REXROTH A6VE Series 65 User manual

Variable plug-in motor
A6VE
Series 65 and 71
Replaces: 09.2013
English
Instruction manual
RE 91616-01-B/10.2014

The data specified above only serve to
describe the product. No statement about
a specific characteristic or suitability for a
certain application can be derived from this
information. Information from the catalog
does not represent assured properties.
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 application.
The product delivered may differ from the
image on the cover.
The original instruction manual was created
inGerman.

RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
3/60Contents
1 About this documentation 5
1.1 Validity of the documentation 5
1.2 Required and supplementary documentation 5
1.3 Display of information 6
1.3.1 Safety instructions 6
1.3.2 Symbols 7
1.3.3 Designations 7
1.3.4 Abbreviations 7
2 Safety instructions 8
2.1 About this chapter 8
2.2 Intended use 8
2.3 Improper use 8
2.4 Personnel qualifications 9
2.5 General safety instructions 9
2.6 Product-specific safety instructions 10
2.7 Personal protective equipment 13
3 General instructions on damage to property and the product 14
4 Scope of delivery 17
5 About this product 18
5.1 Performance description 18
5.2 Product description 18
5.2.1 Layout of the axial piston unit 18
5.2.2 Functional description 19
5.3 Product identification 20
6 Transport and storage 21
6.1 Transporting the axial piston unit 21
6.1.1 Transporting by hand 21
6.1.2 Transporting with lifting device 22
6.2 Storing the axial piston unit 23
7 Installation 25
7.1 Unpacking 25
7.2 Installation conditions 25
7.3 Installation position 27
7.3.1 Below-reservoir installation (standard) 27
7.3.2 Above-reservoir installation 28
7.4 Installing the axial piston unit 29
7.4.1 Preparation 29
7.4.2 Dimensions 29
7.4.3 General notes 29
7.4.4 Installation with coupling 30
7.4.5 Installation on a gearbox 31
7.4.6 Installation with cardan shaft 31
7.4.7 Completing installation 31
7.4.8 Hydraulically connecting the axial piston unit 32
7.4.9 Electrically connecting the axial piston unit 39
7.5 Performing flushing cycle 40
Contents

4/60
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
8 Commissioning 41
8.1 Initial commissioning 41
8.1.1 Filling the axial piston unit 41
8.1.2 Testing the hydraulic fluid supply 43
8.1.3 Performing functional test 43
8.2 Running-in phase 44
8.3 Recommissioning after standstill 44
8.4 Integrated counterbalance valve (BVI) – Brake release function lock/unlock 45
9 Operation 46
10 Maintenance and repair 47
10.1 Cleaning and care 47
10.2 Inspection 47
10.3 Maintenance 48
10.4 Repair 48
10.5 Spare parts 49
11 Removal and replacement 50
11.1 Required tools 50
11.2 Preparing for removal 50
11.3 Carrying out removal 50
11.4 Preparing the components for storage or further use 50
12 Disposal 51
13 Extension and conversion 51
14 Troubleshooting 52
14.1 How to proceed with troubleshooting 52
14.2 Malfunction table 53
15 Technical data 55
16 Alphabetical index 56
Contents

About this documentation 5/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
1 About this documentation
1.1 Validity of the documentation
This documentation is valid for the following product:
•Variable plug-in motor A6VE Series 65
•Variable plug-in motor A6VE Series 71
This documentation is intended for machine/system manufacturers, fitters and
service technicians.
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 8 and chapter3 “General instructions on damage to
property and the product” on page 14 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 variable plug-in motor A6VE.
– Order confirmation
Installation drawing
Contains the outer dimensions, all connections and the hydraulic circuit diagram
for your plug-in variable motor A6VE.
Please request
the installation
drawing via your
contact person at
BoschRexroth.
Installation drawing
Variable plug-in motor A6VE Series 65
Variable plug-in motor A6VE Series 71
Contains the permissible technical data.
91615
91616
Data sheet
Mineral-oil based hydraulic fluids and related hydrocarbons
Describes the requirements for 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 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 HF hydraulic fluids
Contains additional information on the use of Rexroth axial piston units with HF
hydraulic fluids.
90223 Data sheet
Information for 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

