This document discusses different types of gears, including their defining characteristics, advantages, disadvantages, and applications. It describes internal and external gears, and various gear types based on axis positioning such as spur gears, helical gears, bevel gears, and worm gears. Each gear type is defined, and their uses in applications like washing machines, textile machines, and vehicle steering are outlined. The document also briefly covers herringbone gears.
3. According to the position of axes
of the shaft :
a. Parallel
Spur Gear
Helical Gear
Rack and Pinion
b. Intersecting
Bevel Gear
c. Non Intersecting and Non Parallel
Worm Gears
4. SPUR GEAR
Most commonly used Gear type.
Teeth are parallel to the axis of the gear.
Transmit power from one shaft to other
parallel shaft.
5. Advantage:
Low Cost
Ease of manufacture
Availability
Disadvantage:
Only works with mating gear
Axis of each gear must be parallel
Applications:
Washing Machines, Rolling Mills, Marine Engines .
6. HELICAL GEAR
Teeth are at an angle to the gear axis
This gradual arrangement makes helical
gear Operate much more smoothly and
quietly than spur gear
Can transmit power between Right angle
or Parallel Axis
7. Advantage:
Smooth and quiet due to gradual tooth engagements
Parallel to perpendicular shaft arrangement
Disadvantage:
Difficult to Manufacture
Cost is High
Resulting axial thrust component
Applications:
Fertilizer industries, Printing industries, hearth moving industries, Conveyors,
Elevators
8. BEVEL GEAR
Useful when the direction of shaft location
has to be changed.
Mounted on shaft that are 90deg apart, can
also be designed to work in other angles.
Teeth can be straight, Spiral or Hypoid
9. Advantage:
Operate on Shafts intersecting at an Angle.
Sliding friction will be low.
Disadvantage:
Assembled with respective shaft precisely.
At high speed it will produce noise.
Applications:
Textile Machine, Sewing Machine.
10. WORM GEAR
Used when large Gear Reduction
is needed.
Have good intersecting property.
Used widely in material Handling
and transportation machinery,
machine tools etc.
11. Advantage:
Higher speed reduction could be secured; speed reduction could be secured
up to 300:1
Worm and worm gears operate silently
Disadvantage:
Manufacturing cost is high as compared with manufacturing cost of bevel
gear
Worm and worm gear set will have heavy power losses.
Efficiency will be low
Applications:
Tuning Instruments, Lifts/Elevators.
12. RACK AND PINION
Convert Rotational to Linear motion
Round Gear – Pinion
Flat or Straight Gear – Rack
Best example is Vehicle Steering System.
13. Advantage:
Rack and pinion gives easier and more compact control over the vehicle
Cheap, Compact, Robust
Disadvantage:
The rack and pinion can only work with certain levels of friction
Applications:
Rack Elevators, Steering
14. HERRINGBONE GEAR
Two helical gears that have been placed
side by side as a mirrored pair.
Referred to as “double helical”.
No thrust loading on the bearings
15. Advantage:
The double helical form balances the inherent thrust forces
Efficient transfer of torque and smooth motion at very high rotational
velocities
Disadvantage:
High cost due to special gear shaping.
equipment and special cutting tools
Applications:
Used in Heavy Machineries