Bosch Rexroth A4VG 35 Series User manual

Instruction manual
RE92035-01-B/2019-11-25
Replaces: 04.2018
English
Axial piston variable pump
A4VG
Series35

© BoschRexrothAG 2019. All rights reserved,
also regarding any disposal, exploitation,
reproduction, editing, distribution, as well as in
the event of applications for industrial property
rights.
The data specified within only serves
to describe the product. No statements
concerning a certain condition or suitability
for a certain application can be derived from
our information. 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.
The cover shows an example application.
Theproduct delivered may differ from the
image on the cover.
The original instruction manual was created in
the German language.

Contents 3/64
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1 About this documentation 5
1.1 Validity of the documentation 5
1.2 Required and supplementary documentation 5
1.3 Representation of information 6
1.3.1 Safety instructions 6
1.3.2 Symbols 7
1.3.3 Designations 7
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 Personnel qualifications 10
2.5 General safety instructions 11
2.6 Product-specific safety instructions 12
2.7 Personal protective equipment 15
3 General instructions on property damage and product damage 16
4 Scope of delivery 19
5 About this product 20
5.1 Performance description 20
5.2 Product description 20
5.2.1 Axial piston unit layout 20
5.2.2 Functional description 21
5.3 Bypass function 22
5.3.1 Activating and deactivating the bypass function 22
5.4 Product identification 24
6 Transportand storage 25
6.1 Transporting the axial piston unit 25
6.1.1 Transportby hand 25
6.1.2 Transportwith lifting devices 25
6.2 Storing the axial piston unit 28
7 Installation 30
7.1 Unpacking 30
7.2 Installation conditions 30
7.3 Installation position 32
7.3.1 Below-reservoir installation (standard) 32
7.3.2 Above-reservoir installation 33
7.4 Installing the axial piston unit 34
Contents
7.4.1 Preparation 34
7.4.2 Dimensions 35
7.4.3 General instructions 35
7.4.4 Installation with a coupling 36
7.4.5 Installation on a gearbox 36
7.4.6 Installation with cardan shaft 37

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7.4.7 Completion of assembly 37
7.4.8 Hydraulically connecting the axial piston unit 39
7.4.9 Electrically connecting the axial piston unit 43
7.5 Performing flushing cycle 43
8 Commissioning 44
8.1 Initial commissioning 44
8.1.1 Filling the axial piston unit 45
8.1.2 Testing the hydraulic fluid supply 46
8.1.3 Performing a functional test 47
8.2 Running-in phase 47
8.3 Recommissioning after standstill 48
9 Operation 49
10 Maintenance and repair 50
10.1 Cleaning and care 50
10.2 Inspection 51
10.3 Maintenance 51
10.4 Repair 52
10.5 Spare parts 52
11 Removal and replacement 53
11.1 Required tools 53
11.2 Preparing for removal 53
11.3 Performing the disassembly 53
11.4 Preparing the components for storage or further use 53
12 Disposal 54
13 Extension and conversion 55
14 Troubleshooting 56
14.1 How to proceed for troubleshooting 56
14.2 Malfunction table 57
15 Technical data 61
16 Alphabetical index 62
Contents

