Electric Drives and Controls Hydraulics Linear Motion and Assembly Technologies Pneumatics Service General Operating Notes for External Gear Units RE 07012-B1/06.07 General operating notes
2/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 Manufacturer Bosch Rexroth AG Hydraulics Product Unit Drives Schwieberdingen Robert-Bosch-Str. 2 71701 Schwieberdingen, Germany brm-az.info@boschrexroth.de www.boschrexroth.com/brm Under this Internet address you can find the contact address for contact persons in the various countries as well as informational material and catalog sheets for mobile hydraulic products and their applications. Contents 1 About this document...3 1.1 Structure and requirements...3 1.2 Personnel requirements...5 1.3 Hazard markings and pictograms...6 2 Safety...7 2.1 Basic safety notes...7 2.2 Due diligence of the user...9 2.3 Responsibility of the machine or system manufacturer..10 3 Product description... 11 3.1 Identification of the external gear unit...11 3.2 Functional description...12 3.3 Delivery contents...12 3.4 Guarantee...12 3.5 Technical data...13 3.6 Intended use...13 3.7 Information for use at low temperatures...14 3.8 Project planning notes...14 4 Installation...19 4.1 General installation notes... 20 4.2 Information on unpacking...21 4.3 Preparing the external gear unit for assembly... 22 4.4 Transporting the external gear unit to the installation location... 23 4.5 Assembling the external gear unit... 24 4.6 Connecting lines... 27 4.7 Fittings... 28 4.8 Disassembling the external gear unit... 30 4.9 Preparing the external gear unit for storage...31 4.10 Disposing of the external gear unit... 32 5 Commissioning...33 5.1 Preparations... 34 5.2 Filling the external gear unit... 34 5.3 Testing the direction of rotation... 36 5.4 Testing the hydraulic fluid supply... 36 5.5 Performing functional test... 37 5.6 Performing flushing cycle... 37 6 Troubleshooting...39 7 Maintenance...43 7.1 Servicing... 43 7.2 Inspection... 43 Index...45
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 3/48 Avoiding dangers! DANGER To ensure reliable operation and to avoid damage during installation, commissioning or maintenance, study these operating notes carefully and thoroughly! Bosch Rexroth AG cannot be held liable for any personal injuries or machine damage arising from non-adherence to these operating notes. In case of damage resulting from disregard of these operating notes, any warranty provided by Bosch Rexroth AG will be rendered null and void and liability placed with the user. 1 About this document 1.1 Structure and requirements Documents General operating notes Operating notes for Rexroth external gear units consist of the following sub-documents: General Operating Notes for External Gear Units These general operating notes for external gear units will assist you during installation, commissioning and operation of Rexroth external gear units. These include external gear pumps and motors for use in open hydraulic circuits. Unless stated differently, the information in these operating notes generally applies to all Rexroth external gear units. Information which only applies to specific pumps or motors or hydraulic concepts is marked in the text accordingly. Project drawing The project drawing contains the preset technical data. The external gear unit may only be operated using the values and conditions specified in the project drawing. In addition, we refer to catalogs, Y sheets and RE sheets. Please contact Rexroth to request the missing parts of the documentation if you are not in possession of the entire set of documents. Safe operation of Rexroth external gear units can only be guaranteed if you observe the details in all available sub-documents. These general operating notes will assist you during installation, commissioning and operation of Rexroth external gear units. You will require the individual chapters of these notes for the different phases of working with the external gear unit: "Safety" explains how the notes in this document are to be understood and contains several basic safety notes on working with external gear units. "Product description" provides you with information on identifying external gear units as well as on their intended use. You will also find notes here on project planning. "Installation" provides you with all of the information you need to install, disassemble and store the external gear unit. "Commissioning" explains what you must observe during commissioning of the external gear unit and the machine or system. The overview in "Troubleshooting" assists you in searching for and tracing faults on the external gear unit and the entire machine or system. "Maintenance" provides you with information on servicing and inspecting the external gear unit.
