Bosch rexroth SYDFED 2X Series User manual

Operating instructions
RE 30017-B Edition: 11.2021, replaces: 01.2015
Pressure and flow
control system
SY(H)DFED
SYDFED series 2X
SYDFED series 3X
SYHDFED series 1X
Valid for the following types:

The data specified only serve to describe
the product. If information on the use of the
product is given, it is only to be regarded as
application examples and recommendations.
Catalog specifications do not constitute
assured characteristics. The information given
does not release the user from the obligation
of own judgment and verification. It must be
remembered that our products are subject to
a natural process of wear and aging.
© This document, as well as the data,
specifications and other information set forth
in it, are the exclusive property of Bosch
Rexroth AG.
It may not be reproduced or given to third
parties without its consent.
The cover shows an example configuration.
The product delivered may differ from the
image on the cover.
Translation of the original operating
instructions. The original operating
instructions were prepared in German
language.

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
Content | SYDFED-2X, SYDFED-3X, SYHDFED-1X 3/96
Content
1 About this documentation....................................................................... 6
1.1 Validity of the documentation.....................................................................6
1.2 Required and supplementary documentation .............................................6
1.3 Representation of information  ...................................................................7
1.3.1 Safety instructions......................................................................................7
1.3.2 Symbols......................................................................................................8
1.3.3 Designations...............................................................................................8
1.3.4 Abbreviations..............................................................................................8
2 Safety instructions................................................................................ 10
2.1 About this chapter ....................................................................................10
2.2 Intended use ............................................................................................10
2.3 Improper use ............................................................................................10
2.4 Qualification of personnel ........................................................................11
2.5 General safety instructions.......................................................................11
2.6 Product- and technology-related safety instructions.................................12
2.7 Personal protective equipment.................................................................14
2.8 Obligations of the machine end-user ........................................................14
3 General notes on damage to property and damage to the product......... 15
4 Scope of delivery .................................................................................. 16
5 Product description .............................................................................. 17
5.1 Performance description ..........................................................................17
5.2 Device description....................................................................................17
5.2.1 Functional description, section of SY(H)DFED..........................................17
5.3 Control of the SY(H)DFED control system ................................................21
5.3.1 Structure of the control ............................................................................21
5.3.2 Controller parameters ..............................................................................22
5.3.3 Controller parameter sets.........................................................................22
5.3.4 Special operating modes ..........................................................................23
5.3.5 Operating pressure limits .........................................................................27
5.3.6 Internal/external pilot oil..........................................................................27
5.4 Ambient conditions...................................................................................29
5.4.1 Oil-immersed applications........................................................................29
5.4.2 Ambient temperature................................................................................29
5.5 Notes on the selection of hydraulic fluids.................................................29
5.6 Generation of noise ..................................................................................31
5.6.1 Generation of noise in the power unit ......................................................31
5.6.2 Pulsation damper .....................................................................................31
5.7 Shaft variant .............................................................................................32
5.8 Spool variants of pilot valve VT-DFPD-X-1X...............................................32
5.9 Master/slave operation .............................................................................33
5.9.1 Circuitry of SY(H)DFED.............................................................................33
5.10 Description of the commissioning tool IndraWorks ..................................35
5.10.1System requirements................................................................................35
5.10.2Firmware update.......................................................................................36
5.11 Switch-on sequence of electronics/hydraulics..........................................36
5.12 Identification of the product.....................................................................37
6 Transport and storage ........................................................................... 38
6.1 Transporting the SY(H)DFED control system ............................................38
6.1.1 Transport using lifting gear.......................................................................39
6.2 Storing the SY(H)DFED control system.....................................................40

