Bosch Rexroth A4VG 40 Series User manual

Instruction manual
RE 92004-01-B/05.2017
Replaces: 04.2008
English
Axial piston variable pump
A4VG
Series 40

© Bosch Rexroth AG 2017. 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.

RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
Contents
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 damage
to property and theproduct 16
4 Scope of delivery 19
5 About this product 20
5.1 Performance description 20
5.2 Product description 20
5.2.1 Layout of the axial piston unit 20
5.2.2 Functional description 21
5.3 Bypass function 22
5.3.1 Activating and deactivating the bypass function 23
5.4 Product identification 24
6 Transport and storage 25
6.1 Transporting the axial piston unit 25
6.1.1 Transporting by hand 25
6.1.2 Transporting with a lifting device 25
6.2 Storing the axial piston unit 27
7 Installation 29
7.1 Unpacking 29
7.2 Installation conditions 29
7.3 Installation position 31
7.3.1 Below-reservoir installation (standard) 32
7.3.2 Above-reservoir installation 33
7.4 Installing the axial piston unit 34
7.4.1 Preparation 34
7.4.2 Dimensions 35
7.4.3 General instructions 35
7.4.4 Installation with coupling 36
7.4.5 Installation on a gearbox 37
7.4.6 Installation with cardan shaft 37
7.4.7 Completing installation 37
Contents 3/68

4/68
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
Contents
7.4.8 Changing the lever position of the HW control 39
7.4.9 Hydraulically connecting the axial piston unit 39
7.4.10 Electrically connecting the axial piston unit 45
7.5 Performing flushing cycle 45
8 Commissioning 46
8.1 Initial commissioning 46
8.1.1 Filling the axial piston unit 47
8.1.2 Testing the hydraulic fluid supply 48
8.1.3 Performing a functional test 48
8.2 Running-in phase 49
8.3 Recommissioning after a standstill 49
9 Operation 50
10 Maintenance and repair 51
10.1 Cleaning and care 51
10.2 Inspection 52
10.3 Maintenance 52
10.3.1Changing the filter element 53
10.4 Repair 53
10.5 Spare parts 54
11 Removal and replacement 55
11.1 Required tools 55
11.2 Preparing for removal 55
11.3 Performing removal 55
11.4 Preparing the components for storage or further use 55
12 Disposal 56
13 Extension and conversion 57
14 Troubleshooting 58
14.1 How to proceed with troubleshooting 58
14.2 Malfunction table 59
15 Technical data 63
16 Alphabetical index 66

About this documentation 5/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
1 About this documentation
1.1 Validity of the documentation
This documentation is valid for the following products:
•Axial piston variable pump A4VG Series 40
This documentation is intended for machine/system manufacturers, assemblers and
service engineers.
This documentation contains important information on the safe and appropriate
transport, installation, commissioning, operation, maintenance, removal and simple
troubleshooting of the axial piston unit.
▶ Read this documentation completely and in particular the chapter 2 “Safety
instructions” on page 9 and chapter 3 “General instructions on damage
to property and theproduct” 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 of your axial piston variable pump A4VG
Series 40.
– Order confirmation
Installation drawing
Contains the outer dimensions, all connections and the hydraulic circuit diagram
for your axial piston variable pump A4VG Series 40.
Please request the
installation drawing
from your contact at
Bosch Rexroth.
Installation drawing
Axial piston variable pump A4VG Series 40
Contains the permissible technical data.
92004 Data sheet
Mineral oil-based hydraulic fluids and related hydrocarbons
Describes the requirements on a mineral oil-based hydraulic fluid and related
hydrocarbons for operation with Rexroth hydraulic components, and assists you
in selecting a hydraulic fluid for your hydraulic system.
90220 Data sheet
Environmentally acceptable hydraulic fluids
Describes the requirements on an environmentally acceptable hydraulic fluid
for operation with Rexroth hydraulic components and assists you in selecting
a hydraulic fluid for your hydraulic system.
90221 Data sheet
Fire-resistant, water-free hydraulic fluids (HFDU/HFDR)
Describes the requirements on fire-resistant, water-free hydraulic fluids (HFDU/
HFDR) for operation with Rexroth hydraulic components and assists you in
selecting a hydraulic fluid for your hydraulic system.
90222 Data sheet
Axial piston units for operation with water-free and water-containing fire-
resistant hydraulic fluids (HFDR, HFDU, HFA, HFB, HFC)
Describes the requirements on fire-resistant, water-free and water-containing
hydraulic fluids (HFDR, HFDU, HFA, HFB, HFC) for operation with Rexroth
hydraulic components and assists you in selecting a hydraulic fluid for your
hydraulic system.
90225 Data sheet
Information on the use of hydrostatic drives at low temperatures
Contains additional information on the use 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

