A mathematical model describing the hydrodynamics of the flow within a disengaged wet transmission clutch is presented. The primary improvement of this model over the existing ones is the inclusion of the surface tension effect, which is expressed in the pressure equation as an additional term. The drag torque predicted by the model correlates well with the test data for nongrooved clutch packs. The significance of the surface tension in this type of flows is discussed as well.

Issue Section:
Technical Papers
Keywords:
clutches, power transmission (mechanical), surface tension, hydrodynamics
Topics:
Drag (Fluid dynamics), Flow (Dynamics), Surface tension, Torque, Pressure, Hydrodynamics
1.
Hashimoto
,
H.
,
Wada
,
S.
, and
Murayama
,
Y.
, 1984, “
The Performance of a Turbulent-Lubricated Sliding Bearing Subject to Centrifugal Effect
,”
Trans. Jpn. Soc. Mech. Eng., Ser. C
0387-5024
49
(
446
), pp.
1753
–
1761
.
Crossref
Search ADS
 
2.
Kato
,
Y.
,
Murasugi
,
T.
,
Hirano
,
H.
, and
Shibayama
,
T.
, 1993, “
Fuel Economy Improvement Through Tribological Analysis of the Wet Clutches and Brakes of an Automatic Transmission
,” SAE Paper No. 938179.
3.
Kitabayashi
,
H.
,
Li
,
C.
, and
Hiraki
,
H.
, 2003, “
Analysis of the Various Factors Affecting Drag Torque in Multiple-Plate Wet Clutches
,” SAE Paper No. 2003–01–1973.
4.
Fairbank
,
D.
, 1996, “
Drag Analysis Open Pack Friction Clutch
,” BorgWarner Technical Report No. 176–05–0029.
5.
Kemp
,
S.
, and
Linden
,
J.
, 1990, “
Physical and Chemical Properties of a Typical Automatic Transmission Fluid
,” SAE Paper No. 902148.
Copyright © 2007
 by American Society of Mechanical Engineers
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