Gears are used to transmit power from one machine element to another. Multiple gears can be meshed together to form a gear train that transfers power between shafts. There are four main types of gear trains: simple, compound, reverted, and epicyclic. A simple gear train uses one gear on each shaft, while a compound gear train uses multiple gears on the shafts to bridge larger distances between the driver and driven gears. The speed ratio of a gear train is the ratio of the driver gear's speed to the driven gear's speed.

2. 09
18
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• Touseef
Haidar
• Arham
saleem
• Muhammad
Asghar

3. Gear
Gear trains
Types of gear
train

4. Gears are basically power transmation
machine equipment . you can transmit power
from one element of the machine to the
other element of the machine by using the
gears

5. Two or more gears are made to mesh with
each other to transmit the power from one
shaft to another shaft .such as the
combination is called Gear train /toothed
wheels.

6. The nature of the train used depend opon
the velocity ratio required and relative
position of the axes of the shaft.
A gear train may be consist of spur bevel and
spiral gear.

7. The different types of gear train depending
upon the arrangment on the wheel.
there are four types of gear train.
Simple gear train
compound gear trai
Reverted gear train
Epicylic gear train

8. In the first three types of the gear train. The
axes of the shafts over which the gears are
mounted are fixed relative to the each other.
But in the case of the epicyclic gear train
the axes of the shafts on which the gear are
mounted may move relative to a fixed axis .

9. There is only one gear on each shaft.it is
called the simple gear train.
when the distance between the two shafts is
small the two gears1 and 2 are made to mesh
with each other to transmit motion from one
shaft to the other.since the gear 1 drives the
gear 2.therefore gear 1 is call driver.
the gear two is called driven /follower.
It may be noted that the motion of the
driven gear is opposite to the motion of
driving gear.

10. v
A
B
GEAR 'A' GEAR 'B'
(Idler gear)

11. The only function of the idler gear is to change the
direction of rotation. It has no affect on the gear
ratio. The teeth on the gears must all be the same
size
use
1) to connect gears where a large centre distance
is required
2) To obtain the desired direction of Motion of the
driven gears (clockwise or anti clockwise)

12. Speed ratio
the speed ratio of the gear train is the ratio of
speed of the driver to the speed of the driven
and ratio of speed any pair of the gears in mesh
is the inverse of their number of the teeth.
Train value
it may be noted that ratio of the speed of the
driver or follower to the speed of the speed of
the driver is known as train value of the gear
train

14. when there are more than one gear on a
shaft.it is called compound gear .
these gears are useful in bridging over the
space between the driver and driven.

15. GEAR 'A'
GEAR 'B'
GEAR 'C'
GEAR 'D'
Compound Gears
A
C
B
D
Output
Input
Compound gears are simply a chain of simple gear trains
with the input of the second being the output of the first. A
chain of two pairs is shown below. Gear B is the output of
the first pair and gear C is the input of the second pair.
Gears B and C are locked to the same shaft and revolve at
the same speed.

16. In the compound gear train.the gear A is the driving
gear mounted on shaft A,gear 1, gear 2and 3 are
compound gear which are mounted on shaft on shaft
B.the gears 4 and 5 are also compound gear which
are mounted on shaft C and the gear 6 is the driver
gear mounted on shaft D.

19. Have a nice day !!!

20. Good bye !!!