6/68 About this documentation
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
1.3 Representation of information
Standardized safety instructions, symbols, terms and abbreviations are used
throughout this documentation so that you can work quickly and safely with your
product. To give you a better understanding they are explained in the sections below.
1.3.1 Safety instructions
This documentation includes safety instructions in chapter 2.6 “Product-specific
safety instructions” on page 12 and in chapter 3 “General instructions on damage
to property and theproduct” on page 16 and before a sequence of actions or an
instruction for action involving a risk of personal injury or damage to equipment.
The described danger prevention measures must be observed.
Safety instructions are set out as follows:
SIGNAL WORD
Type and source of danger!
Consequences of noncompliance
▶ Measures to prevent danger
•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 the safety instructions are not complied
with
•Precautions: states how the danger can be avoided

About this documentation 7/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
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 injuries if it is not avoided.
WARNING Identifies a dangerous situation that may result in death
or serious injuries if it is not avoided.
CAUTION Identifies a dangerous situation that may result in minor
to moderate injuries if it is not avoided.
NOTICE Property damage: The product or the environment may get
damaged.
1.3.2 Symbols
The following symbols indicate information that is not safety-relevant but increases
understanding of the documentation.
Table 3: Meaning of the symbols
Symbol Meaning
If this information is disregarded, the product cannot be used and/or
operated to the optimum extent.
▶ Single, independent action
1.
2.
3.
Numbered instruction:
The numbers indicate that the actions must be completed one after
the other.
1.3.3 Designations
This documentation uses the following designations:
Table 4: Designations
Designation Meaning
A4VG Axial piston variable pump, 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.

8/68 About this documentation
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
1.3.4 Abbreviations
This documentation uses the following abbreviations:
Table 5: Abbreviations
Abbreviation Meaning
ATEX EC directive on explosion protection (Atmosphère explosible)
DA Automatic control, speed related
DIN Deutsches Institut für Normung (German Institute for Standardization)
EP Proportional control, electric
ET Electric control, direct operated with two pressure reducing valves (DRE)
EV Electric control , direct operated
EZ Two-point control, electric
HP Proportional control, hydraulic, pilot-pressure related
HW Proportional control, hydraulic, mechanical servo
HT Hydraulic control, direct operated
ISO International Organization for Standardization
JIS Japan Industrial Standard
RE Rexroth document in the English language
VDI2230 Directive for the systematic calculation of high duty bolted joints and
joints with one cylindrical bolt from the VDI (VereinDeutscherIngenieure -
Association of German Engineers)

Safety instructions 9/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
2 Safety instructions
2.1 About this chapter
The axial piston unit has been manufactured according to the generally accepted
rules of current technology. There is, however, still a danger of personal injury or
property damage if this chapter and the safety instructions in this documentation are
not complied with.
▶ 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 in the
sense of 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 may 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 data sheet92004 and in the order
confirmation. Information about approved hydraulic fluids can be found in data
sheet 92004.
The axial piston unit is only intended for professional use and not for private use.
Intended use includes having read and understood the complete documentation,
especially chapter 2 “Safety instructions” on page 9.
2.3 Improper use
Any use other than that described as intended use shall be considered as improper
and is therefore impermissible.
Bosch Rexroth AG is not liable for damages resulting from improper use. The user
shall bear all risks arising from improper use.
The following foreseeable faulty usages are also be considered to be improper (this
list does not claim to be exhaustive):
•Use outside the operating parameters approved in the data sheet or in the order
confirmation (unless specifically approved by the customer)
•Use of non-approved fluids, e.g.water or polyurethane components
•Changes to factory settings by unauthorized persons
•Use of assembled parts (e.g.attachment filter, control unit, valves) other than the
specified Rexroth components

