The robust Flange-mounted axial piston motor of the se-
ries DMFA have been developed especially for use in
mobile machinery for tough environmental conditions.
The swashplate design with a constant swing angle is
ideal for applications that require a constant displace-
ment.
Due to its cleverly devised modular system, DMFA the
basic engine can be combined as desired with various
special through-drives, mounting flanges, shaft ends
and sensors. p
N
p
N
Configuration is even possible with an external, flanged
multi-disc brake with a special flange and end-to-end
drive shaft.
Applies to:
DMFA 355
Features:
Series D
Constant motor
Open-loop and closed-loop circuit
Nominal pressure p
N
= 400 bar
Maximum pressure p
max
= 450 bar
Document identification:
ID number: 11444561
Issue: 03/2016
Applies to: DMFA 355
Authors: Liebherr - Departments: ED5/HR1
Version: 1.0
Flange-mounted axial piston motor with
constant displacement: DMFA
Data sheet
Table of Contents
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
2
1 Type code 3
2 Technical data 1
2.1 Table of values 4
2.2 Rotation direction 5
2.3 Permissible pressure range 5
2.4 Shaft seal ring 7
2.5 Housing flushing 8
2.6 Hydraulic schematics 9
2.7 Sensor system 11
2.8 Hydraulic fluids 12
3 Installation conditions 16
4.1 Installation variants 17
4.2 Mounting positions 18
4 Dimensions 19
4.1 NG 355/MH/Flush, open-loop circuit with high-pressure relief 19
4.2 NG 355/SO/Flush, closed-loop circuit 20
4.3 NG 355 Mounting flange 21
4.4 NG 355 Shaft end 22
4.5 Through-drive DIN 5480 23
1 Type code
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
3
x Available
-on request
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
DMFA 355 00 1 W A
1. Motor type
Series D/Motor/Fixed/Mounted DMFA
2. Circuit type
closed X G
open X O
3. Nominal size (NG) = displacement V
g max
in cm
3
NG 355
4. Actuation / control type
Without activation/regulation 00
5. Version
1
6. Direction of rotation with view of the drive shaft
Alternating W
7. Mounting flange
ISO 3019-2 - 31
Special flange X 51
8. Shaft end
Splined shaft
DIN 5480
X
1
ANSI B92.1a
-
2
Feather key shaft DIN 6885 (form A)
X
3
9. Ports/connectors
High-pressure connection (SAE J518) 6000 PSI A
10. Accessories
No attachment X 0
Multi-disc brake - L
11. Through-drive
No through-drive (closed) - 0
Custom through-drive X K
12. Valve
Flush/open-loop circuit with high-pressure relief X MH
Flush closed-loop circuit X SO
13. Sensor system
Without sensor X 0
Motor speed sensor X D
Note
Contact addresses for queries can be found on the reverse side of this document.
1 Type code
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
4
2.1 Table of values
Nominal size 355
Displacement
V
g max
cm
3
355.6
V
g min
cm
3
-
Flow rate at n
max
qv
max
l/min 853
Max. rotational speed at V
g max
and 8 b a r o n th e
low-pressure side
n
max
rpm 2400
Output torque at V
g max
and Δp = 360 bar M
max
Nm 2037
Drive power for qv
max
and Δp = 360 bar p
max
kW 512
Drive shaft mass moment of inertia
J
TW
kgm
2
0.13
Mass (approx.) M Kg 140
Max. radial force
F
q max
N
The permissible forces result from the load
collective. Please contact Liebherr Customer
Service when planning a belt drive.
Max. axial load
F
a± max
N
Send values to Liebherr Customer Service
with your query.
Note
The values provided (maximum data) are theoretical values, rounded, without efficiencies and tolerances.
2 Technical data
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
5
2.2 Rotation direction
2.3 Permissible pressure range
2.3.1 Operating pressure:
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
DMFA 355 00 1 W A
The direction of rotation is provided with a view of the drive
shaft, as depicted in the illustration.
R
Right = Clockwise
L
Left = counterclockwise
W
Alternating = Depending on control signal on A / B
Operating pressure on port A / B
Nominal size Open-loop circuit Closed-loop circuit
Nominal pressure (sustained operation)
p
N
Bar 400 400
Maximum pressure (short term)
p
max
Bar 450 450
Note
Definition of "short term": unless stated otherwise: t < 1s, t
total
= 300 Oh.
