a gearwheel with teeth projecting parallel to the wheel's axis.

1. SPUR GEAR
13ME304 MANFACTURING PROCESSES
REVIEW 1
Team members
P.Aravind
B.Dhayanandhan
C.Jeeva bharathi
A.Joseph praveen
Guide
M.Bala kumaran
AP/MECH/NEC

2. SPUR GEAR
• Spur gears are the
simplest type of
gear
• Transmitting
power between
parallel axes, the
teeth project
radially on the disc

3. Types of Spur Gears
• External Spur Gear
• Internal Spur Gear
• Rack and Pinion Gears

4. External Spur Gears
• External Spur Gears are
the most popular and
common type of spur
gear.
• They has their teeth cut
on the outside surface of
mating cylindrical wheels.
• Single reduction stage is
the most basic type of
arrangement of single
pair of spur gears.

5. Internal Spur Gear
• This is actually a type of
Spur Gear.
• Internal Spur Gear is
not much different from
a regular spur gear.
• These gear by
appearance shows pitch
surface that is
cylindrical.

6. Rack and Pinion Gears
• Rack and pinion Gear are
another variety of Spur
gears.
• Actually a Rack is defined
as a straight bar that has
teeth which are cut
straight and across.
• Basically, The Rack is
considered as a spur gear
that is unrolled and laid
flat. Pinion is the normal
gear.

7. How Spur Gears Work
• 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 gear
sets
• Spur gears mate only one tooth at a time,
resulting in high stress on the mating teeth and
noisy operation.

8. Spur Gear Materials
• Cast iron provides durability and ease of
manufacture.
• Alloy steel provides superior durability and
corrosion resistance. Minerals may be added to
the alloy to further harden the gear.
• Cast steel provides easier fabrication, strong
working loads and vibration resistance.
• Carbon steels are inexpensive and strong, but are
susceptible to corrosion.
• Aluminum is used when low gear inertia with
some resiliency is required.

9. Applications of Spur Gear
Spur gears have a wide range of applications
• Metal cutting machines
• Power plants
• Marine engines
• Mechanical clocks and watches
• Fuel pumps
• Washing Machines
• Gear motors and gear pumps
• Rolling mills

10. Advantages of Spur Gear
• Spur gears have high power transmission
efficiency.
• They are compact and easy to install.
• They offer constant velocity ratio.
• Unlike belt drives, spur gear drives have no slip.
• Spur gears are highly reliable.
• They can be used to transmit large amount of
power (of the order of 50,000 kW).

11. Disadvantages of Spur Gear
• Spur gear drives are costly when compared to belt
drives.
• They have a limited center distance.
• This is because in a spur gear drive, the gears should
be meshed and they should be in direct contact with
each other.
• Spur gears 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.