Various types of gear profile.pdf

Gear Profiles

2. •Agearisarotatingmachineparthavingcut teeth,
which meshwith anothertoothedparttotransmit
torque.
•Geareddevicescanchangethespeed,torque,
and directionofa powersource.
•The teeth on the two meshing gears all have the
same shape.
•Gearsalmostalwaysproduceachangeintorque,
creatingamechanicaladvantage,throughtheirgear
ratio,andthusmaybeconsideredasimplemachine.

3. Different types of Gear Profiles:-
Spurgear
Helicalgear
Herringbonegear
Rackandpinion
Bevelgear
Wormandwormgear

4. ⦿Teethisparallelto axisof
rotation
⦿Transmitpowerfromone
shafttoanotherparallelshaft
⦿Usedin Electricscrewdriver,
oscillatingsprinkler,windup
alarmclock,washingmachine
andclothesdryer

5. ⦿Inexternalgearing,thegearsof
the two shafts mesh externally
witheachotherwhichisshownin
figure .The larger of these two
wheels is called spur wheel or
gear and the smaller wheel is
called pinion.

6. ⦿Ininternal gearing,the
gears of these two shafts
meshinternallywitheach
otherasshowninfigure.
The larger of these two
wheels is called annular
wheelandsmallerwheel
iscalled pinion.

7. ⦿Theteeth onhelical gearsarecut
atanangletothefaceofthegear.
⦿Thisgradualengagementmakes
helicalgearsoperatemuchmore
smoothly and quietly than spur
gears.
⦿Ifthe anglesofthe gearteeth are
correct, they can be mounted on
perpendicular shafts, adjusting
therotationangleby90degrees.

8. ⦿Aherringbonegear is a
specific type of double
helicalgear,whichissideto
side (not face to face)
combination of two helical
gearsofoppositehands.
⦿Herringbonegearsare
mostlyusedonheavy
machinery.

9. ⦿Rackandpiniongearsare
used to convert rotation
(From the pinion) into
linear motion (of the
rack).
⦿Aperfectexampleof thisisthe
steering system onmanycars.

10. ⦿Bevel gears are used for transmitting power at a
constant velocity ratio between two shafts whose axes
intersectat acertain angle.
⦿Theyareusuallymountedonshaftsthatare90 degrees
apart, but can be designed to work at other angles as
well.
⦿Theteethonbevelgearscanbestraight,spiralor
hypoid.
⦿Bevelgearusedinmarineapplications,automobiles,
printingpresses,powerplants,steelplantsetc.

12. ⦿Wormgearsareusedwhenlargegearreductionsare
needed. It is commonforwormgears tohave
reductionsof20:1,andeven upto300:1orgreater
⦿Many worm gears have an interesting property that
noothergearsethasthewormcaneasily turn the
gear,butthegearcannotturntheworm
⦿Wormgearsareusedwidelyinmaterialhandlingand
transportationmachinery,machinetools,automobiles
etc