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1 About this documentation
1.1 Validity of the documentation
This documentation is valid for the following products:
• Axial piston variable pump A4VG Series35
This documentation is intended for machine/system manufacturers, assemblers and
service engineers.
This documentation contains important information on the safe and proper
transport, installation, commissioning, operation, maintenance, removal and simple
troubleshooting of the axial piston unit.
▶ Read this documentation completely, in particular chapter 2 "Safety instructions"
on page 9 and chapter 3 "General instructions on property damage and
product damage" on page 16 before you start work with the axial piston unit.
1.2 Required and supplementary documentation
▶ Only commission the axial piston unit if the documentation marked with the book
symbol is available to you and you have understood and observed it.
Table 1: Required and supplementary documentation
Title Document number Document type
Order confirmation
Contains the order-related technical data for your axial piston variable
pump A4VG.
– Order confirmation
Installation drawing
Contains the outer dimensions, all ports and the hydraulic circuit diagram
for your axial piston variable pump A4VG.
Please request the
installation drawing
from your contact at
BoschRexroth.
Installation drawing
Axial piston variable pump A4VG
Contains the permissible technical data, ports, main dimensions and
circuit diagrams.
92035 Data sheet
Hydraulic fluids based on mineral oils and related hydrocarbons
Describes the requirements for hydraulic fluids on mineral oil basis and
related hydrocarbons for operation with Rexroth hydraulic components
and provides supportfor selection of suitable hydraulic fluids for the
hydraulic system.
90220 Data sheet
Environmentally acceptable hydraulic fluids
Describes the requirements for environmentally acceptable hydraulic
fluids on mineral oil basis and related hydrocarbons for operation with
Rexroth hydraulic components and provides supportfor selection of
suitable hydraulic fluids for the hydraulic system.
90221 Data sheet
Fire-resistant, water-free hydraulic fluids (HFDR/HFDU)
Describes the requirements on fire-resistant, water-free hydraulic fluids
(HFDR/HFDU) for operation with Rexroth hydraulic components and
assists you in selecting a hydraulic fluid for your hydraulic system.
90222 Data sheet

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Table 1: Required and supplementary documentation
Title Document number Document type
Axial piston units for operation with fire-resistant
hydraulic fluids – water-free, water-containing
(HFDR, HFDU, HFA, HFB, HFC)
Describes the requirements on fire-resistant, water-free and
water-containing hydraulicfluids (HFDR, HFDU, HFA, HFB, HFC) and
contains the technical data for operation
with Rexroth hydraulic components.
90225 Data sheet
Component class: 92035-CC-0001_ETPump
The component class specification explains what data is available,
howthis data was obtained, and gives further notices to be observed.
92035-CC-0001_ETPump Component class
specification
BODAS-drive eDA application software
BODAS-drive eDA is a software solution integrated in the Rexroth
SRC-eDA1/31 control unit for controlling the hydrostatic drive train in
wheeled vehicles.
95315 Data sheet
BoschRexroth Fluid Rating List for Rexroth hydraulic components
(pumps and motors)
Contains the hydraulic fluids positively evaluated by BoschRexroth.
90245 Data sheet
Information on the application of hydrostatic drives at low temperatures
Contains additional information on the application of Rexroth axial piston
units at low temperatures.
90300-03-B Manual
Storage and preservation of axial piston units
Contains additional information on storage and preservation.
90312 Data sheet
1.3 Representation of information
Uniform safety instructions, symbols, terms and abbreviations are used throughout
this documentation to ensure safe and proper use of the product. For clarification,
they are explained in the sections below.
1.3.1 Safety instructions
This documentation contains safety instructions in chapter 2.6 "Product-specific
safety instructions" on page12 and in chapter 3 "General instructions on property
damage and product damage" on page16, as well as before a sequence of actions
or an instruction for action involving a risk of personal injury and property damage.
Always follow the measures for danger prevention associated with the use of this
product.
Safety instructions are set out as follows:
SIGNAL WORD
Type and source of danger!
Consequences of noncompliance
▶ Danger prevention measures
•Warning sign: draws attention to the danger
•Signal word: identifies the degree of the danger
•Type and source of danger: indicates the type and source of the danger
•Consequences: describes what occurs if safety instructions are disregarded
•Precautions: states how the danger can be avoided

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Table 2: Hazard classes as defined in ANSI Z535.6
Warning sign, signal word Meaning
DANGER Identifies a dangerous situation that will result in death or
serious injury if it is not avoided.
WARNING Identifies a dangerous situation that may result in death or
serious injury if it is not avoided.
CAUTION Identifies a dangerous situation that may result in minor to
moderate injury if it is not avoided.
NOTICE Property damage: The product or surrounding area may be
damaged.
1.3.2 Symbols
The following symbols indicate notices that are not safety-relevant but increase
understanding of the documentation.
Table 3: Meaning of symbols
Symbol Meaning
If this information is disregarded, the product cannot be used and/or
operated to its full extent.
▶ Single, independent action
1.
2.
3.
Numbered instruction:
The numbers indicate that the actions must be completed in order.
1.3.3 Designations
This documentation uses the following designations:
Table 4: Designations
Designation Meaning
A4VG Axial piston variable pump and closed circuit
Threaded plug Metal screw, pressure-resistant
Protective plug Made out of plastic, not pressure-resistant, only for transportation
As umbrella term for "axial piston variable pump A4VG" the designation
"axialpistonunit" will be used in the following.

