Automatic transmission-24
Front servo and brake belt Rear servo and brake belt
Figure 4.4 brake belt
One-way clutch
The transmission has two one-way clutches, 1-2 one-way clutch and 3-4 one-way clutch (notice that the third one-way clutch is
located on torque converter, also called as retainer)
1-2 one-way clutch is located between the planet carrier assembly and central shaft. The structure makes the planet carrier only
can rotate in single direction around the central shaft. The one-way clutch is only engaged in automatic 1
st
-Gear.
3-4 one-way clutch is located between the clutch C4 and clutch C2.The structure makes the clutch C2 drive the front planetary
gear in 1
st
, 2
nd
and 3
rd
–Gear, but is disengaged in 4
th
-Gear and overspeed.
Planetary gear assembly
The planetary gear block used in transmission is the traditional lavena gear block consisted of6 pinions.
Parking mechanism
When select the parking-Gear, the steering column will move the parking lever backwardly to engage with the parking ratch
(refer to Figure 4.5). The ratchet is engaged with the tooth of external gear ring fear to lock the output shaft axle in the
transmission. When it is not in parking-gear, the return spring will release the parking ratchet and unlock the output shaft to
prevent the occurrence of accident parking action.
Figure 4.3 Clutch assembly
Brake belt
The transmission has two brake belts, brake belt B1 (named as 2-4 brake belt sometimes ) and brake belt B2 (named as low-speed
– reverse gear brake belt ) refer to Figure 4.4.
The brake belt B1 is a flexible brake belt which is engaged with front servo piston. When it is in 2
nd
and 4
th
–Gear, the brake belt
B1 starts to act. When the brake belt acts, it can prevent the rotation of reverse central gear by maintaining the clutch C3 assembly
is in static. In 2
nd
–Gear, only the external surface of piston is used. In 4
th
Gear, both sides are used to acquire more clamping force.
The brake belt B2 is a solid brake belt which is meshed with the rear servo piston. When the B2 acts, it prevents the rotation of
planet carrier assembly. When in manual 1
st
-Gear, only the external surface of piston is used. In reverse-Gear, both sides are used
to acquire more clamping force.
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