Charging, Basic Function - GF09.00-P-9900A
Engine all (CAR)
Shown: Charging of engine 260
Overview
This document contains information on:
- General
- Turbocharger
- Electric additional compressor
- Two-stage charging
General
The charging compresses the intaken fresh air and increases the cylinder charge level. The engine output increases.
Turbocharger
The exhaust gases reach the turbine wheel via the intake on the exhaust gas turbocharger's turbine wheel housing.
Via a constriction, thermal energy is converted into kinetic energy and the turbine wheel starts to rotate.
The turbine wheel sits on the same shaft as the compressor wheel. The compressor wheel is set in motion by the rotation of the turbine wheel and intakes fresh air.
The fresh air sucked in is compressed in the compressor wheel housing and reaches the engine through an outlet via the charge air cooler.
Electric additional compressor
The additional compressor consists of an electric motor that drives a rolling-element-bearing-supported compressor shaft. The electric additional compressor is supplied with voltage by the 48 V on-board electrical system. This means that it works independently of the air flow of the exhaust gases that drive the classic exhaust gas turbocharger.
Two-stage charging
In the case of two-stage charging, two exhaust gas turbochargers of different sizes are used. The small exhaust gas turbocharger is responsible for the low engine speed range. For the higher engine speed range, an exhaust valve opens the supply to the large exhaust gas turbocharger depending on the load request. An additional exhaust valve controls the opening to the exhaust gas line.
The exhaust valves are opened and closed by pneumatic vacuum cells.
The pneumatic vacuum cells are actuated by the combustion engine control unit via the pressure transducer.
| Additional basic functions | |||
| Boost pressure control, basic function | Engine all (CAR) | GF09.40-P-1000A | |
| Overrun mode bypass air, basic function | Engine 256, 260, 264, 282 | GF09.40-P-1002A | |
| Charge air cooling, basic function | Engine all (CAR) | GF09.41-P-1000A | |
| Electric additional compressor, basic function | Engine 256 | GF09.50-P-1002A | |
| Components | |||
| Exhaust gas turbocharger, detailed information | Engine 608 | GF09.40-P-2500A | |
| Function schematics | |||
| Function schematic for charging | Engine 608 in model 118, 177, 247 | PE09.00-P-2500A | |
| Engine 282 in model 118, 177, 247 | PE09.00-P-2500B | ||
| Engine 260 in model 118, 177, 247 Engine 264 in model 167 |
PE09.00-P-2500C | ||
| Engine 654 in model 118, 177, 247 Engine 654, 656 in model 167 |
PE09.00-P-2500D | ||
| Engine 256 in model 167 | PE09.00-P-2500E |