gear presentationn

PRESENTED BY: SUBMITTED TO

TAUHA NADEEM, SIR MAZAR JAMEEL

SUMBUL TUFAIL,

ALI AITBAR KADRI,

SAKINA ZAHID.

GEAR

It is a mechanism to transmit or to

change the direction of motion/force.

What is a gear?

This shows how motion is transferred from the pedal to the

tyre.

Example #1:

This shows how one gear connected to the motor, can cause the other gear to move in the opposite direction which changes the direction of the motion.

Example #2:

Another simplistic example:

This shows how the size and number of teeth affects the

speed of the gear.

The relationship between the teeth and speed of a gear:

This shows how increase in one variable causes a decrease in

the other and vice versa.

Hyperbola showing the relationship of speed and teeth:

•Gear train: when 2 or more gears are joined together for a particular purpose.•Driver gear: a gear which is connected to the motor.•Driven gear: a gear which is connected to the driver gear.

The actual formula:

Velocity of driven= Velocity of driver * (# of teeth in driver gear/ # of teeth driven)

•Manipulation of the formula:

Velocity of driven/ Velocity of driver= # of teeth in driver gear/ # of teeth driven

Number of teeth in driven gear

15 20 25 30 35

Velocity of driven gear 667

500

400

334

286

Velocity of driven= Velocity of driver * (# of teeth in driver gear/ # of teeth driven) = (200*50/15) = 667

15 20 25 30 350

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Number of teeth in driven gear

Velo

city

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dri

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gear

Twist factor:It measures how much turns a yarn

has and can be calculated by counting the number of twists in an inch of yarn.

Twist is inserted into the fine strand of fibres to hold the fibres together. Without twist, the fine strand of fibres would be

very weak and of little practical. Formula:

Twist factor= (turns per centimetre) √linear density

Twist factor 30 35 35

Turns per centimetre 6 7 8

Twist factor= (turns per centimetre) √linear density 30 = (x) √25 30/5 = x 6 = x

30 35 400

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Twist factor

Tu

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