The MDC changes the pump displacement between no flow and full flow into opposite directions. Under
some circumstances, such as contamination, the control spool could stick and cause the pump to stay at
some displacement.
A 170 μm screen is located in the supply line immediately before the control porting spool.
The MDC is sealed by means of a static O-ring between the actuation system and the control block. Its
shaft is sealed by means of a special O-ring which is applied for low friction. The special O-ring is
protected from dust, water and aggressive liquids or gases by means of a special lip seal.
Manual Displacement Control
Pump displacement vs. control lever rotation
"0"
Lever rotation
"A"
Displacement
100 %
a
-a
100 %
"B"
-b
-d
b
c
d
-c
MDC schematic diagram
Where:
Deadband on B side – a = 3° ±1°
Maximum pump stroke – b = 30° +2/-1°
Service Manual
MP1
Operation
20 |
©
Danfoss | April 2019 AX00000244en-000201