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1.3.4 Abbreviations
This documentation uses the following abbreviations:
Table 5: Abbreviations
Abbreviation Meaning
ATEX EC directive on explosion protection (Atmosphère explosible)
DIN Deutsches Institut für Normung (German Institute for Standardization)
ET Electric control, direct-operated with two pressure reducing valves
(PRV)
ISO International Organization for Standardization
RE Rexroth document in the English language
VDI2230 Directive for the systematic calculation of high duty screwed
joints and cylindrical screw joints from the VDI(Verein Deutscher
Ingenieure-Association of German Engineers)

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2 Safety instructions
2.1 About this chapter
The axial piston unit has been manufactured to generally accepted engineering
standards. There is still, however, a risk of personal injury or property damage if this
chapter and the safety instructions in this documentation are not observed.
▶ Read this documentation completely and thoroughly before working with the axial
piston unit.
▶ 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 axial piston unit
on to third parties.
2.2 Intended use
Axial piston units are hydraulic components, meaning that in their application
area they are classified neither as complete nor as partly completed machinery as
defined in the ECMachineryDirective2006/42/EC. The component is exclusively
intended to form partly completed machinery or complete machinery together with
other components. The component should only be commissioned after it has been
installed in the machine/system for which it is intended, and the safety of the entire
system has been established in accordance with the Machinery Directive.
This product is intended for the following use:
The axial piston unit is only approved as a pump for hydrostatic drives in closed
circuit.
▶ Observe the technical data, the application and operating conditions and
the performance limits as specified in the datasheet 92035 and in the order
confirmation. Information about approved hydraulic fluids can be found in
datasheet92035.
The axial piston unit is only intended for commercial use and not for private use.
Intended use includes having fully read and understood this documentation,
especially chapter 2 "Safety instructions" on page9.
2.3 Improper use
Any use other than that described as intended use is considered improper.
BoschRexrothAG is not liable for damages resulting from improper use. The user is
solely responsible for any risks arising from improper use.
The following foreseeable forms of faulty usage are also considered improper
(thislist is not exhaustive):
• Use outside the operating parameters approved in the datasheetand in the order
confirmation (unless specifically approved by the customer)

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• Use of non-approved fluids, e.g.water or polyurethane components
• Changes to factory settings by unauthorized persons.
• Use of assembled parts (e.g.control unit, valves) not in combination with the
specified Rexroth components
• Use of the axial piston unit with assembled parts under water at a depth of
more than 10 meters without the necessary additional measures, e.g.pressure
equalization. Units with electrical components (e.g.sensors) generally cannot
come into contact with water.
• Use of the axial piston unit under a continuous pressure differential between
housing and ambient pressure greater than 2bar, with the ambient pressure
always lower than the case pressure. Momentary (t< 0.1 s) pressure peaks of
up to 10bar are allowed, but no more than 1000 pressure peaks over the entire
service life. Beyond this, the maximum permissible case pressure specified in the
datasheetshould not be exceeded.
• Application of the axial piston unit in explosive environments unless the
componentor machine/system has been certified as compliant with the
ATEXDirective 2014/34/EU
• Use of the axial piston unit in a corrosive atmosphere
• Use of the axial piston unit in aircraft or spacecraft
2.4 Personnel qualifications
The activities described in this documentation require a basic understanding of
mechanics, electricity and hydraulics, as well as familiarity with associated technical
terms. For transporting and handling the product, knowledge regarding the use of
lifting devices and lifting accessories is required. In order to ensure safe use, these
activities should only be performed by skilled personnel or an instructed person
under the direction and supervision of skilled personnel.
Skilled personnel refers to persons who possess the professional training,
knowledge and experience, as well as the understanding of the regulations relevant
to the work to be done that are necessary to recognize possible dangers and take
the appropriate safety measures. Skilled personnel must follow the rules relevant to
their field and have the necessary hydraulic expert knowledge.
Hydraulic expert knowledge includes:
• Being able to read and fully understand hydraulic circuit diagrams
• In particular, fully understanding the relationships with regard to safety devices
• Knowledge regarding the function and interaction of hydraulic components
BoschRexroth offers you measures supporting training in specific areas.
Youcanfind an overview of the training contents on the Internet at:
www.boschrexroth.com/training.

