Gears%20

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Gears Spline Shafts

• Sharif Ali

• What are they?
• What are they used for?

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GearsA Brief History

• Began as wood with pegs and used animal fat
  grease as lubrication
• Used in wind and water wheel machinery and to
  power textile machinery

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GearsUses

• Three main uses

• To change the rate of rotation of a machinery
  shaft
• To change the direction of the axis of rotation
• To change between rotary and linear motion

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GearsExample 1

• Spur Gears
• Rate of Rotation
• Most common type of gear
• Straight teeth, parallel shafts
• Can be used to create large gear reductions
• Used in oscillating sprinkler, wind up alarm
  clock, washing machine and clothes dryer
• Loud due to teeth collision

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Spur gears
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Gears Example 2

• Helical Gears
• Much more quiet and smooth than spur gears due to
  the angled cut of the teeth
• Can be mounted on perpendicular shafts to adjust
  angle of rotation by 90o
• Used in most car transmissions

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Helical Gears
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GearsExample 3

• Worm Gears
• Used when large gear reductions are needed
• Worm can turn gear but gear cannot turn worm
• Useful in conveyor systems

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GearsExample 4

• Rack Pinion Gears
• Rotation into Linear
• Used in the steering system on automobiles
• Also used on same scales

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Spline Shafts

• Grooves or tongues are machined along the length
  of the shaft
• This allows for both the shaft and another
  corresponding shaft or component to rotate
  together

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References

• www.bergen.org
• www.howstuffworks.com
• www.efunda.com