4/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Content
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
7 Installation ........................................................................................... 42
7.1 Unpacking.................................................................................................42
7.2 Installation conditions ..............................................................................42
7.3 Installation positions and piping of SY(H)DFED systems ..........................43
7.3.1 General information..................................................................................43
7.3.2 Piping .......................................................................................................44
7.4 Installing the SY(H)DFED control system..................................................46
7.4.1 Preparations .............................................................................................46
7.4.2 Dimensions of connections.......................................................................47
7.4.3 General notes...........................................................................................47
7.4.4 Installation with coupling .........................................................................47
7.4.5 Completing the installation ......................................................................48
7.5 Connecting the SY(H)DFEE control system hydraulically ..........................48
7.6 Connecting the SY(H)DFED control system electrically ............................52
7.6.1 Cabling of electronic components ............................................................52
7.6.2 Electrical connection of the pilot valve ....................................................53
7.6.3 Connection to the swivel angle sensor .....................................................53
7.6.4 X2M1 and X2M2: Analog, configurable sensor interface (coding A), M12,
5-pin, socket.............................................................................................54
7.6.5 X7E1 and X7E2: Plug-in connector pinout for Ethernet interface (coding D),
M12, 4-pin, socket ....................................................................................54
7.6.6 LED status indicator lamps.......................................................................55
7.6.7 Power supply of the VT-DFPD pilot valve ..................................................55
7.6.8 Selection, place of installation and mounting orientation of the pressure
transducer ................................................................................................56
8 Commissioning ..................................................................................... 58
8.1 Initial commissioning................................................................................59
8.1.1 Filling the SY(H)DFED control system.......................................................59
8.1.2 Testing the hydraulic fluid supply .............................................................60
8.1.3 Performing a flushing cycle.......................................................................60
8.1.4 Connection to the control (IndraWorks) ...................................................60
8.1.5 Making basic settings on the control electronics......................................61
8.1.6 Switching on the drive motor of the pump................................................64
8.1.7 Bleeding the pre-load valve ......................................................................65
8.1.8 Setting controller parameters...................................................................65
8.1.9 Calibrating the SY(H)DFED control system ...............................................70
8.2 Recommissioning after standstill..............................................................71
8.3 Running-in phase......................................................................................71
9 Operation.............................................................................................. 72
10 Maintenance and repair ........................................................................ 73
10.1 Cleaning and care.....................................................................................73
10.2 Inspection.................................................................................................73
10.3 Maintenance .............................................................................................74
10.4 Repair.......................................................................................................74
10.5 Spare parts...............................................................................................75
10.5.1Replacement of components ....................................................................75
10.5.2Test devices, assembly tools and note on commissioning.........................77
11 Decommissioning.................................................................................. 77
12 Demounting and replacement ............................................................... 78
12.1 Required tools ..........................................................................................78
12.2 Preparing demounting ..............................................................................78
12.3 Demounting..............................................................................................78
12.4 Preparing the components for storage or further use ...............................78
13 Disposal................................................................................................ 79
13.1 Environmental protection .........................................................................79
13.2 Return to Bosch Rexroth AG .....................................................................79
13.3 Packaging .................................................................................................79
13.4 Materials used ..........................................................................................79
13.5 Recycling ..................................................................................................80

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
Content | SYDFED-2X, SYDFED-3X, SYHDFED-1X 5/96
14 Extension and modification................................................................... 80
15 Troubleshooting.................................................................................... 81
15.1 How to proceed for troubleshooting.........................................................81
15.2 Error/diagnostic memory..........................................................................81
15.2.1Error diagnosis .........................................................................................82
15.3 Fault table ................................................................................................83
15.3.1Swivel angle measurement check .............................................................86
16 Technical data....................................................................................... 87
17 Annex ................................................................................................... 88
17.1 List of addresses ......................................................................................88
17.2 Open Source Software .............................................................................89
18 Alphabetical index................................................................................ 92

