Week 4 Project - Simple Crank Mechanism

Week 4

A Slider crank mechanism is a modified 4 bar mechanism in which rotational motion is converted to translatory motion and vice versa

Here the green body is the crank that undergoes rotational motion
While the grey body undergoes oscillatory motion

The pink/blue parts are the various joints , used to restrict the working of mechanism and reduce the degree of freedom

This is the basic summary of all the steps involved

First add 3 points to mark all the required dimensions of the slider crank mechanism as given in problem statement

Create 2 bodies
And use get properties from assiciated graphics

Create graphics

You would need 2 graphics to represent crank and connecting rod

Use point 0-1 for first crank
And use point 1-2 for connecting rod

Create joints
3 joint in total
Ground and body 0(crank) revolute joint
Body 0 and body 1, revolute

Body 1 and ground translatory joint

Add a motion at joint 0 to start the mechanism
Obtain the required graphs

1- at point p2 we should have a translatory joint so the system has all the DOF restricted and it wont have any redundancy issues

DOF = 3(4-1) - 2*4 = 1

2- DOF will remain same and wont be affected when motion is applied

This is the graph of point C wrt to ground
As we can see the piston (point C under goes SHM motion)

3-
In this case as the force is only one directional
Thus the piston will expand , but wont return as there is no retracting force