Internal Geneva Mechanism

Aim: Multibody Dynamic Study of Internal geneva mechanism.

Introduction

Multibody Dynamics

(MBD) the system is one that consists of solid bodies, or links, that are connected to each other by joints that restrict their relative motion. The study of MBD is the analysis of how mechanical systems move under the influence of forces, also known as forwarding dynamics.

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 main wheel also has an elevated circular blocking disc that "locks" the rotating driven wheel in position between steps.

Contact Force

A contact force is any force that requires contact to occur.[1] Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball or pushing a desk across a room are some of the everyday examples where contact forces are at work.

Angular Displacement

The angular displacement of a body is the angle in radians (degrees, revolutions) through which a point revolves around a centre or line has been rotated in a specified sense about a specified axis. When a body rotates about its axis, the motion cannot simply be analyzed as a particle, as in circular motion it undergoes a changing velocity and acceleration at any time (t). When dealing with the rotation of a body, it becomes simpler to consider the body itself rigid. A body is generally considered rigid when the separations between all the particles remain constant throughout the body's motion, so for example parts of its mass are not flying off. In a realistic sense, all things can be deformable, however, this impact is minimal and negligible. Thus the rotation of a rigid body over a fixed axis is referred to as rotational motion.

Solidworks Drawing:

Settings For Precise Contacts:

Results of Motion Analysis:

Precise contact forces at 10 RPM

Precise contact forces at 20 RPM:

Angular velocity of Driven wheel:

Angular Displacement of Driven wheel:

Animation of Mechanism:

Design Files:

https://drive.google.com/drive/folders/1LMMGz2oF0ePfTj9mOU17_OjytV6Gy2eZ?usp=sharing