gears classification and application
TRANSCRIPT
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PRESENTATION ON
Classification And Application Of
Gears
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GEAR
CONTENTS
POWER TRANSMISSION
GEAR
TYPES OF GEARS
APPLICATIONS OF GEARS
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GEAR..
Power transmission is the movement of energy
from its place of generation to a location where
it is applied to performing useful work
A gear is a component within a transmission
device that transmits rotational force to another
gear or device
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TYPES OF GEARS
1. According to the position of axes of theshafts.
a. Parallel
1.Spur Gear
2.Helical Gear3.Rack and Pinion
b. Intersecting
Bevel Gearc. Non-intersecting and Non-parallel
worm and worm gears
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TYPES OF GEARS CONT
2.According to the peripheral velocity of the gears.
(a) Low velocity-
The gears having velocity less than 3 m/s.(b) Medium velocity-
gears having velocity between 3 and 15
m/s.(c) High velocity-
gears having velocity more than 15 m/s.
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TYPES OF GEARS CONT
3. According to the type of gearing.(a) External gearing-
The gears of the two shafts mesh externally
with each other.(b) Internal gearing-
The gears of the two shafts mesh internally
with each other(c) Rack and pinion-
The gear of a shaft meshes externally and
internally with the gears in a straight line
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TYPES OF GEARS CONT
4. According to the position of teeth on the gear
surface.
(a) Straight,
(b) Inclined, and
(c) Curved.
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SPUR GEAR
Teeth is parallel to axisof rotation
Transmit power fromone shaft to anotherparallel shaft
Used in Electric
screwdriver, oscillatingsprinkler, windup alarmclock, washing machineand clothes dryer
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External and Internal spur Gear
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Helical Gear
The teeth on helical gears are cut at an angleto the face of the gear
This gradual engagement makes helical gears
operate much more smoothly and quietly thanspur gears
One interesting thing about helical gears is
that if the angles of the gear teeth are correct,they can be mounted on perpendicular shafts,
adjusting the rotation angle by 90 degrees
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Helical Gear
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Herringbone gears
To avoid axial thrust, two
helical gears of opposite
hand can be mounted side
by side, to cancel resultingthrust forces
Herringbone gears are
mostly used on heavy
machinery.
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Rack and pinion
Rack and pinion gears
are used to convert
rotation (From the
pinion) into linear
motion (of the rack)
A perfect example of
this is the steering
system on many cars
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Bevel gears
Bevel gears are useful when the direction of a shaft'srotation needs to be changed
They are usually mounted on shafts that are 90degrees apart, but can be designed to work at other
angles as well
The teeth on bevel gears can be straight, spiral orhypoid
locomotives, marine applications, automobiles,printing presses, cooling towers, power plants, steelplants, railway track inspection machines, etc.
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Straight and Spiral Bevel Gears
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WORM AND WORM GEAR
Worm gears are used when large gear reductions are
needed. It is common for worm gears to have
reductions of 20:1, and even up to 300:1 or greater
Many worm gears have an interesting property thatno other gear set has: the worm can easily turn the
gear, but the gear cannot turn the worm
Worm gears are used widely in material handling
and transportation machinery, machine tools,
automobiles etc
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WORM AND WORM GEAR
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APPLICATION OF GEARS
1.Spur
Applicable to all types of trains and a wide range of
velocity ratios.
2. HelicalMost applicable to high speeds and loads, also used
whenever spurs are used.
3.Crossed HelicalRelatively low velocity ratio; low speeds and light
loads only. Any angle skew shafts
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APPLICATION OF GEARS
4.Internal spura) Internal drives requiring high speeds and high loads;b) Offers low sliding and high stress loading;
c) Good for high capacity, long life.
d) Used in planetary gears to produce large reduction ratios.
5.Bevel
Suitable for 1:1 and higher velocity ratios and for right-angle
meshes (and other angles)
6.Worm mesh
High velocity ratio Angular meshes
High loads
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