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working of Automatic Transmission

As you can see, there are a lot of moving parts inside an automatic transmission. It uses a combination of mechanical, fluid, and electrical engineering to give you a smooth ride from dead stop to highway cruising speed.
So let’s walk through a big picture overview of the power flow in an automatic transmission.
The engine sends power to the torque convertor’s pump.
The pump sends power to the torque converter’s turbine via transmission fluid.
The turbine sends the transmission fluid back to the pump via the stator.
The stator multiples the power of the transmission fluid, allowing the pump to send more power back to the turbine. A vortex power rotation is created inside the torque converter.
The turbine is connected to a central shaft that connects to the transmission. As the turbine spins, the shaft spins, sending power to the first planetary gear set of the transmission.
Depending on which multiple disc clutch or brake band is engaged in the transmission, the power from the torque converter will either cause the sun gear, the planetary carrier, or the ring gear of the planetary gear system to move or stay stationary.
Depending on which parts of the planetary gear system are moving or not determines the gear ratio. Whatever planetary gear arrangement you have (sun gear acting as input, planetary carrier acting as output, ring gear stationary — see above) will determine the amount of power the transmission sends to the rest of the drive train.
That, broadly speaking, is how an automatic transmission works. There are sensors and valves that regulate and modify things, but that’s the basic gist of it.


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