Pump Output Flow Direction Vs. Control Pressure; Manual Displacement Control (Mdc), Options Ma, Mb; Features And Benefits - Danfoss Series 90 Technical Information

Technical Information
Control Options

Manual Displacement Control (MDC), Options MA, MB

34
Series 90 Axial Piston Pumps
Pump displacement vs. signal pressure
100 %
-b -a
"0"
100 %
Hydraulic signal pressure range*
a
b

Pump output flow direction vs. control pressure

Pump output flow direction vs. control pressure
Input shaft rotation CW
Control pressure to port X1
Port A flow (M1) Out
Port B flow (M2) In
Servo cylinder (side) M5 (2)
Refer to Installation Drawings
W
Warning
Avoid designing a system which puts swashplate into full stroke when control operation is blocked by
contamination.
The manual displacement control converts a mechanical input signal to a hydraulic signal that tilts the
cradle swashplate through an angular rotation varying the pump's displacement from full displacement
in one direction to full displacement in the opposite direction.
The manual displacement control has a mechanical feedback mechanism which moves a servo valve in
the proper relationship to the input signal and the angular position of the swashplate. The control is
designed so that the angular rotation of the swashplate is proportional to the mechanical input signal.
The control is designed with an internal override mechanism which allows the mechanical input to be
moved at a faster rate than the movement of the swashplate without damage to the control.

Features and benefits

•
Precision parts provide repeatable, accurate displacement settings with a given input signal.
520L0603 • Rev 0804 • March 2016
Signal pressure
a b
P102 031E
3 ± 0.5 bar
11 ± 0.5 bar
X2
In
Out
M4 (1)
on page 50, for port locations.
[43 ± 6 psi]
[160 ± 6 psi]
CCW
X1 X2
In Out
Out In
M5 (2) M4 (1)