6/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | About this documentation
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
1 About this documentation
1.1 VALIDITY OF THE DOCUMENTATION
This documentation is valid for the following pressure/flow control systems:
• SYDFED series 2X
• SYDFED series 3X
• SYHDFED series 1X
This documentation is intended for engineers, fitters, operators, service
technicians and plant operators.
This documentation contains important information on the safe and appropriate
installation, transport, commissioning, operation, use, maintenance, disassembly
and simple troubleshooting of the pressure and flow control systems SYDFED
series 2X, 3X and SYHDFED series 1X.
▶ Read this documentation thoroughly, especially Chapter 2 “Safety instructions“
and Chapter 3 “General notes on damage to property and damage to the
product“, before working with the pressure/flow control system.
1.2 REQUIRED AND SUPPLEMENTARY DOCUMENTATION
▶ Only commission the product, when you have the documents marked with the
book symbol at hand and have understood and observed them.
Table 1: Required and supplementary documentation
Title Document no. Document type
Order confirmation
Installation drawing
General instruction manual for axial piston units RE 90300-B Operating instructions
Pressure and flow control system, type SYDFE1, SYDFEE, SYDFED,
SYDFEF, component series 2X
RE 30030 Data sheet
Pressure and flow control system, type SYHDFEE, SYHDFED, SYHDFEF,
component series 1X
RE 30035 Data sheet
Pressure and flow control system, type SYDFE1, SYHDFEE, SYDFED,
SYHDFEF, component series 3X
RE 30630 Data sheet
Axial piston variable pump A10VSO series 31, sizes 18 to 100 RE 92711 Data sheet
Axial piston variable pump A10VSO series 32, sizes 45 to 180 RE 92714 Data sheet
Axial piston variable pump A4VSO Series 1x and 3x,
Size 40...1000
RE 92050 Data sheet
Axial piston variable pump A4VSO Series 1x and 30 for HFC hydraulic
fluids
RE 92053 Data sheet
Fire-resistant hydraulic fluids - containing water (HFAE, HFAS, HFB, HFC) RE 90223 Data sheet
Hydraulic fluids based on mineral oils and related hydrocarbons RE 90220 Data sheet
Pump pre-load valve for the SYDFE control system RE 29255 Data sheet
Proportional directional valves, direct operated, with electrical position
feedback as pilot control valve for control systems SY(H)DFE.,
Type VT-DFP.
RE 29016 Data sheet
Swivel angle sensor, type BAUSATZ VT-SWA-1 RE 30268 Data sheet
Pressure transducer for hydraulic applications, type HM20 RE 30272 Data sheet
Pressure transducer for hydraulic applications, type HM20 RE 30272-B Operating instructions

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
About this documentation | SYDFED-2X, SYDFED-3X, SYHDFED-1X 7/96
Title Document no. Document type
Installation, commissioning and maintenance of hydraulic systems RE 07900 Data sheet
Rexroth HydraulicDrive HDS-16, HDx17 to HDx-20 Functions RE 30338-FK Functional description
Rexroth HydraulicDrive HDS-16, HDx17 to HDx-20 Parameters RE 30330-PA Parameter description
Rexroth HydraulicDrive HDS-16, HDx17 to HDx-20 Diagnostic Messages RD 30330-WA Description of
diagnostic messages
Rexroth HydraulicDrive HDx-20 pump control RE 30237-Z Supplementary
information
1.3 REPRESENTATION OF INFORMATION
In order that this documentation allows you to work directly and safely with your
product, standardized safety notes, symbols, terms, and abbreviations are used.
For a better understanding, they are explained in the following sections.
1.3.1 Safety instructions
In this documentation, safety instructions precede a sequence of activities
whenever there is a risk of personal injury or damage to equipment. The hazard
avoidance measures described must be observed.
Safety instructions are structured as follows:
SIGNAL WORD
Type and source of danger
Consequences in case of non-compliance
▶ Hazard avoidance measures
▶ <Enumeration>
• Warning symbol: draws attention to a hazard
• Signal word: identifies the degree of hazard
• Type and source of danger: Specifies the type and source of danger
• Consequences: describes the consequences in case of non-compliance
• Precautions: states, how the hazard can be avoided
Table 2: Hazard classifications according to ANSI Z535.6-2011
Warning sign, signal word Meaning
DANGER Indicates a hazardous situation which, if not avoided, will
certainly result in death or serious injury.
WARNING Indicates a hazardous situation which, if not avoided, could
result in death or serious injury.
CAUTION Indicates a hazardous situation which, if not avoided, could
result in minor or moderate injury.
NOTICE Damage to property: The product or the environment could
be damaged.

