Design of a classic automatic transmission with torque converter
Main components:
* Torque Converter: A fluid coupling that transfers torque from the engine to the transmission.
*Planetary Gear: A set of gears providing different gear ratios.
* Friction Clutches and Brake Bands: Used to engage and disengage certain planetary gear components.
* Control unit: Electronic or hydraulic module that controls gear shifts.
* Pump: Forces hydraulic fluid through the system.
Working principle:
1. Start: When the ignition is turned on, the pump begins to pump hydraulic fluid into the torque converter.
2. Torque Transmission: The torque converter transmits torque from the engine to the turbine, which is connected to the planetary gear.
3. Gear selection: The control unit uses sensor inputs (eg engine speed, throttle position) to determine the desired gear ratio.
4. Shifting gears: Friction clutches and brake bands are engaged, changing the gears in mesh and therefore the gear ratio.
5. Torque Converter Lockup: In higher gears, the torque converter locks up, creating a direct mechanical connection between the engine and transmission for improved efficiency.
Advantages:
* Smooth gear changes.
*Easy to operate.
* High reliability.
Flaws:
* Lower fuel efficiency compared to manual or CVT transmissions.
* More complex and expensive to maintain.
*Not suitable for high performance vehicles.