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1. CONTINUOUSLY VARIABLE
TRANSMISSION
(CVT)

2. CONTENTS
• INTRODUCTION
• HISTORY
• TYPES OF CVT
• ADVANTAGES
• CVT VS AT
• DISADVANTAGES
• APPLICATION
• CONCLUSION
• REFERENCE

3. INTRODUCTION
 CVT is an advanced technology of automatic transmission.
 Unlike traditional automatic transmissions, continuously variable
transmissions don't have a gearbox with a set number of gears.
 CVT also known as single-speed transmission, gearless
transmission, one-speed automatic, variable pulley transmission.
 Varies the transmission ratio continuously.
 Shifts automatically with an infinite number of ratios.

4. HISTORY
• Leonardo da Vinci sketches is the basis for the first
continuously variable transmission in 1490.
• First patent for the CVT Transmission was made by Daimler &
Benz in 1886.
• The first workable belt driven CVT was designed and built by
the Dutchman Huub van Doorne in 1958.
• In Early 1990's Nissan introduced CVT in their Nissan March

5. TYPES OF CVT
1. Pulley based CVT
2. Cone CVT
3. Toroidal CVT
4. Hydraulic CVT

6. PULLEY BASED CVT
• It consist of main 3 parts
1.Primary clutch
2.Secondary clutch
3.Belt

7. 1. PULLEY BASED CVT
• Low Gear • Top Gear
In this most common CVT system , there are two V-belt pulleys that
are split perpendicular to their axes of rotation, with a V-belt running
between them.

8. CVT belts

9. • https://www.youtube.com/watch?v=dp8lHBD
Fhpo

10. 2. CONE CVT

11. CONE CVT
Fig 1.4a: Cone CVT showing the initial position of the belt as it
grips the driver shaft (lower) and the driven shaft (upper).
Fig 1.4b: Cone CVT showing the intermediate position as the belt
moves to the right with increase in rpm on the driver shaft.
Fig 1.4c: Cone CVT showing the final position of the belt as it has
moved to the end on right due to increase in rpm on the driver shaft

12. 3. TOROIDAL CVT
• Toroidal CVTs are made up of discs and rollers that transmit
power between the discs by means of tractive force.
• A viscous fluid(EHL) is placed between the rollers and discs.
• The change in angle by a roller must be mirrored by the
opposing roller.
• The position of the rollers is controlled hydraulically.

13. TOROIDAL CVT

14. 4. HYDRAULIC CVT
• It consist of variable-displacement pumps and hydraulic motor.
• In this type of transmission, the rotational motion of the engine
operates a variable-displacement pumps on the driving side.
• The pump converts rotational motion into fluid flow.
• A hydraulic motor located on the driven side, the fluid flow is
converted back into rotational motion.

15. HYDROSTATIC CVT

16. ADVANTAGES
• Allow for an infinite number of gear ratios.
• Eliminates "shift shock" -- makes it smoother ride
• Responds better to changing conditions.
• Better fuel economy & power loss than automatic transmission

17. ADVANTAGES
• The main advantage of CVTs is that they allow an engine to
run at its ideal RPM regardless of the speed of the vehicle.
• There are fewer moving parts to a CVT transmission.

18. DISADVANTAGES
• Limited torque capacity as compared to the manual
transmission system
• More costlier than manual transmission
• Slipping in the drive belt or pulleys.
• Additional gear train required for reverse condition.

19. APPLICATIONS
• Commonly used in automobiles
• New continuous variable transmission for medium duty trucks
and buses.
• Starts development on wind turbine cvt

20. CONCLUSION
• The applications and benefits of continuously variable
transmissions can only increase based on today’s research and
development.
• With an increase in the number of companies opting for CVTs
there will be a consequent decrease in the cost of the vehicle as
well as the transmission.

21. REFERENCE
• Nilabh Srivastava, Imtiaz Haque, “A review on belt and chain continuously
variable transmissions (CVT): Dynamics and control” ,Mechanism and
Machine Theory, Volume 44, Issue 1, January 2009, Pages 19-41.
• Mr. Jadhav S. S Prof. Hanamapure N. S, “ Toroidal Drive System for
Vehicle Transmission Control”, IJSRD - International Journal for Scientific
Research & Development| Vol. 2, Issue 09, 2014 | ISSN (online): 2321-0613.
• Da Wen Ge, Sugeng Ariyono and Daw Thet Thet Mon, “ A REVIEW ON
CONTINUOUSLY VARIABLE TRANSMISSIONS CONTROL”, National
Conference in Mechanical Engineering Research and Postgraduate Students
(1st NCMER 2010) 26-27 MAY 2010

22. THANK YOU…