Correct Answer - Option 3 : Stator
Concept:
A torque converter is a type of fluid coupling which is used to transfer rotating power from the engine of a vehicle to the transmission.
It takes place of mechanical clutch in an automatic transmission.
The main function of it is to allow the load to be isolated from the main power source. It sits in between the engine and transmission. It has the same function as the clutch in manual transmission. As the clutch separates the engine from the load when it stops, in the same way it also isolates the engine from load and keep engine running when vehicle stops.
Its main functions are:
- It transfers the power from engine to the transmission input shaft.
- It drives the front pump of the transmission.
- It isolates the engine from the load when the vehicle is stationary.
- It multiplies the torque of the engine and transmits it to the transmission. It almost doubles the output torque.
The torque converter has three main parts
Impeller or Pump
The impeller is connected to the housing and the housing connected to the engine shaft. It has curved and angled vanes. It rotates with the engine speed and consists of automatic transmission fluid. When it rotates with the engine, the centrifugal force makes the fluid move outward. The blades of the impeller are designed in such a way that it directs the fluid towards the turbine blades. It acts as centrifugal pump which sucks the fluid from the automatic transmission and delivers it to the turbine.
Stator
The stator is located in between the impeller and turbine. The main function of the stator is to give direction to the returning fluid from the turbine, so that the fluid enters to the impeller in the direction of its rotation. As the fluid enters in the direction of the impeller, it multiplies the torque. So stator helps in the torque multiplication by changing the direction of the fluid and allows it to enter in the direction of the impeller rotation. The stator changes the direction of fluid almost up to 90 degree. The stator is mounted with a one way clutch that allows rotating it in one direction and preventing its rotation in other direction. Turbine is connected to the transmission system of the vehicle. And the stator is placed in between the impeller and turbine.
Turbine
Turbine is connected to the input shaft of the automatic transmission. It is present at the engine side. It also consists of curved and angled blades. The blades of the turbine are designed in such a way that it can change the direction of the fluid completely that strikes on its blades. It is the change in the direction of the fluid that forces the blades to move in the direction of the impeller. As the turbine rotates the input shaft of the transmission also rotates and made the vehicle to move. The turbine is also has a lock up clutch at its back. The lock up clutch comes into play when the torque converter achieves coupling point. the lockup eliminates the loses and improves the efficiency of the converter.
