Continuously Variable Transmissions (CVT)

What is a CVT?A continuously variable transmission

(CVT) is a transmission which can change steplessly through an infinite number of effective gear ratios. This allows the motor to putout the proper amount of power improving on efficacy of traditional transmissions.

Types of CVT’sVariable-diameter pulley (VDP) or Reeves

drive

Toroidal or roller-based CVT

Infinitely Variable Transmission (IVT)

Ratcheting CVT

Hydrostatic CVTs

Variable toothed wheel transmission

Possible Markets for CVTsAutomobile

Heavy industry

Oil production

Wind Energy technology

Automobile applicationsMost major automobile companies have

already started experimenting with CVT technology.

Can adapt to older vehicles with traditional transmissions.

Claims of a 20% gain in fuel economy compared to past transmission technology.

Heavy industry Applications

Fully adaptable drive system for industrial Land Vehicles.

Adjustments and maintenance made easer through smaller parts and computer monitoring technology.

Oil ProductionCould reduce Power costs by allowing

motors to maintaining constant loads.

Testing will show actual results. Right now its only speculation.

Wind Energy technology

Allows for a Possible 3.5 speed increase, allowing for a increase in efficiency.

Prevents over speeding of fan blades.

REDUCED COST!

Using CVT technology can reduce the cost of a wind turbine by about $80,000

Possible CompetitionContinuously Variable Drive – Controls Electric

motors up to 10hp, low threat.

Other New Experimental Transmissions- Fuzzy Logic Is being applied to Old transmission technology. Still experimental.

Traditional Gear box transmissions.

Other CVT manufacturing companies

CVT Draw BacksBecomes Jerky in automobile applications

at slow speeds.

Intricate parts with high material cost. Examples of materials in CVT, Silicon Nitride, Silicon Carbide, Electroless Nickel, Electroplated Nickel

New technology so there are limited people that understand the operations with in a CVT.

AdvantagesCVTs can compensate for changing vehicle

speeds, allowing the engine speed to remain at its level of peak power and efficiency. This improves fuel economy and reduce exhaust emissions.

There are 25% fewer moving parts to a CVT transmission.

Cheaper on wind power applications. And can prevent damage from high winds.

Conclusion

This technology is still experimental, although some companies have proven that CVT are practical.

With proper funding for research it is possible to create a CVT to satisfy each of the four categories listed.

Works Cited• http://www.synchrotronic.com/• http://www.wipo.int/pctdb/en/wo.jsp?

IA=WO2007047352&wo=2007047352&DISPLAY=CLAIMS

• http://auto.howstuffworks.com/cvt.htmAssessing the Potential of a

Mechanical Continuously Variable Transmission for Wind Turbines, National Renewable Energy Laboratory, J. Cotrell, 2005