8/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | About this documentation
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
1.3.2 Symbols
The following symbols indicate notices which are not safety-relevant but increase
the comprehensibility of the documentation.
Table 3: Meaning of the symbols
Symbol Meaning
If this information is disregarded, the product cannot be used or operated in an
optimum manner.
▶ Individual, independent action
1.
2.
3.
Numbered instruction:
The numbers indicate that the actions must be carried out one after the other.
1.3.3 Designations
The following terms are used in this documentation:
Table 4: Designations
Designation Meaning
A10VSO Axial piston variable displacement pump, open circuit
A4VSO Axial piston variable displacement pump, open circuit
HDx Firmware for HydraulicDrive
HM20 Pressure transducer
IndraWorks Service tool for commissioning, parameterization and
diagnostics HydraulicDrive
SYDFED-2X Pressure/flow control system, series 2X
SYDFED-3X Pressure/flow control system, series 3X
SYHDFED-1X Pressure/flow control system, high pressure, series 1X
SY(H)DFED Pressure/flow control system, all series
VT-DFP Pilot valve for SY(H)DFED
VT-SWA-1-1X/DFEE-G15 Swivel angle sensor
1.3.4 Abbreviations
The following abbreviations are used in this documentation:
Table 5: Abbreviations
Abbreviation Meaning
DB Pressure relief valve
PT Pressure Transducer
EMC Electromagnetic compatibility
GND Ground (signal ground)
n.c. Not connected
p Pressure (symbol)
PC Personal Computer
PCV Precompression Volume
pDiff Control deviation between pressure command value and actual
pressure value
PE Protective Earth
pact Actual pressure value

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
About this documentation | SYDFED-2X, SYDFED-3X, SYHDFED-1X 9/96
Abbreviation Meaning
pcommm Pressure command value
RE Rexroth document in English language
SWA Swivel Angle
SWAact Actual swivel angle value
SWAcomm Swivel angle command value
UBSupply voltage
VDE Verband der Elektrotechnik, Elektronik und Informationstechnik
(Association for electrical, electronic and information technologies)

10/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Safety instructions
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
2 Safety instructions
2.1 ABOUT THIS CHAPTER
The SY(H)DFED control system has been manufactured according to good
engineering practice. However, there is still a risk of personal injury and damage
to property if you do not observe this chapter and the safety instructions in this
documentation.
▶ Read these instructions completely and thoroughly before working with the
SY(H)DFED control system.
▶ Keep this documentation in a location where it is accessible to all users at all
times.
▶ Always include the required documentation when you pass the product on to
third parties.
2.2 INTENDED USE
The product is electrical/hydraulic equipment.
You may use the product as follows:
• for the electrohydraulic pressure and swivel angle control of an axial piston
variable displacement pump
The pressure/flow control system is intended exclusively for being integrated in
a machine or installation or for being assembled with other components to form
a machine or system. The product may be commissioned only if it is integrated in
the machine/system for which it is designed.
Observe the technical data, operating conditions and performance limits according
to the data sheet and the order confirmation.
The product is intended exclusively for professional use and not for private usage.
Operation according to the intended use also implies that you have read
and understood this documentation completely, especially chapter 2 “Safety
instructions“.
2.3 IMPROPER USE
Any use other than described in the section “Intended use” is considered as
improper and is therefore not permitted.
The installation or use of inappropriate products in safety-relevant applications
could result in unintended operating states in the application which in turn
could cause personal injuries and/or damage to property. Therefore, please only
use a product for safety-relevant applications if this use is expressly specified
and permitted in the documentation of the product. For example, in explosion-
protection areas or in safety-related parts of a control (functional safety).
Bosch Rexroth AG does not assume any liability for damage caused by improper
use. The user assumes all risks involved with improper use.
Improper use of the product includes:
• If you do not adhere to the technical data, operating conditions and performance
limits specified in the data sheet and given in the order confirmation.
• If you do not observe national EMC regulations during operation for the
application at hand. The manufacturer of the system or machine is responsible
for complying with the limit values stipulated in national regulations (European
countries: EU Directive 2014/30/EU (EMC Directive); USA: See National