4/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 Area of validity for these notes These operating notes apply for external gear units from Rexroth for operation under permissible operating conditions (see also "Intended use" on page 13). These operating notes are for the: machine or system manufacturer, the user. The respective installation drawing, technical data sheet and order confirmation from Bosch Rexroth AG are also binding for the machine or system manufacturer. Important documents Before starting with the tasks described in these operating notes, make sure that the following documents are already available: Product-specific operating notes For special application cases, the product-specific operating notes contain supplementary information for the respective external gear unit. Technical data sheet The technical data sheet contains, among other things, the permissible technical data for the external gear unit. Also observe the specifications in the project drawing. Note that, depending on the external gear unit (e.g. pump, motor, silence series), different technical data sheets apply. Project drawing The project drawing contains the essential specifications (e.g. speed, displacement, dimensions) for your external gear unit. Please also observe the notes in Y-sheets. The following Rexroth publications provide further information on the installation and operation of the external gear unit: RE 07075: Mineral oil based pressure fluids for vane pumps, radial piston pumps and gear pumps as well as MCR-, MR- and MKM/MRM motors Describes the requirements on a mineral-oil based hydraulic fluid for the operation with the specified Rexroth pumps and motors and assists you in selecting a hydraulic fluid for your system.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 5/48 1.2 Personnel requirements General requirements, qualification Requirements for the maintenance staff Assembly, service and repair of the external gear units may only be performed by authorized, skilled and instructed personnel. Bosch Rexroth offers training courses for this purpose. If you are interested, please contact the Bosch Rexroth Service Department. Persons, who are under the influence of alcohol or other drugs or medications which affect the ability to react must not operate or maintain Rexroth hydraulic products. Maintenance measures may be necessary in order to maintain the functional capability of the external gear unit. For details, please refer to chapter "Maintenance" on page 43. Maintenance measures include inspection and repair of hydraulic and electrical components. Personnel who perform inspections on the external parts of the external gear unit must be trained in performing this task. Repair work on the external gear unit may only be performed by repair shops who are authorized by Rexroth. Rexroth offers a complete range of services for the repair of Rexroth external gear units. The following generally applies for electric work: Work on electric equipment may only be performed by an authorized and trained electrician or by instructed persons under the direction and supervision of an authorized, trained electrician according to the electro-technical regulations.
6/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 1.3 Hazard markings and pictograms These notes differentiate between dangers categories as per ISO Guide 37:! DANGER This hazard marking warns of high risk, lethal dangers and severe injuries.! WARNING This hazard marking warns of medium risk, injuries and severe property damage.! CAUTION This hazard marking warns of low risk and property damage. Note This marking refers to information which helps to better understand the machine processes or which refers to special or important circumstances. Tip This marking refers to information which assists in improving work efficiency. This symbol refers to information on the disposal of components and operating materials.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 7/48 2 Safety! DANGER Danger to life Read this chapter carefully before starting to work with the external gear unit. Rexroth external gear units are to be installed as components in machines or systems. The safety directives in these notes relate to external gear units only. Please also note the safety directives provided by the machine or system manufacturer. 2.1 Basic safety notes Please strictly observe the following safety notes as well as the safety notes of the machine or system manufacturer to avoid any injuries and health damages as well as property damage and environmental pollution. Working on operating machines or systems poses a danger to life and limb. The work described in this document may only be performed on disconnected machines or systems. Before beginning work: Ensure that the engine cannot be switched on. Ensure that all power-transmitting components and connections (electric, pneumatic, hydraulic) are switched off according to the manufacturer's notes and cannot be switched on again. If possible, remove the main fuse on the machine or system. Ensure that the machine or system is completely hydraulically relieved (depressurized). Please follow the notes of the machine or system manufacturer.! WARNING Risk of injury To prevent injuries, please observe the following recommendations: While working on the machine or system, always wear safety shoes with steel caps. While working with hazardous materials (for example hydraulic fluids), always wear safety gloves, safety glasses and suitable working clothes. While working with oily objects, be aware of a possible risk of injury caused by slipping on an oily underground and the object falling down.! DANGER Risk of toxication and injury Contact with hydraulic fluids may damage your health (e.g. eye injuries, skin and tissue damage, toxication resulting from the inhalation of vapors). Check the lines for wear or damage before each commissioning. Wear safety gloves and safety glasses when performing this inspection. If hydraulic fluid should, nevertheless, come into contact with your eyes or penetrate your skin, consult a doctor immediately. When working with hydraulic fluids, strictly observe the safety notes provided by the hydraulic fluid manufacturer.
8/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07! WARNING Risk of burn injuries The external gear unit heats up during operation. Touching the external gear unit can result in severe burn injuries. Allow the external gear unit to cool down and protect yourself against burn injuries by wearing heat-resistant gloves and protective clothing.! DANGER Risk of toxication and injury While searching for leakages, escaping hydraulic fluid can penetrate the skin and cause severe toxication and injuries. Only search for leakages when the machine is switched off and depressurized.! WARNING Risk of injury and damage Incorrectly connected components can cause severe malfunctions. Ensure that piping is connected according to the circuit diagram. Perform component-oriented functional tests.! DANGER Risk of fire and explosion Hot hydraulic fluid will explode on contact with water. Never bring hot hydraulic fluids into contact with water. Keep hydraulic lines and hydraulic fluids away from heat sources.! WARNING Hearing damage The noise emission of external gear units depends on, among other factors, speed, operating pressure and installation conditions. You can be certain that the sound pressure level will rise above 70 dba during normal operating conditions. This may cause hearing damage. Always wear hearing protection while working in the vicinity of the operating external gear unit.! WARNING Environmental pollution Hydraulic fluids are water-endangering fluids. Leaking hydraulic fluids can cause toxication of the groundwater and ground contamination. Place a catch pan under the external gear unit. Remedy the leakage immediately. National laws and regulations must be observed at all times. In Germany, hydraulic machines or systems are classified as "systems for working with water-endangering materials within the scope of the Federal Water Act (WHG)". In this context, please especially note 1 and 19 of the WHG ( 19g, 19i, 19l).