6/60 About this documentation
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
1.3 Display 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, these are explained in the sections below.
1.3.1 Safety instructions
This manual includes safety instructions in chapter2.6 “Product-specific safety
instructions” on page10 and in chapter3 “General instructions on damage to
property and the product” on page 14 and before a sequence of actions or an
instruction involving a risk of personal injury or damage to equipment.
The measures described to avert danger must be observed.
Safety instructions are set out as follows:
SIGNAL WORD
Type and source of danger
Consequences of non-compliance
▶ Measures to avert danger
•Warning sign: draws attention to the danger
•Signal word: identifies the degree of danger
•Type and source of the danger: identifies the type and source of the danger
•Consequences: describes what will happen if the safety instructions are not
complied with
•Precautions: states how the danger can be avoided
Table 2: Hazard classes as defined in ANSI Z535.6-2006
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 be
damaged.

About this documentation 7/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
1.3.2 Symbols
The following symbols indicate information that is not directly relevant to safety but
increases understanding of the manual.
Table 3: Meaning of the symbols
Symbol Meaning
If this information is disregarded, the product cannot be used or operated
to its optimum potential.
▶ Single, independent step
1.
2.
3.
Numbered instruction:
The numbers indicate that the steps must be completed one after the
other.
1.3.3 Designations
This documentation uses the following designations:
Table 4: Designations
Designation Meaning
A6VE Variable plug-in motor, open and closed circuits
Threaded plug Metal screw, pressure-resistant
Protective plug Made out of plastic, not pressure-resistant, only for transportation
As a generic term for the “variable plug-in motor A6VE” the designation “axial piston
unit” is used in the following.
1.3.4 Abbreviations
This manual uses the following abbreviations:
Table 5: Abbreviations
Abbreviation Meaning
ATEX EU directive on explosion protection (Atmosphère explosible)
BVI Integrated counterbalance valve
DIN Deutsche Industrie Norm (German Institute for Standardization)
EP Proportional control electric
EZ Two point control electric
HA Automatic control, high-pressure related
HP Proportional control hydraulic
HZ Two-point control, hydraulic
ISO International Organization for Standardization
(Internationale Normierungsorganisation)
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)

8/60 Safety instructions
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
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 damage to equipment 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 they
are classified neither as complete nor as incomplete machines in the sense of the
EU machine directive 2006/42/EC. A component is exclusively intended to form an
incomplete or a complete machine 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 machine directive.
The product is intended for the following use:
The axial piston unit is only approved as a hydraulic motor in hydrostatic drive systems.
▶ Observe the technical data, application and operating conditions and
performance limits as specified in data sheet 91615 and 91616and in the order
confirmation. Information about approved hydraulic fluids can be found in data
sheet91615 and 91616.
The axial piston unit is only intended for professional use and not for private use.
Intended use also includes having read and understood the documentation in full,
especially the chapter 2 “Safety instructions” on page8.
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 shall accept no liability whatsoever for damages resulting from
improper use. The user shall bear all risks arising from improper use.
The following foreseeable forms of misuse shall 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 customer-specific approval has been granted and confirmed in
writing)
•Use of non-approved fluids, e.g.water or polyurethane components
•Modification of the factory settings by non-authorized personnel
•Use of add-on parts (e.g. control unit, valves) not in combination with specified
Rexroth components

Safety instructions 9/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
•Using the axial piston unit under water at a depth of more than 10 meters without
necessary additional measures, e.g., pressure equalization
•Using the axial piston unit when the ambient pressure is greater than the interior
pressure (case pressure)
•Using the axial piston unit in explosive environments unless the component or
machine/system has been certified as compliant with the ATEX directive 94/9/EC
•Use of the axial piston unit in an aggressive atmosphere
•Use of the axial piston unit in aircraft or space craft
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 gear and the corresponding attachment equipment.
In order to ensure safe use, these activities may therefore only be performed by
an appropriately qualified person or an instructed person under the direction and
supervision of a qualified person.
Qualified personnel are those who can recognize possible hazards and institute
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 done. Qualified personnel must observe the rules relevant to the
specialist field and have the necessary hydraulics expertise.
Hydraulic expertise includes:
•Reading and fully understanding hydraulic diagrams,
•Specifically, 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 specialist fields. An overview of the
training contents can be found on the Internet at:
www.boschrexroth.com/training.
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 technical order and condition.
•Observe all notes on the product.
•Persons who install, operate, remove or maintain Rexroth products must not
consume any alcohol, drugs or pharmaceuticals that may affect their ability to
respond.
•Only use genuine Rexroth accessories and spare parts to ensure there is no risk to
personnel from unsuitable spare parts.
•Adhere to the technical data and ambient conditions specified in the product
documentation.

