Data sheet
Axial piston pump DPVO
The Liebherr DPVO 550 axial piston pumps are designed
as swashplates for open circuits. They were developed for
mining applications. Thanks to their robust and reliable
design, they are also highly suitable for industrial plant and
maritime applications.
All these variable displacement pumps are available in
nominal size 550 as a single pump with impeller, or as a
double pump without an impeller. The nominal pressure of
the units is 5,511psi (380bar) and the maximum pressure
is 6,092 psi (420bar) absolute.
The DPVO 550 models stand out with their wide swivel
angle of 20° and high pressure capacity. The pumps offer
100% through-drive capability, and can be combined
with hyperbolic power control with pressure control and
pressure cut-off. With the impeller, higher speed and higher
displacement are possible as well.
Valid for:
DPVO 550 / DPVO 550i
Features:
D series
Open circuit
Control types:
Additional control types upon request
Pressure range:
Nominal pressure p
N
= 5,511psi (380bar)
Maximum pressure p
max
= 6,092 psi (420bar)
Document identification:
ID number: 13877152
Date of issue: 04/2023
Authors: Liebherr - Abteilung VH13
Version: 1.0
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 2
1 Type code 3
2 Technical data 5
2.1 Table of values 5
2.2 Direction of rotation 8
2.3 Permitted pressure range 8
2.4 Hydraulic fluids 11
2.5 Temperature 12
2.6 Shaft lip seal 18
3 Activation and control type 19
3.1 Control types 19
3.2 Standard hydraulic diagrams 20
3.3 Control functions 21
3.4 Electrical components 26
4 Installation conditions 27
4.1 General information about project planning 27
4.2 Installation variants 29
5 Dimensions 32
5.1 Main dimensions 32
5.2 Mounting flange 34
5.3 Shaft end 34
5.4 Through-drive 35
5.5 Multi-circuit pump 37
Table of contents
1 Type code
Date: 04/2023 Version: 1.0 ID No.: 13877152
■ = Available / □= On request / -= Not available
Page 3
DPV O 550 / 1 A 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
1. Pump type
D series / pump / variable displacement DPV
2. Type of circuit
Open O
3. Nominal size (NS)
550
4. Residual displacement V
g
min
15% of V
g max
, not adjustable, enter value in cm
3
/rev
(enter "not adjustable" in the
order text)
■
0 or 15% of V
g max
, hydraulically adjustable, enter value in cm
3
/rev
(enter "hydraulic
ally adjustable" in the order text)
■
5. Activation / control type
Electro-proportional regulation (positive characteristic) / pressure cut-off □ EL1 - DA
Power control / load sensing □ LR - LS
Power control / steering pressure-proportional (positive characteristic) / pressure cut-off ■ LR - SD - DA
Electro-proportional regulation (positive characteristic) / load sensing □ EL1 - LS
Pressure cut-off □ DA
Total performance regulation / steering pressure-proportional (positive characteristic) □ SL - SD
Load sensing / pressure cut-off □ LS - DA
6. Design
1
7. Direction of rotation (viewed towards the drive shaft)
right □ R
left ■ L
8. Mounting flange
Diesel engine flange SAE J617a
SAE 1 □ 11
SAE 2 □ 12
DIN / ISO 3019-2 ■ 31...
Special flange □ 51...
9. Shaft end
Splined shaft
DIN 5480 ■ 1
ANSI B92.1a □ 2
10. Connections
ISO 6162-2 / SAE J518-2, high-pressure connection 6000 psi A
1 Type code
1 Type code
Date: 04/2023 Version: 1.0 ID No.: 13877152
■ = Available / □= On request / -= Not available
Page 4
■ = Available
□ = On request
- = Not available
550
11. Add-on parts
Without add-on parts ■ 0
With impeller □ I
12. Gear pump
Without gear pump ■ 00
With gear pump, V
g
= XX cm
3
, enter value in cm
3
/rev
□
13. Through-drive
Ready for through-drive, with cover closed ■ K02G
ANSI B 92.1a-1976, 1 in 15T 16/32 DP, SAE-B, 2-hole Open hole ■ B21D
ISO 3019-2 DIN 5480 8-hole Open hole ■ U32D
Special
diameter
DIN 5480 Special design Open hole ■ K33D
14. Valve
Without valve 0
15. Sensors
Without sensor ■ 0
With angle sensor ■ W
With pressure sensor □ P
Note
Contact addresses for queries are provided on the back of this document.
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 5
2.1 Table of values
*) Depending on the application, a special approval for a lower minimum speed at a lower
operating pressure is possible. Please consult Liebherr, stating the expected load cycle.
**) Missing values were not yet available by the editorial deadline.
2.1.1 Maximum radial and axial load of the driving shaft
Generally applicable data for calculation
•Vg
max
• Operating pressure pHD: 380 bar
Nominal size 550
Displacement volume
V
g max
cm
3
550
V
g min
cm
3
0 or 82
Volume flow at V
g max
and n
max
q
v max
l/min 797
Min. speed* at V
g max
and p
abs
= 1 bar at the suction port n
min
rpm 500
Max. speed at V
g max
and p
abs
= 1 bar at the suction port n
max
rpm 1450
Torque at V
g max
and Δp = 380 bar M
max
Nm 3330
Driving power at qv
max
and Δp = 380 bar p
max
kW 505
Driving gear moment of inertia
J
TW
kgm
2
0.28
Maximum angular acceleration** α
rad/s
2
Weight without through-drive (approx.) m kg 373
Torsional rigidity Driving shaft code “1” kNm/rad 980
Note
Theoretical rounded values, not taking into account efficiency, tolerances, contamination of the
hydraulic fluid or deflection of the driving shaft.
