Internal Geneva Mechanism
AIM: TO ANALYSE THE MULTI BODY DYNAMICS FOR INTERNAL GENEVA MECHANISM USING SOLIDWORKS.
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.
- To create motion study for two conditions-
- 60 frames per second and 10 rpm motor speed.
- 120 frames per second and 20 rpm motor speed.
- To export the results to a spreadsheet.
INTRODUCTION
Geneva mechanism, also called Geneva Stop, one of the most commonly used devices for producing intermittent rotary motion, characterized by alternate periods of motion and rest with no reversal in direction. It is also used for indexing (i.e., rotating a shaft through a prescribed angle).
INTERNAL GENEVA DRIVER
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.
APPLICATION
Geneva drive is earlier used in film movie projector. It is also used in mechanical watch.
It is used in automobile sector and various manufacturing industries.
3D MODEL FOR DRIVEN AND DRIVER
- DRIVEN WHEEL:- 3D model is made by using 2D sketch of driven
Extruded boss base command is to made 3D model
- DRIVING WHEEL
- ASSEMBLY
Assembly is done by using some right constrained mates
BODY CONTENT
- STUDY-1
Firstly we setup the motor speed 10 rpm and frame size 60
Now setup solid body contact
Now calculate the motion study and will get plots of contact force, angular displacement, velocity as a function of time.
Plots are as follow
- CONTACT FORCE BETWEEN DRIVING WHEEL AND DRIVEN WHEEL AT 10 RPM AND 60 FRAMES WITHOUT PRECISE CONTACT
ANGULAR DISPLACEMENT OF DRIVEN WHEEL
- ANGULAR VELOCITY OF DRIVING WHEEL
NOW USING PRECISE CONTACT
- PLOTS OF CONTACT FORCE WITH PRECISE CONTACT AT 10 RPM AND 60 FRAMES
2. STUDY-2
Firstly we setup the motor speed 20 rpm and frame size 120
Now setup solid body contact
Now calculate the motion study and will get plots of contact force, angular displacement, velocity as a function of time.
Plots are as follow
- CONTACT FORCE BETWEEN DRIVING WHEEL AND DRIVEN WHEEL AT 20 RPM AND 120 FRAMES WITHOUT PRECISE CONTACT
- ANGULAR DISPLACEMENT OF DRIVEN WHEEL
- ANGULAR VELOCITY OF DRIVING WHEEL
NOW USING PRECISE CONTACT
- PLOTS OF CONTACT FORCE WITH PRECISE CONTACT AT 20 RPM AND 120 FRAMES
Link for spread sheet of result and parts
https://drive.google.com/drive/folders/10RgqUj9QHsOZtfpdYoucRCBuArkFo9R-?usp=sharing
Animation video