10/60 Safety instructions
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
•If unsuitable products are installed or used in applications that are relevant for
safety, unexpected operating conditions may occur in the application, which could
result in injury to personnel or damage to equipment. For this reason, only use
the product in a safety-related application 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 (e.g., machinery or system) in which the Rexroth products are installed
complies with the country-specific provisions, safety regulations and standards for
the application.
2.6 Product-specific safety instructions
The following safety instructions apply for chapters 6 to 14.
WARNING
Danger from excessively high pressure!
Danger to life or risk of injury, damage to equipment.
An inappropriate change in 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 specialist
personnel.
▶ In addition, a pressure relief valve is needed as back-up in the hydraulic system.
If the axial piston unit is equipped with a pressure cut-off and/or a pressure
control, this is not an adequate back-up against pressure overload.
Danger from suspended loads!
Danger to life or risk of injury, damage to equipment.
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 forklift truck or lifting device has adequate lifting capacity.
▶ Never step or reach under a suspended load.
▶ Ensure a stable position during transportation.
▶ Use your personal protective equipment (e.g., safety glasses, safety gloves,
suitable working clothes, safety shoes).
▶ Use suitable lifting gear for transportation.
▶ Observe the prescribed position of the lifting strap.
▶ Observe the national laws and regulations on work and health protection and
transportation.

Safety instructions 11/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
WARNING
Pressurized machine/system!
Danger to life or risk of injury, serious injuries when working on machines/systems
not shut down. Damage to equipment.
▶ Switch off the entire system and secure it against reconnection according to
information provided by the machine/system manufacturer.
▶ Make sure that all relevant components of the hydraulic system are
depressurized. Follow the machine/system manufacturer’s specifications.
▶ Note that the hydraulic system may still may be under pressure even after the
separation of the actual pressure supply.
Do not disconnect any line connections, ports and components while the hydraulic
system is pressurized.
Escaping oil mist!
Risk of explosion, fire, health hazard, environmental pollution.
▶ Depressurize the machine/system 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 to be situated in the vicinity of ignition sources or
powerful thermal radiators, a shield must be erected to ensure that any escaped
hydraulic fluid can not ignite, and to protect hose lines from premature aging.
Electrical voltage!
Risk of injury due to electric shock or damage to equipment.
▶ 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 plugs. Protect the machine/system against being energized.
Overloading of the axial piston motor!
Risk of injury or damage to equipment!
When using the axial piston motor in winch drives it may, when extremely
overloaded (e.g., if the maximum permissible rotational speeds are exceeded
during weighing of the anchor while the ship is in motion), cause the rotary group
to be damaged and, in the worst case, the axial piston motor may burst.
▶ Ensure that the technical limits are not exceeded in any operating conditions.
▶ Check whether any additional measures are needed for your machine/system
(up to an encapsulation) in order to avoid injury to persons. If necessary, make
sure that these are properly implemented.
▶ For safety reasons, axial piston variable motors with beginning of control at Vg min
(e.g., HA) are not permissible for winch drives (e.g. anchor winches).

12/60 Safety instructions
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
WARNING
Limitation of the control function!
Risk of injury or damage to equipment!
Moving parts in control equipment (e.g. valve pistons) can, under certain
circumstances get blocked in position as a result of contamination (e.g. impure
hydraulic fluid, abrasion, or residual dirt from components). As a result, the flow of
hydraulic fluid and the build-up of momentum in the axial piston unit can no longer
meet the operator's specifications. Even the use of various filter elements (external
or internal flow filtering) cannot rule out errors, but can only help minimize risks.
▶ Check whether remedial measures for your application are needed on your
machine in order to put the driven consumer in a safe state (e.g. safe stop).
▶ If necessary, make sure that these are properly implemented.