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
6
2.3.2 Minimum operating pressure
In order to prevent cavitation at maximum speed in the deceleration, there must be at least an applied pressure in
the pneumatic circuit, measured on the low-pressure side, e.g. M1 or M2 (if not available on A/B), of pHD
min
= 8 bar.
These values depend on external circumstances, such as the type of hydraulic oil used or the temperature, and
need to be calculated for each specific case. Values upon request.
2.3.3 Housing pressure, leakage-oil pressure
The housing or leakage oil pressure pL must not exceed maximum values, see chapter 2.4.3 for threshold values.
The number of leakage oil connections T can vary depending on the application.
U* Drain port U is optional and only designed to be used for an externally connected multi-disc brake.
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
7
2.4 Shaft seal ring
2.4.1 General
The rotary shaft seals (RWDR) from Liebherr are special sealing elements that permit a specific casing pressure.
In order to ensure that the tribological system functions optimally, the operating conditions must be observed.
Sealing edge temperature varies due to the following factors in the housing:
- Peripheral speed
- Hydraulic fluid temperature
- Lubricant
- Pressure buildup
The sealing edge temperature is between 20°C and 40°C above the leak-oil temperature of a hydraulic
axial-piston unit.
2.4.2 Temperature range
The FKM radial shaft seal ring is rated for housing temperatures from -25°C to +115°C.
In the case of use below -25°C: Contact Liebherr Machines Bulle SA Customer Service.
2.4.3 Rated pressure load for hydraulic motors
The service life of the radial shaft seal ring is influenced by the engine speed "n" of the axial piston unit and the
leakage oil pressure "p
L
". The sustained leakage oil pressure "p
L
" should not exceed 3 bar
abs
. at operating
pressure. The maximum rated leakage oil pressure is 6 bar absolute at reduced engine speed (see chart).
Short-term pressure peaks of max. 10 bar abs. are permitted for a short duration (t < 0.1 s). The more pressure
peaks that occur, the shorter the service life of the shaft seal. The pressure in the axial piston unit must always be
higher than the outer pressure on the shaft seal.
Shaft diameter (mm) Nominal size
70 355
Permissible pressure p
abs.
max.
Engine speed n in rpm
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
8
2.5 Housing flushing
Under various operating conditions, such as a very low volumetric flow rate over an extended period, a boundary
value increase in temperature could occur in the housing. see chapter 2.8
Depending on the hydraulic system design, a flushing circuit 1 may be required for cooling and filtration that directs
the "hot" hydraulic oil to an external cooling unit, where the oil is cooled and then fed back into the hydraulic system.
The flushing quantity Q
V
in l/min must be individually set for each nominal size in connection with the application
and is the responsibility of the device or system manufacturer.
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
9
2.6 Hydraulic schematics
2.6.1 MH/Flush, open-loop circuit with high-pressure relief
Note
The following applies to flushing:
Closed circuit = flushing mandatory
Abbreviation Designation Abbreviation Designation
A, B Working ports SAE J 518 T1, T2 Leakage-oil connections ISO 9974-1
M1, M2
High-pressure measuring connections
ISO 9974-1
- -
Note
Oil entry for port A: Direction of rotation = right
Oil entry for port B: Direction of rotation = left
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
10
2.6.2 SO/Flush, closed-loop circuit
Abbreviation Designation Abbreviation Designation
A, B Working ports SAE J 518 T1, T2 Leakage-oil connections ISO 9974-1
E3 Speed sensor connection V
Drain port ISO 9974-1 (for external
multi-disc brake)
Note
Oil entry for port A: Direction of rotation = right
Oil entry for port B: Direction of rotation = left
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
11
2.7 Sensor system
Motor speed sensor
General information
- E5: Deutsch connector DT04-4P-CE04
- Technical specifications in accordance with BA 374E-64799
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
DMFA 355 00 1 W A
0 Without sensor
D With motor speed sensor
Note
The motor speed sensor cannot be retrofitted and needs to be taken into account when the DMFA
is reconfigured.
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
12
2.8 Hydraulic fluids
2.8.1 General
The selection of the suitable hydraulic fluid is substantially influenced by the expected operating temperature
depending on the ambient temperature that is equivalent to the tank temperature.