Note
The radial and axial loads are calculated separately and for the specific load cycles (pressure and di-
rection of force). If planning a belt drive or if continuous axial and/or radial forces are expected, please
contact Liebherr, stating the expected load cycle.
Note
Theoretical rounded values, not taking into account efficiency, tolerances, contamination of the hy-
draulic fluid or deflection of the driving shaft.
2 Technical data
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 6
2.1.2 Maximum input and through drive torques
Generally applicable data for calculation
•Vg
max
• Operating pressure pHD: 380 bar
Nominal size 550
X mm 45
Position at which radial force is applied - All
Max. radial force F
r
Reduction of bearing service life by 20%
N
3000
Reduction of bearing service life by 50% 10000
Max. axial force F
a+
Reduction of bearing service life by 20%
N
4000
Reduction of bearing service life by 50% 12000
Max. axial force F
a-
Reduction of bearing service life by 20%
N
2000
Reduction of bearing service life by 50% 6000
Note
Theoretical rounded values, not taking into account efficiency, tolerances, contamination of the
hydraulic fluid or deflection of the driving shaft.
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 7
1) M
E
= M1+M2+M3
M
E
< M
E max
2) M
D
= M2+M3
M
D
< M
D max
M1 Torque of axial piston pump 1 P2 Axial piston pump 2
M2 Torque of axial piston pump 2 P3 Axial piston pump 3
M3 Torque of axial piston pump 3
M
E
1
Input torque
P1 Axial piston pump 1
M
D
2
Through drive torque
Nominal size 550
Torque* at V
g max
and Δp = 380 bar M
max
Nm 3330
Max. torque of
drive shaft input
(installed without
lateral force)
1 Ø80, 25 teeth, with undercutting
M
E max
Nm 6940
Max. torque of through drive
M
D max
Nm 3610
Note
Higher through-drive torques on request.
2 Technical data
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Page 8
2.2 Direction of rotation
2.3 Permitted pressure range
2.3.1 Operating pressure
DPV O 550 / 1 A 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
The direction of rotation is stated with view of the driving
shaft, as shown in the figure.
R right = clockwise
L left = anti-clockwise
Note
Standard with two opposite high-pressure connections A1 / A2.
Operating pressure at connection A1/A2
Nominal size 550
Minimum pressure
1
VG
min
pHD
min
bar
10
VG
max
18
Nominal pressure (fatigue resistant)
pHD
N
bar 380
time t
DB-DPVO 550-006
t
p
pN
pHD [bar]
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 9
*) OH = operating hours
1
) There must be minimum pressure in the working circuit at connection A1/A2 to ensure adequate lubrication
of the driving gear at all swivel angles during operation.
*) Other values upon request
2.3.2 Housing, leakage oil pressure
Maximum pressure (single operating period)
pHD
max
bar 420
Single operating period at maximum pressure pHD
max
t s < 1
Total operating period at maximum pressure pHD
max
t OH* 300
Rate of pressure change RA bar/s 17000
DANGER
Failure of the fastening screws at working connection A1/A2
Danger to life.
Use fastening screws of strength category 10.9.
Suction pressure at port S
Nominal size 550
Minimum absolute pressure
pS
min
bar 1*
Maximum absolute pressure
pS
max
bar 3*
Leakage oil pressure at connection T
Nominal size 550
Permanent absolute leakage oil pressure pL bar 3
Maximum absolute pressure
pL
max
bar 6*
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 10
*) Short pressure peaks of max. 10 bar abs. are permitted (t < 0.1 s).
Permitted pressure pL
abs. max
in bar
Speed n in rpm
DB-DPVD 550-010
Characteristic
curve
Nominal size
Shaft diameter (mm)
Seat of the rotary shaft lip seal
550 90
Note
The pressure in the axial piston unit must, under all circumstances, be higher than the external pres-
sure on the shaft lip seal.
2 Technical data
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Page 11
2.4 Hydraulic fluids
2.4.1 General information
Selection of the appropriate hydraulic fluid is significantly influenced by the anticipated operating temperature
relative to the ambient temperature, which is equivalent to the tank temperature.
Minimum required quality
2.4.2 Fill quantity
2.4.3 Filtering
- Filtering of the hydraulic fluid is necessary to maintain the specified purity class "21/17/14 according to
ISO 4406" under all circumstances.
- The hydraulic fluid is filtered by the device-specific use of oil filters in the hydraulic system.
- Cleaning and maintenance intervals for the oil filters and the entire oil circuit depend on use of the unit: see
the device-specific operating instructions.
ATTENTION
You must not mix different mineral oil hydraulic fluids!
Specification
LH-00-HYC3A
LH-00-HYE3A
Note
For additional information, see: www.liebherr.com
(brochure: Lubricants and operating fluids) Alter-
natively: Contact lubricants@liebherr.com
.
Nominal size 550
Fill quantity Litres 30
Note
Before commissioning, the axial piston unit must be filled with oil and vented.
This process must be checked and repeated if necessary during operation and after long downtimes!
2 Technical data
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Page 12
2.5 Temperature
If the axial piston unit is operated in the optimum operating range of the hydraulic fluid within the permitted op-
erating conditions and operating limits, it is low-wear and is protected against temperature-dependent ageing.
