Airless tires or non-pneumatic tires (NPT), or flat-free tires are tires that are not supported by air pressure.

1. AIRLESS TIRES
Presented by:
Soham Majumdar(1703112)
School of Ellectrical Engineering
KIIT-DU , Bhubaneswar, Odisha 1

2. Contents
2
Serial No. Topic Slide No.
1 Introduction 3-4
2 Airless tire 5
3 Main parts of tweel 6-7
4 Working principle 8-9
5 Types of tweels 10-11
6 Advantages 12-13
7 Disadvantages 14
8 Future Challenges 15
9 Applications 16
10 References 17

3. Introduction
1. For more than 100 years , vehicles have been rolling along on cushions
of air encased rubber.
2. A few tire companies have started exprimenting with designs for non-
pneumatic tires.
3. Creating a non-pneumatic design has more positive implications than
one might think.
4. The Tweel Airless Tire was first developed in 2005 by Michelin.
5. Huge safety benefits.
3

4. 5. As the Tweel is extremely resistant, wear working on a range of
other application including military vehicle.
6. The name “Tweel” is the contraction in English of “ tyre” and
“Wheel”. Mounting and removal operation will be simpler. To start
with, Tweelscould be fitted on vehicles with small wheels, such as
wheelchairs, thus substantially improving the mobility of disabled
people.
7. Tweel's hub connects to flexible polyurethane spokes which are used
to support an outer rim.
4

5. Airless tire
1. Airless TIREs or Non-pneumatic
TIREs (NPT) ,are TIREs that are not
supported by airpressure.
2. The basic design of all pneumatic
tyres is very similar, even though
there are many different types. They
all include an inner core that holds
pressurized air which is then
covered with a layer of rubber that
comes in contact with the road,
called a tread. The tread helps keep
traction with the road and prevents
slipping and skidding.
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6. Main parts of tweel
6
1. TREAD
2. SHEER BAND
3. DEFORMEBLE WHEEL
4. FLEXIBLE SPOKES
5. HUB

7. 1. Tread : The rubber layer that wrap around the circumference
and touches the pavement.
2. Sheer band : Surrounds the spoke.
3. Deformable wheel : Lies is in between spokes and hub, which
deforms together with flexible spokes during road impacts. It
is also called as energy wheel.
4. Flexible spokes : Made up of polyurethane material with are
flexible, help to absorb road impacts.
5. Hub : A rigid attachment point to the axle.
7

8. Working principle
1. On working the Tweel is a single unit,
though it actually begins an assembly
of four pieces bonded together: the
hub, polyurethane spoke section, a
“sheer band” surrounding the spoke
and the tread band.
2. The sheer band surrounding the
spokes effectively takes the place of
air pressure, distributing the load.
3. The tread is similar in appearance to a
conventional tyre.
8

9. 4. When the Tweel put to the road, the spokes
absorb road impact the same way air
pressure does in pneumatic tyres. So,weel
works well over rocky terrains, so it should
work well for four-wheel vehicles too.
5. The tension of the sheer band on the spokes
and the strength of spokes themselves
replace the air pressure of a traditional tyre.
6. The tread is then attached to the sheer band.
7. The tread and sheer bands deform
temporarily as the spokes bend, then quickly
spring back into shape.
9

10. Types of tweels
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1. NASA’s Apollo Lunar
Rover
2. Michelin

11. 11
3. Bridgestone
4. Resilient Technologies,
LLC

12. Advantages
1. The tyres require less maintenance. The materials
used in the tyres and spokes are 100% recyclable.
2. Nothing to do with fuel efficiency in a direct way,
only offering the benefit that it will never influence
consumption.
3. The worry of punctures is eliminated.
4. Using high-strength but flexible high performance
resin as a material has increased versatility through
improved load-bearing capabilities and driving
performance. 12

13. 5. High speed travel (maximum 60 km/h) in ultra light
vehicles has also become possible.
6. Provides low rolling resistance and contributing to
reduction CO2 emissions.
7. Less environmental impact.
8. Durability & Long Life.
9. Remains mobile even with some of the spokes are
damaged or missing.
13

14. Disadvantages
1. One of the biggest disadvantages of the Tweel is that once
manufactured, it cannot be adjusted. In this case if a car
needed a different kind of setting, a whole new set of Tweel
will be required.
2. Vibrations becomes considerate once a vehicle is driving
above 50 mph, while causing a lot of noise.
3. Also disturbing is the amount of heat the Tweels generate.
4. Not as economic as pneumatic TIREs.
14

15. Future Challenges
• Goodyear in collaboration with NASA Glenn Research Center
(GRC), develop non-pneumatic tyres for use first on the moon,
and eventually on Mars .
• The basic rubber-pneumatic design used on Earth does not have
the same utility on the moon so Lunar tyres need to be
designed to develop traction on sandy undulated terrain.
• The Spring Tire has now been recognized with a so-called
“Oscar of Innovation” at the 44th Annual R&D 100 Awards in
Orlando, Florida.
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16. Applications
1. Used on some small
vehicles such as riding
lawnmowers
andmotorized golf carts.
2. In backhoe or bulldozers.
3. For Military vehicles
4. All Terrine Vehicles
(ATV)
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17. References
1. http://www.bridgestone.co.in/
2. http://www.newindianexpress.com/business/news/article28468
2.ece
3. http://gizmodo.com/tag/tires
4. http://www.toxel.com/tech/2009/07/05/innovative-airless-tires-
by-michelin/
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18. THANK YOU
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