Use the comparative oil values for the selection of the suitable hydraulic fluid. see chapter 2.8.5
2.8.2 Operating limits
Depending on the operating temperature, the appropriate oil must be selected taking into account the viscosity cha-
racteristics according to the following conditions:
- Cold start: max. approx. 1600 mm
2
/s *
- Normal operation: at or above approx. 500 mm
2
/s *
- Optimal range of application: 16-36 mm
2
/s *
-
At max. leakage-oil temperature, the viscosity must not be below 8 mm
2
/s (short term, meaning < 3 min., 7mm
2
/s).
- The shear stability (KRL) has to be observed for multigrade oils.
*) open circuit: relative to reservoir temperature
Closed circuit: relative to circuit temperature
In addition to the viscosity characteristics, the Liebherr GSP specification ID No. 10465804 must be observed.
2.8.3 Filling quantity
The required filling quantity can be customized; values upon request.
2.8.4 Filtering
- To maintain the specified purity class "21/17/14 according to ISO 4406" under all circumstances,
filtering the hydraulic fluid is required.
- The hydraulic fluid is filtered by means of the device-specific use of oil filters in the hydraulic system.
- Cleaning and maintenance intervals of the oil filter and for the entire oil circuit depend on the
device usage, and are found in the device-specific operating manual.
ATTENTION
Mixing various mineral oil pressure fluids is prohibited!
Note
The hydraulic unit must be filled with oil and bled prior to initialization.
This must be inspected during operation and after extended downtime, and must be
repeated as necessary!
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
13
2.8.5 Comparative oil values
*) Preheating is mandatory at temperatures below -25°C.
**) Applicable to Liebherr Mining Excavators: -40°C to +45°C (at temperatures below -25°C, the use of the
appropriate Liebherr Arctic Kit must be used).
***)Preheating is mandatory at temperatures below -40°C.
1
) Applicable to Liebherr Mining Excavators: -50°C to +30°C (at temperatures below -30°C, the appropriate
Liebherr Arctic Kit must be used).
2
) For use in automatic transmissions.
3
) For use in cranes.
4
) For use in Liebherr cranes.
5
) The two high-performance oils Liebherr Hydraulic Plus and Liebherr Hydraulic Plus Arctic on the basis of
Polyalphaolefines (PAO) from the group of HEPR oils are bio-degradable (bio-degradability (21 days, also
called primary degradation) in accordance with CEC-L-103-12 ≥ 60%) and are suited for use in environmentally
sensitive regions.
Oil grade
Outdoor operating
temperature
°
C
Density at 15 °C
kg/m
3
Viscosity
class ISO
VG
Kinematic
viscosity at
40/100 °C
mm²/s
Pour
point
°
C
Liebherr Hydraulic Basic 68
(standard)
-10 to +45 882 68 68/8.7 -24
Liebherr Hydraulic Basic 100
(hot countries)
+/- 0 to +55 882 100 100/11.5 -18
Multi-range oils
Liebherr Hydraulic HVI
(low temperatures)
-20 to +40 877 46 (32-68) 46/8.3 -39
Liebherr Hydraulic Plus
5
(low temperatures)
-25* to +45 +** 838 46 (32-68) 46/9.5 -45
Liebherr Hydraulic Plus Arctic
5
(low temperatures)
(-40*** to +30)
1
828 15-46 07/25/2004 < -54
Liebherr Hydraulic Gear ATF
(crane hydraulics)
(-40 to +50)
2
(-25 to +50)
3
877 - 39/7.2 -45
Liebherr Hydraulic 37
(crane hydraulics)
(-25 to +50)
4
870 32-46 37/7.2 -39
Liebherr Hydraulic FFE 30
(crane hydraulics,
low temperatures)
(-40 to +50)
4
844 15-46 07/28/2005 < -51
Note
Primary degradation: The test method directly measures oil dispersion up to the degradation phase
of water solubility.
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
14
2.8.6 Viscosity diagrams
2 Technical data
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
15
3 Installation conditions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
16
When configuring the axial piston unit, the installation version planned for the device, the system, or the drive engine
in combination with the installation orientation must be coordinated with Liebherr and approved by Liebherr.
The default values from Liebherr are therefore only rough settings and may have to be readjusted in the device, the
plant, or the drive motor.
Below the minimum liquid level, the leakage lines must flow into the tank in every mounting position in order to pre-
vent the building up of foam.
The oil tank must be designed in such a manner that the hydraulic fluid cools sufficiently during circulation and any
impurities are deposited on the floor of the tank.
Note
Liebherr differentiates axial piston units into two installation versions A and B and into six installation
orientations 1-6.
