This document discusses gears and how they transfer motion. It contains the following key points: 1) Gears are a mechanism that can transmit or change the direction of motion/force. A driver gear connected to a motor can cause another gear (the driven gear) to move in the opposite direction. 2) The size and number of teeth on gears affects the speed and direction of motion. A gear with more teeth will cause the driven gear to rotate at a slower speed than the driver gear. 3) A gear train involves two or more gears joined together. The velocity of a driven gear can be calculated using a formula that involves the velocity of the driver gear and the number of teeth on each gear.

1. 
PRESENTED BY: SUBMITTED TO
TAUHA NADEEM, SIR MAZAR JAMEEL
SUMBUL TUFAIL,
ALI AITBAR KADRI,
SAKINA ZAHID.

2. It is a mechanism to
transmit or to change
the direction of
motion/force.

3. This shows how motion is transferred
from the pedal to the tyre.

4. 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.

6. This shows how the size and
number of teeth affects the speed
of the gear.

7. This shows how increase in one
variable causes a decrease in the
other and vice versa.

8. •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.
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

9. Number of teeth in driven
gear
15 20 25 30 35
Velocity of driven gear 667 500 40
0
334 28
6
Velocity of driven= Velocity of driver * (# of teeth in driver gear/ # of teeth driven)
= (200*50/15)
= 667

10. 0
100
200
300
400
500
600
700
15 20 25 30 35
Number of teeth in driven gear
Velocityofdrivengear

11. 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

12. 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

13. 0
1
2
3
4
5
6
7
8
9
30 35 40
Twist factor
Turnspercentimetre