From a viscosity < 11 mm
2
/s (for Liebherr Hydraulic HVI (ISO VG 46) = 80 °C), a halving of the service life of the
hydraulic fluid must be assumed for every 10 °K increase in temperature.
If the optimum range cannot be met, a hydraulic fluid with a more suitable viscosity range must be selected or
the hydraulic system must be preheated or cooled.
To prevent temperature shocks, the temperature difference between the hydraulic fluid and the axial piston unit
must be kept to less than 25 °C. This can be achieved by, among other things, a continuous flow through all axial
piston units in the hydraulic system.
2.5.1 Operating limits
Maximum values:
Maximum leakage oil temperature: 115 °C.
Low temperatures: (For additional information see: 2.5.2 Low temperatures, page 12)
2.5.2 Low temperatures
Note
The optimum operating range of the hydraulic fluid of 16-36 mm
2
/s for Liebherr Hydraulic HVI
(ISO VG 46) is from 32° to 62 °C.
ATTENTION
The temperature should be assumed to be highest in the drive shaft bearing area (rotary shaft lip seal and
bearing). Experience has shown this temperature to be 10-15 °K higher than the leakage oil temperature.
Note
The operating limits of Liebherr hydraulic fluids are provided in the viscosity chart included below to
allow users to make an informed choice.
(For additional information see: 2.5.6 Viscosity chart, page 17)
ATTENTION
When temperatures drop below freezing point, the sealing lip of the rotary shaft lip seal may freeze if it be-
comes wet or frosted. This can cause the sealing lip to tear off when the axial piston unit is started. The risk
must be prevented by preheating/thawing the rotary shaft lip seal/the shaft.
Note
At temperatures at which there is already a risk of hardening from freezing, the frictional heat may be
sufficient to keep the seal elastic or to bring it to a functional state quickly enough after the start of
movement.
2 Technical data
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Page 13
Overview
*) Idle state < -50 °C
**) Idle state < -40 °C
Regardless of the viscosity < 1600 mm
2
/s, the axial piston unit must be operated for at least 60 s under the
following conditions before entering the cold start including the warm-up phases or on warm start:
• Operating pressure range: p
HD min
≤ p
HD
≤ 50 bar
•Speed: n
min
≤ n ≤ 1000 rpm, or idle speed of the drive motor*
• Displacement volume: V
g min
≤ V
g
≤ 15% of V
g max
• Do not move any of the equipment.
*) When using a drive with higher speeds than required in the conditions (e.g. an electric motor), please consult
Liebherr, stating the potential speed(s).
After the 60 s have elapsed, determine the viscosity using the available temperature values and the viscosity
chart, select the appropriate warm-up phase and operate the axial piston unit in the defined period and ap-
propriate conditions (see Warm-up phases).
Temperature [°C] Phase
Viscosity [mm
2
/s]
Note
< -50 °C Idle state -* No storage or operation permitted
< -40 °C Idle state -**
No operation permitted, preheat to at
least -40 °C, select appropriate
hydraulic fluid
ATTENTION
Temperatures < -50 °C on the system = no operation of the axial piston unit permitted.
Risk of damaging the sealing elements of the axial piston unit.
Avoid temperatures < -50 °C.
ATTENTION
Temperatures < -40 °C on the system = no operation of the axial piston unit permitted.
Functioning of the sealing elements in the axial piston unit is not guaranteed at temperatures < -40°C.
Preheat the axial piston unit and tank to at least -40 °C and use Liebherr Hydraulic Plus Arctic/
Liebherr Hydraulic FFE 30 hydraulic fluid with a viscosity < 1600 mm
2
/s.
(For additional information see: 2.5.6 Viscosity chart, page 17)
30
Δ60
„I“
Warm-up phases
Start at
any viscosity
„II“ „III“
15
1600
1200
1000
400
16
Viscosity
[mm²/s]
VG/VGmax [%]
n/nmax [%]
100
nom
200
0.5
time t [s]
50
n
idle
p
HD
p [bar]
0 0
0
DB-LH30VO-158
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 14
Overview
*) The viscosity must not fall below 8 mm
2
/s (for a short period, i.e. < 3 minutes, 7 mm
2
/s) at maximum leakage
oil temperature.
2.5.3 Cold start with subsequent warm-up phases
Temperature [°C] Phase
Viscosity [mm
2
/s]
Note
> -40 °C Cold start 1600-400
The current viscosity of the hydraulic
fluid before start-up determines the
type of start.
In the range of 1600-400 [mm
2
/s], it is
a cold start.
Entry into the warm-up phase must be
selected according to the viscosity and
the further warm-up phases must be run
through according to the time specifica-
tions and operating conditions.
For additional informa-
tion see: 2.5.6 Viscosity
chart, page 17
Warm-up phase "I" 1600-1200
Observe conditions and measures
(see Warm-up phase "I")
Warm-up phase "II" 1200-1000
Observe conditions and measures (see
Warm-up phase "II")
Warm-up phase "III" 1000-400
Observe conditions and measures
(see Warm-up phase "III")
Normal operation 400-16*
Axial piston unit, fully loadable
(see Normal operation)
Optimum
operating range
36-16
Axial piston unit, fully loadable
(see Normal operation)
ATTENTION
Before cold start, the viscosity* must be determined on the basis of the oil temperature (e.g. tank tem-
perature) in order to avoid damage to the axial piston units from excessive viscosity* of the hydraulic
fluid. At a viscosity* > 1600 mm
2
/s, the hydraulic system must be preheated.