Note
Recommended installation variant(s):
Below-tank installation A
Installation variant(s) to be avoided:
None
Note
Recommended mounting position(s):
Drive shaft horizontal
Mounting position(s) to be avoided:
None
3 Installation conditions
3 Installation conditions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
17
3.1 Installation variants
Below-tank installation “A”: Axial piston unit is installed below the minimum fluid level of the tank.
Above-tank installation “B”: Axial piston unit is installed above the minimum fluid level of the tank.
Note
When using the DMFA in a closed circuit configuration, the installation version is irrelevant because of
the missing reservoir.
Abbreviation Designation Comment
4 Swash plate for pacifying the hydraulic fluid in the tank
L1, L2...LX leak-oil pipe
The shown supply line to the reservoir is only for
illustration. Other connection versions are possible.
Observe line end clearance M!
M
Minimum distance from the end of the line to
the floor of the tank
Select minimum large enough to prevent dirt from
being sucked in!
T Tank -
T1 Leakage oil connection -
3 Installation conditions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
18
3.2 Installation orientations
There are six possible installation orientations for each of the three installation versions.
Note
Please consult Liebherr for installation orientation 3.
ATTENTION
An air buffer in the bearing area or on the radial shaft seal ring, in particular for installation orientation
1 and 3, can result in damage to the hydraulic unit e.g. due to overheating. During commissioning and
operation, make certain that the housing is completely filled with hydraulic fluid and has been bled.
Regularly inspect the hydraulic fluid level in the housing space; re-initialize if necessary.
Note
To prevent emptying of the axial piston unit in mounting position 3 and installation variant B, a check valve
with an opening pressure of max. 0.5 bar can be installed in the leakage-fluid line after consultation with
Liebherr.
4 Dimensions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
19
4.1 NG 355/MH/Flush, open-loop circuit with high-pressure relief
A, B Working ports SAE J 518 T1, T2 Leakage-oil connections ISO 9974-1
M1, M2
High-pressure measuring connections
ISO 9974-1
- -
4 Dimensions
4 Dimensions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
20
4.2 NG 355/SO/Flush, closed-loop circuit
A, B Working ports SAE J 518 T1, T2 Leakage-oil connections ISO 9974-1
E3 Speed sensor connection V
Oil leakage port ISO 9974-1 (for external multi-
disc brake)
4 Dimensions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
21
4.3 NG 355 Mounting flange
Special flange
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
DMFA 355 00 1 W A
51
4 Dimensions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
22
4.4 NG 355 Shaft end
DIN 5480 Splined shaft W60x2x28x9g
DIN 6885 Feather key shaft (form A)
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
DMFA 355 00 1 W A
1
3
4 Dimensions
Flange-mounted axial piston motor
DMFA 355
Date: 03/2016
Version: 1.0
ID No.: 11444561
23
4.5 Through-drive DIN 5480
4.5.1 NG 355 Custom through-drive shaft
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
DMFA 355 00 1 W A
K
W45x1.25x34x9g
Sales
Liebherr-Components AG
Postfach 222, CH-5415 Nussbaumen /AG
+41 56 296 43 00, Fax +41 56 296 43 01
www.liebherr.com, E-mail: info.cos@liebherr.com
Development / Production
Liebherr Machines Bulle SA
45 rue de l'Industrie, CH-1630 Bulle / FR
+41 26 913 3479, Fax: +41 26 913 3485
www.liebherr.com, E-mail: info.lmb@liebherr.com
Changes, conditions, copyright
Over the course of technical development, we reserve the right to make changes without prior announcement.
©: Information and images in this data sheet may neither be duplicated and distributed nor used for commercial
purposes. All rights are expressly reserved for Liebherr according to copyright law, including in the event of
applications for industrial property rights.
The information in this data sheet does not release the user from the obligation to perform his own assessments and
tests.
If not otherwise indicated, this data sheet primarily illustrates an example configuration
(DMFA 355) illustrated. Therefore, the product delivered to you may deviate from the illustration.
Deviations are also possible for data and values in this data sheet. These only serve as the default selection for the
product configuration, and they are not binding. Unless stated otherwise, the indicated values always refer to the
example configuration (DMFA 355). Always use the values from the installation drawing that was delivered to you.
Warranty and liability conditions of the General Conditions of Business of Liebherr Machines Bulle SA and Liebherr-
Components AG are not extended by the above notice.