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
Safety instructions | SYDFED-2X, SYDFED-3X, SYHDFED-1X 11/96
Electrical Code (NEC), National Electrical Manufacturers Association (NEMA) as
well as regional engineering regulations.
• If you use the SY(H)DFED control system in a potentially explosive atmosphere.
2.4 QUALIFICATION OF PERSONNEL
The activities described in this documentation require basic knowledge of
mechanics, electrics and hydraulics as well as knowledge of the appropriate
technical terms. In order to ensure safe use, these activities may only be carried
out by an expert in the respective field or an instructed person under the direction
and supervision of an expert.
Experts are those who are able to recognize potential hazards and apply the
appropriate safety measures due to their professional training, knowledge and
experience, as well as their understanding of the relevant requirements pertaining
to the work to be undertaken. An expert must observe the relevant specific
professional rules and have the necessary expert knowledge.
Expert knowledge means for example for hydraulic products:
• Reading and completely understanding hydraulic circuit diagrams,
• in particular, completely understanding the correlations regarding safety
equipment and
• knowledge of the function and structure of hydraulic components.
Bosch Rexroth offers training courses that support your qualification in specific
fields. You can find an overview of training contents on the Internet at: http://
www.boschrexroth.com
2.5 GENERAL SAFETY INSTRUCTIONS
• Observe the valid regulations on accident prevention and environmental
protection.
• Observe the safety regulations and provisions of the country in which the
product is used/applied.
• Exclusively use Rexroth products in technically perfect condition.
• Observe all notices on the product.
• Persons who install, commission, operate, demount or maintain Rexroth
products must not consume any alcohol, drugs or pharmaceuticals that may
affect their ability to respond.
• Only use accessory and spare parts released by the manufacturer in order to
rule out personnel hazards arising from unsuitable spare parts.
• Comply with the technical data and ambient conditions specified in the product
documentation.
• If unsuitable products are installed or used in safety-relevant applications,
unintended operational states can occur in these applications, which can cause
personal injury and damage to property. Therefore, use the product only in
safety-relevant applications, if this use is expressly specified and permitted in
the documentation of the product.
• You may commission the product only when it has been established that the
final product (for example, a machine or system), in which the Rexroth product
is installed, complies with national regulations, safety regulations and standards
relevant for the application.

12/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Safety instructions
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
2.6 PRODUCT- AND TECHNOLOGY-RELATED SAFETY
INSTRUCTIONS
WARNING
Control system falling down!
SY(H)DFED control systems are heavy. When improperly handled, they can fall
down and cause severe injuries and crushing, because the parts can be, for
example, sharp-edged, heavy, oily, loose or bulky.
▶ Transport the SY(H)DFED control system using suitable lifting gear at the
points provided for this purpose.
▶ Ensure a stable position while transporting the control system to the place of
installation.
▶ Wear personal protective equipment when transporting the control system.
▶ Comply with the national laws and regulations regarding occupational health
and safety for transporting/handling.
Systems not shut down!
Working on running systems poses a danger to life and limb. The work steps
described in these operating instructions may only be performed on shut down
systems. Before beginning work:
▶ Make sure that the drive motor cannot be switched on.
▶ Make sure that all power-transmitting components and connections
(electrical, pneumatic, hydraulic) are switched off according to the
manufacturer’s instructions and are secured against being switched on again.
If possible, remove the main fuse of the system.
▶ Ensure that the system is completely hydraulically unloaded and
depressurized. Please follow the system manufacturer’s instructions.
▶ Only qualified personnel (see chapter 2.4“Qualification of personnel“ on page
11) are authorized to install the SY(H)DFED control system.
Lines under pressure!
Risk of injury.
▶ Never disconnect, open or cut pressurized lines!
▶ Before carrying out any installation or other work, depressurize the control
system.
High electrical voltage!
Danger to life and risk of injury due to electric shock.
▶ Before starting installation work, plugging and unplugging connectors and
carrying out any work, switch the control system off. Secure the electrical
equipment against restarting.
▶ Before switching the control system on, check the protective conductor on all
electrical devices for proper connection according to the wiring diagram.

