Bosch rexroth SYDFE1 2X Series User manual

Operating instructions
RE 30011-B Edition: 10.2021, replaces: 07.2014
Pressure and flow
control system
SYDFE1 series 2X, 3X with external control
electronics VT 5041-3X
SYDFE1 series 2X
SYDFE1 series 3X
with external control
electronics
VT 5041-3X
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 30011-B, Edition 10.2021, Bosch Rexroth AG
Content | Pressure and flow control system SYDFE1 series 2X, 3X 3/96
Content
1 About this documentation ...................................................................... 6
1.1 Validity of the documentation ....................................................................6
1.2 Required and supplementary documentation ............................................6
1.3 Presentation 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 ................................................................................. 9
2.1 About this chapter .....................................................................................9
2.2 Intended use..............................................................................................9
2.3 Improper use .............................................................................................9
2.4 Qualification of personnel........................................................................10
2.5 General safety instructions ......................................................................10
2.6 Product- and technology-related safety instructions ................................11
2.7 Personal protective equipment ................................................................13
2.8 Obligations of the machine end-user .......................................................13
3 General notes on damage to property and damage to the product ........ 14
4 Scope of delivery ................................................................................. 15
5 Product description.............................................................................. 16
5.1 Performance description..........................................................................16
5.2 Device description ...................................................................................16
5.2.1 Functional description, section of SYDFE1 ..............................................16
5.3 Controller structure and basic operating modes......................................19
5.3.1 Swivel angle control.................................................................................20
5.3.2 Pressure control ......................................................................................21
5.3.3 Power limitation (optional) with VT 5041-3X/3... .....................................21
5.4 Special operating modes .........................................................................22
5.4.1 Regenerative operation  ...........................................................................22
5.5 Operating pressure limits ........................................................................25
5.5.1 Internal/external pilot oil.........................................................................25
5.6 Ambient conditions..................................................................................27
5.6.1 Oil-immersed applications .......................................................................27
5.6.2 Ambient temperature ...............................................................................27
5.7 Notes on the selection of hydraulic fluids................................................27
5.8 Generation of noise .................................................................................28
5.8.1 Generation of noise in the power unit .....................................................29
5.8.2 Pulsation damper.....................................................................................29
5.9 Shaft variant ............................................................................................29
5.10 Spool variant of the VT-DFPE-x-2X pilot valve...........................................30
5.11 Functions of control electronics VT 5041-3X............................................30
5.11.1 Enable .....................................................................................................30
5.11.2 Switch
TD .................................................................................................31
5.11.3 Pressure controller OFF - master/slave operation
(VT 5041-3X/1... and ...2... only)..............................................................31
5.11.4 Fault message..........................................................................................31
5.11.5 Signaling of type of control......................................................................31
5.11.6 Actual values............................................................................................31
5.11.7 Test jacks on the front panel of control electronics VT5041-3X ..............32
5.11.8 Leakage compensation.............................................................................32
5.11.9 Power limitation (VT 5041-3X/3... only) ...................................................33
5.12 Master/slave operation ............................................................................34