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 9/48 2.2 Due diligence of the user The user must ensure that the external gear unit is only used as intended (see "Intended use" on page 13). the external gear unit is stored, operated and repaired according to the operating and ambient conditions defined in the technical data, and especially that the limit values given in the technical data are not exceeded. following repair, the external gear unit may only be operated if in a proper and fully functional condition. required personal protective equipment is available to the personnel and that it is worn. while working on the external gear unit, the engine has been securely switched off and the system has been depressurized. the operating notes are always in a legible conditions and available in their entirety at the location at which the external gear unit is used. only qualified and authorized personnel are deployed for the maintenance of the external gear unit. Note In addition to the operating notes, please observe generally valid, statutory and other binding regulations of the national legislation for accident prevention and environmental protection.
10/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 2.3 Responsibility of the machine or system manufacturer Rexroth external gear units are components for the purpose of the Machine Directive 98/37/ EC (sub units), which are used for the installation in a machine or a system. Rexroth external gear units are not ready-to-use machines for the purpose of the EC Machine Directive. Bosch Rexroth AG indicates that the delivery contents are exclusively intended for the installation in a machine or system or to be connected with other components to a whole new machine or system. These notes serve as a basis for the general system notes to be issued by the machine or system manufacturer. Commissioning is prohibited until it has been determined that the machine or system in which these products are installed complies with the regulations of the EC Directives and all other directives regarding the machine or system. In addition to the machine directives, additional directives such as, e.g. pressure vessel directive and explosion protection directive for the application, are also valid. The interaction of the hydraulic product with the machine or system in which the hydraulic product is installed can cause various dangers. For this reason make sure that the hydraulic product is unreservedly applicable for its intended use at its installation point. The interfaces to the general machine and the operating conditions are of major significance. We recommend that the result of the danger analysis (risk assessment) for the general machine also be incorporated in the planning for the hydraulic product.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 11/48 3 Product description This chapter explains how to identify an external gear unit using the name plate. Information is also provided on the intended use of the external gear unit. 3.1 Identification of the external gear unit The external gear unit can be identified on the name plate (sticker). Shown in the following is an example for the structure of the name plate (alternatively, rolled markings similar to a name plate are also permissible): 1 2 4 3 5 The name plate contains the following information: 1 Factory ID 2 Specification of the direction of rotation 3 Material number of the external gear unit 4 Standard marking, country of manufacture 5 Optional (below the material number): customer-specific number and other markings
12/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 3.2 Functional description External gear pumps External gear motors The product spectrum of Rexroth external gear units includes pumps and motors for both open as well as closed hydraulic circuits. For the speed and temperature range of the Rexroth external gear units, refer to the technical data sheet or the project drawing. Rexroth external gear pumps are available in various series in which the displacements are graded by different gear widths. Further configuration variants are given by different flanges, shafts, valve arrangements and multiple pump combinations; refer to the product-specific operating notes for details. The external gear pump consists essentially of a pair of gears supported in bearing bushings or bearings, and the case with a front and a rear cover. The drive shaft protrudes from the front cover where it is sealed by the shaft seal ring. The bearing forces are absorbed by slide bearings. These are designed for high pressures and have excellent resistance to galling. External power is supplied on the driven gearwheel, which is turned by means of the gearing of the driven wheel. As the teeth chambers open, the hydraulic fluid is drawn in from the suction chamber via the pump inlet and transported through the gaps between the teeth in the two gearwheels to the pressure chamber. There, the meshing of the teeth forces the hydraulic fluid out of the gaps between the teeth, transporting it to the pump outlet. Rexroth external gear motors are available in various series. Their displacements are graded by different gear widths. The displacement principle of external gear motors is the reverse of that used in pumps. For motors, configuration variants are given by different flanges, shafts, valve arrangements and integrated speed sensor. When hydraulic fluid is fed into the gear motor, a torque can be made available at the external shaft. A distinction is made between motors with one direction of rotation and reversible motors. Gear motor for one direction of rotation External gear motors for one direction of rotation have an asymmetrical structure, i.e. the high-pressure side and low-pressure side are fixed. Reversing operation is not possible. The case drain fluid which arises is drained internally. Pressure loading of the drain is limited due to the shaft seal. Reversible gear motor The reversible motors are characterized by a special feature. Due to their structure, the high-pressure and low-pressure chambers are separated from the bearing ring and shaft-seal ring chamber. The case drain fluid which arises is drained via a separate case drain port. By means of this case drain fluid drainage, it is possible to load the motor on the return side. As a result, series connections are possible. 3.3 Delivery contents The following components are part of the delivery contents of the external gear unit: External gear unit with transport protection Protective caps for the hydraulic ports Flange and shaft covers (optional) 3.4 Guarantee The guarantee period is two years from the delivery date.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 13/48 3.5 Technical data Details on the technical data of your external gear unit can be found in the technical data sheet and in the project drawing. 