Document b5YKRDjjoB0kLnrk5KK4e4zKo

8 While this concentration does little to alter the fluid flow and REFERENCES viscous shear behavior, it is more than adequate to lower the adhesive forces greatly. The change of torque was immediately 1. G. R. Smith, V. J. Jandasek, S. R- Sprague, and R. B. apparent on the next clutch application and was repeatable Springer, "A New Concept of Measuring Frictional Charac thereafter. The shaded area of Pig. 14 should be indicative of teristics." SAE Transactions, Vol. 70 (1962), paper 363A. the relative amount of mechanical contact during the dutch 2. G. R. Smith, W. D. Ross, P. L. Silbert, and W. B. application, since this is the result of a change primarily to the Herndon, "Putting Automatic Transmission Clutch Friction adhesive component of friction. Researchers on Speaking Terms." SAE Transactions, Vol. 76 (1967), paper 670051. SUMMARY AND CONCLUSIONS 3. E. D. Davison, "A New Bench Test for Evaluating Clutch Plate Lubrication," Paper 642A presented at SAE Annual Meeting, Detroit, January 1963. A simple model of the engagement process has been con 4. J. J. Rodgers and M. L Haviland, "Friction of Trans ceived for wet friction materials, especially those with porous mission Clutch Materials as Affected by Fluids, Additives and paper surfaces. The model consists of three phases: a time- Oxidation." Paper 194A presented at SAE Midyear Meeting, dependent hydrodynamic squeeze film phase where no Chicago, June 1960. mechanical contact is made and torque is generated through 5. S. R. Sprague and R. G. Cunningham, "Chemical Addi viscous shear alone; a time- and velocity-dependent squash tives Control Friction Characteristics of Lubricants." film phase where intermittent nibbing of asperities generates Industrial and Engineering Chemistry, Vol. 51, No. 9 (Septem some adhesive friction, produces additional hydrodynamic ber 1959), pp. 1047-1050. action, and provides local cooling; an adhesive contact phase 6. Hai Wu, "Squeeze Film Behavior for Porous Annular where hydrodynamic effects are minimal and where physical Disks." Jrl. of Lubrication Technology, October 1970. and chemical reaction surface films largely control the friction. 7. Hai Wu, "An Analysis of the Squeeze Film Between In support of the model, laboratoiy test results were pre Porous Rectangular Plates." Paper 71 Lub-2 presented at sented of paper clutch squeeze/squash film behavior in a new ASLE-ASME Joint Lubrication Conference, Pittsburgh, laboratory test fixture. Alto SEM photographs, profllometer October 1971. , data, and clutch inertia dynamometer friction and wear 8. Hai Wu, "The Squeeze Film Between Rotating Porous results were discussed in the context of the new engagement Annular Disks," Wear, Vol. 18(1971) pp. 461-470. model 9. Hai Wu, "An Analysis of the Engagement of Un- While no incontrovertible conclusions may be reached at this Grooved Wet Clutch Plates." Private Communication, May time about the validity of the model, it has proven to be useful 26,1971. in understanding inconsistencies of test results from different 10. C. E. Albertson and H. S. Okubo, "Influence of Lubri test machines. Both the model and the squeeze film fixture cant Breakdown on Frictional Performance." Paper 642C have aided in diagnostic investigations. presented at SAE Annual Meeting, Detroit, January 1963. 7>uj paper fa subject to revision. Statements and opinions advanced In papers or discussion are the author*! and are hfa responsibility, not the Society's; however, the paper has Society ofAutomotive Engineers. Inc. iwe aiaamvaota *!. *. .. mu ^ been edited by SAE fee uniform ityling and formal. Diicimion will be primed with Die paper if it ii publithed in SAE Tranudioni For permiuion lo publish this paper in full or in pan, contact the SAE Publication! Diviiion and the authors 12 page booklet. B002 1699 Ptintcd in USA. PRODUCED BY FORD