The device of an automatic transmission with a torque converter (automatic)
Torque converter
* Consists of two impellers (pump and turbine) and a stator.
* Transmits torque from the engine to the gearbox without mechanical connection.
* Allows the vehicle to move away without using the clutch pedal.
Planetary gears
* Consists of sun gear, planetary gears and internal ring gear.
* Provide a change in gear ratio for changing gears.
Friction discs
* Located between planetary gears.
* When turned on, hydraulic pressure is used to transmit rotation from one transmission element to another.
Gear shift drum
* Controls friction discs.
* Changes the position of the friction discs, selecting the required gear.
Hydraulic control unit
*Contains valves that direct the flow of hydraulic fluid.
* Controls gear shifting depending on vehicle speed, engine load and other factors.
Sensors
* Provide information about vehicle speed, engine speed, etc.
* Used by the hydraulic control unit to determine when to shift gears.
How the machine works
1. When moving away: The torque converter allows the vehicle to move away by transferring torque from the engine to the gearbox without slipping the clutch.
2. Gear Shift: The hydraulic control unit uses sensors to detect shift timing and directs hydraulic fluid to the appropriate friction discs. This locks or unlocks the planetary gears, changing the gear ratio.
3. Upshift: As the vehicle speed increases, the hydraulic control unit shifts into upshift to reduce engine speed and improve fuel efficiency.
4. Downshift: When accelerating hard or going downhill, the hydraulic control unit downshifts to increase torque to the wheels.