3.6 Intended use Observe the following while operating the external gear unit: The external gear unit may only be stored in a dry and dust-free atmosphere which is free of corrosives and vapors. The factory corrosion protection is sufficient when stored under the specified conditions provided no condensate or leakage water can penetrate the external gear unit. The external gear unit may only be operated with mineral oils in accordance with data sheet RE 07075. We recommend mineral oil HLP acc. to DIN 51524 part 2. Information on using the product with other hydraulic fluids is available on request. The external gear unit may only be operated under the specified operating conditions. The external gear unit may only be operated when technically in perfect working order and further it may only be stored, operated and repaired according to the technical data, operating and ambient conditions mentioned in the project drawing. In particular, the limit values specified in the technical data must not be exceeded. The external gear unit may only be operated with the specified power data. The operation with connection, application or power data other than that which is specified in the general and (if available) product-specific operating notes and the technical data sheet is only permitted with a written agreement of Bosch Rexroth AG. The external gear unit may only be used for the specified purpose. The external gear unit may not be used for purposes other than that which is specified unless Bosch Rexroth AG approves the other purpose in writing. The operating notes of the machine or system manufacturer and, if necessary, any technical specifications must be strictly observed. The external gear unit with aluminum housing may not be used below ground. For applications in explosive atmospheres (ATEX applications), the respective business unit is to be contacted. The external gear unit may not be used in explosive environments. Ignition sources are not allowed in the immediate vicinity of the external gear unit, because hydraulic fluid escaping under pressure may be flammable or even explosive. General use and predictable fault usage must also be considered (Device and Product Safety Act GPSG, Product Liability Act PHG). Note Any deviations from the intended usage or specifications contained in these notes, technical modifications and conversions of the external gear unit and the operation of individual parts or the installation of individual parts into other products will affect safety. In this case, Bosch Rexroth accepts no responsibility and any warranty is rendered null and void.
14/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 3.7 Information for use at low temperatures Observe the following limit values: Minimum temperature during storage to -50 C Warm-up phase with low loading above -40 C Operation with loading above -25 C Also observe the following notes: For use at temperatures below -20 C, we recommend using an NBR shaft seal ring. Note, however, that the max. operating temperature for NBR is 80 C. Avoid moisture near the external gear unit, as moisture which collects on the shaft seal ring could freeze the sealing lip to the shaft during downtime. During startup, the seal ring could be destroyed in this case. The limit viscosities specified in the catalog sheets for the external gear unit must be maintained by selecting a suitable operating material over the entire operating period, both in winter as well as in summer with warmer temperatures. Special attention must be given to the startup viscosity. In pumps, there is an acute risk of cavitation when starting up with highly viscous ("jellied") operating materials in the suction line. When installing new components, these must first be filled in advance at relatively high temperatures to ensure adequate lubrication in all ranges. 3.8 Project planning notes Only some conventional notes are listed below. Rexroth is not responsible for correctness and completeness in individual cases. Project planning notes are available for the following topics: Selection of hydraulic fluid Tank design Filter design Cooler Hose lines and piping Note When designing, always take into account the maximum possible application data from the relevant data sheets.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 15/48 Selection of the hydraulic fluid The hydraulic fluid in the hydraulic circuit must be chosen very carefully during project planning of the drive to ensure failure-free and efficient operation. Often, not all requirements for the hydraulic fluid can be fulfilled uniformly. We therefore recommend that you perform a detailed assessment together with the hydraulic fluid supplier. In addition, also observe the specifications in "Mineral-oil based pressure fluids" (RE 07075). The viscosity or viscosity temperature characteristics are of primary importance, whereby the density and pour point must also be taken into account. Mineral-oil based fluid grades are suitable for use with external gear pumps and motors. Among other factors, their suitability for use is dependent on: Wear properties Viscosity temperature characteristics Oxidation and corrosion protection Material compatibility Air separation properties (LAV) Water separation properties (WAV) Tank design Due to the heat balance, the tank has to be large enough. The following applies for an initial estimate of the tank volume V (in l): for mobile systems: V = 0.25...0.4 Q + 1,25 EZ, whereby Q is the counter value of the pump suction volume (in l/min) and EZ is the sum of the filling volumes of all cylinders (in l). for static systems: V = 3...5 Q Also take into account an air space of 10 to 15 % of the hydraulic fluid volume. Note Attach a sign at an easily visible point on the tank which identifies the tank as a hydraulic fluid tank. The specification, volume and hydraulic fluid change intervals should also be specified. Add a reference to the filter change intervals and the designation of the interchangeable filter cartridge. Make sure that the tank filling process can only be performed using a permanently installed filter. Usually, new hydraulic fluid from new barrels is contaminated. Ground clearance Make sure that the ground clearance is at least 15 cm to ensure good heat dissipation. Drain options Stabilizer plates Due to temperature fluctuations, condensation water forms in the tank. It must be possible to collect this water and contaminants at the lowest point of the tank. Therefore, incline the base and provide a drain option at the lowest point. Provide stabilizer plates which serve to prevent turbulent flows in the tank and which promote dirt depositing and air separation.