10/68 Safety instructions
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
•Use of the axial piston unit with assembled parts under water at a depth of more
than 10 meters without the necessary additional measures, for example 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 case
to ambient pressure greater than 2bar, whereby the ambient pressure must always
be lower than the case pressure. Momentary (t<0.1s) pressure peaks of up to
10bar are allowed. Beyond this, the maximum case pressure specified on the data
sheet cannot be exceeded.
•Use 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/EC
•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 basic mechanical, electrical
and hydraulics expertise, as well as knowledge of the associated technical terms.
For transporting and handling the product, additional knowledge is necessary with
regard to working with lifting devices and their slings. 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 persons are those who can recognize possible dangers and take the
appropriate safety measures due to their professional training, knowledge, and
experience, as well as their understanding of the relevant regulations pertaining to
the work to be done. Skilled personnel must follow the rules relevant to their field
and have the necessary hydraulics expert knowledge.
Hydraulic expert knowledgeincludes:
•Reading and fully understanding hydraulic circuit diagrams,
•especially fully understanding the relationships with regard to safety devices
•and understanding how hydraulic components work and are put together.
Bosch Rexroth offers training support for specialized fields. An overview of the
training contents can be found online at: www.boschrexroth.com/training.

Safety instructions 11/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
2.5 General safety instructions
•Observe the applicable accident prevention and environmental protection
regulations.
•Observe the safety regulations and provisions 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.
•Persons who install, operate, remove or maintain Rexroth products may not be
under the influence of alcohol, drugs or medication that may affect their reaction
time.
•Only use genuine Rexroth accessories and spare parts to ensure there is no hazard
to persons due to 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 injury to personnel or property damage. For this reason, only use
the product in safety-relevant applications if this use is expressly specified and
permitted in the product documentation, for example in explosion protection
applications or in safety-related parts of a control system (functional safety).
•You may only commission the product if it has been determined that the end
product (for example, machinery or 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 that these are properly implemented.
•Depending on the type of control used, electromagnetic effects can be produced
when using solenoids. When a direct current is applied, solenoids do not cause
electromagnetic interference nor is their operation impaired by electromagnetic
interference. Other behavior can result when a modulated direct current (e.g.
PWM signal) is applied. Potential electromagnetic interference for persons (e.g.
persons with a pacemaker) and other components must be tested by the machine
manufacturer.

12/68 Safety instructions
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
2.6 Product-specific safety instructions
The following safety instructions apply to chapters 6 to 14.
WARNING
Danger from excessively high pressure!
Risk of death or injury, or property damage!
Improperly changing the factory pressure settings can result in a pressure increase
beyond the permissible maximum pressure.
Operating the unit above the permissible maximum pressure can cause
components to burst and hydraulic fluid to escape under high pressure.
▶ Changes to the factory settings must only be made by Bosch Rexroth specialists.
▶ In addition, a pressure relief valve is required in the hydraulic system as a back-
up. If the axial piston unit is equipped with a pressure cut-off and/or a pressure
controller, this is not an adequate back-up against pressure overload.
Danger from suspended loads!
Risk of death or injury, or property damage!
Improper transportation may cause the axial piston unit to fall down and lead to
injuries e.g. crushing or broken bones 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 stand or put your hands under a suspended load.
▶ Make sure the unit remains stable during transport.
▶ Wear your personal protective equipment (e.g.safety goggles, safety gloves,
suitable working clothes, safety shoes).
▶ Use suitable lifting devices for transportation.
▶ Observe the prescribed position of the lifting strap.
▶ Observe the national laws and regulations on work and health protection and
transportation.
System/machine under pressure!
Danger to life or risk of injury, serious injuries when working on machines/systems
not secured! Risk of property damage!
▶ Switch off the entire system and secure it against reconnection according to the
parameters provided by the machine/system manufacturer.
▶ Make sure that all relevant components of the hydraulic system are
depressurized. Follow the parameters given by the machine/system
manufacturer.
▶ Note that the hydraulic system may still may be under pressure even after the
pressure supply itself has been disconnected.
▶ Do not disconnect any line connections, ports and components as long as the
hydraulic system is under pressure.

