I learned a lot of things about pulleys from http://www.beltcorp.com/pulleys.html and so I made a slide set of what I've learned from this primary source and a couple of other sources. It's great to learn about these timing belt pulleys and how they help make many products and services more available.

1. Timing Belt Pulley
Overview and Uses

2. What’s a timing belt pulley?
• A timing belt pulley is a wheel on a shaft or an
axle.
• It is developed in order to support the change
of direction and movement of a belt or a cable
along the circumference.
• Also called a drum or sheave and might be
grooved in between two flanges all over its
circumference.

3. Applications
• Pulleys are applied in a number of ways such
as using forces, lifting loads and transmitting
the power.
• In nautical cases, the assembly of axle, wheel
and supporting shell is termed as a block.
• The drive component of a pulley system may
in terms of cable, belt, rope or chain that
flows over the pulley inside the groove.

4. Standard Belt
• The timing belt pulley is the system that is
characterized by two or more pulleys tied into
a standard belt.
• This enables torque, mechanical power and
acceleration to be distributed across the axles.
• If the pulleys are of diverse diameters, then a
mechanical advantage can be gained.

5. Belt Drive
• A belt drive is similar to that of a chain drive.
• A belt sheave can be smooth, without discrete
interlocking members as seen on a spur gear,
chain sprocket, or timing belt
• The mechanical advantage is roughly given by
the ratio of the pitch diameter of just sheaves,
not fixed as per the ratio of teeth to sprockets
and gears.

6. Common Uses
• Timing pulleys are extensively used in many
mechanical devices such as:
– sewing machines
– office equipment
– photocopiers
– And more
• The primary application of this pulley is that it
is used for driving the camshafts in an
automobile engine.

7. High Power Transmissions
• Timing belt pulleys are able to give more
power than a friction drive belt.
• These are also utilized for very high power
transmissions.
• These also include the primary drive of certain
motorcycles, especially the world famous
Harley-Davidson.

8. High Speed
• These pulleys are also used in aircraft that are
driven by high speed and two stroke engines.
• The purpose is to decrease the drives to
enable use of a more efficient slower speed
and quieter propeller.
• Various amateur-developed airplanes driven
by automotive engines also use these pulleys
to reduce the drive units.

9. Construction Industry
• The timing belts pulleys are heavily applied in
the construction industry as well.
• Belts in these pulleys are developed from a
flexible polymer on the fabric reinforcement.
• Mostly this was a rubber material fixed over a
natural textile, but later developments in
material usage gave a very significant change
in increasing the lifetimes of these belts.

10. Natural vs. Synthetic
• Take into account the changes from the
natural or organic to synthetic or artificial.
• There is also the use of:
– artificial polyurethane
– rubber
– Kevlar
– Nylon
– carbon
– and other fibers.

11. Failure Modes
• The timing belt pulley has two failure modes.
• One is gradual, and the other is catastrophic
• Both boost their risk with the passage of time
• It is quite common for highly stressed pulleys
to be provided with a service lifetime and to
be replaced with the new one regularly

12. Want more timing pulley info?
http://www.beltcorp.com/
pulleys.html
Visit our official site!

13. End of Presentation
Thanks!