16/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 Ventilation filter Hydraulic fluid level control Suction line Case drain line Make sure that the specified air filters have at least the same filter grade as the installation filters. Make sure that a hydraulic fluid level control is mounted at an easily visible position. Hydraulic fluid which escapes through a leaky component is always contaminated and must not be returned to the tank. Perform a corresponding replenishment in good time so that the lowest hydraulic fluid level is never reached. Suction lines should be routed so that they are approx. 5 cm over the tank base or, in case of a lateral exit, are this distance from the tank base. The inlet diameter should be enlarged by means of an inclined gate and should be aligned with the oil-stabilized side. A suction line which ends too close to the surface may enable air intake. Therefore, bear in mind that hydraulic fluid is temporarily removed by cylinders and also take into account a possible inclined position of the system or machine when determining the lowest hydraulic fluid level. The negative pressure must not drop below 0.7 bar (abs.) (see also the respective data sheet). Route the junction of the case drain fluid in the tank below the minimum hydraulic fluid level. Ensure a sufficient cross section when integrating several case drain lines into a collecting line. Filter design The major share of premature failures in gear pumps is due to contaminated hydraulic fluid. As a warranty cannot be issued for dirt-specific wear, we recommend filtration be used, which can reduce the degree of contamination to a permissible level in terms of the size and concentration of dirt particles: Required cleanliness level DIN ISO 4406: 1999(E) 20/18/15 We recommend that a full-flow filter always be used. The filter manufacturer must verify the function of the filter and compliance with the required cleanliness level. Accessibility Take care to ensure optimal accessibility of the filters in order to simplify maintenance work. If possible, equip the filter with a contamination display and a pressure-resistant filter cartridge.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 17/48 Cooler Usually, air-oil or water-oil cooling is sufficient in the case drain lines. The cooling load is dependent on the loading and speed of the hydraulic components. Here, the load rhythm and the radiating surface are very important. Check the temperature balance by measuring the temperature during commissioning. Arrange the air-oil heat exchangers so that they are not near the hot exhaust air of the engine or the working machine. Provide a cooler bypass for the protection of the oil cooler during cold starts. This can be realized by installing a check valve or a therm-bypass-valve. Give special attention to regular dedusting of the lamella of air-oil heat exchangers. Hose lines and piping Hose lines are used in hydraulic systems to connect ports which move relative to one another. Hose lines also serve to dampen the transmission of structure-borne sound. We would like to point out that the system or machine manufacturer is responsible for ensuring that the design and installation of hose lines and piping are in accordance with applicable standards. In particular, the system or machine manufacturer must ensure that the hose lines and armatures are designed to match the maximum dynamic pressures of the pumps and motors which are specified in the project drawing, evident from dynamic measurements or which could occur at the operator. In this context, we refer to the EN norms for hoses and hose lines according to DIN EN 853 857 and their installation according to the safety regulations of the BIA in ZH 1/74. Furthermore, the following notes apply to the ports: To achieve favorable noise values, decouple all connecting lines (suction, pressure and case drain ports) from the tank using flexible elements. Route any case drain fluid back to the tank so that as little case drain pressure (= case pressure) as possible is generated.
18/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 19/48 4 Installation This chapter describes the essential, generally valid steps for the installation of Rexroth external gear units. Read this chapter if you: wish to install an external gear unit into a static or mobile hydraulic system or wish to disassemble or dispose an external gear unit. If product-specific operating notes are available for your external gear unit, observe the information contained therein regarding installation in addition to the information contained in these notes. Note Observe the basic safety notes on page 7 of these operating notes for all work performed during the installation of the external gear unit. During this work, please also take into account the selection of hydraulic fluid and the design of the tank. Structure of chapter This chapter is structured as follows: "General installation notes" on page 20 contains notes that must be observed prior to and during installation. "Information on unpacking" the external gear unit is available on page 21. In "Preparing the external gear unit for assembly" beginning on page 22, you will find information on the procedure to be followed during installation. The following sections describe the necessary steps. Transporting to the installation location Assembly of the external gear unit at the specified installation location Connection of the hydraulic lines In "Disassembling the external gear unit" on page 30 and the following sections, you will find information on disassembling, storing and disposing of the external gear unit.
