Automatic transmission with torque converter (AT)
A torque converter automatic transmission (TCA) is a common type of automatic transmission found in many vehicles. It provides smooth and efficient gear changes, and allows the driver to select the driving mode that best suits the current conditions.
Design and principle of operation of automatic transmission with gas turbine engine
An automatic transmission with a gas turbine engine consists of the following main components:
* Torque Converter (TCC): A device that connects the engine and transmission and replaces the clutch in a manual transmission. The diesel engine uses a circulating fluid (usually ATF) to transfer torque from the engine to the transmission.
* Planetary Gearbox: A series of gears that provide different gear ratios and gear changes.
* Hydraulic control unit (HCU): A device that controls the fluid flow in the gas turbine engine and planetary gearbox, determining gear changes depending on engine speed, vehicle speed and gear selector position.
Operating principle of automatic transmission with gas turbine engine
1. Starting the car: When the driver presses the gas pedal, the engine begins to rotate and drives the gas turbine engine. The fluid circulates in the gas turbine engine and transmits torque from the engine to the turbine connected to the planetary gearbox.
2. Gear shifting: The speed of fluid circulation in the gas turbine engine and the gear ratio of the planetary gearbox are regulated by the GCU, providing the required gear ratio for the current driving conditions. When engine speed increases and vehicle speed decreases, the GCU shifts to a lower gear, providing more torque to the wheels.
3. Engine Lockup: Under certain conditions, such as when driving at high speeds, the engine engine may be locked to provide a direct mechanical connection between the engine and transmission. This increases efficiency and reduces energy loss.
4. Reverse: For reversing, a special planetary gearbox is used, which provides a gear ratio in the reverse direction.
Driving modes
Many automatic transmissions with diesel engines have various driving modes that allow the driver to configure the transmission to suit current conditions. These modes may include:
* Drive (D): Normal driving mode that automatically shifts gears for optimal fuel efficiency and performance.
* Sport (S): A mode that allows for more aggressive shifts, keeping them at lower revs for improved acceleration.
* Manual (M): A mode in which the driver can manually change gears using the paddle shifters or gear selector.
* Snow (S): A mode designed for driving on snow or ice, which provides smooth starting and shifting at lower speeds.
Advantages and disadvantages of automatic transmission with gas turbine engine
Advantages:
*Smooth and easy shifting
* Makes driving easier by eliminating the need to use a clutch
* Provides manual shift capability on some models
*Effective when towing heavy loads
Flaws:
*May be less efficient than manual transmission
*More expensive to manufacture and maintain
*May be more sensitive to overheating and wear