Internal Geneva Mechanism
PROJECT TITLE : INTERNAL GENEVA MECHANISM
AIM :
- To Create 3D models for driver and driven wheels
- To Perform motion analysis by rotating the driver wheel at 10rpm, 20 rpm
- Contact force (between driving and the driven wheel) vs time and Compare the contact forces with and without "Precise contact"
- Angular Displacement of the driven wheel.
INTRODUCTION:
Geneva Drive is a gear mechanism that translates rotation motion into intermittent rotary motion.
The rotating drive wheel has a pin that enters into the slot of driven wheel and make it rotate step by step. The driving wheel has also an elevated half circle that lock the driven wheel in position between steps.
The main difference between Geneva drive and other gears is that Geneva drive have unusual teeth. Unlike other gears ,in Geneva drive the interaction between the driving and the driven part is not continuous and the resultant motion is intermittent.
MODELLING AND ASSEMBLY:
Modelling of Internal Geneva Mechanism has been completed in Solidworks
GRAPH RESULTS :
note: Graph names in order(60 frames for 10rpm,120 frames for 20rpm): 1.Contact forces @10rpm ,2.Contact forces @10rpm with precise,3.Contact forces@20rpm,4.Contact forces@20rpm with precise,5.Angular displacement @10rpm(driver),6.Angular displacement@10rpm(driven),7.Angular displacement@10rpm with precise contact(driver),8.Angular displacement @10rpm with contact (driven).
Precise contact selection:
Conclusion :
1.We can observe that precise contact gives more accuracy , the curves obtained are very smooth when compared to without precise contact graph.
2.When the driver slot enters the driven, we can observe a sudden spike in contact force as shown in graph, and it no more smooth when entering the slot.
3.From Angular displacement graph we can observe the linear trend in driven wheel, Driving wheel shows angular rotation between(0 and -180 degrees).