08-16-2017, 10:25 PM
INTRODUCTION OF GEAR
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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
TYPES OF GEARS
1. According to the position of axes of the shafts.
Parallel
1.Spur Gear
2.Helical Gear
3.Rack and Pinion
b. Intersecting
Bevel Gear
c. Non-intersecting and Non-parallel
worm and worm gears
SPUR GEAR
Teeth is parallel to axis of rotation
Transmit power from one shaft to another parallel shaft
Used in Electric screwdriver, oscillating sprinkler, windup alarm clock, washing machine and clothes dryer
Helical Gear
The teeth on helical gears are cut at an angle to the face of the gear
This gradual engagement makes helical gears operate much more smoothly and quietly than spur 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
Herringbone gears
To avoid axial thrust, two helical gears of opposite hand can be mounted side by side, to cancel resulting thrust forces
Herringbone gears are mostly used on heavy machinery.
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
Bevel gears
Bevel gears are useful when the direction of a shaft's rotation needs to be changed
They are usually mounted on shafts that are 90 degrees apart, but can be designed to work at other angles as well
The teeth on bevel gears can be straight, spiral or hypoid
locomotives, marine applications, automobiles, printing presses, cooling towers, power plants, steel plants, railway track inspection machines, etc.