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
Safety instructions | SYDFED-2X, SYDFED-3X, SYHDFED-1X 13/96
WARNING
High noise emission during operation!
The noise emission of SY(H)DFED control systems depends, among others, on
speed, operating pressure and the installation situation. Under normal operating
conditions, the noise pressure level may rise above 70 dB(A). This can cause
hearing damage.
▶ Always wear hearing protection when you work in the vicinity of a running
SY(H)DFED control system.
Hot surfaces!
Risk of burning.
The SY(H)DFED control system heats up considerably during operation. The pilot
valve of the SY(H)DFED control system gets so hot during operation that you may
burn yourself.
▶ Let the SY(H)DFED control system cool down before touching it.
▶ Protect yourself by wearing heat-resistant protective clothing, e.g. gloves.
Health-damaging hydraulic fluid!
Contact with hydraulic fluids can be damaging to your health (e.g. eye injuries,
skin damage, intoxication upon inhalation and swallowing).
▶ Always check the lines for wear and damage before each commissioning.
▶ When doing so, wear protective gloves, safety goggles and suitable working
clothes.
▶ If nevertheless hydraulic fluid comes into contact with the eyes or penetrates
the skin, please consult a doctor immediately.
▶ When handling hydraulic fluids, strictly observe the safety notes of the
hydraulic fluid manufacturer.
Easily inflammable hydraulic fluid!
Risk of fire.
▶ Keep open fire and sources of ignition away from the SY(H)DFED control
system.
▶ Ensure sufficient ventilation.
CAUTION
Improperly laid lines and cables!
Risk of stumbling!
▶ Lay cables and lines so that no one can stumble over them.
Uncontrolled system behavior!
The failure of individual components can lead to malfunction of the assembly and
therefore to unforeseeable behavior!
▶ Replace or have defective components replaced immediately.

14/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Safety instructions
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
2.7 PERSONAL PROTECTIVE EQUIPMENT
Personal protective equipment for users of the product consists of:
• Protective gloves and safety shoes for transporting the SY(H)DFED control
system.
• Hearing protection for working in the direct vicinity of the running system.
All components of personal protective equipment must be intact.
2.8 OBLIGATIONS OF THE MACHINE END-USER
The operation of installations, systems and machines basically requires the
implementation of a holistic IT security concept which is state-of-the-art in terms
of technology. Accordingly, BoschRexroth products and their properties must be
considered as components of installations, systems and machines for their holistic
IT security concept.
Unless otherwise documented, BoschRexroth products are designed for operation
in local, physically and logically secured networks with access restrictions for
authorized persons, and they are not classified according to IEC62443-4-2.

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
General notes on damage to property and damage to the product | SYDFED-2X, SYDFED-3X, SYHDFED-1X15/96
3 General notes on damage
to property and damage to
the product
NOTICE
Inadmissible mechanical load!
Hitting or impulsive forces on the drive shaft or the pilot valve can damage or
even destroy the SY(H)DFED control system.
▶ Do not hit the coupling or drive shaft of the axial piston unit.
▶ Do not set/place the axial piston unit on the drive shaft or the pilot valve.
▶ Never use the SY(H)DFED control system as a handle or step. Do not place/
put any objects on top of it.
Foreign bodies and contaminants in the control system!
Risk of damage, wear and malfunctions due to ingress of dirt and foreign
particles.
▶ During installation, ensure utmost cleanliness in order to prevent foreign
particles such as welding beads or metal chips from getting into the hydraulic
lines.
▶ Before commissioning, make sure that all hydraulic connections are tight
and that all seals and closing elements of plug-in connections are correctly
installed and not damaged.
▶ Take care that no cleaning agents enter the hydraulic system.
▶ Do not use cotton waste or linty cloths for cleaning.
Wear!
Wear may lead to malfunctions.
▶ Carry out the prescribed maintenance work at the time intervals specified in
the operating instructions.
Environmentally harmful hydraulic fluid!
Leaking hydraulic fluid leads to environmental pollution.
▶ Immediately remedy any leakage.
▶ Dispose of the hydraulic fluid in accordance with the national regulations in
your country.
Insufficient pressure!
If the pressure falls below the specified value, damage can occur or the product
be destroyed.
▶ Make sure that the pressure cannot fall under the prescribed minimum value.
Insufficient hydraulic fluid!
If you commission or operate the SY(H)DFED control system without or with
insufficient hydraulic fluid, the control system is immediately damaged or even
destroyed.
▶ When commissioning or re-commissioning a machine or system, make
certain that the housing chamber as well as the suction and working lines
of the control system are filled with hydraulic fluid and remain filled during
operation.

