What is the Principle of a Torque Converter?

The core principle of a torque converter is the transfer of rotational power from an engine to a transmission using fluid dynamics.

A torque converter operates by using fluid to transmit and multiply torque. It essentially acts as a fluid coupling that allows the engine to spin independently of the transmission when the vehicle is stopped, and transfers power smoothly as the engine speed increases.

Based on the provided information:

*   **Fluid Propulsion:** Inside the casing of the torque converter, there is fluid that is propelled by the pump using centrifugal force.
*   **Fluid Flow to Turbine:** The energized fluid then flows towards the turbine.
*   **Turbine Rotation:** The turbine contains small grates (or vanes) that allow the fluid to enter and move the turbine. As the turbine absorbs the torque from the flowing fluid, it begins to rotate.

This process allows the engine to continue running while the vehicle is stationary (like holding a car with the brake in 'Drive') and provides a smooth transfer of power when accelerating. While the provided reference focuses on the basic fluid coupling mechanism, the full principle involves a stator that redirects fluid flow to multiply torque, especially during initial acceleration, acting much like a gearbox in fluid form.

## Key Components

While the reference specifically mentions the casing, fluid, pump, and turbine, a typical torque converter also includes a stator:

*   **Pump (Impeller):** Connected to the engine crankshaft, it spins and accelerates the transmission fluid outwards.
*   **Turbine:** Connected to the transmission input shaft, it is spun by the fluid coming from the pump.
*   **Stator:** Located between the pump and turbine, this component is crucial for torque multiplication by redirecting the fluid flow back to the pump. (Note: The provided reference does not explicitly name the stator or explain its torque multiplication role, but describes the fundamental fluid flow and turbine rotation).
*   **Casing:** Houses the fluid and components.

## How it Works Simply

Imagine two fans facing each other. If you turn on one fan (the pump), it pushes air (the fluid) which then makes the other fan (the turbine) spin. A torque converter works on a similar concept but uses hydraulic fluid inside a sealed unit. The engine spins the pump, which flings fluid at the turbine, causing it to rotate and drive the transmission.

This allows for smooth starts and automatic shifting in vehicles equipped with automatic transmissions, providing a more convenient driving experience compared to a manual clutch.