This document discusses spur gears, including their types, materials, applications, advantages, and disadvantages. It describes how spur gears are the simplest type of gear that transmit power between parallel axes with teeth projecting radially. The main types are external, internal, and rack and pinion gears. Common materials include cast iron, alloy steels, cast steel, carbon steels, and aluminum. Spur gears are widely used in machines, engines, clocks, and other applications. Their advantages are high efficiency, compact size, and reliability, while disadvantages include cost, limited center distance, noise, and stress on teeth.

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.