INTERNAL GENEVA MECHANISM

AIM

To perform motion analysis for Internal Geneva Mechanism.

OBJECTIVE

• Create 3D models for driver and driven wheels.
• Create an assembly of Internal Geneva Mechanism.
• Perform motion analysis by rotating the driver wheel at 10 rpm and 20 rpm respectively.
• Plot Contact force graph between driving and driven wheel as a function of time.
• To plot the angular displacement of the driven wheel.
• To plot the angular velocity of the driver wheel.

THEORY

The Geneva drive is a mechanism that translates a continuous rotation motion into an intermittent rotary motion. The driving wheel has a pin that advances into the slot of the driven wheel advancing it my one step.

APPLICATIONS

• Geneva wheels are used in mechanical watches.
• Modern film projectors.
• CNC Machines for changing tools.

3D MODEL OF DRIVEN WHEEL

3D MODEL OF THE DRIVER WHEEL

ASSEMBLY MODEL OF INTERNAL GENEVA MECHANISM

MOTION ANALYSIS SETUP

• Under the motor tab, rotary motor is selected. The direction of rotation is done by selecting the axis of the driver wheel and the required rpm of the motor is specified.
• The contact force between the driver wheel and the driven wheel is specified.
• Steel (dry) is the material chosen for both the wheels.
• Frames per second can be changed in the settings tab.
• Click on Calculate icon to start the process.
• Under the Results and plots tab, the required results can be obtained by selecting the desired parameters.

Contact force plot for motor at 10 rpm with 60 fps

Contact force plot for motor at 10 rpm without precise contact

Angular displacement of the driven wheel at 10 rpm with 60 fps

Contact force plot for motor at 20 rpm with 120 fps

Angular displacement plot for the driven wheel at 20 rpm

Angular velocity plot for the driver

YOUTUBE LINK

https://youtu.be/1If_SpkeSfE

PART FILES AND ASSEMBLY

https://drive.google.com/file/d/1J0hXAYnnlXe4GqYeMM2BxiJQM_YtH5lB/view?usp=sharing

https://drive.google.com/file/d/159gnObRYBIK-TERmXp4vEge6hE4lROKd/view?usp=sharing

https://drive.google.com/file/d/1Y8rG_OYQRGHbzso-fQ4vSrJcUNo5z579/view?usp=sharing

CONCLUSION

• Using precise contact gives us better result.
• The contact force between the driver and driven wheel increases as the speed of the motor increases.
• Angular displacement of the driven wheel remains constant as the rpm increases.

REFERENCE

https://learnmech.com/introduction-to-geneva-mechanis/