20/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 4.1 General installation notes Suction pressure for pumps The installation location and position of an external gear unit essentially determine the procedures during installation and commissioning (such as when filling the external gear unit). During this work, observe the notes in data sheet RE 10 089. Valid for all installation positions: The case of the external gear unit must be filled and remain filled with hydraulic fluid at commissioning and during operation. To achieve favorable noise values, decouple all connecting lines (suction, pressure and case drain ports) from the tank using flexible elements. Generally, in all installation positions and locations a minimum suction pressure at port "S" is specified for pumps: minimum suction pressure 0.7 bar abs (see technical data sheet for additional values).! CAUTION Risk of damage to the external gear unit The external gear unit must always be filled with hydraulic fluid. During initial commissioning, make sure that the external gear unit is supplied with sufficient hydraulic fluid. Ensure that the entire hydraulic system is tight. Should unusual noises or vibrations develop, immediately switch off the machine or system and check whether the external gear unit is filled with hydraulic fluid. Ensure that the system is safeguarded against bursting in the event of overpressure in the system by means of an additional pressure relief valve in the system.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 21/48 Cleanliness Cleanliness must be observed: Absolute cleanliness is required. The external gear unit must be installed in a clean condition. Contaminants in the hydraulic fluid may severely impair the service life of the external gear unit. Do not use any cotton waste or linty cloths for cleaning. Use suitable liquid detergents to remove lubricants and other difficult-to-remove contamination. Detergents must not penetrate the hydraulic system. Do not use hemp or mastic as sealant. When spraying and brushing on paint, cover the shaft seal ring. 4.2 Information on unpacking While unpacking the external gear unit, please observe the following information:! CAUTION Risk of parts falling down If the packaging is not opened correctly, parts may fall out and damage the parts or even result in injury. Place the packaging on a flat and solid underground. Only open the packaging from the top. Wear safety clothing and safety shoes with steel caps.! CAUTION Risk of injury If handled improperly, sharp and pointed parts of the packaging could cause injuries. Open the packaging carefully and correctly.! CAUTION Risk of injury Lifting heavy parts can cause back injuries. Use appropriate tools to remove the external gear unit from the packaging and observe basic ergonomic principles. The external gear unit is usually delivered packaged in oil paper (wax paper). For environmental protection reasons, Bosch Rexroth uses reusable packaging for the external gear unit. As a rule, this packaging is the property of Bosch Rexroth. When disposing of the packaging, always observe the local regulations.
22/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 4.3 Preparing the external gear unit for assembly To prepare the external gear unit for assembly: 1 Remove the packaging material and dispose it according to the applicable regulations. 2 Check the delivery contents for transport damages. 3 Compare the material number and designation (ordering code) with the details in the project drawing. If the material number of the external gear unit on the name plate (and delivery paper) does not match the number in the project drawing, contact your responsible Bosch- Rexroth office for clarification. The same applies for the R number. 4 Check the direction of rotation of the external gear unit (on name plate) and ensure that this matches the direction of rotation of the engine or output drive (clockwise turning pump on counterclockwise turning motor and vice versa). Counterclockwise Clockwise Note The direction of rotation of the external gear unit as viewed on the drive shaft is specified in the project drawing. The engine's direction of rotation is described in the engine manufacturer s operating notes.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 23/48 4.4 Transporting the external gear unit to the installation location Depending on size and local conditions, external gear units can be transported e.g. using a fork lift truck or hoisting gear. Appropriate transport containers (plastic containers, some with gridded partitions) which meet the requirements and ensure protection against damage are to be used for this purpose.! CAUTION Dangers during transport In the event of improper transport, the external gear unit can fall down and cause damage to the external gear unit or even injure people. Transport the unit in accordance with the applicable specifications.! CAUTION Risk of damage Hitting or impulsive forces on the drive shaft can damage the external gear unit. While transporting, make sure that the drive shaft of the external gear unit is not subjected to hitting or impulsive forces. In concrete terms, this means: Do not hit the coupling or drive shaft of the external gear unit. Do not set/place the external gear unit on the drive shaft.
