Internal Geneva Mechanism MBD Simulation in Solidworks

Internal Geneva Mechanism in Solidworks

Aim:- To perform Multibody Dynamics of internal geneva mechanism using solidworks. and studying motion analysis, design of it.

Theory:-

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.

Internal Geneva Mechanism:-

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.

Internal Geneva Mechanism

Geneva Mechanism

Design Dimensions:-

Driven Wheel

Driver wheel:-

Taking dimensions using measure tool of Inspect.

Designs Of Parts:-

Final Assembled Parts:-

Plots without precise contact:-

Plot of Contact force between driver wheel and driven wheel in without precise contact. With 10 rpm and 60 Frame Per Seconds.

Where there is a sudden raise of curve at that stage driver wheel is in contact with driven wheel.

Plot of Contact force between driver wheel and driven wheel in without precise contact. With 10 rpm and 120 Frame Per Seconds.

The difference between this graph and above graph is that the motion is set to 120 frame per second due to which the process of calculation has become slower and we get a perfect solution or graph.

Plot of angular displacement of driven wheel

From this plot we get information that the angular displacement decreases gradually then remains constant and then again decreases.

Plots with precise Contact:-

Plot of Contact force between driver wheel and driven wheel in with precise contact. With 20 rpm and 60 Frame Per Seconds.

Their is a change in graph due to precise contact with sudden rise and fall.

Plot of Contact force between driver wheel and driven wheel in without precise contact. With 20 rpm and 120 Frame per seconds

For this we get a clear solution due to increase of frame per second.

Plot of angular displacement of driven wheel

Due to precise contact the graph has changed than previous.

Precise Contact option in Motion Analysis:-

Result :- Maximum Force at 10 rpm is 1331 Newton.

Maximum Force at 20 rpm is 2705 Newton.

Conclusion:-

It can be concluded that as we increase frames per seconds in motion analysis. Clearity in graph also increases. The plot for with precise contact and without precise contact are different.