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2.5 General safety instructions
• Observe applicable accident prevention and environmental protection regulations.
• Observe the safety regulations of the country in which the product is used/operated.
• Use Rexroth products only when they are in good working order.
• Observe all notices on the product.
• Do not install, operate, remove or maintain Rexroth products if under the influence
of alcohol, drugs or medication that may affect your reaction time.
• Only use genuine Rexroth accessories and spare parts to ensure there is no hazard
to persons from unsuitable spare parts.
• Observe the technical data and ambient conditions specified in the product
documentation.
• If unsuitable products are installed or used in applications that are of relevance to
safety, unexpected operating conditions may occur in the application, which could
result in personal injury or property damage. For this reason, only use the product
in safety-relevant applications if this use is expressly indicated and approved in the
product documentation, e.g.in explosion protection areas or in safety-related parts
of a control system (functional safety).
• Only commission the product if it has been determined that the end product
(e.g.machinery/system) in which the Rexroth products are installed complies
with the country-specific provisions, safety regulations and standards for the
application.
• Use tools appropriate for the work being performed and wear appropriate
protective clothing to prevent punctures and cuts (e.g.when removing protective
covers, disassembly).
• There is a risk of entanglement when operating the axial piston unit with abare
shaft end. Check whether or not your machine requires additional safety measures
for your application. If necessary, make sure these are appropriately implemented.
• Depending on the type of control used, electromagnetic effects can be produced
when using solenoids. Applying a direct voltage signal (DC) to solenoids does not
create electromagnetic interference (EMI) nor is the solenoid affected by EMI.
Potential electromagnetic interference (EMI) exists if the solenoid is energized
with a modulated direct current (e.g.PWM signal). The machine manufacturer
should conduct appropriate tests and take appropriate measures to ensure that
other components or operators (e.g.with a pacemaker) are not affected by this
potentiality.

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2.6 Product-specific safety instructions
The following safety instructions apply to chapters 6 to 14.
WARNING
Danger from excessive pressure!
Danger to life, risk of injury or property damage!
Improperly changing the factory pressure settings can result in a pressure increase
beyond the maximum permissible pressure.
Operating the unit above the maximum permissible pressure can cause
components to burst and hydraulic fluid to escape under high pressure.
▶ Changes to the factory settings may only be made by BoschRexroth specialists.
▶ In addition, a pressure relief valve is required in the hydraulic system as back-up.
If the axial piston unit is equipped with a pressure cut-off and/or pressure
controller, this is not an adequate safeguard against pressure overload.
Danger due to suspended loads!
Danger to life, risk of injury or property damage!
Improper transportation may cause the axial piston unit to fall down and lead to
injury, e.g.crushing or fracture, or damage to the product.
▶ Make sure that the load bearing capacity of the lifting device is sufficient to
safely bear the weight of the axial piston unit.
▶ Never step or grip under suspended loads.
▶ Ensure a stable transportposition.
▶ Use your personal protective equipment (e.g.safety goggles, safety gloves,
suitable working clothes, safety shoes).
▶ Use suitable lifting devices for transport.
▶ Observe the prescribed position of the lifting strap.
▶ Observe the national laws and specifications of occupational safety and health
and transport.
System/machine under pressure!
Risk of death or serious injury when working on unsecured machines/systems!
Property damage!
▶ Switch off the relevant machine/system part and secure it against reactivation
according to the parameters by the machine/system manufacturer.
▶ Ensure that all relevant components of the hydraulic system are depressurized.
For this purpose, observe the parameters indicated by the machine/system
manufacturer.
▶ Please note that the hydraulic system might still be pressurized even after
separation from the actual pressure supply.
▶ Do not disconnect any line connections, ports and components as long as the
hydraulic system is under pressure.

