Description
Code: 92801
A. REGULATED ENGINE OIL PUMP:
Engines 276 and 278 incorporate a newly developed vane-type oil pump with demand-driven volume regulation with two map-controlled, switched pressure stages.
This control concept allows the engine lubricating and cooling points to be supplied totally independently of the engine load and engine speed with a significantly lower drive power, especially in the part-load range, than would be possible with a non-controlled pump.
The engine oil pump works with two pressure levels according to the engine map. At the high pressure level (4 bar), all of the engine’s lubrication and cooling points are supplied with the maximum volume of oil, while the volume flow rate is reduced to 2 bar at the low pressure level. At the same time, the oil jets for cooling the piston crowns are switched off.
Special features include the anodised aluminium oil pump housing and aluminium intermediate flange for lasting wear resistance combined with low leakage levels. In the M 278, an external gear pump acts as the suction stage for the oil return lines from the turbochargers. This is intended to prevent oil being pushed into the suction or exhaust gas system. The external gear pump is arranged at the back of the engine oil pump.
The oil level is detected by the oil level check switch in the sump and sent to the engine control unit. The engine oil pump’s valve is a solenoid valve with three hydraulic connections and two working positions (open and closed). The valve is map-controlled by the engine control unit using an earth signal. It switches between the two pressure stages (2 bar and 4 bar) according to demand.
B. FRONT VIEW OF ENGINE OIL PUMP:
- Drive sprocket
- Oil pump cover
- Rotor with vane
- Adjusting ring
- Oil pump housing
- Cold start protection valve
- Control piston Y130 Valve for engine oil pump.
B. BACK VIEW OF ENGINE OIL PUMP WITH EXTERNAL GEAR PUMP:
- Engine oil pump housing
- Oil return line from turbocharger, right
- Oil return line from turbocharger, left
- Toothed wheel for drive shaft
- Toothed wheel for oil pump
