MECHANISMS
Mechanisms are devices that transmit and convert forces and motions from a driving force hnput) to an output element. They enable us to carry out certain tasks with greater comfort and less effort.
They all have many different uses:
• telling the time
entretining children in a park
• moving people from one place to another
• raising or lowering objects
We can classify mechanisms in:
To transmit to motions
To convert to motion
Linear motion
Rotary motion
Rotary to linear
Rotary to reciprocating
LINEAR MOTION MECHANSMS
MOVEABLE PULLEYS
LEVERS
COMPOUND PULLEYS
FIXED PULLEYS
The lever is balanced when the effort F, multiplied by its distance d is
equal to the load R multiphed by its distance from the fulcrum r.
There are three types of levers:
class 1
class 2
class 3
A fixed pulley is balanced when the effort, F is equal to the load. R.
A moveable pulley is balanced when it iulfils
this equat.
This is a set of fixed and moveable pulleys, often called a block and
tackle.