Safety instructions 13/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
CAUTION
High noise levels during operation!
Danger of hearing damage, deafness.
The noise emission of axial piston units depends on, among other factors,
rotational speed, operating pressure and installation conditions. The sound
pressure level may rise above 70 dB (A) during normal 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 burns!
▶ 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!
Tripping danger and damage to equipment!
▶ Lay cables and lines so that they can not be damaged and nobody can trip
overthem.
Contact with hydraulic fluid!
Health hazard / risk of health impairment, e.g., eye injuries, skin damage, poisoning
on inhalation.
▶ Avoid contact with hydraulic fluids.
▶ When working with hydraulic fluids, strictly observe the safety instructions
provided by the lubricant manufacturer.
▶ Use your personal protective equipment (e.g., safety glasses, safety gloves,
suitable working clothes, safety shoes).
▶ If hydraulic fluid should, nevertheless, come into contact with your eyes, get into
your bloodstream or be swallowed, consult a doctor immediately.
Escaping hydraulic fluid due to machine/system leakage!
Risk of burns and risk of injury due to escaping oil jet.
▶ Depressurize the machine/system and repair the leak.
▶ Never attempt to block or seal the leak or oil jet with a cloth.
2.7 Personal protective equipment
The personal protective equipment is the responsibility of the user of the axial piston
unit. Observe the safety regulations and provisions in your country.
All components of the personal protective equipment must be intact.

14/60 General instructions on damage to property and the product
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
3 General instructions on damage to
property and the product
The following instructions apply for chapters 6 to 14.
NOTICE
Danger from improper handling.
Product can be damaged.
▶ Do not expose the product to a non-permitted mechanical load.
▶ Never use the product as a handle or step.
▶ 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 fittings.
▶ Do not strike fittings (e.g., sensors or valves).
▶ Do not strike sealing surfaces (e.g. working line ports).
▶ Leave the protective covers on the axial piston unit until shortly before the lines
are connected.
▶ Disconnect all electrical connectors before performing electro-welding or
painting operations.
▶ Make certain that the electronic components (e.g., sensors) do not become
electrostatically charged (e.g., during painting operations).
Damage to equipment due to improper lubrication.
Product can be damaged or destroyed.
▶ Never operate the axial piston unit with insufficient hydraulic fluid. In particular,
make sure that the rotary group has sufficient lubrication.
▶ When commissioning a machine/system, make sure that the case interior 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 motor housing regularly; if necessary,
recommission. With above-reservoir installation, the motor housing may drain
via the drain line afterlonger standstill periods (air enters via the shaft seal)
or via the working line (gap leakage). When switched on, the bearings are thus
insufficiently lubricated.
Mixing of 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 mixing of hydraulic fluids from different manufacturers or different types
from the same manufacturer is not generally permitted.

General instructions on damage to property and the product 15/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, 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 could
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 connections, hydraulic lines and attachments (e.g. measuring
equipment).
▶ No contaminants may enter the ports when they are sealed.
▶ Before commissioning, make sure that all hydraulic connections are tight and
that all of the connection seals and plugs are installed correctly to ensure that
they are leak proof and fluids and contaminants are prevented from penetrating
the product.
▶ Use a suitable filter system to filter hydraulic fluid during filling to minimize solid
impurities and water in the hydraulic system.
Improper cleaning!
Product can be damaged.
▶ Plug all openings with the appropriate protection equipment in order to prevent
cleaning agents from entering the hydraulic system.
▶ 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 the high-pressure cleaner at sensitive components, e.g., shaft seal,
electrical connections and components.
▶ Use lint-free cloths for cleaning.
Environmental pollution due to incorrect disposal!
Careless disposal of the axial piston unit and its fittings, the hydraulic fluid and the
packaging material can lead to pollution of the environment!
▶ 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.
Escaping or spilling hydraulic fluid!
Environmental pollution and contamination of groundwater.
▶ Always place a drip tray under the axial piston unit when filling and draining the
hydraulic fluid.
▶ Use an oil binding agent if hydraulic fluid is spilt.
▶ Observe the information in the safety data sheet for the hydraulic fluid and the
specifications provided by the system manufacturer.

16/60 General instructions on damage to property and the product
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
The warranty only applies to the delivered configuration.
The warranty entitlement is rendered void if the product is incorrectly installed,
commissioned or operated, as well as in cases of improper use and/or handling.