4/96 Pressure and flow control system SYDFE1 series 2X, 3X | Content
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
5.12.1 Switch-on sequence of electronics/hydraulics .........................................37
5.13 Identification of the product ....................................................................38
6 Transport and storage .......................................................................... 39
6.1 Transporting the SYDFE1 control system .................................................39
6.1.1 Transport using lifting gear ......................................................................39
6.2 Storing the SYDFE1 control system..........................................................41
7 Mounting.............................................................................................. 42
7.1 Unpacking ................................................................................................42
7.2 Installation conditions .............................................................................42
7.3 Installation positions and piping of SYDFE1 systems...............................43
7.3.1 General information.................................................................................43
7.3.2 Piping ......................................................................................................44
7.4 Installing the SYDFE1 control system.......................................................46
7.4.1 Preparations ............................................................................................46
7.4.2 Dimensions of connections......................................................................46
7.4.3 General notes ..........................................................................................47
7.4.4 Installation with coupling.........................................................................47
7.4.5 Completing the installation......................................................................48
7.5 Connecting the SYDFE1 control system hydraulically...............................48
7.6 Connecting the SYDFE1 control system electrically .................................52
7.6.1 Cabling of electronic components ...........................................................52
7.6.2 Voltage supply of control electronics VT 5041-3X ....................................53
7.6.3 Selection, place of installation and mounting orientation of the pressure
transducer ...............................................................................................53
7.6.4 Connecting the valve position transducer ................................................55
7.6.5 Connecting the swivel angle sensor .........................................................57
7.6.6 Connecting the solenoid of the proportional valve ..................................58
7.6.7 Command values for pressure, swivel angle and power limitation ...........58
8 Commissioning..................................................................................... 59
8.1 Initial commissioning ...............................................................................60
8.1.1 Filling the SYDFE1 control system ...........................................................60
8.1.2 Testing the hydraulic fluid supply ............................................................61
8.1.3 Performing a flushing cycle......................................................................61
8.1.4 Configuring switches and jumpers of the VT 5041-3X ..............................62
8.1.5 Switching on the supply voltage for the control electronics.....................65
8.1.6 Switching on the drive motor of the pump...............................................66
8.1.7 Checking and correcting the valve zero point...........................................66
8.1.8 Bleeding the pre-load valve......................................................................67
8.1.9 Adjusting the operating pressure  ............................................................67
8.1.10 Pressure control ......................................................................................68
8.1.11 Checking swivel angle sensing .................................................................70
8.1.12 Adjusting the power limitation (with VT-5041-3-3X/... only) .....................70
8.1.13 Performing a functional test ....................................................................71
8.1.14 Bleeding during commissioning or after longer standstill periods ...........71
8.2 Recommissioning after standstill .............................................................72
8.3 Running-in phase .....................................................................................72
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
10.5.1 Replacement of components ...................................................................75
11 Decommissioning ................................................................................. 76
12 Demounting and replacement............................................................... 77
12.1 Required tools .........................................................................................77
12.2 Preparing demounting..............................................................................77
12.3 Demounting .............................................................................................77

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Content | Pressure and flow control system SYDFE1 series 2X, 3X 5/96
12.4 Preparing the components for storage or further use ..............................77
13 Disposal ............................................................................................... 78
13.1 Environmental protection.........................................................................78
13.2 Return to Bosch Rexroth AG ....................................................................78
13.3 Packaging.................................................................................................78
13.4 Materials used .........................................................................................78
13.5 Recycling .................................................................................................79
14 Extension and modification .................................................................. 79
15 Troubleshooting ................................................................................... 80
15.5.1 Fault analysis ...........................................................................................82
15.1 How to proceed for troubleshooting ........................................................84
15.2 Fault table ...............................................................................................85
16 Technical data ...................................................................................... 88
17 Annex................................................................................................... 89
17.1 List of addresses .....................................................................................89
17.2 Block circuit diagram of control electronics VT 5041-3X .........................90
17.3 Display and setting elements of control electronics VT 5041-3X..............92
18 Alphabetical index ............................................................................... 93