24/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 4.5 Assembling the external gear unit General notes How to assemble the external gear unit depends on the connecting elements to the drive or the output side. The following descriptions explain the installation of the external gear unit: via a coupling via a gearbox During assembly (and disassembly) of the external gear unit, observe the following general notes:! CAUTION Risk of injury The external gear unit is to be fixed so that the expected forces and torques can be transferred without any danger. The permissible loads with regards to pressure and minimum/maximum speeds can be found in the respective technical data sheet and the project drawing. For axial and radial loading, see chapter "Product description", section "Project planning notes". The occurrence of radial and axial forces is to be examined by the customer during the course of the project planning phase. After a short operating time, toothed belts lose a major portion of their pre-tension and thus cause speed variations and rotational vibrations. Rotational vibrations may result in leakages on the shaft seal ring of the driven external gear unit. Particularly at risk are diesel drives with a small number of cylinders and low flywheel mass. Rexroth recommends avoiding this type of toothed belt drive or equipping it with an automatic tensioning device. V-belt drives without automatic tensioning device are also critical with regards to speed variations and rotational vibrations. Among other problems, these can also lead to leakages on the shaft seal ring. An automatic tensioning device can lessen the speed variations and vibrations and thus prevent consequential damage. Rexroth recommends the use of V-belt drives only with an automatic tensioning device. For both types of belt drive, the permissible radial forces on the shaft are to be observed and be inspected during the project planning phase. If necessary, the belt disc must be separately mounted. The drive and output elements are to be assembled by pulling onto the drive shaft with the aid of the threaded stem in the drive shaft end. For geared drives, see chapter "Project planning notes". When assembling the external gear unit, there is a risk of crushing, cutting and other injuries, particularly in the area near pump installation. Use appropriate tools to remove the external gear unit from the packaging and observe basic ergonomic principles. Wear your personal safety equipment. Perform the assembly work properly and carefully.! CAUTION Risk of damage Incorrect tightening torques can result in malfunctions, leakage and increased wear. When fixing, ensure that the correct tightening torque is applied to through-hole threads on the external gear unit.
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 25/48! CAUTION Risk of damage Hitting or impulsive forces on the drive shaft can damage the external gear unit. During installation make sure that the drive shaft of the external gear unit is not subjected to hitting or impulsive forces. In concrete terms, this means: Do not hit the coupling or drive shaft of the external gear unit. Do not set/place the external gear unit on the drive shaft. Details on the permissible axial and radial forces are available in the technical data sheet. Coupling To assemble the external gear unit with a coupling: 1 Assemble the specified coupling half to the drive or output shaft of the external gear unit according to the coupling manufacturer s specifications. There must be no radial and axial forces acting on the shaft and coupling sleeve.! CAUTION Risk of injury Always observe the maximum torques. These values can be found in the relevant Y-sheets and catalog sheets. For flexible couplings, note: The maximum radial runout of shaft spigot is 0.2 mm. Refer to the fitting notes provided by the coupling manufacturer for details of the maximum permissible shaft misalignment. For coupling sleeves, note: The coupling sleeve must be free to move axially. Maintain the spacing between drive shaft and output shaft (see technical data sheet). Oil-bath or oil-mist lubrication is necessary. 2 Make sure that the installation location is clean and free of dirt and contaminants. 3 Clamp the coupling hub onto the drive shaft or ensure permanent lubrication of the drive shaft. This prevents the formation of frictional corrosion and the associated wear. 4 Transport the external gear unit to the installation location and assemble the coupling onto the drive or output drive according to the coupling manufacturer s specifications. Please note that the external gear unit should not be tightened until the coupling has been correctly assembled. 5 Fix the external gear unit at the installation location. If necessary, details on the required tools and tightening torques for the fixing screws can be obtained from the machine or system manufacturer. a) For bell housing installation, check the coupling axial play through the bell window according to the manufacturer s notes. b) For flange installation, align the external gear unit support with the drive or output drive. Excessive tightening of bolt nuts while assembling the coupling half can cause the shaft to snap. This can result in injury to persons. Only tighten the screws using a torque wrench and only to the appropriately set torque.
26/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 Note Observe the following note: Frictional corrosion on the coupling elements is to be prevented through permanent lubrication. Tangs V-belt and gearwheel Completing assembly Tangs and drivers are provided for direct mounting of the external gear unit to an engine, gearbox etc. Plug connections (tangs) of the drive shaft are to be protected against frictional corrosion (permanent lubrication). The concealed installation means that it is no longer possible to inspect whether the external gear unit s centering diameter actually centers the external gear unit (observe tolerances) after mounting, or whether axial or radial forces act on the drive shaft of the external gear unit (installation length). The inspection must therefore take place prior to installation during assembly. For installation and sealing, observe the recommendations in the technical data sheet. If using a V-belt or gearwheel to drive the unit, please contact Rexroth. Provide information on the operating conditions and mounting arrangement. External gear units with outboard bearings are available to help avoid problems when driving the units via V-belts or gearwheels. To complete assembly, remove the transport protection. The external gear unit is delivered with protective covers and plastic plugs. These must be removed before connecting. The protective covers and plastic plugs are to be removed with a suitable tool. Take care not to damage any sealing surfaces (hydraulic ports).! DANGER Risk of toxication and injury Contact with residual quantities of operating materials or conservation agents in the case can cause health damage (e.g. allergies, eye injuries, skin and tissue damage, toxication upon inhalation). When removing the plugs, wear safety gloves and safety glasses. If operating materials or conservation agents should, nevertheless, come into contact with your eyes or penetrate your skin, consult a doctor immediately. When working with operating materials and conservation agents, you must absolutely observe the manufacturer's safety notes (safety data sheet). Note Seal rings and sealing surfaces may be damaged if the transport protection is not removed correctly. Please note the following: Do not damage the sealing surfaces! All ports must have pipes or hoses connected according to the hydraulic circuit diagram or the ports must be plugged with locking screws. The service line ports and function ports are designed exclusively for mounting hydraulic lines (see under "Connecting lines").