Safety instructions 13/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
WARNING
Escaping hydraulic fluid mist!
Risk of explosion and fire, health hazard, risk of environmental pollution!
▶ Depressurize the relevant machine/system component and repair the leak.
▶ Only perform welding work then 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 that any escaped hydraulic
fluid cannot be ignited, and to protect hose lines from premature aging.
Electrical voltage!
Risk of injury from electric shock or risk of property damage!
▶ Always set up the relevant part of the machine/system so that it is free of electrical
voltage before you install the product or when connecting and disconnecting
connectors. Protect the machine/system against being re-energized.
Danger from unforeseen 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 additional protective measures are necessary for the application
on your machine in order to avoid unintentional actuation. If necessary, make
sure that these are properly implemented.
▶ Wear suitable protective clothing.
Restriction of the control function!
Risk of injury or property damage!
Moving parts in control equipment (e.g.valve spools) can, under certain
circumstances, get stuck in position as a result of 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 that remedial measures be taken on
your machine in order to bring the driven consumer into a safe position
(e.g. safe stop).
▶ If necessary, make sure that these are properly implemented.

14/68 Safety instructions
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
WARNING
Restriction of the load holding function in lifting winches!
Risk of injury or property damage!
Moving parts in high-pressure relief valves may in certain circumstances become
stuck in an undefined position due to contamination (e.g. contaminated hydraulic
fluid). This can result in restriction or loss of the load holding function in lifting
winches.
▶ Check whether the application on your machine requires additional safety
measures, in order to keep the load in a safe position.
▶ If necessary, make sure that these are properly implemented.
CAUTION
High noise development during operation!
Risk of hearing damage or hearing loss!
The noise emission of axial piston units depends on, among other factors,
rotational speed, working pressure and installation conditions. The sound pressure
level may rise above 70dB(A) in certain application conditions.
▶ Always wear hearing protection when in the vicinity of the operating axial piston
unit.
Hot surfaces on the axial piston unit!
Risk of burning!
▶ Allow the axial piston unit to cool down sufficiently before touching it.
▶ Wear heat-resistant protective clothing, e.g.gloves.
Improper 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, for
example, tearing of lines and connectors.
▶ Always route cables and lines in such a way that no one can trip over them,
that they do not become kinked or twisted, do not rub on edges and do not run
without adequate protection through sharp-edged ducts.
Contact with hydraulic fluid!
Risk of adverse health effects, e.g.eye injury, skin irritation, poisoning from
inhalation!
▶ Avoid contact with hydraulic fluids.
▶ When working with hydraulic fluids, strictly observe the safety instructions
provided by the lubricant manufacturer.
▶ Wear your personal protective equipment (e.g.safety goggles, safety gloves,
suitable working clothes, safety shoes).
▶ Consult a doctor immediately if hydraulic fluid gets in your eyes or bloodstream,
or is swallowed.

Safety instructions 15/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
CAUTION
Escaping hydraulic fluid due to machine/system leakage!
Risk of burns and risk of injury due to escaping hydraulic fluid jet!
▶ 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.
Danger from improper handling!
Risk of slipping! 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 and provisions in your country.
All pieces of personal protective equipment must be intact.

16/68 General instructions on damage to property and theproduct
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
3 General instructions on damage
to property and theproduct
The following instructions apply to chapters 6 to 14.
NOTICE
Danger from improper handling!
Product can get damaged!
▶ Do not expose the product to excessive mechanical loads.
▶ Never grab or climb onto the product.
▶ Do not place/lay 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 or valves).
▶ Do not strike sealing surfaces (e.g. working ports).
▶ Leave the protective covers on the axial piston unit until you connect the lines.
▶ Disconnect all electrical connectors before electro-welding or painting
operations.
▶ Make certain that the electronic components (e.g.sensors) do not become
electrostatically charged (e.g.during painting operations).
Risk of property damage due to inadequate lubrication!
Product can get 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. Air inclusions in the forward drive shaft bearing
are to be prevented, especially with the installation position “drive shaft
upwards”.
▶ Check the hydraulic fluid level in the housing area regularly; if necessary,
recommission. With above-reservoir installation, the housing area may drain
via the drain line after longer periods of disuse (air enters via the shaft seal)
or via the working line (gap leakage). This means the bearings are insufficiently
lubricated when the system is turned on.
▶ Make sure that the suction line is always filled with hydraulic fluid during
commissioning and operation.
Mixing of hydraulic fluids!
Product can get damaged!
▶ Before installation, remove all fluids from the axial piston unit to prevent mixing
with the hydraulic fluid used in the machine/system.
▶ Any mixing of hydraulic fluids from different manufacturers or different types
from the same manufacturer is generally not permitted.