6/96 Pressure and flow control system SYDFE1 series 2X, 3X | About this documentation
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
1 About this documentation
1.1 VALIDITY OF THE DOCUMENTATION
This documentation is valid for the following products:
• SYDFE1 series 2X
• SYDFE1 series 3X
This documentation is intended for engineers, fitters, operators, service
technicians and plant operators.
These instructions contain important information on the safe and appropriate
installation, transport, commissioning, maintenance, disassembly and simple
troubleshooting of the pressure and flow control systems SYDFE1 series 2X and
3X.
▶ Read these instructions completely, especially chapter 2 “Safety instructions“
on page 9, before working with the product.
1.2 REQUIRED AND SUPPLEMENTARY DOCUMENTATION
▶ The product must not be commissioned until you have been provided with the
documentation marked with the book symbol and you have understood and
observed it.
Table 1: Required and supplementary documentation
Title Document no. Document type
Installation drawing On request Contains the outer dimensions,
all ports and the hydraulic circuit
diagram of your pressure/flow control
system SYDFE1
General operating instructions 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 SYDFE1, SYDFEE,
SYDFED, SYDFEF, component series 3X
RE 30630 Data sheet
Axial piston variable displacement pump A10VSO series 31,
sizes 18 to 100
RE 92711 Data sheet
Axial piston variable displacement pump A10VSO series 32,
sizes 45 to 180
RE 92714 Data sheet
External control electronics for the SYDFE1 control of the
A10VSO axial piston variable pump, type VT 5041-3X/...
RE 30242 Data sheet
External control electronics (variant) for the SYDFE1
adjustment of the axial piston pump A10VSO
RD 30242-01 Data sheet
3/3 proportional directional valves, direct operated, with
electrical position feedback, as pilot valve for control
systems SY(H)DFE, type VT-DFP
RE 29016 Data sheet
Axial piston units for use with HF fluids RE 90223 Data sheet
Hydraulic fluids on a mineral oil basis for axial piston units RE 90220 Data sheet
Pump pre-load valve for control system SYDFE,
type SYDZ 0001-1X
RE 29255 Data sheet
Pressure transducer for hydraulic applications, type HM20 RE 30272 Data sheet
Pressure transducer for hydraulic applications, type HM20 RE 30272-MON Installation instructions

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
About this documentation | Pressure and flow control system SYDFE1 series 2X, 3X 7/96
Title Document no. Document type
Installation, commissioning and maintenance of hydraulic
systems
RE 07900 Data sheet
1.3 PRESENTATION 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 Pressure and flow control system SYDFE1 series 2X, 3X | About this documentation
Bosch Rexroth AG, Edition 10.2021, RE 30011-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
HM20 Pressure transducer
IW9 Swivel angle sensor for the SYDFE1 control system
SYDFE1 Pressure/flow control system for external electronics
SYDFE1-2X Pressure/flow control system, series 2X, for external electronics and
A10 VSO series 31
SYDFE1-3X Pressure/flow control system, series 3X, for external electronics and
A10 VSO series 32
VT-DFP Pilot valve for SYDFE1
VT 5041-3X External control electronics for SYDFE1
1.3.4 Abbreviations
The following abbreviations are used in this documentation:
Table 5: Abbreviations
Abbreviation Meaning
PT Pressure Transducer
EMC Electromagnetic compatibility
GND Ground
NG Nenngröße (size)
p Pressure (symbol)
PPower
PCV PreCompression Volume
pDiff Control difference between pressure command value and actual
pressure value
PE Protective Earth
pact Actual pressure value
pcomm Pressure command value
RE Rexroth document in English language

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Safety instructions | Pressure and flow control system SYDFE1 series 2X, 3X 9/96
Abbreviation Meaning
Switch TDSwitching input for volume adjustment
SWA Swivel angle
SWAact Swivel angle feedback value
SWAcomm Swivel angle command value
UBSupply voltage
US Undervoltage
VDE Verband der Elektrotechnik, Elektronik und Informationstechnik
(Association for electrical, electronic and information technologies)
2 Safety instructions
2.1 ABOUT THIS CHAPTER
The SYDFE1 control system has been manufactured according to the generally
accepted rules of current technology. 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
SYDFE1 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 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).

10/96 Pressure and flow control system SYDFE1 series 2X, 3X | Safety instructions
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
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
Electrical Code (NEC), National Electrical Manufacturers Association (NEMA) as
well as regional engineering regulations.
• if you use the SYDFE1 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 conditions pertaining to
the work to be undertaken. Qualified personnel must observe the rules relevant to
the subject area.
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.

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Safety instructions | Pressure and flow control system SYDFE1 series 2X, 3X 11/96
2.6 PRODUCT- AND TECHNOLOGY-RELATED SAFETY
INSTRUCTIONS
WARNING
Control system falling down!
SYDFE1 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 SYDFE1 control system using suitable lifting gear at the point
provided for this purpose.
▶ Ensure a stable position during transport 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.
Risk of injury caused by 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 “Personnel qualifications” on
page 10) are authorized to install the SYDFE1 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.