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WARNING
Escaping hydraulic fluid mist!
Risk of explosion and fire hazard, health hazard, risk of environmental pollution!
▶ Depressurize the relevant machine/system component and repair the leak.
▶ Only perform welding work when the machine/system is depressurized.
▶ Keep open flames and ignition sources away from the axial piston unit.
▶ If axial piston units are located in the vicinity of ignition sources or powerful
thermal radiators, a shield must be erected to ensure any escaping hydraulic
fluid cannot be ignited, and to protect hose lines from premature aging.
Electrical voltage!
Danger to life or risk of injury due to electric shock or property damage!
▶ Always disconnect the voltage supply to the relevant machine/system part
before installing the product and/or connecting or disconnecting the connector.
Protect the machine/system against being re-energized.
Danger from unexpected machine movement!
Danger to life or risk of injury! Unintentional or careless actuation of the manual
override of the solenoids can cause unexpected machine movements.
▶ Use the manual override only for functional testing or in the event of technical
malfunctions.
▶ Using the manual override on a permanent basis (e.g.by wedging, blocking)
isnot permitted.
▶ The use of the manual override is only permitted with limited technical data
(e.g.0.25 ×maximum data).
▶ Check whether or not your machine requires additional safety measures for your
application to avoid unintentional actuation. If necessary, make sure these are
appropriately implemented.
▶ Wear suitable protective clothing.
Limitation of the closed loop control and/or open loop control function!
Risk of injury or property damage!
Under certain circumstances, moving parts in control equipment (e.g.,valvespools)
can get stuck in an undefined position due to contamination (e.g.,impure hydraulic
fluid, abrasion or residual dirt from components). As a result, the hydraulic fluid
flow and the build-up of torque in the axial piston unit can no longer respond
correctly to the operator’s specifications. Even the use of various filter elements
(external or internal flow filtration) will not rule out a fault but merely reduce the
risk.
▶ Check whether your application requires remedial measures on your machine in
order to bring the driven consumer to a safe position (e.g.safe stop).
▶ If necessary, make sure these are appropriately implemented.

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WARNING
Danger caused by pressurized, leaking hydraulic fluid or ejected components!
Danger to life or risk of injury! When selecting or using connecting elements
without sufficient high-pressure resistance, they may burst or lead to the leakage of
hydraulic fluid and/or to ejected components. The ports and fastening threads of
the axial piston unit are designed for the specified maximum pressure.
▶ Only ever connect connecting elements and lines that match the ports of the
axial piston unit and can resist the intended application conditions (e.g.pressure
level, flow, hydraulic fluid, temperature) with the necessary safety factors.
Escaping hydraulic fluid through leaking machine/system components!
Risk of burning and risk of injury due to escaping hydraulic fluid jet!
In case of leakage at the axial piston unit, high-pressure fluid jets may escape.
▶ Depressurize the relevant machine/system component and repair the leak.
▶ Never attempt to block or seal the leak or hydraulic fluid jet with a cloth.
CAUTION
High noise development during operation!
Danger of hearing damage, hearing loss!
The noise emission of axial piston units depends on rotational speed,
workingpressure and installation conditions, among other factors. The sound
pressure level may rise above 70 dB (A) in certain application conditions.
▶ Always wear hearing protection near a running axial piston unit.
Hot surfaces on axial piston unit!
Risk of burning!
▶ Allow the axial piston unit to cool down sufficiently before touching it.
▶ Protect yourself with heat-resistant protective clothing, e.g.gloves.
Inappropriate routing of cables and lines!
Risk of stumbling and property damage! Improper routing of cables and lines
can cause a risk of stumbling as well as damage to equipment and components,
e.g.due to lines and connectors being torn off.
▶ Always install cables and lines in a way that nobody can fall over them, that
they are not bend or twisted, do not chafe on edges and are not guided through
ducts with sharp edges without sufficient protection.

