THE COMPLEX MACHINE

Mr. Ilko

FROM SIMPLE MACHINE TO COMPLEX MACHINE

Over the years people needed better ways to live in their expanding communities Running Water Transportation Systems for moving goods Ways to build larger

Over the last two centuries, scientists and engineers and other inventors have developed machines that use different sources of energy (coal, oil, and electricity)

COMPLEX MACHINES

A simple machine is able to perform a task based on the amount of human force that is put into it.

When you combine several simple machines together you create a complex machine

In these machines all of the simple machine work together to increase the amount of force that is being released.

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SIMPLE MACHINES IN A BICYCLE

1. Pedals acts as a lever, increasing the force you apply to the wheel and axel

2. The Chain and gear act as a pulley creating a constant pulling motion to create movement

3. The tire and pin act as a wheel and axel using the chain to turn and create movement

4. Brakes act as a lever to increase to force you apply with your hand

SYSTEM & SYSTEM

System – A group of parts that work together in order to perform a task E.g. a bicycle

Subsystem – groups within the system that perform specific tasks E.g. Steering or braking on a bicycle

The subsystem in a complex machine just has one function and one simple machine

SUBSYSTEMS PROVIDE MOVEMENT

Some of the most common subsystems that help us transfer force are; Linkages Transmissions Gears

LINKAGE

A complex machine moves an object by transferring energy from an energy source to the object.

Using a bicycle as an example; you are the energy source The bicycle wheels are what you must move the linkage is the chain

The linkage is any item that connects two different wheels so that when one turns the other will turn in the same direction

GEARS

Are an essential in most modern day systems

They consist of a pair of wheels that have interlinking teeth

When they rotate together, one gear transfers turning motion and force to the other

The larger gear turns more slowly than the smaller wheel, but has a greater force

GEARS CONTINUED…

Gears are used to increase or decrease the speed of a machine

Gears can be as simple as a bicycle or a complex as a watch or engines

Gears commonly work together in gear trains of two or more

The gear that has force applied to it from the outside the gear train is called the driving gear

HOW GEARS AFFECT SPEED

If the driving gear is smaller than the driven gear, the turning speed increases Large rotates once and smaller rotates several

Gears that increase the speed of rotation are called multiplying gears Egg beater

Reducing gears decrease the devices turning speed

TRANSMISSIONS Is a special kind of linkage that helps move heavy loads

A transmission transfers energy from the engine to the wheels

In a car it starts at a lower gear and then moves higher as you gain speed

In a low gear, the transmission connects a small wheel to a large wheel so they rotate more slowly than the engine Increase car power, but lowers speed

In a high gear, the larger wheels is connected to a smaller wheel so the wheels rotate faster than the engine Decrease car power, but increases speed