12/96 Pressure and flow control system SYDFE1 series 2X, 3X | Safety instructions
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
WARNING
High noise emission during operation!
The noise emission of SYDFE1 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
SYDFE1 control system.
Hot surfaces!
Risk of burning.
The SYDFE1 control system heats up considerably during operation. The pilot
valve of the SYDFE1 control system gets so hot during operation that you may
burn yourself.
▶ Let the SYDFE1 control system cool down before touching it.
▶ Protect yourself by wearing heat-resistant protective clothing, e.g. gloves.
Risk of intoxication and injury!
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.
Risk of fire!
Hydraulic fluid is easily inflammable.
▶ Keep open fire and sources of ignition away from the SYDFE1 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.

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Safety instructions | Pressure and flow control system SYDFE1 series 2X, 3X 13/96
2.7 PERSONAL PROTECTIVE EQUIPMENT
Personal protective equipment for users of the product consists of:
• Protective gloves and safety shoes for transporting the SYDFE1 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.

14/96 PressureandflowcontrolsystemSYDFE1series2X,3X|Generalnotesondamagetopropertyanddamagetotheproduct
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
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 SYDFE1 control system.
▶ Do not hit on 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 SYDFE1 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 SYDFE1 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.

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Scope of delivery | Pressure and flow control system SYDFE1 series 2X, 3X 15/96
4 Scope of delivery
Fig. 1: Control system SYDFE1-3X
The following is included in the scope of delivery:
• 1 control system SYDFE1
When delivered, the following parts are mounted additionally:
1 Transport protection for drive shaft end in the case of keyed shaft
2 Protective cover with mounting screws
3 Plastic plugs/plug screws
4 Protective cover (NG140) or plastic plug on pre-load valve
5 The connection flange is closed operationally safe with a cover (optionally on
variant with through-drive)
2
2
5
3
1
5
4
3

16/96 Pressure and flow control system SYDFE1 series 2X, 3X | Product description
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
5 Product description
5.1 PERFORMANCE DESCRIPTION
The SYDFE1 control system is designed and built for the electrohydraulic control
of swivel angle, pressure and power (optional) of an axial piston pump. 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 SYDFE1 control system.
5.2 DEVICE DESCRIPTION
The SYDFE1 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 5.4.1 “Regenerative operation“ on
page 22) the hydraulic fluid can also flow from the consumer through the pump
to the tank.
5.2.1 Functional description, section of SYDFE1
In the following description, the numbers in brackets refer to Fig. 2 and Fig. 3 on
page 18.
Pressure and swivel angle control of the SYDFE1 control systems is accomplished
using an electrically controlled 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 pre-loaded by a spring (5), is permanently pressurized
to pump pressure.
With a non-rotating pump and depressurized actuating system, the swashplate is
held by the spring (5) 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 p is applied to the actuating piston (4) via valve port “A”. A balance
between the pump pressure on the actuating piston (4) and the spring force (5) is
achieved at a pressure of 8 to 12 bar. This basic position (= zero stroke operation)
is obtained when the control electronics is inactive (e.g. when the controller is
disabled).
In contrast to this, a pump with external supply swivels to the negative limit
stop (regenerative operation).
The proportional valve is controlled by external control electronics VT 5041-3X,
which is part of the system. This electronics processes all of the control signals
required to operate the SYDFE1 control system.
The external control electronics type VT 5041-3X is designed as plug-in card in
Euro-format. As a standard, it is provided with one command value input each
for pressure and swivel angle (and optional input for power command value). A
pressure transducer senses the actual pressure value. A swivel angle sensor (7)
on the pump senses the actual swivel angle value. The acquired actual values
Open circuit

