Torque converter
| Index | Explanation |
|---|---|
| 1 | Turbine wheel |
| 2 | Vane-type compressor drive |
A hydrodynamic torque converter is used in the 8-speed automatic gearbox. Its basic design with impeller, turbine wheel and stator remains unchanged. However, the three-way converter is a power-optimized development where the converter lockup clutch is actuated by an individual oil line. This provides the following advantages:
- The torque converter is optimally supplied and cooled even if the converter lockup clutch is closed
- Better activation of the converter lockup clutch is possible in all driving situations.
Line 1 is for oil supply.
Line 2 is for oil return.
Line 3 is for pressurized oil supply of the converter lockup clutch.
To decouple rotational vibrations from the engine to the gearbox, this type of torque converter can be combined with known damper systems:
- Turbine torsional vibration damper
- Dual damper system
The converter lockup clutch is for suppressing slip during torque transmission. It therefore contributes towards reduced consumption. The new three-way converter actuates the converter lockup clutch by a separate oil line. This means it is independent and disconnected from the turbine chamber. As before, the converter lockup clutch has a control range, i.e. an operating range in which a defined slip between gearbox input and output end is permitted. Mainly the transmission during opening or closing. This slip reduces rotational vibrations that are transferred from the engine to the gearbox. Improved control results from the possibility of considerably smaller mechanical slip in many operating ranges. An open converter lockup clutch was previously required for comfort reasons. Previously opening and closing the converter lockup clutch was performed by the pressure regulation of the gearbox. The direction of oil flow in the converter was influenced. Depending on the direction of oil flow, different pressure stages developed on both sides of the piston. This was how it was moved to either open or close. The improvement of the new gearbox is that independent activation results in improved control. This enables more operating ranges to be operated with a controlled instead of an open converter lockup clutch. Additionally, the flow of the converter can be optimized to suit the respective requirements at any time (e.g. cooling).