Sauer Danfoss 51 Series Service Manual page 14

Bent Axis Variable Displacement Motors
Functional Description (Continued)
Fig. 10-26 - Series 51 Motor with HP
Control
Fig. 10-27 - HP Control Components
M6
L2
A
A1
U4 (opt.)
B1
U5 (plug for
ext. servo press.)
Servo
B
Press,
internal
L1
Fig. 10-28 - HP Control Schematic
14
M4 M3
M1
max.
disp.
T3
T2
T7,
T8
M9
T1
X3 (M5)
Servo press,
external
M2
X2 X1
Two Line Hydraulic Proportional Control
(Type HP)
This control consists of a valve block with two (2)
hydraulic ports mounted on the multi-function block.
The valve block incorporates a shuttle spool and a
pilot piston with centering springs. A pin transmits
force from the pilot piston to the control spool in the
end cap. Feedback springs (single spring for 060,
080, and 110) and a threshold spring are installed in
51000023
the end cap. These springs function similar to the HS
control. Servo pressure may be supplied from an
external source or internally by the shuttle spool in the
multi-function block. PCOR is available with this
control.
Two pilot pressures are provided to the control. The
shuttle spool directs the higher pilot pressure to the
end of the pilot piston opposite the feedback spring,
and the lower pressure to the opposite side of the pilot
piston. The rod transmits a force, proportional to the
difference of the pilot pressures, to the control spool.
An increase in the difference between the pilot pres-
51000024
sures will result in a decrease in motor displacement,
while a decrease will result in an increase in displace-
ment.
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Series 51
10 - 10