designing of spur gear

1. Submitted by:- VIBHOR KUMAR
DESIGN OF SPUR GEAR

2. WHAT IS GEAR ?
Gears are defined as
toothed wheel or
multilobbed cam
which transmitted
power and motion
from one shaft to
another by means of
successive
engagement of teeth.

3. FUNCTION OF GEAR
 It is used to transmit very
large power which is
beyond the range of belt
or chain drive.
It is used to transmit
motion at very low speed
which is not possible in
belt drive.
It is used to increase or
decrease the speed of the
shafts.

4. TYPES OF GEAR
Spur Gear
Helical Gear
Bevel Gear
Worm Gear

5. SPUR GEAR
In case of spur gear
teeth are cut parallel to
the axis of the shaft and
tooth profile is identical
along the width of teeth.
Spur gear causes radial
load on the shaft and
transmit power only
when the shaft are
parallel to each other.

6. Working Of Spur Gear
 Spur gears are regularly
used for speed reduction or
increase, torque
multiplication, resolution
and accuracy enhancement
for positioning systems.
 The teeth run parallel to the
gear axis and can only
transfer motion between
parallel-axis sets.
 Spur gear mate only one
tooth at a time, resulting in
high stress on the mating
teeth and noisy operation

7. Types Of Spur Gear
External Spur Gear
Internal Spur Gear
Rack and Pinion
Gear

8. Spur Gear Material
Cast Iron
Alloy Steel
Cast Steel
Carbon Steel
Aluminum

9. Advantages Of Spur Gear
Spur gear have high power transmission
efficiency.
Spur gear are compact and easy to install.
Spur gear offer constant velocity ratio.
Spur gear have no slip.
Spur gear are highly reliable.

10. Disadvantages Of Spur Gear
Spur gear drivers are costly when compared to
belt drives.
They have a limited center distance.
Spur gear produce a lot of noise when
operating at high speeds.
They cannot be used for long distance power
transmission.
Gear teeth experience a large amount of
stress.

11. Applications of Spur Gear
Metal Cutting Machines
Power Plants
Marine Engines
Washing Machines
Gear Motors and Gear Pumps
Rolling Mills

12. DESIGNING OF SPUR GEAR
STEP 1 – Find the minimum no. of teeth on
pinion.
STEP 2 – Find the minimum no. of teeth on
gear using velocity ratio.
STEP 3- Find the value of velocity factor .
STEP 4- Find the weaker in gear and pinion
with the help of Lewis factor.
STEP 5- Find the tangential load on the tooth
of the gear.

13. STEP 6- Find the beam strength of tooth using
Lewis equation.
STEP 7- For safe design tangential load should
be equal and less than of beam strength.
STEP 8- Find the diameter of face width of
gear and pinion.
STEP 9- Check the design for dynamic load.
STEP 10- Check the design for wear load.
DESIGNING OF SPUR GEAR