Axial Piston Variable Pump A4VG Series 32
Operating Instructions
RE 92003-01-B/04.08 Replaces: RE 92003-11-B/06.06 RE 92003-21-B/05.06 English
The data specified above only serve 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. © 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. An example configuration is shown on the title page. The delivered product may, therefore, differ from the product which is pictured. The original operating instructions were created in the German language.
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Contents 1 About this document.......................................................................................4 1.1 Related documents....................................................................................4 1.2 Abbreviations used....................................................................................5 2 General safety instructions............................................................................6 2.1 Intended use..............................................................................................6 2.2 Improper use..............................................................................................6 2.3 Personnel qualifications.............................................................................6 2.4 Safety instructions in this document..........................................................7 2.5 Adhere to the following instructions...........................................................7 2.6 Operator's obligations................................................................................9 3 Delivery contents...........................................................................................10 4 Product description.......................................................................................11 4.1 Performance description..........................................................................11 4.2 Device description...................................................................................11 4.3 Bypass function.......................................................................................19 4.4 Product identification...............................................................................23 5 Transport and storage...................................................................................24 5.1 Transporting the axial piston unit.............................................................24 5.2 Storing the axial piston unit......................................................................25 6 Assembly........................................................................................................27 6.1 Unpacking................................................................................................27 6.2 Installation conditions..............................................................................27 6.3 Installation position..................................................................................29 6.4 Assembling the axial piston unit..............................................................33 7 Commissioning..............................................................................................43 7.1 First commissioning.................................................................................44 7.2 Recommissioning after downtime............................................................46 7.3 Running-in phase.....................................................................................46 8 Operation........................................................................................................47 9 Maintenance and repair.................................................................................48 9.1 Cleaning and care....................................................................................48 9.2 Inspection................................................................................................48 9.3 Maintenance............................................................................................49 9.4 Repair......................................................................................................49 9.5 Spare parts..............................................................................................49 10 Decommissioning..........................................................................................50 11 Disassembly and replacement.....................................................................50 11.1 Required tools..........................................................................................50 11.2 Preparing for disassembly.......................................................................50 11.3 Disassembling the axial piston unit..........................................................50 11.4 Preparing the components for storage or further use.............................. 51 12 Disposal.......................................................................................................... 52 12.1 Environmental protection.........................................................................52 13 Extension and conversion............................................................................52 14 Troubleshooting............................................................................................53 14.1 How to proceed for troubleshooting.........................................................53 14.2 Malfunction table......................................................................................54 15 Technical data................................................................................................56 16 Appendix........................................................................................................ 56 16.1 Address directory ....................................................................................56 17 Index...............................................................................................................57
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About this document
1 About this document These instructions contain important information on the safe and appropriate assembly, transport, commissioning, maintenance, disassembly and simple troubleshooting of the A4VG series 32 axial piston variable pump. ff Read these instructions completely, especially chapter "2 General safety instructions" on page 6, before working with the A4VG axial piston variable pump.
1.1 Related documents The A4VG axial piston variable pump is a system component. Also observe the instructions for the other system components. Further information on the A4VG axial piston variable pump, its installation and operation can be found in the Rexroth documents listed in the following table. Table 1: Related documents Related documents
Contents
Order confirmation
Contains the preset technical data of your A4VG axial piston variable pump.
Installation drawing
Contains the outer dimensions, all connections and the hydraulic circuit diagram for your A4VG axial piston variable pump.
Data sheet RE 92003
Contains the permissible technical data for the A4VG series 32 axial piston variable pump.
Data sheet RE 90220
Describes the requirements for a mineral-oil based hydraulic fluid for operation with Rexroth axial piston units and assists you in selecting a hydraulic fluid for your system.
Data sheet RE 90221
Describes the requirements for an environmentally acceptable hydraulic fluid for operation with Rexroth axial piston units and assists you in selecting a hydraulic fluid for your system.
Data sheet RE 90223
Contains additional information on the use of Rexroth axial piston units with HF hydraulic fluids.
Data sheet RE 90300-03-B
Contains additional information on the use of Rexroth axial piston units at low temperatures.
Also observe the generally applicable, legal or otherwise binding regulations of the European and national legislation and the rules for the prevention of accidents and for environmental protection applicable in your country.
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About this document
1.2 Abbreviations used As umbrella term for "A4VG axial piston variable pump", the designation "axial piston unit" will be used in the following. Table 2: Abbreviations Abbreviation
Meaning
A4VG
Axial piston variable pump, closed circuits
DA
Automatic control, hydraulic, speed related
EP
Proportional control, electric
HD
Proportional control, hydraulic, pilot-pressure related
HW
Proportional control, hydraulic, mechanical servo
RE
Rexroth document in the English language
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General safety instructions
2 General safety instructions The axial piston unit has been manufactured according to the accepted rules of current technology. There is, however, still a danger of personal injury or damage to equipment if the following general safety instructions and the warnings before the steps contained in these instructions are not complied with. ff Read these instructions completely and thoroughly before working with the axial piston unit. ff Keep these instructions in a location where they are accessible to all users at all times. ff Always include the operating instructions when you pass the axial piston unit on to third parties.
