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Interaction Between ATFs and Friction Material for Modulated Torque Converter Clutches
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Abstract
Automatic transmissions equipped with Modulated Torque Converter Clutches (MTCC) require an effective combination of automatic transmission fluid (ATF) - friction material in order to maintain frictional integrity. However, in this study, thermal analysis has shown that ATFs can interact chemically with a friction material used in the MTCC under service conditions, potentially affecting the frictional characteristics. A technique was developed to evaluate friction material degradation. The results of this study showed that the friction material my be chemically altered by static aging in certain ATFs at elevated temperatures. The statically aged friction material samples exhibited thermal analysis signatures which were similar to identical material degraded during dynamometer and fleet vehicle tests. These vehicle tests resulted in deterioration in friction characteristics and experienced shudder. In contrast, an ATF with which the friction material was shown to be relatively inert demonstrated excellent anti-shudder performance in both dynamometer and vehicle durability tests. This suggests that the interaction between ATFs and friction material my contribute significantly to the degradation of friction material systems and the performance of the MTCC.
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Guan, J., Willermet, P., Carter, R., and Melotik, D., "Interaction Between ATFs and Friction Material for Modulated Torque Converter Clutches," SAE Technical Paper 981098, 1998, https://doi.org/10.4271/981098.Also In
1998 Transmission and Driveline Systems Symposium: New Developments and Advanced Concepts in Systems and Components
Number: SP-1324; Published: 1998-02-13
Number: SP-1324; Published: 1998-02-13
References
- Naruse N. “Tribology of Minimum Slip Lock-Up Control System” Proceedings of the International Tribology Conference Yokohama 1995
- Kugimiya T. Mitsui J. Yoshimura N. Kanekada H. Akamatsu H. Ueda F. Nakada T. Akiyama S. “Development of Automatic Transmission Fluid for Slip-Controlled Lock-Up Clutch Systems” Engine Lubricants SAE SP-1121 SAE Fuels and Lubricants Meeting Toronto October 1995 SAE 952348
- Ward, W. C. Jr. Sumiejski J. L. Castanien C. J. Taglimonte T. A. Schiferi E. A. “Friction and Stick-Slip Durability Testing of ATF” SAE 941883 1994
- Ohtani H. Hartley R. J. Stinnett D. W. “Prediction of Anti-Shudder Properties of Automatic Transmission Fluids using a Modified SAE No. 2 Machine” SAE International Congress and Exhibition Detroit, MI 1994 SAE 940821
- Watts R. F. Nibert R. K. “Prediction of Low Speed Clutch Shudder in Automatic Transmissions Using the Low Velocity Friction Apparatus” Engine Oils and Automotive Lubrication Bartz Wilfried J. Marcel Dekker, Inc. New York 1993
- Papay A. G. “Automatic Transmission Fluids-State of the Art” Engine Oils and Lubrication Bartz Wilfried J. Marcel Dekker, Inc. New York 1993
- Hopkins A. G. Anderson J. N. “Effect of Commercial Oil Additives on Wet Friction Systems” International Off-Highway Meeting & Exposition Milwaukee, Wisconsin September 12-15 1983
- Shirahama S. Ohtsuka M. Ikemoto Y. “Frictional Characteristics of Some Additives in ATFs” Proceedings of the Japan International Tribology Conference Nagoya 1990
- Nibert R. K. Albertson C. E. “Wet Clutch Lining-Lubricant Additive Interactions” Automotive Engineering Congress Detroit, MI 1974 SAE 740052
- Cavdar B. Lam R. “Wet Clutch Performance in a Mineral-Based and in a Partial-Synthetic Based Automatic Transmission Fluid” SAE International Congress and Exposition Detroit, MI 1997 SAE 970976
- Osanai H. Ikeda K. Kato K. “Relations between Temperature in Friction Surface and Degradation of Friction materials During Engaging of Wet Friction Paper” SAE International Congress and Exposition Detroit, MI 1990 SAE 900553
- Throop M.J. McWatt D.G. “Slipping Torque Converter Clutch Interface Temperature, Pressure and Torque Measurements Using Inductively Powered Radiotelemetry” SAE International Congress and Exposition Detroit, MI 1997 SAE 970679