Infinitely Variable Transmissions Using a Toroidal Traction Variator Web Seminar RePlay PD331709ON

Topics: Powertrain & Propulsion


An Infinitely Variable Transmission (IVT) is a subset of a CVT (Continuously Variable Transmission) defined as a device that has a range of ratios of input shaft speed to output shaft speed which includes an Infinite ratio in which the output speed is zero.  Typically these devices include both positive and negative ratios on either side of zero resulting in the ability to move forward and reverse from rest without a clutch:  IVTs can improve vehicle performance while maintaining or exceeding benchmark functionality and performance. IVTs are a good candidate for future, fuel-efficient vehicles, particularly hybrids and AWDs. An IVT can maintain superb functionality and performance while reducing fleet CO2 levels. No vehicles other than heavy tractors currently use IVT transmissions.  A number of companies have looked at implementing IVT but they have failed to find an economical solution with sufficient upside to warrant its introduction, despite the attractive functional benefits. The use of the newly developed Double Roller Full Toroidal Variator - Continuously Variable Transmission (DFTV-CVT) has enabled a much simpler IVT solution that can be manufactured for potentially a lower cost than other belt or chain style CVT designs and / or multispeed transmissions The technology presented in this Webinar is based on the combination of a Double Roller Toroidal Traction Drive (DFTV-CVT) with a Planetary gear train (PGT).

This two-hour course will discuss the packaging, functionality, and economics of IVT architecture and expose the positive and negative aspects of IVT. The IVTs discussed use a particular type of CVT called a Double Roller Full Toroidal Variator (DFTV) which is the most compact and efficient CVT technology currently available.


By participating in this course, you'll be able to:

  • Describe in principal the physical mechanism involved in traction drives and the functional components of the DFTV-CVT
  • Describe and illustrate the IVT mechanical principal using a CVT including hybrid variants
  • Identify where the functional attributes of the IVT can be best used in real vehicle applications
  • Compare the cost benefits, packaging advantages and design flexibility of the IVT
  • Define the control system philosophy required for an IVT
  • Develop representative simulation models of real vehicles using an IVT drivetrain, if familiar with simulation software such as Simulink®

Materials Provided

  • 90 days of online single-user access (from date of purchase) to the 85 minute presentation
  • Course workbook (downloadable, .pdf's)
  • Online learning assessment
  • Instructor follow up to your content questions 
  • .2 CEUs* (upon completion of all course modules and satisfactory assessment score)

*SAE International is authorized by IACET to offer CEUs for this course.


Is this Web Seminar RePlay for You?

This course addresses the needs of engineers involved in the selection or design of the most appropriate drivetrain solutions should attend. A cross-section of professionals within OEMs and Tier1 transmission manufacturers, including technical sales people and control engineers, will benefit. 


Have colleagues who need this course? See Special Offers to the right.

For More Details

Email, or call 1-877-606-7323 (U.S. and Canada) or 724-776-4970 (outside US and Canada).

  • Introduction What is an IVT?
    • Packaging, weight and cost advantages
    • Functionality with IVT; off road vehicles and hybrids
  • Traction Drives and Toroidal Variators
    • Traction drives
    • Toroidal variators; full, half and double roller; spin and efficiency
    • Steering, clamping and parasitic losses
  • “Single Regime IVT”
    • Ratio choices for optimum performance; the importance of CVT ratio spread
    • Recirculating power, geared neutral; how these are managed in an IVT
    • The efficiency “map” of an IVT using the DFTV-CVT
  • Direct Over Drive (DOD) as a method of maximizing efficiency at cruise
  • Design of a Transmission for a Compact SUV with Off-road Capabilities
    • Functional OEM specification; maximum wheel torque and duty cycle
    • Concept and preliminary design
    • Design validation
  • Component Parts of the IVT, associated BOM and transmission costing
  • The Method of Control of an IVT and its Performance Characteristics
  • Preferred PHEV and MHEV Solutions for an IVT

  • Windows 7, 8 (Apple OSX and Unix/Linux are not supported but may work)
  • Pentium 4 PC
  • Minimum 512 MB RAM; recommended 1 GB RAM
  • Internet Explorer 10-11, Mozilla Firefox 37, Google Chrome 42 (Safari and Opera are not supported)
  • Broadband-1Mbps minimum

Michael Durack
Michael Durack

Michael Durack is currently Technology Director and Managing Director of Ultimate Transmissions. He was educated as an Architect but quickly moved into the role of Contractor and construction systems and building materials innovator. Much of his working life has been spent in South East Asia delivering large scale low and medium cost housing projects and the machinery and systems associated with the delivery of these projects. Towards the beginning of this century, he specialized in the development of building materials manufacturing equipment. This led to specific involvement in the development of more energy efficient variable speed industrial drives. He used the experience associated with the design and manufacture of industrial drives to develop a type of mechanical CVT that has direct application to the automotive industry. Michael has published a large number of technical papers on the subject of traction drives and was awarded the best paper at the 2014 FISITA conference in Maastricht.

Access Period: 90 Days      CEUs: 0.2

Duration: 2 Hours
Members save up to 10% off list price.
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Special Offers: To cost effectively train multiple team members, contact Corporate Learning Solutions for discount pricing. Email, call 724-772-8529, or complete a Corporate Learning Solutions Request Form.