16/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Scope of delivery
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
4 Scope of delivery
Fig. 1: Control system SYDFED
Fig. 2: Control system SYHDFED
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2
3
4
6
5
6
The following is included in the scope of delivery:
• 1 control system SY(H)DFED
When delivered, the following parts are mounted
additionally:
• Transport protection for drive shaft end (1) in the
case of keyed shaft
• Protective caps (2, 4)
• Plastic plugs/plug screws (3)
• Pressure transducer (optional) (5)
• The connection flange is closed operationally safe
with a cover (optionally on variant with through-
drive) (6)
1
2
2
3

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
Product description | SYDFED-2X, SYDFED-3X, SYHDFED-1X 17/96
5 Product description
5.1 PERFORMANCE DESCRIPTION
The SY(H)DFED control system is designed and built for the electrohydraulic
control of swivel angle, pressure and power/torque of an axial piston unit. It is
intended for stationary applications.
Please refer to the data sheet and order confirmation for the technical data,
operating conditions and operating limits of the SY(H)DFED control system.
5.2 DEVICE DESCRIPTION
The SY(H)DFED control system is based on an axial piston variable displacement
pump of swashplate design for hydrostatic drives in the open circuit. The flow is
proportional to drive speed and displacement. The flow can be steplessly varied
by adjusting the swashplate.
In an open circuit, the hydraulic fluid flows from the tank to the variable
displacement pump and is transported from there to the consumer via a
directional valve. From the consumer, the hydraulic fluid flows via the directional
valve back to the tank.
In the regenerative operating mode (see chapter 5.3.4.1 “Regenerative operation“
on page 24) the hydraulic fluid can also flow from the consumer through the
pump to the tank.
For the control system SY(H)DFED we offer the order option “variable-speed
operation”. Variable speed operation is an additional function, which determines
the optimum drive speed for the motor in dependence on the current working
point and passes it on to the drive. In addition, this additional function allows
power losses to be reduced.
5.2.1 Functional description, section of SY(H)DFED
The numbers in the description below refer to the numbers in brackets in Fig. 3, 4
and 5 on pages 19 and 20.
The pressure and swivel angle of the A10VSO variable displacement pump of the
SY(H)DFED control system is controlled using an electrically operated proportional
valve (2). The proportional valve determines the position of the swashplate (1)
by means of the actuating piston (4). The displaced flow is proportional to the
position of the swashplate. The counter-piston (3), which is preloaded by a spring
(5), is permanently pressurized to pump pressure.
While the pump is not rotating and the actuating system is depressurized, spring
(5) holds the swashplate in position +100 %. With a driven pump and a de-
energized proportional solenoid (8) the system swivels to zero stroke pressure
as the valve spool (9) is pushed to the initial position by the spring (10) and,
therefore, pump pressure pis applied to the actuating piston (4) via valve port
“A”. A balance between the pump pressure on the actuating piston and the spring
force (5) is achieved at a pressure of 8 to 12 bar. This basic position (= zero stroke
operation) is obtained e.g. when the valve electronics is de-energized.
In contrast to this, a pump with external supply swivels to the negative limit
stop (regenerative operation). See also section 5.3.4.1 “Regenerative
operation“ on page 24.
Open circuit
Variable-speed operation