2.1 Intended use Axial piston units are components in terms of the EU machine directive 98/37/EC (sub units). Axial piston units are not ready-to-use machines for the purpose of the EU machine directive. The product/component is exclusively intended for being integrated in a machine or system or for being assembled with other components to form a machine or system. The product may only be commissioned after it has been installed in the machine/system for which it is intended. The axial piston variable pump generates, controls and regulates a hydraulic-fluid flow. It is approved for use as a hydraulic pump in hydrostatic drives in closed circuits. ff Observe the technical data, operating conditions and performance limits as specified in the data sheet and order confirmation. The axial piston unit is not designed for private use. Intended use includes having read and understood these instructions, especially chapter "2 General safety instructions".
2.2 Improper use The axial piston unit may not be used in explosive environments. In addition, any use of the axial piston unit other than described in chapter "2.1 Intended use" is considered to be improper.
2.3 Personnel qualifications Assembly, commissioning and operation, disassembly, maintenance and repair require basic mechanical, hydraulic and electrical knowledge, as well as knowledge of the appropriate technical terms. For transporting and handling the product, additional knowledge is necessary with regard to working with a crane and the corresponding attachment equipment. In order to ensure operating safety, these activities may therefore only be carried out by qualified personnel or an instructed person under the direction and supervision of qualified personnel.
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General safety instructions
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 subject area.
2.4 Safety instructions in this document In this manual, there are safety instructions before the steps whenever there is a danger of personal injury or damage to equipment. The measures described to avoid these hazards must be observed. Safety instructions are set out as follows: Signal word!
Type of danger! Consequences ff Precautions Safety sign: (warning triangle): draws attention to the danger Signal word: identifies the degree of the danger Type of danger: identifies the type or source of the danger Consequences: describes what occurs if the safety instructions are not complied with •• Precautions: states how the danger can be avoided. •• •• •• ••
The signal words have the following meaning: Signal word
Danger!
Application Indicates an imminently hazardous situation which, if not avoided, will certainly result in death or serious injury.
Warning!
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
Caution!
Indicates a potentially hazardous situation which, if not avoided, could result in minor or moderate injury or damage to equipment. If this information is disregarded, the operating procedure may be impaired.
2.5 Adhere to the following instructions General instructions
•• Observe the regulations for accident prevention and environmental protection for the country where the product is used and at the workplace. •• Only use Rexroth axial piston units in good technical order and condition. –– Inspect the product for obvious defects. •• Do not modify or retrofit the axial piston unit. •• Only use the product within the performance range provided in the technical data. •• Persons who assemble, commission, operate, disassemble or maintain Rexroth products must not consume any alcohol, drugs or pharmaceuticals that may affect their ability to respond.
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General safety instructions
•• The warranty only applies to the delivered configuration. •• The warranty is rendered void if the product is incorrectly assembled, commissioned or operated, as well as if not used as intended and/or handled improperly. •• Do not expose the product to any mechanical loads under any circumstances. Never use the product as a handle or step. Do not place/lay any objects on it. •• The noise emission of axial piston units depends on speed, operating pressure and installation conditions. The sound pressure level may rise above 70 dBA during normal operating conditions. This can cause hearing damage. –– Always wear hearing protection while working in the vicinity of the operating axial piston unit. •• The axial piston unit heats up considerably during operation. The solenoids of the axial piston unit get so hot during operation that you may burn yourself: –– Allow the axial piston unit to cool down sufficiently before touching it. –– Wear heat-resistant protective clothing, e.g. gloves. During transport
•• Make certain that the lifting gear has adequate lifting capacity. The weight can be found in chapter "5 Transport and storage".
During assembly
•• Before assembling, make sure that all fluids have been completely removed from the axial piston unit to prevent mixing with the hydraulic fluid used in the system. •• Make sure the relevant system component is not under pressure or voltage before assembling the product or when connecting and disconnecting plugs. Protect the system against being switched on. •• Lay cables and lines so that they cannot be damaged and no one can trip over them. •• Before commissioning, make sure that all hydraulic connections are tight and that all the connection seals and plugs are installed correctly to ensure that they are leakproof and fluids and contaminants are prevented from penetrating the product. •• When assembling, provide for absolute cleanliness in order to prevent contaminants such as welding beads or metal cuttings from getting into the hydraulic lines and causing product wear or malfunctions.
During commissioning
•• Ensure that all electrical and hydraulic connections and ports are occupied or plugged. Only commission a completely installed product.
During cleaning
•• Plug all openings with the appropriate protective equipment in order to prevent detergents from penetrating the system. •• Never use solvents or aggressive detergents. Use only water and, if necessary, a mild detergent to clean the axial piston unit. •• Do not point a high-pressure cleaner at sensitive components such as, e.g. shaft seal ring, electrical connections and electrical components.