Using the determined viscosity*, the type and duration of the warm-up must be followed, using the
cold start chart**.
*) For additional information see: 2.5.6 Viscosity chart, page 17
The following conditions apply:
• Viscosity: 1600-1200 mm
2
/s = operate the axial piston unit for 600-360 s with measures listed for
Wa
rm-up phase "I".
• Viscosity: 1200-1000 mm
2
/s = operate the axial piston unit for 360-120 s with measures listed for
W
arm-up phase "II".
• Viscosity: 1000-400 mm
2
/s = operate the axial piston unit for 120-60 s with measures listed for
W
arm-up phase "III".
• Viscosity: 400-16 mm
2
/s = operate the axial piston unit for 60 s with measures listed for "Warm
start". This means that even at ≤ 400 mm
2
/s, the measures must be applied for at least 60 s.
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 15
**) Cold start chart
2.5.4 Warm-up phases
Warm-up phase "
Ⅰ"
Condition:
• Viscosity: 1600-1200 mm
2
/s = operate the axial piston unit with measures listed below until a viscosity of
1200
mm
2
/s is reached.
Measures:
• Operating pressure range: p
HD min
≤ p
HD Warm-up "I"
≤ 200 bar
•Speed: n
min
≤ n
Warm-up "I"
≤ 50% of n
max
• Displacement volume: V
g min
≤ V
g Warm-up "I"
≤ 15% of V
g max
30
VG/VGmax [%]
n/nmax [%]
HD
p [bar]
„I“
Warm-up phases
1600
1200
1000
400
16
360
120
60
Viscosity
[mm²/s]
Cold starttime t
[s]
„II“ „III“
600
1600
1200
1000
400
16
15
Viscosity
[mm²/s]
100
200
0.5
DB-LH30VO-157
nom
p
0 0
0
Note
Depending on the current viscosity, continue with the corresponding warm-up phase after the cold
start. In the subsequent warm-up phases, the operating parameters may be increased to allow the hy-
draulic system to warm up rapidly.
2 Technical data
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Page 16
Warm-up phase "Ⅱ"
Condition:
• Viscosity: 1200-1000 mm
2
/s = operate the axial piston unit with measures listed below until a viscosity of
1000
mm
2
/s is reached.
Measures:
• Operating pressure range: p
HD min
≤ p
HD Warm-up "II"
≤ 200 bar
•Speed: n
min
≤ n
Warm-up "II"
≤ 50% of n
max
• Displacement volume: V
g min
≤ V
g Warm-up "II"
≤ 15-30% of V
g max
Warm-up phase "Ⅲ"
Condition:
• Viscosity: 1000-400 mm
2
/s = operate the axial piston unit with measures listed below until a viscosity of
40
0 mm
2
/s is reached.
Measures:
• Operating pressure range: p
HD min
≤ p
HD Warm-up "III"
≤ p
HD max
•Speed: n
min
≤ n
Warm-up "III"
≤ 50% of n
max
• Displacement volume: V
g min
≤ V
g Warm-up "III"
≤ 30-100% of V
g max
Warm start
Condition:
• Viscosity: 400-16 mm
2
/s = operate the axial piston unit for at least 60 s, even at viscosity < 400 mm
2
/s,
with measu
res listed below.
Measures:
• Operating pressure range: p
HD min
≤ p
HD
≤ 50 bar
•Speed: n
min
≤ n ≤ 1000 rpm, or idle speed of the drive motor
• Displacement volume: V
g min
≤ V
g
≤ 15% of V
g max
2.5.5 Normal operation
Note
Optimum operating range: 16-36 mm
2
/s
The viscosity must not fall below 8 mm
2
/s (for a short period, thud < 3 minutes, 7 mm
2
/s) at maximum
leakage oil temperature.
Note
In the viscosity range of 400-8 mm
2
/s, the axial piston unit can be put under full load.
• Operating pressure range: p
HD min
≤ p
HD
≤ p
HDmax
•Speed: n
min
≤ n ≤ n
max
• Displacement volume: V
G min
≤ V
G
≤ V
g max
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 17
2.5.6 Viscosity chart
5 5
6 6
7 7
8 8
9 9
10 10
15 15
20 20
30 30
40 40
50 50
75 75
100 100
150 150
200 200
300 300
400 400
500 500
1000 1000
2000 2000
3000 3000
5000 5000
-40
-40
-30
-30
-20
-20
-10
-10
0
0
10
10
20
20
30
30
40
40
50
50
60
60
70
70
80
80
90
90
100
100
0
2
nÉÎÅÍÁÔÉÓÃÈÅyÉÓËÏÓÉÔßÔÉÎÍÍƀƐÓ
nÉÎÅÍÁÔÉÃÖÉÓÃÏÓÉÔÙÉÎÍÍƀƐÓ
wÅÍÐÅÒÁÔÕÒÉÎƄf
wÅÍÐÅÒÁÔÕÒÅÉÎƄf
/LHEKHUU+\GUDXOLF%DVLF &PPV&PPV9,
/LHEKHUU+\GUDXOLF+9, &PPV&PPV9,
/LHEKHUU+\GUDXOLF3OXV &PPV&PPV9,
/LHEKHUU+\GUDXOLF3OXV$UFWLF
&PPV
&PPV9,
/LHEKHUU+\GUDXOLF%DVLF&PPV&PPV9,
/LHEKHUU+\GUDXOLF &PPV&PPV9,
/LHEKHUU+\GUDXOLF))( &PPV&PPV9,
/LHEKHUU+\GUDXOLF3OXV &PPV&PPV9,
1ϭ0
1Ϯ0
1ϭ0
1Ϯ0
2 Technical data
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 18
2.6 Shaft lip seal
2.6.1 General information
The rotary shaft lip seals (RWDR) are special sealing elements which permit a specific housing pressure. In order
to ensure that the tribological system functions optimally, the operating conditions must be adhered to.