18/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Product description
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
The proportional valve is controlled by digital electronics (11), which is integrated
in the valve. This closed-loop control electronics processes all of the control
signals required to operate the A10VSO respectively A4VSO variable displacement
pump under closed-loop pressure and flow control.
The control electronics receives its command values for pressure, swivel angle
and torque limit over the field bus systems (for the selection, see order option 13
in the type code) (14). Alternatively, the command values for pressure and swivel
angle can be provided via one analog input each. A pressure transducer can be
connected to the central plug (12). Alternatively, an HM20 pressure transducer can
be connected to port P of the pump or, if a SYDZ preload valve is used, installed in
port MP1 and connected to X2M1.
A position transducer with integrated electronics (7) fitted to the pump
establishes the actual swivel angle value. The acquired actual values are processed
in the amplifier and compared with the given command values. A minimum value
comparator ensures that automatically only the controller assigned to the desired
working point is active. Thereby, a system variable (pressure, swivel angle or
torque) is exactly corrected, the other two variables are below the specified
command values. The output signal of the minimum value comparator becomes
the command value for the valve control loop.
The actual value of the valve spool position is sensed using an inductive position
transducer (6). The output value of the valve position controller determines via the
amplifier output stage the current through the proportional solenoid 8). As soon
as the working point is reached the control spool (9) of the proportional valve is
held in the centered position.
When the higher-level controllers demand an increase in the swivel angle (increase
in flow), the valve spool (9) must be moved away from the central position
(connection of the actuating piston (4) A → T) until the swivel angle has reached
the required value. The movement of the valve spool against the force of the spring
(10) is achieved by a corresponding increase in the electrical current through the
proportional solenoid (8).
A reduction of the swivel angle (reduction in flow) is achieved by connecting the
actuating piston (4) from P → A.
The actuating system of the pump can be supplied with pilot oil in three different
ways:
1. Internal, without pre-load valve (only possible for operating pressures >20bar)
2. Internally, with pre-load valve (operating pressure 0…100 %)
3. External supply via a shuttle valve - automatic switching between internal/
external via a shuttle valve sandwich plate! (See chapter 5.3.6 “Internal/
external pilot oil“ on page 27).

RE 30017-B, Edition 11.2021, Bosch Rexroth AG
Product description | SYDFED-2X, SYDFED-3X, SYHDFED-1X 19/96
Fig. 3: Sectional drawing of SYDFED, series 2X
Fig. 4: Sectional drawing of SYDFED, series 3X
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26, 8
10 9
12
11
14
14
–100% Nullhub +100%
5313
7
2
6, 8
10 9
12
11
14

20/96 SYDFED-2X, SYDFED-3X, SYHDFED-1X | Product description
Bosch Rexroth AG, Edition 11.2021, RE 30017-B
Fig. 5: Section of SYHDFED, series 1X
1 Swashplate 2 Proportional valve VT-DPFD
3 Counter-piston 4 Actuating piston
5 Spring 6 Inductive position transducer
7 Swivel angle position transducer 8 Proportional solenoid
9 Proportional valve spool 10 Spring
11 Digital electronics 12 Central connector
13 Pre-compression volume PCV 14 Multi-Ethernet interface
The sectional drawings above show the mechanical basic position “+100 %“ of
the pump (depressurized, drive at rest). This corresponds to the maximum swivel
angle of the pump.
Zero stroke pressure: Pressure, which the pump with internal supply generates for
its own supply without activation of the pilot valve. The pressure level is usually
within the range of 8 to 12 bar. This pressure level can only be achieved when the
maximum oil flow, which the pump can deliver, is not exceeded. The pump with
internal supply automatically swivels in to zero stroke operation after the electric
drive was started and when the control electronics is de-energized, provided that
the required pilot pressure can build up (consumer line is closed).
In contrast to this, the pump with external supply swivels in to the negative limit
stop “-100 %“!
NOTICE! Cavitation of the pump!
Risk of damage to the pump in the case of systems with external supply.
▶ To prevent damage to the pump, provide a pressure relief/anti-cavitation valve
for systems with external supply. If a fault occurs during operation - not during
start-up - the motor must be switched off.
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1
46, 8
3
10 9
14