Scope of delivery 17/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
4 Scope of delivery
1
2
Fig. 1: Axial piston unit
Included in the scope of delivery are:
•Axial piston unit as per order confirmation
The following parts are also fitted prior to delivery:
•Protective covers (1)
•Protective plug/threaded plug(2)

18/60 About this product
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
5 About this product
5.1 Performance description
A Variable plug-in motor converts hydrostatic flow into mechanical rotation and
controls or regulates this. It is designed for mobile applications such as construction
machinery.
Refer to data sheets 91615 and 91616 and to the order confirmation for the
technical data, operating conditions and operating limits of the axial piston unit.
5.2 Product description
The A6VE is a variable motor with axial piston rotary group of bent-axis design, for
hydrostatic drives in open and closed circuits. For axial piston units with bent-axis
design, the pistons (7) are arranged at an angle to the drive shaft (1). The pistons
rest directly on the drive shaft where they generate torque depending on the
pressure and swivel angle. The specific torque and displacement can be changed by
adjusting the bent axis.
In the open circuit, the hydraulic fluid flows from the reservoir to the hydraulic pump
from where it is transported to the hydraulic motor. From the hydraulic motor, the
hydraulic fluid flows directly back to the reservoir. The output direction of rotation of
the hydraulic motor can be changed, e.g. by a directional valve.
In the closed circuit, the hydraulic fluid flows from the hydraulic pump to the
hydraulic motor and from there directly back to the hydraulic pump. The output
direction of rotation of the hydraulic motor is changed, e.g. by reversing the flow
direction in the hydraulic pump.
5.2.1 Layout of the axial piston unit
1
2
3
4
5
6
7
Fig. 2: Layout of the A6VE
1 Drive shaft
2 Control piston
3 Stroke piston
4 Port plate
5 Lens plate
6 Cylinder
7 Piston
Open circuit
Closed circuit

About this product 19/60
RE 91616-01-B/10.2014, A6VE Series 65 and 71, Bosch Rexroth AG
5.2.2 Functional description
A hydraulic motor converts hydrostatic energy into mechanical energy. Hydraulic fluid
is directed via the port plate (4) and the lens plate (5) to the cylinder bores.
The pistons(7) in the cylinder bores execute a stroke that is converted into rotary
movement by the piston on the drive shaft flange. During this process, the pistons
move the cylinder (6) and generate an output torque at the drive shaft. The output
torque increases with the pressure difference between the high- and low-pressure
sides and increasing displacement. The output speed is proportional to the inward
flow and inversely proportional to the displacement of the hydraulic motor.
The flushing and boost pressure valve is used to remove heat from the hydraulic
circuit. In an open circuit, it is used exclusively for flushing the case. In a closed
circuit, it ensures a minimum boost pressure level in addition to the case flushing.
Hydraulic fluid is directed from the respective low pressure side into the motor case.
This is then fed into the reservoir, together with the case drain fluid. The hydraulic
fluid removed from the closed circuit must be replaced by cooled hydraulic fluid
from the boost pump.
The swivel angle of the bent-axis rotary group is steplessly variable. With two-point
control (HZ, EZ), the swivel angle can be switched from maximum to minimum angle.
Control of the swivel angle of the bent-axis rotary group changes the piston stroke
and therefore the displacement. The swivel angle is changed hydraulically via the
stroke piston(3). Here, the cylinder is swiveled including the pistons and lens plate.
The lens plate is mounted for easy motion in a guideway. Increasing the swivel angle
results in an increase in the displacement and specific torque; decreasing the swivel
angle results in a corresponding decrease of these values. The output speed is
dependent on the input flow and the displacement of the hydraulic motor.
Various control devices are available depending on requirements. Information
about this can be found in data sheet 91615 and 91616.
Motor function
Flushing and boost
pressure valve (optional)
Control

20/60 About this product
Bosch Rexroth AG, A6VE Series 65 and 71, RE 91616-01-B/10.2014
5.3 Product identification
The axial piston unit can be identified from the name plate. The following example
shows an A6VEname plate:
CNR:
MNR:
SN:
FD: Rotation:
DE - 89275 Elchingen
Made in Germany
X1234567890Y
R90XXXXXXX SC: X
12345678
Rexroth
2013W15
m XXX kg
7202
Typ: A6VE085EP600P000A/71MWV0Y2Z9100-0
1
2
3
4
5
6
13
12
11
10
9Vg min = XXX,X cm3
78
Fig. 3: Name plate A6VE
1 Manufacturer
2 Sample category (optional)
3 Internal plant designation
4 Specified area for test stamp
5 Direction of rotation (looking at
driveshaft) – here: bi-directional
6 Weight (optional)
7 Barcode
8 Minimum displacement
9 Production date
10 Serial number
11 Material number of the axial
pistonunit
12 Ordering code
13 Customer material number