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CAUTION
Contact with hydraulic fluid!
Danger to health/damage to health, e.g.eye injury, skin damage, toxication in the
event of inhalation!
▶ Avoid any contact with hydraulic fluids.
▶ When handling hydraulic fluids, the safety instructions of the lubricant
manufacturer need to be observed at all times.
▶ Use your personal protective equipment (e.g.safety goggles, safety gloves,
suitable working clothes, safety shoes).
▶ Immediately seek medical attention, however, if hydraulic fluid gets into your
eyes or blood circuit or if you swallow it accidentally.
Danger from improper handling!
Slip hazard! Risk of slipping on wet surfaces when climbing on the axial piston unit.
▶ Never grab or climb onto the axial piston unit.
▶ Check how to safely get on top of the machine/system.
2.7 Personal protective equipment
Personal protective equipment is the responsibility of the user of the axial piston unit.
Observe the safety regulations in your country.
All pieces of personal protective equipment should be intact.

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3 General instructions on property
damage and product damage
The following notices apply to chapters 6 to 14.
NOTICE
Danger from improper handling!
Product can be damaged!
▶ Do not subject the product to improper mechanical loads.
▶ Never use the product as handle or step.
▶ Do not put/place any objects on the product.
▶ Do not strike the drive shaft of the axial piston unit.
▶ Do not set/place the axial piston unit on the drive shaft or assembled parts.
▶ Do not strike assembled parts (e.g.sensors. solenoids or valves).
▶ Do not hit sealing surfaces (e.g.on the work connections).
▶ Leave the protective covers on the axial piston unit until you connect the lines.
▶ Disconnect all electrical connectors before arc welding and painting operations.
▶ Ensure that the electronic components (e.g.sensors) are not electro-statically
charged (e.g.during painting operations).
Risk of property damage due to inadequate lubrication!
Product can be damaged or destroyed!
▶ Never operate the axial piston unit with insufficient hydraulic fluid. Specifically,
make sure that the rotary group has sufficient lubrication.
▶ When commissioning a machine/system, make sure that the housing area and
the working lines of the axial piston unit are filled with hydraulic fluid and
remain filled during operation.
▶ Check the hydraulic fluid level in the housing area regularly and recommission,
if necessary. For above-reservoir installation, the housing area may drain out
through the drain line after prolonged standstill periods (air enters through the
shaft seal) or through the working line (gap leakage). This means the bearings
are insufficiently lubricated when the system is turned on.
▶ Make sure the suction line is always filled with hydraulic fluid during
commissioning and operation.
Mixing hydraulic fluids!
Product can be damaged!
▶ Before installation, remove all fluids from the axial piston unit to prevent mixing
with the hydraulic fluid used in the machine/system.
▶ Any mixture of hydraulic fluids of different manufacturers and/or different types
of the same manufacturer is generally not permissible.

