Automatic transmission torque converter design
The torque converter is a component of an automatic transmission (AT) that transfers power from the engine to the transmission. It performs clutch functions, converting torque and gear ratio.
The main elements of the torque converter are:
* Pump is a rotating element connected to the engine crankshaft.
* Turbine is a rotating element connected to the input shaft of the gearbox.
* Reactor – a fixed element located between the pump and the turbine.
Operating principle of a torque converter
When the engine starts, the pump begins to rotate. The pump blades direct the transmission fluid in a radial direction where it meets the turbine blades. This fluid causes the turbine to move.
However, the turbine does not rotate at the same speed as the pump. The transmission fluid pushed out of the turbine is directed to the reactor. The reactor redirects the liquid back to the pump, changing the direction of its flow.
This changed flow direction puts additional force on the pump blades, increasing torque on the turbine. Thus, the torque converter acts as a torque converter.
Because the turbine rotates slower than the pump, it also increases the gear ratio. This allows the car to start and accelerate smoothly.
Torque converter functions
The torque converter performs several important functions:
* Torque Conversion – Increases torque output from the engine, making starting and acceleration easier.
* Variable Gear Ratio – Increases gear ratio at low speeds for smooth acceleration.
* Clutch – works like a clutch, smoothly transferring power from the engine to the gearbox.
* Vibration Absorption – Transmission fluid absorbs engine vibrations to keep the transmission running smoothly.