Manual transmissions are more widely used than automatic. In addition, they are a lot simpler to understand. The engine in a manual transmission is connected to the transmission with a clutch. If you want to shift gears you press the clutch and it disconnects the engine power from the transmission. However, on an automatic transmission there is no clutch. Therefore, to allow safe gear shifting the automatic transmission uses a torque converter.
Like manual transmissions, automatic ones need a way to let the engine spin freely while the gear is being changed. The torque converter allows the engine to do so while the car is stopped or is in drive. This is like a device that transfers rotating power. If you don’t hit the throttle, it just requires a touch of the brake pedal to keep the car halted. On the other hand, if you press the throttle, it will require a lot of pressure to keep the car halted with the gear. In both situations, the car is in gear but the torque converter controls the amount of torque that is passed onto the transmission with the engine speed.
The torque converter has three major components to aid its functionality.
The pump in the torque converter moves with the engine speed. As the engine speed increases the pump flings fluid to the outsides. This process is much like a washing machine flinging water outwards. This action creates a vacuum and the fluid enters the turbine. Once the turbine spins, it causes the transmission to move and as a result your car moves forward. The stator allows the fluid that enters the turbine to exit in a different direction.
There are certain advantages of a torque converter. Firstly, the torque converter enhances the torque of your engine when you accelerate. Torque converters in newer cars can actually boost the torque up to 2 or 3 times. At high speeds the transmission speed almost matches the engine speed, but not exactly. For a car to be fuel efficient, it is important for the transmission speed and engine speed to match. Due to this reason, the torque converter is equipped with a lockup clutch. The car becomes more fuel efficient.