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NOTICE
Contamination of hydraulic fluid!
The cleanliness of the hydraulic fluid impacts the service life of the axial piston
unit. Contamination of the hydraulic fluid may lead to premature wear and
malfunctions!
▶ Always ensure a work environment in the assembly location that is free from
dust and foreign particles to prevent foreign particles, e.g.welding beads
or metal cuttings, from entering the hydraulic lines and lead to wear and
malfunctions in the product. The axial piston unit should be clean when
installed.
▶ Only use clean ports, hydraulic lines and assembled parts
(e.g.measuringdevices).
▶ When plugging the ports, no contamination may ingress.
▶ Before commissioning, ensure that all hydraulic connections are tight and
that all seals and plugs of the plug-in connection are correctly installed and
undamaged to prevent fluids and foreign particles from entering the product.
▶ Filter the hydraulic fluid when filling the system with a suitable filter system to
minimize the solid particle contamination and water in the hydraulic system and
to achieve the required cleanliness level.
Improper cleaning
Product can be damaged!
▶ Plug all openings with appropriate protective covers in order to prevent cleaning
agents from entering the axial piston unit.
▶ Never use solvents or aggressive cleaning agents. Use only water and,
ifnecessary, a mild cleaning agent to clean the axial piston unit.
▶ Do not point a high-pressure cleaner at sensitive components, e.g.shaft seal,
electrical connections and components.
▶ Use fiber-free cleaning cloths for cleaning.
Environmental pollution due to incorrect disposal!
Careless disposal of the axial piston unit and its assembled parts, the hydraulic
fluid and the packaging material can cause environmental pollution!
▶ Dispose of the axial piston unit, hydraulic fluid and packaging in accordance
with the regulations in your country.
▶ Dispose of the hydraulic fluid in accordance with the applicable safety
datasheetof the hydraulic fluid.

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NOTICE
Danger due to chemical or aggressive environmental conditions!
Product can be damaged! If the axial piston unit is exposed to chemical or
corrosive environmental conditions, such as sea water, fertilizer or road salt, it can
result in corrosion or, in extreme cases, malfunction. Leaks may lead to a leakage of
hydraulic fluid.
▶ Take appropriate measures to protect the axial piston unit from chemical or
corrosive environmental conditions.
Leakage or spilling of hydraulic fluid!
Environmental pollution and contamination of the ground water!
▶ Always place a drip tray under the axial piston unit when filling and draining
hydraulic fluid.
▶ Use a suitable binding agent to collect any leaked hydraulic fluid.
▶ Observe the safety datasheetfor the hydraulic fluid and the specifications
provided by the machine/system manufacturer.
Danger due to heat development in components!
Adjacent products may be damaged! Due to a heat development in components
(e.g.solenoids), adjacent products may be damaged during assembly if no
sufficient safety distance is complied with.
▶ When installing the axial piston unit, check the safety distances to nearby
products to ensure that they are not damaged.
The warranty exclusively applies to the delivered configuration.
The warranty will be voided if the product is incorrectly installed,
commissionedoroperated, or if it is used or handled improperly.

Scope of delivery 19/64
RE92035-01-B/2019-11-25, A4VG Series35, Bosch Rexroth AG
4 Scope of delivery
1
2
2
4
3
Fig. 1: Axial piston unit
Included in the scope of delivery:
• Axial piston unit as per order confirmation
The following parts come assembled on the unit:
• Protective covers(1)
• Protective plug/threaded plugs(2)
• Protective covers for sensors and connectors(3)
• For version with through drive, protective cover incl. mounting bolts(4)

20/64 About this product
Bosch Rexroth AG, A4VG Series35, RE92035-01-B/2019-11-25
5 About this product
5.1 Performance description
The axial piston variable pump generates, controls and regulates a hydraulic fluid
flow. It is designed for mobile applications such as construction machinery.
Refer to datasheet92035 and the order confirmation for the technical data,
operating conditions and operating limits of the axial piston unit.
5.2 Product description
A4VG is a variable pump with an axial piston rotary group in swashplate design
for hydrostatic drives in closed circuits. Flow is proportional to drive speed and
displacement. The flow can be smoothly changed using the control (cradle) (12).
Foraxial piston units with swashplate design, the pistons are arranged axially
relative to the drive shaft.
In the closed circuit, the hydraulic fluid flows from the hydraulic pump to the
consumer, e.g.hydraulic motor and from there directly back to the hydraulic pump.
There is a high-pressure side and a low-pressure side which alternate depending on
which side is under load.
5.2.1 Axial piston unit layout
1
2
3 4
5
6
7
891011
12
Fig. 2: Series35 A4VG layout
1 Drive shaft
2 Retaining plate
3 Stroking piston
4 Control plate
(Distributor plate)
5 High-pressure side
6 Boost pump
7 Low-pressure side
8 Suction port
9 Cylinder
10 Piston
11 Slipper pad
12 Cradle
Closed circuit