Electronic automatic transmission (EAT)
An automatic transmission is a type of automatic transmission that is controlled by an electronic control unit (ECU) instead of a traditional hydraulic system. It combines the convenience and efficiency of an automatic transmission with more precise and faster gear changes.
Operating principle
1. Input shaft: The engine transmits torque to the automatic transmission input shaft.
2. Planetary gear: The automatic transmission consists of several planetary gears that use sun gears, planetary gears and a carrier to change the gear ratio.
3. Friction Discs: Packs of friction discs and steel plates are located around the planetary gears. These discs can be engaged or disengaged using hydraulic pressure created in the automatic transmission housing.
4. Solenoids: The ECU controls solenoids that apply hydraulic pressure to the friction discs. When the solenoid is activated, it directs oil to the disc pack, clamping them together. When the solenoid is turned off, the pressure is released and the discs are disconnected.
5. Sensors: The automatic transmission is equipped with sensors that monitor various parameters such as vehicle speed, engine speed and gear selector position. This data is transmitted to the ECU.
6. ECU: The ECU receives data from the sensors and uses it to determine the optimal gear ratio. It activates the appropriate solenoids to control the clamping and release of the friction discs, changing the gear ratio.
Advantages of automatic transmission
* Precise Shifting: Eautomatic transmission can shift gears faster and more accurately than traditional automatic transmissions.
* Fuel Economy: The automatic transmission can optimize gear ratios to reduce fuel consumption.
* Smooth Shifting: Hydraulic control ensures smooth and seamless gear shifting.
*Manual Mode: Many automatic transmissions offer a manual mode, allowing the driver to change gears independently.
* Slip control: Automatic transmissions may have a slip control feature that improves traction on slippery surfaces.
Disadvantages of automatic transmission
*More complex design: Automatic transmissions are more complex in design than traditional automatic transmissions.
*Higher Cost: Eautomatic transmissions are typically more expensive than traditional automatic transmissions.
* Maintenance required: Automatic transmissions require regular maintenance, including changing the automatic transmission fluid and filters.