Continuously Variable Transmissions (CVT)

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Continuously Variable Transmissions (CVT)
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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.

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Types of CVTs

• Variable-diameter pulley (VDP) or Reeves drive
• Toroidal or roller-based CVT
• Infinitely Variable Transmission (IVT)
• Ratcheting CVT
• Hydrostatic CVTs
• Variable toothed wheel transmission

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Possible Markets for CVTs

• Automobile
• Heavy industry
• Oil production
• Wind Energy technology

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Automobile applications

• Most 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.

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Heavy industry Applications

• Fully adaptable drive system for industrial Land
  Vehicles.
• Adjustments and maintenance made easer through
  smaller parts and computer monitoring technology.

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Oil Production

• Could reduce Power costs by allowing motors to
  maintaining constant loads.
• Testing will show actual results. Right now its
  only speculation.

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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

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Possible Competition

• Continuously 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

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CVT Draw Backs

• Becomes 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.

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Advantages

• CVTs 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.

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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.

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Works Cited

• http//www.synchrotronic.com/
• http//www.wipo.int/pctdb/en/wo.jsp?IAWO200704735
  2wo2007047352DISPLAYCLAIMS
• http//auto.howstuffworks.com/cvt.htm
• Assessing the Potential of a Mechanical
  Continuously Variable Transmission for Wind
  Turbines, National Renewable Energy Laboratory,
  J. Cotrell, 2005