Sealing edge temperature varies due to the following factors in the housing:
- Circumferential speed
- Hydraulic fluid temperature
- Lubricating medium
- Pressure build-up
The sealing edge temperature could be 20 °C to 40 °C above the leakage oil temperature of a hydraulic axial pis-
ton unit.
3 Activation and control type
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Page 19
3.1 Control types
The following applies to all control types:
The following modular control types can be ordered for the DPVO series:
3.1.1 Mechanical-hydraulic control
-LR-SD-DA- control, See chapter 3.2.1
Further control types on request.
DPV O 550 / 1 A 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
Note
For each control type or function, only one nominal size is illustrated, typically nominal size 550. Spe-
cial applications and designs are not included in this chapter. Always use the information from the
installation drawing provided or contact Liebherr.
DANGER
The spring-guided reset in the regulating valve is not a safety device!
Contaminants in the hydraulic system such as chips or residual dirt from parts of the device or sys-
tem can cause blockages at undefined points of various control components.
Under some circumstances, the machine operator’s specifications can no longer be implemented.
It is the device or system manufacturer’s responsibility to install a safety device e.g. an emergency
stop.
DANGER
The regulating valve is not a safety device against overload!
It is the device or system manufacturer’s responsibility to install protection against overload, e.g. a
pressure limiting valve.
Pressure limiting valves are available in the portfolio and can be ordered separately.
3 Activation and control type
3 Activation and control type
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Page 20
3.2 Standard hydraulic diagrams
3.2.1 LR-SD-DA- - power control/steering pressure-proportional/pressure cut-off
A1 / A2
Working connection (SAE J518) 2",
6000 psi
T
Leakage oil connections,
oil filler neck or oil drain
S Suction port (SAE J518) 5", 500 psi Fa Filter outlet ISO 9974-1
M3
Suction pressure measuring port,
Minimess port
M2
High pressure measuring port,
Minimess port
M1
Regulated high pressure measuring port,
Minimess port
X6
Vg
min
regulation
Screw connection GE 10LM
X1 SD steering pressure ISO 9974-1 TS Thermostatic switch ISO 9974-1
X3 LR steering pressure ISO 9974-1 SS Dirt switch ISO 9974-1
X5 DA- override pressure ISO 9974-1 GS Housing flushing ISO 9974-1
1 Not included in the scope of delivery BS1 / BS2 Acceleration sensor thread M8
DB-DPVO 550-012
X1
Qmax
Qmin
A2
Fa
M1
LR
M2
DA
X5
50 bar
X6
T
A1
M3
SD
X3
S
1
3 Activation and control type
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Page 21
3.3 Control functions
- LR- function, power control, See chapter 3.3.1
- LR1- function, power control, override option, See chapter 3.3.2
- SD- function, steering pressure-dependent regulation, See chapter 3.3.3
- DA- function, pressure cut-off, See chapter 3.3.4
- DA1-function, pressure cut-off, override option, See chapter 3.3.5
3.3.1 LR- function
Characteristic
LR*) Maximum drive power for a driving gear at 1450 rpm
The LR function adjusts the flow rate V
g
(volume flow) of the axial piston unit, depending on the pump high pres-
sure pHD (the capacity reduction), to the performance characteristic of the drive motor while limiting the flow
at a constant speed n.
Optimal performance utilisation is achieved, if the regulation runs along the hyperbolic characteristic.
When regulation of the axial piston unit starts, the working pressure pHD in the system rises to the pressure at
regulation start. This increases the force at the measuring piston 1 to lever 2. The spool 3 is moved against the
pressure spring package 4 and opens the connection of the adjusting chamber pReg to the tank T via a steering
cam S2.
The axial piston unit thereby pivots back in direction V
g min
.
The force of the lever 2 on the spool 3 decreases so that the pressure spring package 4 pushes the spool 3 back
to its neutral position. The connection of the adjusting chamber pReg to the tank pT is interrupted. The axial pis-
ton unit stops at a constant flow rate that corresponds to a constant performance decrease at the existing high
pressure pHD.
Options
Combination with other control types
Override LR1
DB-DPVO 550-027
5
1
2
pReg
pT
3
pHD
4
S2
pX3
Note
Liebherr recommends combining the LR function with a pressure cut-off.
3 Activation and control type
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Page 22
3.3.2 LR1- function
Characteristic
Override
The external control pressure pX3 is directed to the LR control axis via port X3 and acts against the spool 3 in
addition to the force of the pressure spring package 4, so that the pressure spring package 4 pushes the spool 3
back to its neutral position. The connection of the adjusting chamber pReg to the tank pT is interrupted. To main-
tain the force balance, the axial piston unit swivels towards V
g max
to a higher performance level.
The load limiting regulation is independent of the drive motor speed.
With increasing regulating pressure pX3, the pressure for starting the regulation of the axial piston unit increas-
es proportionally.
DB-DPVO 550-027
5
1
2
pReg
pT
3
pHD
4
S2
pX3
3 Activation and control type
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Page 23
3.3.3 SD- function
SD regulation is suitable for applications that require proportional regulation of the volume flow.
