The transformation ratio in an automatic transmission (AT) is the ratio of the output torque of the gearbox to the input torque from the engine.
Transformation ratio goal:
* Multiply engine torque for improved traction at low speeds.
* Ensure smooth starting and gear shifting.
* Reduce the load on the engine by allowing it to operate at lower speeds.
Changing the transformation ratio:
The transformation ratio varies depending on the speed and load on the gearbox.
* At low speeds and under high loads, the transformation ratio is increased to provide maximum traction.
*As speed increases, the transformation ratio decreases to optimize gear ratio and fuel economy.
Typical transformation ratio values:
*Hydraulic transformers: From 2.0 to 3.0
* Transformers with clutch: From 1.5 to 2.5
* Variable Transmissions (CVT): Continuously variable from 2.0 to 0.5 or lower
Transformation ratio in different types of automatic transmission:
* Hydraulic automatic transmissions: Have the highest transformation ratio, providing maximum traction at low speeds.
*Dual Clutch Transmissions (DCT): Has a lower transmission ratio for a sportier feel.
* CVTs: Provide a continuous change in gear ratio, rather than step-by-step gear changes.