Oil Supply
To lubricate and cool the components of the active gearbox and to actuate the multidisc clutches, sufficient pressure and volumetric flow of the transmission oil must be provided in each operating state. The transmission oil supply must be ensured even when the combustion engine is at a standstill.
Therefore, the transmission oil pump is driven in two ways:
- Mechanically by the combustion engine via the transmission input shaft
- Electrically by an electric motor installed specifically for this purpose
The actual transmission oil pump is connected to the transmission input shaft via a freewheel. When the transmission input shaft rotates (while the combustion engine is running), the transmission oil pump is also driven. If the speed of the combustion engine is sufficient, this type of drive is adequate. However, it must be driven by the electric motor if the speed of the combustion engine is not adequate or the combustion engine is at a standstill. The electric motor is connected to the actual transmission oil pump via a freewheel. When the transmission input shaft rotates (while the combustion engine is running), the electric motor also rotates. However, in this case, it is activated such that it can rotate without load. If the transmission input shaft is at a standstill (when the combustion engine is also at a standstill), the electric motor must power the transmission oil pump. The electric motor is then activated such that the transmission oil pump rotates at an adequate speed and the transmission oil supply is ensured.
The maximum speed of the electric motor corresponds to that of the combustion engine (6500 RPM), but it is operated actively only at a significantly lower speed range (approx. 0 to 2000 RPM). At higher speeds, the combustion engine drives the transmission oil pump and the electric motor only has to rotate at the same speed.
The electric motor of the transmission oil pump does not have any sensors (such as motor position sensors or temperature sensors).
"Dexron-VI" is used as the transmission oil.
| Index | Explanation |
|---|---|
| A | EMPI |
| B | Detailed view of the electrical connection |
| 1 | Electrical connector |
| 2 | Coils of the stator |
| 3 | Rotor equipped with permanent magnets |
| 4 | Contacts of the high voltage interlock loop |
| 5 | Housing of the connector for connection to the power electronic box |
| 6 | Contacts for three phases |