The automatic transmission is connected to the engine through a transmission consisting of:
* Torque converter:
* Fluid clutch that transmits torque from the engine to the gearbox.
* Serves to transfer power and smooth shifts.
*Planetary gear:
* A mechanism that provides different gear ratios through a combination of gears and clutches.
* Control unit:
* Controls the transmission, selecting the optimal gear ratio for the current driving conditions.
* Uses inputs from various sensors (such as engine speed, temperature and pressure) to determine optimal switching points.
The automatic transmission interacts with the engine as follows:
* Starting the engine:
* The torque converter is not locked, allowing the engine to rotate separately from the gearbox.
* This makes it easier to start the engine and reduces the load on the starter.
* Gear shift:
* The control unit determines the need to change gear based on various factors.
* The appropriate clutches and brake bands in the planetary gear are activated to provide the desired gear ratio.
* The torque converter smoothly transmits torque during shifting, ensuring smooth shifts.
* Torque converter lock:
* At higher speeds, the torque converter can be locked, creating a direct mechanical connection between the engine and transmission.
* It improves transmission efficiency by reducing slippage.
* Reverse:
* Disabling the torque converter lock-up and activating the associated clutches and bands allows the vehicle to move in the opposite direction.
The automatic transmission also includes the following features that improve engine performance:
*Torque Conversion: The torque converter increases engine torque at low speeds, making acceleration easier.
* Engine protection: The control unit protects the engine from overloads and shifting to too high gears.
* Improved fuel consumption: Optimized shift points help minimize power loss and improve fuel efficiency.