DnT Chapter 5 :mechanism

WHAT IS A MECHANISM?
A MECHANISM IS CONSIDERED AS A "SYSTEM" WHICH CONVERTS A GIVEN "INPUT" into an "OUTPUT".

INPUT

process

output

FUNCTIONS OF MECHANISM

1. Type of movement
2. Place of movement
3. Speed of movement
4. Direcion of movement
5. Distance of movement
6. Amount of force movement provides

A basic types of movement

1. linear motion- Motion in a st. line e.g. motion of a train
2. Rotary motion- Circular motion e.g. a bicycle wheel
3. Reciprocating motion- Repeatinf forwards & backwards motion e.g piston in a car engine
4. Oscillating motion- repeating forward & backwards in a circular motion e.g. the motion of a clock pendulum

SCHEMATIC DIAGRAMS

LINKAGES

-They are connected to LEVERS and PIVOTED BARS used to transmit FORCE & MOVEMENT
-Only Linear and oscillating motions can be transmitted
-Linkages are IMPORTANT as they allow forces to be transmitted where they are needed. Thus, they can change the DIRECTION , SIZE OF THE FORCE or MAKE THINGS at the SAME time