RE 07012-B1/06.07 General Operating Notes for External Gear Units Bosch Rexroth AG 27/48 4.6 Connecting lines The machine or system manufacturer is responsible for dimensioning the lines. The external gear unit must be connected to the rest of the hydraulic system in accordance with the hydraulic circuit diagram of the machine or system manufacturer. Observe the following safety notes:! CAUTION Risk of damage Hydraulic lines and hoses that are installed under tension generate additional mechanical forces during operation and thus reduce the service life of the external gear unit and of the overall machine or system. Install all lines and hoses free of pre-tension.! CAUTION Risk of damage Generally, a minimum permissible suction pressure at port "S" is specified for external gear units in all installation positions. If the pressure at the suction port (pressure and suction ports can be identified by the symbols in the project drawing) falls below the specified values, damage may occur which could result in the destruction of the pump. Make certain that the required suction pressure is reached by using the appropriate piping (suction cross-sections, pipe diameter, tank position) as well as appropriate viscosity. Note The service line ports and function ports are designed exclusively for mounting hydraulic lines. Notes on routing the lines Observe the following notes when routing the suction, pressure and case drain lines as well as the "Project planning notes" under 3.8. The suction line (pipe or hose) must be as short and straight as possible. The line cross section is to be measured so that the minimum permissible pressure at the suction port is not dropped below and the maximum permissible pressure is not exceeded. Observe the air tightness of the junctions and the pressure resistance of the hose compared with the external air pressure. Sufficient burst resistance of the pipes, hoses and connecting elements must be observed for pressure lines. Route case drain lines so that the case is constantly filled with hydraulic fluid and to ensure that no air gets through the shaft seal ring even during extended standstill periods. The case internal pressure must not exceed the limit values listed for the external gear unit in the technical data sheet under any operating conditions.
28/48 Bosch Rexroth AG General Operating Notes for External Gear Units RE 07012-B1/06.07 Procedure To connect the external gear unit to the hydraulic system: 1 Remove the transport protection (if not already removed). 2 Clean the lines. Contaminants in the hydraulic fluid may severely impact the service life of the external gear unit. The lines must be cleaned before being installed. 3 Fix the lines according to the fitting manufacturer s specifications. Either pipes or hoses must be connected to all ports according to the installation drawing and machine or system circuit diagram or the ports plugged using suitable locking screws. For the permissible tightening torques of the used armatures, observe the specifications in the project drawing and those provided by the manufacturer. For fixing screws according to DIN 13/ISO 68, we recommend checking the tightening torque in individual cases as per VDI 2230 4 Make sure that the cap nuts are correctly tightened on the fittings and flanges (observe tightening torques!). Mark all checked fittings using e.g. a permanent marker. the pipes and hose lines and every combination of connecting piece, coupling or connecting point with hoses or pipes have been inspected by a technically qualified person for safe working condition. 4.7 Fittings Please observe the following notes in order to avoid damage to screws and threads. Risk of mix-ups Due to the lacking options for optically detecting differences, there is a risk of mix-ups between the following threaded holes and locking screws with different systems of units: Risk of mix-ups for threaded hole with UN UNF thread with metric locking screw or with pipe thread: Threaded hole Thread type Risk of mix-ups with locking screw 1/2-20 9/16-18 3/4-16 7/8-14 1 3/16-12 1 5/16-12 UNF UNF UNF UNF UN UN M12 x 1.5 M14 x 1.5 M18 x 1.5 G 1/2 M30 x 2 M33 x 2 Risk of mix-ups for threaded hole with fine metric thread with locking screws with UN, UNF and pipe thread: Threaded hole Thread type Risk of mix-ups with locking screw M8 x 1 M10 x 1 M12 x 1.5 M14 x 1.5 M20 x 1.5 M22 x 1.5 M42 x 2 M48 x 2 5/16-24 UNF G 1/8 3/8-24 UNF 7/16-20 UNF G 1/4 3/4-16 UNF G 1/2 1 5/8-12 UN 1 7/8-12 UN Risk of mix-ups for threaded hole with pipe thread with locking screws with UN, UNF and metric thread: Threaded hole Thread type Risk of mix-ups with locking screw G 1/8 G 1/4 G 3/8 G 1/2 G 1 1/4 3/8-24 UNF 1/2-20 UNF M16 x 1.5 M20 x 1.5 1 5/8-12 UN