Pic. 3.73. Transmission mechanism design: 1 - forward clutch; 2 - one-way clutch; 3 - reverse gear and low gear brake; 4 - planetary forward gear; 5 - planetary reverse gear; 6 – brake bands 2–4; 7 - reverse clutch; 8 - clutch 3-4
transmission mechanism (pic. 3.73) consists of three pairs of clutches, a brake, a band brake, a one-way clutch and two pairs of single planetary gears. The planetary gear changes gear ratio according to the driving conditions of the vehicle. In the transmission mechanism, hydraulic pressure is transmitted from control valves or shift solenoids A, B, or C (work cycle) to clutches and brakes.
Forward clutch
Transmits torque from the turbine shaft to the front sun wheel.
Operates in 1st, 2nd or 3rd gear forward range.
Clutch 3/4
Transmits torque from the turbine shaft to the rear planet carrier.
Operates in 4th or 3rd gear forward range.
Reverse clutch
Transmits torque from the turbine shaft to the rear sun wheel.
Operates when the vehicle is in reverse.
Brake bands 2/4
Blocks the rotation of the reverse drum and fixes the rear sun wheel.
Operates in 2nd or 4th gear.
Reverse and low gear brake
Fixes the rotation of the front inner gear.
Operates when the vehicle is in reverse or in first gear (l range, HOLD mode)
One way clutch
Blocks counterclockwise rotation of the front inner gear in first gear.
Planetary gear
The planetary gear works in the transmission by engaging/disengaging the clutches and/or brakes, converts the driving force of the turbine shaft and transfers it to the final drive gear.
Note. All directions of rotation are viewed from the side of the torque converter.