During maintenance and repair
•• Perform the prescribed maintenance work at the intervals specified in the operating instructions (see chapter "9.3 Maintenance"). •• Make sure that no lines, connections or components are disconnected as long as the system is under pressure. Protect the system against being switched on.
During disposal
•• Dispose of the product and the hydraulic fluid in accordance with the currently applicable national regulations in your country.
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General safety instructions
2.6 Operator's obligations The operator of the axial piston unit from Rexroth must provide personnel training on a regular basis regarding the following subjects: •• Observation and use of the operating instructions and the legal regulations. •• Intended use and operation of the axial piston unit. •• Observation of the instructions from the factory security offices and of the work instructions from the operator. Rexroth offers training support for special fields. You can find an overview of the training contents on the Internet at: http://www.boschrexroth.de/didactic.
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Delivery contents
3 Delivery contents 3
2
4
3
1 2 3 Fig. 1: Axial piston unit
Included in the delivery contents are: •• 1 Axial piston unit The following parts are also assembled on delivery: •• •• •• ••
Transport protection for drive shaft end (1). Protective covers (2). Plastic plugs / locking screws (3). Flange cover and fixing screws (4) (optional for versions with through drive).
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Product description
4 Product description 4.1 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 the data sheet and order confirmation for the technical data, operating conditions and operating limits of the axial piston unit.
4.2 Device description The A4VG is an axial piston variable pump with swashplate design for hydrostatic drives in closed circuits. Flow is proportional to drive speed and displacement. The flow can be steplessly changed by controlling the swashplate (11). Closed circuit
A hydraulic system is considered to be closed if the hydraulic fluid which flows back from the consumer is directed directly back to the pump. Here, there is a high-pressure side and a low-pressure side depending on the load direction (output torque on the consumer).
4.2.1 Assembly of the axial piston unit 4
3
5
2
6 7
1
12
11
10
9
8
Fig. 2: Assembly of the A4VG series 32
1 Drive shaft
5 Control plate
10 Piston
2 Retaining plate
6 Low-pressure side
11 Slipper pad
3 Stroke piston
7 Auxiliary pump
12 Swashplate
4 Controller (using the EP as an example here)
8 High-pressure side 9 Cylinder
For axial piston units with swashplate design, the pistons (10) are arranged axially with respect to the drive shaft (1). They are guided in the rotating cylinder (9) and support themselves with the slipper pads (11) on the non-rotating swashplate (12). The drive shaft (1) and cylinder (9) are connected to one another by means of gearing.
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Product description
4.2.2 Functional description Pump
Pressure cut-off
Torque is applied to the drive shaft (1) by an engine. The cylinder (9) turns with the drive shaft, turning with it the pistons (10). On each rotation, the pistons perform a stroke movement which is defined by the pitch of the swashplate (12). The slipper pads (11) are held on and guided along the glide surface of the swashplate by the retaining plate (2). During a rotation, each piston moves over the bottom and top dead centers back to its initial position. During this action, the fluid volume defined by the piston surface and the stroke is fed in or removed through the two control slits in the control plate (5). On the low-pressure side, (6) fluid flows into the enlarging piston chamber – in a closed circuit this is supported by the return and boost pressures. At the same time, on the high-pressure side (8) the fluid is pushed out of the cylinder chamber into the hydraulic system by the pistons. The operating pressure is limited by the pressure cut-off. The pressure cut-off corresponds to a pressure regulator which reduces the pump capacity once the set specified pressure value is reached so that the set pressure is maintained but not exceeded.
High-pressure safeguarding
The pressure spikes which occur during very rapid swiveling operations as well as the maximum pressure are safeguarded by the superordinate high-pressure relief valves. These valves open if the set value is exceeded, thereby depressurizing the low-pressure side. The fluid quantity remains constant in the closed circuit. The leakage at the pump and motor is replaced by the auxiliary pump (7).
Auxiliary pump
The auxiliary pump continuously supplies a sufficient volume of fluid (boost volume) from a small tank to the low-pressure side of the closed circuit via a check valve to replenish the internal leakage of the variable pump and consumer.
Neutral valve (optional)
The optional neutral valve interrupts the active control pressure and joins the two positioning chambers for pressure equalization. The springs in the positioning chambers move the stroke piston (3) towards the middle position (neutral position). The reset function is influenced by the current operating pressure and the speed. Switching off the control pressure and a bypass function for the two positioning chambers does not ensure that the pump moves to the middle position (neutral position). Use an appropriate emergency-off device to ensure that the drive can be brought to a safe position at any time. The device or system operator is responsible for the installation of a proper emergency-off device. The following warning notice applies to all axial piston units with the HD and EP control units:
Caution!
The spring return in the control unit is not a security device. The slide valve of the control unit can be blocked in an undefined position by internal contamination (impure hydraulic fluid, abrasion or residual contamination from system components). As a result, the axial piston unit can no longer supply the flow specified by the operator. ff Properly install an emergency-off function to ensure that the driven consumer can be brought to a safe position (e.g. immediate stop). ff Maintain the specified cleanliness level 20/18/15 (
