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What Is Torque Converter Automatic Transmission? And How Does It Work?

The torque converter is a type of automatic transmission that does not possess any clutch pedal as a conventional engine transmission couple would. Instead, the technology in use to change gears automatically is called “torque conversion” which is why the name.

Torque Converter Automatic Transmission: How does it work?

Unlike automatic transmissions like AMT and DCT which use sophisticated technology to automatically engage the clutch, torque converters are a type of fluid coupling with a reaction member, which allows the engine to spin somewhat independently of the transmission. It has five principal members: –

  1. Driving member (impeller/pump) — connected to the engine
  2. Driven member (rotor/turbine) — connected to the propeller shaft/output shaft.
  3. Reaction member (stator) — allows a change of torque between input and output shafts. And since it is mounted on a one-way clutch, it can only be turned in one direction. 
  4. Reaction shaft (stationary shaft) — extends from the geared transmission in the back of the converter through the pump to support the stator.
  5. Transmission fluid

As we press the throttle pedal, the engine speed increases and so the pump moves faster. The torque and angular velocity of the pump push the oil outwards and increase its pressure and adds a swirl motion to the liquid leaving the pump. This high-energy liquid enters the blade section near the rim and passes through the blades and applies a force on the turbine and thus rotates it. The stator then sends the oil from the turbine back to the pump.

Advantages of Torque Converter

  • Torque multiplication property.
  • Both upshifts and downshifts are extremely smooth with virtually no lag.
  • Permits starting & stopping the vehicle without any complication.

Disadvantages of Torque Converter

  • The incremental cost of Rs 1 lakh over manual transmissions so slightly expensive.
  • Expensive to maintain.

Verdict on Torque Converter

A full-fledged automatic experience, slightly on the expensive side but will run you a very long time without any hassle if you decide to go with it.