1. CONTINUOUSLY VARIABLE TRANSMISSION (CVT)
BMS COLLEGE OF ENGINEERING
CONTINUOUSLY VARIABLE TRANSMISSION (CVT)
NARAYAN .H.M
SEMESTER -8
1BM07ME060
MECHANICAL ENGG.DEPT.

2. CONTENT OF PRESENTATION
INTRODUCTION
HISTORY
NEED OF TRANSMISSION
CVT
TYPES OF CVT
USE OF CVT
HOW DOES CVT WORK?
BELT DESIGN
ADVANTAGES AND DRAWBACKS
CONCLUSSION

3. INTRODUCTION CVT IS AN EMERGING AUTO MOTIVE TECHNOLOGY THAT
OFFERS A CONTINUUM OF GEAR RATIOS BETWEEN HIGH
AND LOW EXTREMS. TODAY CONTINUOUSLY VARIABLE
TRANSMISSION (CVT) HAVE LURED A GREAT DEAL OF
AUTOMOTIVEMANUFACTURERS AND CUSTOMERS.
engine
planetary set
inertia
CVT
wheel

4. HISTORY CONTINUOUSLY VARIABLE TRANSMISSION(CVT)
DESIGN WAS DEVELOPED BY INVENTOR DR. JAN NAUDE.
CVT WAS FIRST PATENTED IN EUROPE IN 19TH CENTURY
THE FIRST PATENT FOR A CVT WAS FILED AT
THE END OF THE CENTURY.IT WAS DESIGNED AND BUILT
BY HUB VAN DOORNE.
4000
low
overdrive

5. NEED OF TRANSMISSION low
THE TRANSMISSION TAKES THE POWER FROM THE ENGINE TO THE WHEEL,IN DOING SO ACTUALLY MAKES THE VEHICLE USABLE.
Allow the vehicle to start from rest, with the engine running continuously.
Let the vehicle stop by disconnecting the drive when appropriate.
Vary the speed ratio between the engine and wheels.
Allow this ratio to change when required.
Transmit the drive torque to the required wheels.
low

6. How does cvt works?
(CVT) offer a continuum of gear ratios between desired limits. Which allows the engine to operate more time in the optimum range given an appropriate control of the engine valve throttle opening (VTO) and transmission ratio. CVT operates by varying the working diameters of the two main pulleys in the transmission or by changing belt thickness

7. CONTINUOUSLY VARIABLE TRANSMISSION
CVT

8. TYPES OF CVT PULLEY BASED CVT ROLLER-BASED CVT HYDROSTATIC CVT
INTERMESHING CONES
TOROIDAL

9. CVT DESIGN GOALS Truly continuously variable
Transmit torque both forward and backward
Able to transmit high torque levels
Able to shift under load
Computer control not required
MECHANICAL LOSSES ARE LESS

10. CVT WORKING MODEL

11. CVT WORKING MODEL
Another version of the CVT the toroidal CVT system replaces the belts and pulleys with discs and power rollers.
Although such a system seems drastically different, all of the components are analogous to a belt-and-pulley system and lead to the same results a continuously variable transmission. One disc connects to the engine. This is equivalent to the driving pulley. Another disc connects to the drive shaft. This is equivalent to the driven pulley. Rollers, or wheels, located between the discs act like the belt, transmitting power from one disc to the other.
When the wheels are in contact with the driving disc near the center, they must contact the driven disc near the rim, resulting in a reduction in speed and an increase in torque (i.e., low gear). When the wheels touch the driving disc near the rim, they must contact the driven disc near the center, resulting in an increase in speed and a decrease in torque

12. IMPLEMENTATION IMPLEMENTED IN Adaptable for trucks Military vehicles
Audi A4  TDI
Audi A6 2TDI
Ford Escape Hybrid 2.3
Ford Focus C
Honda Civic Hybrid 
Honda HR-V 1.6
Honda Insight 1.0
Nissan Murano 3.5
Nissan Primera 2.0
Nissan Serena 2.0
OPEL VETERA
Saturn VUE 2.2/3.5
Toyota Prius 1.5 4cyl
Adaptable for
trucks
Military vehicles
Heavy construction equipment
Bicycle
Motor cycles
Industrial machinery
any type of motor

13. ADVANTAGES & DRAWBACKS
CVTs have the potential to increase the overall vehicle efficiency and reduce the jerk
CVTs can smoothly compensate for changing vehicle speeds, allowing the engine speed to remain at its level of peak efficiency.
COST IS COMPARITIVELY HIGHER
SIZE IS LARGER And RELATIVELY COMPLEX MECHANISM

14. CONCLUSION
IT IS ADVANTAGEOUS TO USE A CVT INSTEAD A MANUAL TRANSMISSION. THIS IS MAINLY BECAUSE THE ENGINE WILL OPERATE ALWAYS ON THE OPTIMUM REGIMES AND THROTTLE-POSITIONS ADAPTED TO THE VARYING ROAD CONDITIONS AND POWER DEMANDS.

15. REFERENCES Fischetti Mark . "No More Gears".
“Popuplar Mechanics” by MC COSH

16. THANKING YOU