At present, a single-stage two-phase three-component closed-type hydraulic torque converter consisting of pump wheel, turbine and regulating wheel is widely used in the car. The pump wheel and turbine are basins. The pump wheel is integrated with the torque converter shell, which is the active component. The turbine is suspended in a torque converter and is connected to the output shaft through the spline. The regulating wheel is suspended between the pump wheel and the turbine, and is fixed on the transmission housing through a one-way clutch and a guide wheel.
After the engine is started, the crankshaft drives the pump wheel to rotate, and the centrifugal force generated by the rotation causes the working fluid between the blade of the pump to be thrown out from the inner edge to the outer edge. This part of the working fluid has the velocity of the park which is rotating with the pump wheel and the axial velocity of the turbine. These working fluids impinge on turbine blades, pushing the turbine in the same direction as the pump wheel.
The velocity v of the gearbox from the turbine outflow working fluid can be seen as the component of the working liquid phase on the surface flow of the turbine blade, which is combined with the rotational speed of the turbine. When the turbine speed is relatively small, the working fluid from the turbine is backward and the working fluid impels the front of the guide wheel. As carrier is one-way clutch limit can't turn back, so the roller blades will flow backwards working liquid direction forward pump impeller blades, promote the pump wheel rotation, so that the effects on turbine torque increased.
With the increase of the turbine speed, the velocity of the component is also larger. When the combined velocity of omega and u begins to point to the back of the guide blade, the torque converter reaches the critical point. When the turbine speed is further increased, the working fluid will impact the back of the guide blade. Because the one-way clutch allows the guide wheel to rotate along with the pump wheel, so the guide wheel turns freely in the direction of the pump wheel, and the working fluid flows smoothly back to the pump wheel. When the working fluid from the turbine is exactly the same as the exit direction of the guide blade, the torque converter does not generate the torsion action (the hydraulic torque converter is called the hydraulic coupling condition).
Gear box -- hydraulic torque converter can transfer torque by working fluid, which is lower than the transmission efficiency of mechanical transmission. In the hydraulic torque converter, the lock clutch can be set up, and the pump wheel and the turbine can be locked together at high speed to realize the direct transmission of power and improve the transmission efficiency of the torque converter.