Internal Geneva Mechanism

INTERNAL GENEVA MECHANISM

AIM:

To perform and simulate the Multibody Dynamics using Solidworks for the Internal Geneva Mechanism.

OBJECTIVE:

• To create 3D models for driver and driven wheels.
• To perform motion analysis by rotating the driver wheel at 10 rpm.
• To obtain a plot for contact force between driving and driven wheel.
• To obtain a plot for Angular displacement of the driven wheel.
• To compare the contact forces with and without “Precise contact”.
• To obtain a plot for Angular velocity of the driving wheel.

OVERVIEW:

Internal Geneva mechanism:

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.

APPLICATION AND USES:

Applications of the Geneva drive include the pen change mechanism in plotters, automated sampling devices, banknote counting machines, and many forms of index able equipment used in manufacturing (such as the tool changers in CNC machines; the turrets of turret lathes, screw machines, and turret drills; some kinds of indexing heads and rotary tables; and so on). The Iron Ring Clock uses a Geneva mechanism to provide intermittent motion to one of its rings.

3D Model

DRIVER WHEEL

DRIVEN WHEEL

ASSEMBLY

BODY OF CONTENT:

Plots:

For 10 rpm and 60 frames per second - without Precise Contact:

Angular Displacement of Driven Wheel:

For 10 rpm and 60 frames per second - with Precise Contact:

Comparing the contact forces with and without "Precise contact":

Image for Precise Contact selection:

Angular Velocity for Driving Wheel – 120 frames and 20 rpm:

Result

Thus the Internal Geneva Mechanism is been stimulated and performed using MULTIBODY DYNAMICS in solidworks.

Thus the Motion Study helps us to simulate the real time performance of the Internal Geneva Mechanism

the plots for with &without precise contact forces and angular displacement(10 rpm @ 60 fps) & angular velocity ( 20 rpm @120 fps) has been plotted and compared.it is found that reaction force reaches its maximum value while entering the slots of the driven wheel

Youtube video

Drive: Internal Geneva Design Files