youtu.be/UJpr2oep56w

Reference : https://en.wikipedia.org/wiki/Geneva_drive

G-drive Link to access the files :

https://drive.google.com/drive/folders/1Uc13Q7YJa3GH_XjOinTiI7Pq8_xCFKsB?usp=sharing