General instructions on damage to property and theproduct 17/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
NOTICE
Contamination of the hydraulic fluid!
The cleanliness of the hydraulic fluid has a considerable impact on the cleanliness
and service life of the hydraulic system. Contamination of the hydraulic fluid can
cause premature wear and malfunctions!
▶ Make sure that the working environment at the installation site is fully free
of dust and foreign substances in order to prevent foreign particles, such
aswelding beads or metal cuttings, from getting into the hydraulic lines and
causing product wear or malfunctions. The axial piston unit must be installed
in a clean condition.
▶ Use only clean ports, hydraulic lines and assembled parts (e.g.measuring
devices).
▶ No contamination may enter the ports when they are plugged.
▶ Before commissioning, make sure that all hydraulic connections are tight and
that all of the seals and plug-in connections are installed correctly to ensure
that they are leak proof and fluids and foreign particles are prevented from
penetrating the product.
▶ Use a suitable filter system to filter hydraulic fluid during filling to minimize solid
particle contamination and water in the hydraulic system.
Improper cleaning!
Product can get damaged!
▶ Plug all openings with the appropriate protection equipment in order to prevent
cleaning agents from entering the hydraulic system.
▶ Never use solvents or corrosive 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 cloths for cleaning.
Environmental pollution due to improper disposal!
Careless disposal of the axial piston unit and its assembled parts, the hydraulic
fluid and the packaging material can result in environmental pollution!
▶ Dispose of the axial piston unit, hydraulic fluid and packaging in accordance
with the national regulations in your country.
▶ Dispose of the hydraulic fluid in accordance with the applicable safety data
sheet for the hydraulic fluid.
Danger from chemical or corrosive environmental conditions!
Product can get 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. Hydraulic fluid can escape if
leaks occur.
▶ Take appropriate steps to protect the axial piston unit from chemical or
corrosive environmental conditions.

18/68 General instructions on damage to property and theproduct
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
NOTICE
Escaping or spilling hydraulic fluid!
Risk of environmental pollution and contamination of ground water!
▶ Always place a drip tray under the axial piston unit when filling and draining the
hydraulic fluid.
▶ Use a suitable binding agent if hydraulic fluid is spilled.
▶ Observe the parameters in the safety data sheet for the hydraulic fluid and the
specifications provided by the system manufacturer.
Danger from hot components!
Nearby products can become damaged! Components which heat up
(e.g.solenoids) can cause damage to nearby products if they are too close during
installation.
▶ When installing the axial piston unit, check the distances to nearby products to
ensure that they do not get damaged.
The warranty only applies to the delivered configuration.
The entitlement to warranty cover will be rendered void if the product is incorrectly
installed, commissioned or operated, or if it is used or handled improperly.

Scope of delivery 19/68
RE 92004-01-B/05.2017, A4VG Series 40, Bosch Rexroth AG
4 Scope of delivery
1
1
3
2
Fig. 1: Axial piston unit
The scope of delivery includes the following:
•Axial piston unit as per order confirmation
The following parts are also assembled prior to delivery:
•Protective covers(1)
•Protective plug/threaded plug(2)
•For version with through drive, metallic protective cover and mounting bolts(3)

20/68 About this product
Bosch Rexroth AG, A4VG Series 40, RE 92004-01-B/05.2017
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 92004 and the order confirmation for the technical data,
operating conditions and operating limits of the axial piston unit.
5.2 Product description
The A4VG is a variable pump with axial piston rotary group in swashplate design for
hydrostatic drives in closed circuits. The flow is proportional to the drive speed and
displacement. The flow can be changed steplessly by controlling the swashplate
(cradle) (13). 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 Layout of the axial piston unit
9
1011
12
1
2
3
4
5
7
6
8
13
Fig. 2: Layout of the A4VG Series 40
1 Drive shaft
2 Retaining plate
3 Stroking piston
4 Control unit
(using the EP as
an example here)
5 Control plate
(distributor plate)
6 High-pressure side
7 Boost pump
8 Low-pressure side
9 Suction port
10 Cylinder
11 Piston
12 Slipper pad
13 Cradle
Closed circuit