Mazda RX-8 2004 Service Highlights page 314

CENTRIFUGAL BALANCE CLUTCH CONSTRUCTION/OPERATION
Construction
• Centrifugal balance clutch chambers are installed opposite the clutch chambers in the low and high clutches.
The centrifugal balance clutch chambers are constantly filled with ATF from an exclusive hydraulic passage of
the oil pump.
CENTRIFUGAL BALANCE CLUTCH
SEAL
CLUTCH
CHAMBER
CLUTCH
PISTON
CLUTCH
PRESSURE
Operation
When clutch pressure not applied
• When the clutch drum rotates, centrifugal force acts on the residual ATF in the clutch chamber to push against
the piston. However, centrifugal force also acts on the ATF filling the centrifugal balance clutch chamber to push
back the piston. As a result, the two forces are eliminated and the piston remains stationary, thus preventing
clutch engagement.
When clutch pressure applied
• When clutch pressure is applied to the clutch chamber, the clutch pressure overcomes the oil pressure and
spring force in the opposite centrifugal balance clutch chamber, and pushes the piston to engage the clutches.
Because the centrifugal force acting on the clutch pressure in the clutch chamber is canceled by another
centrifugal force acting on the ATF filling the centrifugal balance clutch chamber, the influence of the centrifugal
force created by the clutch drum revolution speed is eliminated. As a result, stable piston pushing force is
obtained in all rotation ranges, and smoother shifts can be made.
AUTOMATIC TRANSMISSION
CLUTCH DRUM
BALANCE CHAMBER
CLUTCH
SEAL
SEAL PLATE
LUBRICATION
PASSAGE
CONVENTIONAL CLUTCH
SEAL
PISTON
CHECK BALL
CLUTCH
CHAMBER
CLUTCH
PISTON
SEAL
CLUTCH
PRESSURE
CHU051301030S10
CLUTCH DRUM
CLUTCH
05–13
SPRING
AEA5710T025
05–13–23