Characteristic
By adjusting the drive from V
g min
towards V
g max
, the axial piston unit swivels to a larger displacement volume
V
g
with increasing SD steering pressure.
The high pressure pHD is applied to the adjusting piston bottom area 1, and the regulated high pressure pReg is
applied to the adjusting piston bottom area 2.
If pReg x adjusting piston bottom area 2 is larger than pHD x adjusting piston ring area 1, the adjusting piston 3
moves and swivels the axial piston unit towards V
g max
.
The hydraulic fluid required for this purpose is taken from high pressure pHD. At high pressure of pHD < 50 bar,
the connection Fa must be supplied with auxiliary pressure to ensure that regulation is possible.
If high pressure pHD < pFA, pFA takes over the supply of the regulation and the control.
If the activating signal is missing or defective, the axial piston unit swivels to V
g min
.
DB-DPVO 550-026
pHD
1
2
pReg
3
3 Activation and control type
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Page 24
3.3.4 DA- function
Characteristic
Additional technical data
*) depending on requirement
DA pressure control minimizes or limits (cut-off) the volume flow of the axial piston unit, when a fixed high pres-
sure value pHD is reached. Swivelling in the direction of V
g min
protects the hydraulic system from damage and
overload.
Swivelling continues in direction V
g min
only until the volume flow of the axial piston unit exactly matches the
consumer need at this pressure stage.
If the system pressure falls below the fixed high-pressure value pHD, the axial piston unit swivels until V
g max
.
With its function, the pressure control ensures that the pressure is kept constant even when the volume flow in
the system changes. This compensates all internal and external leakage oil losses.
Options
- Pressure cut-off with override function, See chapter 3.3.5
DA setting range
XE
300-320 bar*
3 Activation and control type
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Page 25
3.3.5 DA1- function
Characteristic
The DA1 override has the task of overriding the fixed DA cut-off pressure using an externally supplied steering
pressure pX5-pT at port X5 in order to increase the high pressure pHD as required.
It is therefore suitable for systems or devices that need a controlled way to increase performance or are subject
to a multiple use. Examples are working hydraulics in wheeled excavators and their driving hydraulic system.
The effective steering pressure at port X5 is the difference between the total steering pressure applied and the
housing pressure.
At a ratio of 1:1, the high pressure pHD reacts with an increase of 20 bar at maximum steering pressure pX5-pT
of 20 bar.
3 Activation and control type
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Page 26
3.4 Electrical components
3.4.1 Sensors
Rotation angle sensor
DPV O 550 / 1 A 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
0 Without sensor
W With rotation angle sensor
Technical data
Option A Option B
Rated voltage U 5 V Rated voltage U 8-30 V
Measuring range -27° to +27° Measuring range -27° to +27°
Output signal
-27°
0°
+27°
0.5 VDC
2.5 VDC
4.5 VDC
Output signal
-27°
0°
+27°
4 mA
12 mA
20 mA
Working temperature -40 °C to +125 °C Working temperature -40 °C to +85 °C
Deutsch DT04-3P electrical plug-in terminal
Note
The angle sensor cannot be retrofitted and must be included in the configuration of the DPVO.
Dimensions for variant A and B are identical; specify desired variant when ordering.
4 Installation conditions
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Page 27
4.1 General information about project planning
The installation variant for the device or system must be coordinated with Liebherr, as well as the installation
position, at the conceptual design stage of the axial piston unit and must be approved by Liebherr.
Liebherr distinguishes between two installation variants for axial piston units:
A: Under-the-tank installation (axial piston unit is installed under the minimum liquid level of the tank)
B: Over-the-tank installation (axial piston unit is installed above the minimum liquid level of the tank)
Liebherr distinguishes between two installation positions for axial piston units:
1/3/5/7/9/11: Driving shaft horizontal
2/4/6/8/10/12: Driving shaft vertical
*) For installation positions 2/4/6/8 with driving shaft vertical and 1/3/5/7 with driving shaft horizontal with
"control at bottom", complete filling and venting is critical. The axial piston unit must then be connected,
filled and vented before final positioning in installation position 1/3/5/7/9 "control at top".
It can then be rotated to the final installation position 2/4/6/8 driving shaft vertical or 1/3/5/7 driving shaft
horizontal with "control at bottom".
On some axial piston units, an additional T4 leakage oil connection is provided for the installation positions
2/4/6/8 driving shaft vertical and 1/3/5/7 driving shaft horizontal with control at bottom:
Order leakage oil connection T4 as special design. (For additional information see: 1 Type code, page 3)
4.1.1 Suction line
Given the laws of physics and under simple assumptions about the hydraulic fluid, temperature and ambient
pressures, the maximum suction head is 750 mm. This applies in particular to installation variant B: over-the-
tank installation.
At low temperatures with high viscosities, it is essential to observe the minimum suction pressure for axial pis-
ton units. (For additional information see: 2.3 Permitted pressure range, page 8)
The suction line must open into the tank at a minimum distance of 115 mm from the tank bottom to prevent par-
ticles of dirt in the tank from being sucked in.
The suction line must open into the tank at a maximum distance from the leakage oil line to prevent hot leakage
oil from being sucked in directly.
ATTENTION
Damage of the hydraulic product.
Lack of lubrication on the hydraulic product!
Make sure that the following requirements are observed:
- Comply with the approved installation positions for the hydraulic product.
- For other installation positions, contact Liebherr customer service.
- Housing is completely filled with hydraulic fluid during commissioning and operation.
