This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Development of Toroidal Traction Drive CVTF for Automobile
ISSN: 0148-7191, e-ISSN: 2688-3627
Published May 06, 2002 by SAE International in United States
Annotation ability available
Toroidal traction drive continuously variable transmissions (CVTs) for automobiles have adopted the latest automatic transmission technology, including torque converters, wet clutch systems and hydraulic systems. Therefore CVT fluids must function as conventional automatic transmission fluids as well as traction fluids. The performance of an automatic transmission fluid is mainly dependent upon the additive technology, while the traction performance and low-temperature viscosity are strongly dependent on the base fluid. Thus, the optimal traction fluid for automotive applications is a high-traction base fluid containing additives appropriate for conventional automatic transmission fluid. However, a higher traction tends to result in a higher low-temperature viscosity.
In order to resolve this contradiction, several new traction base fluids with either two naphthene rings or a polycyclic structure hydrocarbon were synthesized. The carbon numbers of these base fluids are 14 to 18. A four-roller machine was used to measure the traction coefficient of the base fluids, and a Brookfield viscometer was used to measure their low-temperature viscosity. As a result, new traction base fluids that have a low low-temperature viscosity and high traction coefficient were developed.
The performance of automotive traction fluids made with these base fluids is described in this paper. The traction coefficient, viscosity characteristics, antiwear and antiseizure properties, influence on rolling fatigue, shear stability, oxidative stability, wet clutch properties and material compatibility were compared with conventional automatic transmission fluids and traction fluids for automobiles. It was found that the new automotive traction fluid shows excellent performance.
|Automotive Traction Fluids: A Shift in Direction for Transmission Fluid Technology
|Development of High Torque CVT Fluids
|Lubricant as a Construction Element in the VDT Push-Belt CVT System
CitationMatsuoka, T., Ishida, N., Komatsu, S., and Matsuno, M., "Development of Toroidal Traction Drive CVTF for Automobile," SAE Technical Paper 2002-01-1696, 2002, https://doi.org/10.4271/2002-01-1696.
- Patterson M. “The Full-Totoidal Variator in Theory and in Practice” International Conference on Continuously Power Transmissions, CVT'96, Yokohama Proceedings 1996 95
- Machida H. Abe T. “Fatigue Life Analysis of a Traction Drive CVT” International Conference on Continuously Power Transmissions, CVT'96, Yokohama Proceedings 1996 101
- Tucker D.G. Joaquim M.E. “The Development of High Traction Transmission Lubricants with a Broad Range of Viscosity and Lubrication Properties-A History and Overview of the Current Status” International Congress on Continuously Variable Power Transmission (CVT'99) 1999 159
- Johnson K.L. Cameron R. Proc. I. Mech. E. 203 1967 307
- Gellows T.G. Greenwood C.J. “The Design and Development of an Experimental Traction Drive CVT for a 2.0 liter FWD Passenger Car” SAE paper 910408 1991
- Tipton C.D. Qureshi F. Huston M.E. “Automotive Traction Fluids: A Shift in Direction for Transmission Fluid Technology” SAE paper 2000-01-2906
- Arakawa Y. Murakami Y. Maeda M. Hata H. Miyaji T. Tamoto T. “Development and Testing of CVT Fluid for Nissan Toroidal CVT” International Congress on Continuously Variable Power Transmission (CVT'99) 1999 213
- Muraki M. “An Overview of Tranction Theory and Traction Fluids” 2001 International Symposium on the Tribology of Vehicle Transmissions 2001 81
- Kohno J. Okawa T. Shirahama S. “The Relationship between the Traction Coefficient and Low Temperature Viscosity of Traction Fluid for CVT” '98 International Symposium of Tribology of Vehicle Transmissions 1998 143
- Tamoto Y. Tsubouchi T. Hata H. “Traction Drive CVT Fluid Technology” '98 International Symposium of Tribology of Vehicle Transmissions 1998 87
- Yoshida Y. Tsubouchi T. Hata H. “Study on Molecular Structures of Traction Fluids - Compatibility of High-Temperature Traction Coefficient and Low-Temperature Fluidity-- 2001 International Symposium on the Tribology of Vehicle Transmissions 2001 76
- Muraki M. Molecular structure of synthetic hydrocarbon oils and their rheological properties governing traction characteristics Tribology international 20 6 347 1987
- “High Density Liquid Fuels”