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Product description | Pressure and flow control system SYDFE1 series 2X, 3X 17/96
are processed in the control electronics 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. In this process, one system
variable (pressure, swivel angle or - optionally - power) is exactly corrected, the
other two system variables are below the given command value. 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.
Since the introduction of A10VSO, series 32, a so-called pre-compression volume
(14) PCV has been available as an optional extra. This variant (feature “32” in the
ordering code for the design of the subplate) is an integral part of the subplate
and cannot be retrofitted.
The PCV reduces pressure pulsation and can contribute to an improvement in
the generation of noise and render secondary measures for pulsation reduction
unnecessary. This technology is, however, not employed in the subplate variant
without PCV (feature “22” in the ordering code).
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
>12...20bar, see chapter 5.5.1 “Internal/external pilot oil“ on page 25).
2. Internally, with pre-load valve (operating pressure 0…100 %).
3. External supply via a shuttle valve - automatic changeover between internal/
external via a shuttle valve sandwich plate (see “External pilot oil supply“ on
page 26).
Pre-compression volume
PCV
Actuating system supply

18/96 Pressure and flow control system SYDFE1 series 2X, 3X | Product description
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
Fig. 2: Type SYDFE1, series 2X
Fig. 3: Type SYDFE1, series 3X
PA T
53 7
89102
41
6
14
–100% +100%
5314
P A T
10 98
7
6
2
Zero stroke

RE 30011-B, Edition 10.2021, Bosch Rexroth AG
Product description | Pressure and flow control system SYDFE1 series 2X, 3X 19/96
The sectional drawings overleaf 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. After the electric
drive was started, the pump with internal supply automatically swivels in to zero
stroke operation
• when the enable of the control electronics is missing or
• in the case of an error message of the control electronics (condition: VT 5041-
3X: J1 OFF) or
• in the de-energized state of the control electronics
provided that the required pilot pressure can be built up (consumer line is
closed).
In contrast to this, the pump with external supply swivels in to the negative limit
stop “-100 %“ under the above conditions!
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.
5.3 CONTROLLER STRUCTURE AND BASIC OPERATING
MODES
The controller structure is illustrated in the figure below.
Fig. 4: Controller structure
Up to three controllers are continuously active in the possible operating modes:
• Swivel angle controller
• Pressure controller
• Power limitation (optional)
These controllers alternate automatically and jerk-free through evaluation of
minimum value comparators.
During steady-state operation, one of the above controllers is active. For the other
controllers, the actual value is smaller than the command value.
Basic positions of the
swivel angle adjustment
feature
Controller structure
SYD_006
sU
Up
sU
Power
controller
(option)
(Pin 24c)
Actual pressure (pin 8c/10c)
Pressure
controller
Minimum
value
comparator
Flow
controller
Minimum
value
comparator
Valve
controller
Valve command value
Power setpoint
(potentiometer or
pin 18c/20c)
Swivel angle setpoint
(pin 14c/16c)
Actual swivel angle (pin 12c)
Pressure setpoint (pin 6c/4c)
Basic operating modes

20/96 Pressure and flow control system SYDFE1 series 2X, 3X | Product description
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
The following operating modes are available:
5.3.1 Swivel angle control
With version VT 5041-3X/1...
VT 5041-3X/2...
▶ J4 OFF and
▶ connect pin 18a to +24 V.
With version VT 5041-3X/3...
If the axis is to run exclusively in this operating mode, an analog signal within
the range of +10 V to UBis assigned to the pressure command value and used to
deactivate the pressure controller (0...+10 V ≙ 0...100 % swivel angle).
The pressure transducer signal must be short-circuited or deactivated, because
even actual pressure value signals of ≥8.0 V have an influence on or reduce the
swivel angle output and hence the valve command value (actuating speed!).
A precondition for this is, however, that the electronics is set for an actual
pressure value input “voltage” without raised zero point (e.g. 0 - 10 V, 0 - 20 mA).
Otherwise, electronics set for an actual pressure value branch with raised zero
point would change to an erroneous state when the pressure transducer signal is
missing.
u
u
u
u
u
u
SYD_008
+10 V to UB
external
H
L
6c
4c
8c
10c
14c
16c
pcomm
Reference potential
pact →0 to +10 V
0 to 5 V
SWAcomm → -10 V to +10 V
Reference potential
Fig. 5: Circuitry of control electronics VT 5041-3X for closed-loop swivel angle control