Internal Geneva Mechanism

Objectives of project

1. To create 3D models for driver and driven wheels

2.TO perform motion analysis by rotating the driver wheel at 10 rpm and 20 rpm with and without precise contact.

ASSEMBLY OF THE DRIVER AND DRIVEN WHEEL

Figure 1: CAD Model assembly of the geneva mechanism

This CAD model consists of the driver and driven wheel created using the dimensions given for the project.

The motion analysis was done with the prescriptions of 60 and 120 frames respectively for 10 rpm and 20 rpm with and without precise contact

Figure 2: Selection of precise contact

Results and Discussions

Figure 3: Contact force without precise contact at 10 rpm

From the above figure, it can be seen that the contact forces attains a high value at 6 seconds and 12 seconds

Figure 3: Contact force with precise contact at 10 rpm

With precise contact, the contact forces increases and it can be seen to reach a high at 6 seconds

Figure 4: Contact force without precise contact at 20 rpm

With an increase in the rpm, the contact forces increases, the highest hieght achieved here can be seen at 15 seconds.

Figure 5: Contact forces with precise contact at 20 rpm

With precise contact, the contact forces reaches a value higher than that without precise contact. Tha highest values can be seen at 3, 6, and 9 seconds

Figure 6: Angular displacement without precise contact at 10 rpm

A pattern of increase and decrease is noticed in the angular displacement and this as a result of the degrees of rotation

Figure 7: Angular displacement with precise contact at 10 rpm

Precise contact can be seen to have no effect on the angular displacement

Figure 8: Angular displacement without precise contact at 20 rpm

With an increase in the revolution, there seems to be no change in the angular displacemnt, but the time taken for a revolution decreases which is a normal thing

Figure 9: Angular diplacement with precise contact at 20 rpm

Just like in the case of angular displacement with precise contact at 10 rpm, the precise contact has no significant effect on the displacement

CONCLUSION

1. Increase in the revolutions per minute increases the contact forces

2. Precise contact gives a netter result than without precise contact as can be seen from the figures above

3. Precise contact has no effect on the angular displacements

4. Increase in the Revolitions causes the period needed for a complete revolution to be less.