Browse > Article
http://dx.doi.org/10.9725/kstle.2014.30.2.71

Effect of Angle and Density of Grooves between Friction Plate Segments on Drag Torque in Wet Clutch of Automatic Transmission  

Ryu, Jin Seok (Graduate School, Dept. of Mechanical Engineering, Hannam University)
Sung, In-Ha (Dept. of Mechanical Engineering, Hannam University)
Publication Information
Tribology and Lubricants / v.30, no.2, 2014 , pp. 71-76 More about this Journal
Abstract
As the importance of transmission efficiency to reducing fuel consumption and conserving the environment rapidly increases, reducing the drag torque in an automotive wet clutch is emerging as an important issue in the automotive industry. The drag torque in a clutch occurs from viscous drag generated by automatic transmission fluid in the narrow gap between separate friction plates. In this study, the drag torques in an automotive wet clutch are investigated with respect to the angle and density of the grooves between separate friction plates by three-dimensional finite element simulation of a single set of wet clutch disks considering the two-phase flow of air and oil. The simulation results shows that the drag torque generally increases with the rotational speed to a critical point and then decreases at the high-speed regime. The grooves between the plates plays an important role in reducing the drag peak, and the inclined angle of the grooves affects the oil flow. The grooves with an angle of $50^{\circ}$ shows the lowest drag torques at both low and high speeds. The flow vectors inside the $50^{\circ}$ grooves shows clear evidence that the fluid flows out more easily from the grooves compared with the flow vectors inside grooves with lower angles. The simulation results shows that increasing the number of grooves (density of grooves) decreases the drag torque.
Keywords
computational fluid dynamics; drag torque; two-phase flow; volume of fluid method; wet clutch;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 Madhavan, J., Pandit, G., Barnholt, M. and Suppiger, R., "Application of simulation based methods in development of wet clutch system", SAE Technical Paper, No. 2012-28-0022, 2012.
2 Kitabayashi, H., Li, C. Y. and Hiraki, H., "Analysis of the various factors affecting drag torque in multipleplate wet clutches", JSAE/SAE International Spring Fuels & Lubricants Meeting, Yokohama, Japan, 2003.
3 Hu, J.-B., Jing, C.-B., Peng, Z.-X. and Wang, B., "Research on drag torque prediction model for the wet clutches", J. Beijing Inst. Technol., Vol. 17, No. 4, 405-409, 2008.
4 Yuan, Y., Attibele, P. and Dong, Y., "CFD Simulation of the Flows Within Disengaged Wet Clutches of an Automatic Transmission", SAE Technical Paper, No. 2003-01-0320, 2003.
5 Yang, Y., Lam, R. C. and Fujii, T., "Prediction of torque response during the engagement of wet friction clutch", SAE Trans., Vol. 107, No. 6, pp. 1625-1635, 1998.
6 Lee, H.-Y., Kim, G.-Y. and Hur, M.-D., "Analysis of sliding friction and wear properties of clutch facing for automobile (Part 2)", J. Korean Soc. Tribol. Lubr. Eng., Vol. 21, No. 2, pp. 77-82, 2005.   과학기술학회마을
7 Kim, C. K. and Lee, I. K., "Failure study for tribological characteristic analysis of a clutch system in passenger cars", J. Korean Soc. Tribol. Lubr. Eng., Vol. 22, No. 4, pp. 196-202, 2006.   과학기술학회마을
8 Takagi, Y., Nakata, H., Okano, Y. and Miyagawa, M., Katayama, N., "Effect of two-phase flow on drag torque in a wet clutch", J. Adv. Res. Phys., Vol. 2, No. 2, 021108, 2011.
9 Ryu, J. S. and Sung, I.-H., "Change in the drag torque at an automotive clutch with respect to transmission oil flow rate and rotational speed", Proc. Fall Conference of the Korean Society of Tribologists and Lubrication Engineers, October 2013.
10 Shihua, Y., Peng, Z.-X. and Jing, C.-B., "Experimental research and mathematical model of drag torque in single-plate wet clutch", Chin. J. Mech. Eng. (Engl. Ed.), Vol. 23, pp. 1-8, 2011.