The document discusses mechanical advantage and velocity analysis of mechanisms. It defines mechanical advantage as the ratio of output to input force or torque. Mechanical advantage is infinite when the input link is in line with the coupler link. Velocity analysis involves studying the linear velocities of points on links and angular velocities of links. Velocity analysis can be done analytically or graphically, with the graphical method using the instantaneous center method or relative velocity method.

2. • Inversions of Single Slider Crank Chain
• Crank and Slotted Quick Return Mechanism
(Numerical part)
• Inversions of Double Slider Crank Chain
Summary of previous lecture

3. Today’s lecture
• Mechanical advantage
• Introduction to Velocity analysis

4. Mechanical advantage
The mechanical advantage (MA) of a mechanism is
the ratio of the output force or torque to the input
force or torque at any instant.

5. when the input Link AB is in line with the coupler BC and
the angle between them is either zero or 180°, it makes
the mechanical advantage to be infinite at such
positions.

Only a small input torque can overcome a large output
torque load. The extreme positions of the linkage are known as
Toggle positions.

6. Velocity analysis
The study of velocity analysis involves the linear velocities of
various points-on different links of a mechanism as well as the
angular velocities of the links.
Velocity analysis
Acceleration analysis
Force analysis
Velocities and accelerations in machines can be determined either
analytically or graphically.
How to do velocity or acceleration analysis?
1. Analytical method (advanced computer)
2. Graphical method (directly applicable)

7. Velocity analysis using graphical method
Graphical method based on
(i) Instantaneous center method
(ii)Relative velocity method

8. Instantaneous center method