Internal Geneva Mechanism

Aim :

To design and simulate the Multi-Body Dynamics of an Internal Geneva Gear Mechanism using SOLIDWORKS

Objective :

1. Create 3D models for driver and driven wheels.
2. Perform motion analysis by rotating the driver wheel
3. Obtain the following plots

introduction :

The Geneva drive or Maltese cross is a gear mechanism that translates a continuous rotation movement into intermittent rotary motion.

The rotating drive wheel is usually equipped with a pin that reaches into a slot located in the other wheel (driven wheel) that advances it by one step at a time. The drive wheel also has an elevated circular blocking disc that "locks" the rotating driven wheel in position between steps.

An internal Geneva drive is a variant on the design. The axis of the drive wheel of the internal drive can have a bearing only on one side. The angle by which the drive wheel has to rotate to effect one step rotation of the driven wheel is always smaller than 180° in an external Geneva drive and always greater than 180° in an internal one, where the switch time is therefore greater than the time the driven wheel stands still.

steps :

1. create 3D model based on the gin drawing
2. after crating parts assemnle the parts
3. The motion of the driving wheel is constrained to only rotate about their axes.
4. for simulation turn on the solid works motion tool
5. in motion study , apply motor on the axis of the diving wheel at 10 rpm
6. apply contact between driving and driven wheel
7. click on calculate to get the study and animation
8. After running the simulation, plots for contact force versus time and angular velocity versus time is made using 'Graph and Plot' feature
9. in setting we can change the frame rates and precise contact
10. plot can be exported in excel .

3D parts

Driven wheel

driving wheel

Assembled parts

motion study

Pricise contact selection

Plots:

case1

Speed of driver wheel 10RPM ,Frames per Second 60,Precise contact not considered.

case 2

Speed of driver wheel 10RPM ,Frames per Second 60,Precise contact is considered.

case 3

Speed of driver wheel 20RPM ,Frames per Second 120,Precise contact is not considered.

case 4

Speed of driver wheel 20RPM ,Frames per Second 120,Precise contact is considered.

Conclution:

we studied analysis the motion of the internal geneva wheel and graph are plotted from different condition . The angular velocity of driving wheel velocity increases and then drops rapidly as it completes the rotation.The contact forces are maximum at the point where the driving wheel stub makes contact with the slot

Youtube animation link:

https://www.youtube.com/watch?v=Q7upVupbgRg

drive link:

https://drive.google.com/drive/u/1/folders/19HbdqQUV9Kp7jhNCtZpY53OrsxlRLa8r