- Housing is vented after commissioning and during operation.
Note
Liebherr recommends:
Installation variant: Under-the-tank installation A
Installation location: 1/3/5/7/9/11 Driving shaft horizontal with "control at top"
4 Installation conditions
4 Installation conditions
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Page 28
4.1.2 Leakage oil lines
To prevent draining of the axial piston unit during long downtimes, the leakage oil line must be routed in a bend
so that it runs at the minimum dimension Ü1 = 30 mm above the highest possible level of the axial piston unit.
This applies in particular to installation variant B: over-the-tank installation.
Connect the leakage oil line to the top leakage oil connection T1, T2, T3....Tx depending on the installation position.
The leakage oil line must open into the tank at a minimum distance of 115 mm from the tank bottom to prevent
stirring up dirt particles in the tank.
The leakage oil line must open into the tank at a minimum distance of 250 mm below the minimum liquid level
to prevent foaming in the tank.
The leakage oil line must open into the tank at a maximum distance from the suction line to prevent hot leakage
oil from being sucked in directly.
At low temperatures with high viscosities, it is essential to observe the maximum housing pressure for axial pis-
ton units with multiple driving gears and with a shared leakage oil line. (For additional information see: 2.3.2
Housing, leakage oil pressure, page 9) If the maximum housing pressure is outside the tolerance limit, a separate
leakage oil line must be connected for each driving gear.
4.1.3 Hydraulic fluid tank
Design the hydraulic fluid tank so that the hydraulic oil cools off sufficiently during circulation and impurities
that develop during operation settle to the bottom of the tank.
Make sure that the lines are connected according to recommendations and that they open into the hydraulic flu-
id tank. (For additional information see: 4.1.1 Suction line, page 27 and For additional information see: 4.1.2 Leak-
age oil lines, page 28)
4 Installation conditions
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Page 29
4.2 Installation variants
4.2.1 Under-the-tank installation variant
Note
Liebherr recommends: Under-the-tank installation A, so that:
- There is hydraulic fluid at suction port S when not operated.
- The housing cannot empty to the tank.
1
Baffle (to calm the hydraulic fluid
in the tank)
M
Minimum line end distance
from tank bottom = 115 mm
B
Distance between suction port and leakage
oil connection in the tank (the larger the better)
S Suction line connection
D
Fill and vent connection (external,
not included in scope of delivery)
T Tank
E Minimum immersion depth = 250 mm T_
Leakage oil connections T1 / T2 / T3 / T4
(T4 = optional)
4 Installation conditions
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Page 30
4.2.2 Over-the-tank installation variant
ATTENTION
Damage of the hydraulic product.
The air cushion in the bearing area or on the rotary shaft lip seal “runs hot” in over-the-tank installa-
tion position (installation variant B)! Make sure that the following requirements are observed:
- Housing is completely filled with hydraulic fluid during commissioning and operation.
- Housing is vented after commissioning and during operation.
Note
To prevent draining of the axial piston unit during long shutdowns, the leakage oil line must be
routed in a bend so that it runs at the minimum dimension Ü1 = 30 mm above the highest possible
level of the axial piston unit.
1
Baffle (to calm the hydraulic fluid
in the tank)
M
Minimum line end distance
from tank bottom = 115 mm
B
Distance between suction port and leakage
oil connection in the tank (the larger the better)
S Suction line connection
4 Installation conditions
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Page 31
D
Fill and vent connection (external,
not included in scope of delivery)
T Tank
E Minimum immersion depth = 250 mm T_
Leakage oil connections T1 / T2 / T3 / T4
(T4 = optional)
H Maximum suction head = 750 mm Ü1 Minimum leakage oil line height = 30 mm
5 Dimensions
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Page 32
5.1 Main dimensions
5.1.1 Control type LR-SD-DA
DPV O 550 / 082 LR-SD-DA 1 L 31 1 A I 00 K02G 0 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
F
F
B
B
315 e8
-0.110
-0.191
()
93
47
30
16
220
382.5
24
118
140
150
1
25
29
125
152.4
0.2
92.1
0.2
46.05
0.2
76.2
0.2
M
depth 24
16
15
52
414
315
14
27
M
(8x)
20
47.9
274.1
3.5
441
174.5174.5
343
195
181
269
232
406.5
170
462
341
17
381
12
M
8
12
M
8
17
381
80
328
241
21.5
17.5
17.3
M
x1.5
26
174.5
P1
GS
M3
W80x3x25x9g
DIN 5480
SS
A1
SECTION
D-D
A-A
F-F
TS
SECTION
B-B
Fa
X3
X5
X1
M2
BS1
BS2
M1
Vg min.
