Internal Geneva Mechanism

AIM:-

• Create 3D models for driver and driven wheels.
• Perform motion analysis by rotating the driver wheel at 10rpm.
• Obtain the following plots
  • Contact force (between driving and the driven wheel) as a function of time.
  • Angular Displacement of the driven wheel.
• Compare the contact forces with and without "Precise contact"
  • Show image for precise contact selection
  • Export the results that you get to Excel and make the plots over there.

THEROY:-The Geneva Mechanism 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.

CAD MODELLING AND DESIGN:-A cad model of internal geneva mechansim is created consisting of driven and driver wheel. The following components are assembled using assembly mates.Then Motion analysis is caried out at 10 rpm and 20 rpm.

1) geneva driven part

2)geneva driver part

RRESULT:-

at 10 RPM with contact precise

2)at 10 RPM plot of angluar velocity and time with contact precise

3)at 10RPM plot of contact forces and time with contact precise

at 10RPM without contact precise

During this simulation, I have faced an error which further reduced by decreasing accuracy

1) angular velocity and time without precise

2) contact forces and time without precise

At 20RPM with 120 FPS without precise

At 20 RPM and with precise (120FPS)

Conclusion

1. Precise contact gives analytically correct results.
2. Angular Velocity of the driven wheel increases and then decreases and then for some time remains constant and this pattern repeats ( slightly different curve pattern for 10 rpm and 20 rpm )
3. MAX Angular Velocity of the driven wheel increases as we increase the rpm.
4. Angular Displacement of the driven wheel remains constant as rpm increases.