Sauer Danfoss 51 Series Service Manual page 18

Bent Axis Variable Displacement Motors
Functional Description (Continued)
Fig. 10-38 - Multi-function Block with PCOR
Defeat Spool Components
Shuttle Valve
A1
T5
U7
U6
B1
PCOR
Valve
Standard
Pressure Compensator Override
Fig. 10-39 - PCOR and PCOR with Defeat
Schematic
18
51000032
Shuttle Valve
T4
Defeat
Spool
U7
U6
T6
PCOR
Valve
XA XB
with Defeat
51000033
An optional "brake pressure defeat" spool may be
installed in the multi-function block. When used with
the PCOR, this spool assures that the PCOR does
not cause the motor displacement to increase during
deceleration (which could cause pump overspeed).
Pressure from a source such as the pump servos or
an external valve, shifts the defeat spool to block the
high pressure supply to the PCOR valve from the
"deceleration" side of the closed loop. Either bi-
directional or single direction PCOR operation can be
specified when PCOR defeat is installed.
PCOR Brake Pressure Defeat Operation
Rotation
A1
CW
CCW
B1
Series 51
High pressure Control pressure
port
A
B
on port
XB
XA
10 - 14