TS
S
SECTION
B-B
E-E
A
Z
P2
LR
SD
DA
DB-DPVO 550-018
604
624
590
Location of centre of gravity
5 Dimensions
5 Dimensions
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Page 33
P1 Thread for suspending the pump P2 Angle indicator (unscrew the cover)
A1 / A2
Working connection (SAE J518) 2",
6000 psi
T
Leakage oil connections,
oil filler neck or oil drain
S Suction port (SAE J518) 5", 500 psi Fa Filter outlet ISO 9974-1
M3
Suction pressure measuring port,
Minimess port
M2
High pressure measuring port,
Minimess port
D
D
255
200
602.5
306
235
541
(8x)
21
M
(2x)
16
145145
360
75
221.5
240
246
232
123.5
319.5
349.5
T
X6
DB-DPVO 550-019
5 Dimensions
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Page 34
5.2 Mounting flange
DIN / ISO 3019-2
5.3 Shaft end
Splined shaft DIN 5480 W80x3x25x10g, with undercut
M1
Regulated high pressure,
Minimess port
X6
Vgmin regulation (deactivated)
screw connection DIN3901-L-12M
X1 SD steering pressure ISO 9974-1 TS Thermostatic switch ISO 9974-1
X3 LR steering pressure ISO 9974-1 SS Dirt switch ISO 9974-1
X5 DA- override pressure ISO 9974-1 GS Housing flushing ISO 9974-1
BS1 / BS2 Acceleration sensor thread - -
DPV O 550 / 082 LR-SD-DA 1 L 31 1 A I 00 K02G 0 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
31
(8x)
21
DB-DPVO 550-020
16
315 e8
-0.110
-0.191
()
47
30
360
22.5°
8x
45°
DPV O 550 / 082 LR-SD-DA 1 L 31 1 A I 00 K02G 0 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
1
DB-DPVO 550-021
W80x3x25x10g
DIN 5480
91.6
48.4
R3
5 Dimensions
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Page 35
5.4 Through-drive
5.4.1 Axial piston unit with preparation for mounting kit
5.4.2 Axial piston unit with mounting kit Ø180 mm
Shaft spline DIN 5480 N45x2x21x9H
DPV O 550 / 082 LR-SD-DA 1 L 31 1 A I 00 K02G 0 0
1. 2. 3 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
Note
Preparation for adapter mounting kit, closed with cover.
Dimensions for axial piston unit with preparation for mounting kit; see main dimensions.
K02G
Note
To use the through drive, the selected adapter mounting kit including coupling ferrule (see installa-
tion drawing) must be ordered separately, the cover removed and the adapter mounting kit installed.
U32D
DB-DPVO 550-023
A
A
B
B
180 H7
+0.04
0
()
61.95
241.6
22.6
170
145.6
95 95
105.8 105.8
34.6
SECTION
A-A
11
10
20
N45x2x21x9H
DIN 5480
5 Dimensions
Date: 04/2023 Version: 1.0 ID No.: 13877152
Page 36
5.4.3 Axial piston unit with mounting kit SAE B
Shaft spline ANSI B 92.1a-1976 -1 in 15T 16/32 DP
5.4.4 Axial piston unit with mounting kit, nominal size 550
Shaft spline DIN 5480 W55x1.25x42x9g
Note
To use the through drive, the selected adapter mounting kit including coupling ferrule (see installa-
tion drawing) must be ordered separately, the cover removed and the adapter mounting kit installed.
B21D
DB-DPVO 550-024
A
A
101.6
+0.05
+0.02
146
0.2
20
221
47.9
14
SECTION
A-A
10
21
11
12
20
1
Note
To use the through drive, the selected adapter mounting kit including coupling ferrule (see installa-
tion drawing) must be ordered separately, the cover removed and the adapter mounting kit installed.
K33D
DB-DPVO 550-025
207
130
46
10
20
W55x1.25x42x9g
DIN 5480
5 Dimensions
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Page 37
5.5 Multi-circuit pump
Multi-circuit pumps consisting of 2 or more single units can be supplied on request.
The complete type code must be filled out separately by the customer for each single unit.
These type codes must be written on separate lines. Each single unit has its own type plate.
An abbreviated type designation on an additional type plate attached to the product is used to identify the
multi-circuit pump; see example: DPM
The pump type (type code 1) changes from DPV to DPM.
If all the single units are in the open circuit (type code 2), the type code O stays on the type plate. If there is a
mix between the circuits, the type code changes from O to Y. See the type plate of the single unit for details
about the single units.
The nominal sizes (type code 3) and control types (type code 4) must be separated by a "+".
Write after the last control type (type code 5) for the direction of rotation. (Spaces required before and after the letter)
550+550 / LR-SD-DA+LR-SD-DA _ _
1. 2. 3 4. 5.
Liebherr Machines Bulle SA Rue Hans-Liebherr 7 1630 Bulle/FR, Switzerland
Phone +41 26 013 31 11 , Fax +41 26 013 34 85 info.lmb@liebherr.com www.liebherr.com
Changes, conditions, copyright
Subject to changes without prior notice in the course of technical development.
All texts, images, graphics, tables and other illustrations and their layout are protected by copyright.
The contents of this catalogue may not be copied, distributed, modified or made available to third par-
ties without the express written consent of Liebherr Machines Bulle SA. Some of the images in this data
sheet are subject to third-party copyright.
The information in this data sheet does not release the users from the obligation to complete their own
assessments and tests. The content has been prepared with the greatest possible care.
Nevertheless, no guarantee can be given for the information provided being accurate, complete or
up-to-date.
The data sheet mostly shows an example configuration, unless otherwise stated. The product delivered
to you may therefore differ from the illustrations. Data and values may also deviate. Such data and val-
ues are provided only for the purpose of selecting the product configuration and are not binding. There-
fore, use the values from the installation drawing provided to you.
Warranty and liability conditions under the general terms and conditions of the relevant Liebherr busi-
ness partner are not extended by the above information.
The latest versions of Liebherr's data sheets are available on our website at https://www.liebherr.com.
Do you have any questions? Get in touch with your contact for further information.
Subject to change without prior notice. Copyright © Liebherr Machines Bulle SA
For simplicity, we only use the masculine form without any intention to discriminate.
The masculine is treated as a gender-neutral form. It is used to refer to all gender identities.
