External gear pump SILENCE AZPS

Description

• Platform F
• Fixed displacement
• Size 4 … 28
• Continuous pressure up to 250 bar
• Intermittent pressure up to 280 bar

Features

• Optimized pressure pulsation, reduces noise emissions and oscillations in the system
• Consistent high quality based on large-volume production
• Long service life
• Slide bearings for high loads
• Drive shafts according to ISO or SAE and customer-specific solutions
• Line ports: connection flange or screw thread
• Combination of several pumps possible

Product description

General information

It is the central task of external gear pumps to convert mechanical energy (torque and speed) into hydraulic energy (flow and pressure). To reduce heat losses, Rexroth’s external gear units offer very high efficiencies. They are realized by pressure-dependent gap sealing and highly precise production technology.

Rexroth external gear pumps are built in four frame sizes: Platform B, F, N and G. Within each platform different sizes can be realized by different gear widths. The pumps are available in the versions Standard, High-Performance, SILENCE und SILENCE PLUS. Further configuration variants are given by different flanges, shafts, valve arrangements and multiple pump combinations.

Moreover, in the low-noise SILENCE pumps, the dual-flank principle helps to reduce flow pulsation by up to 75 %.

Pumping principle

The geometry of the displacement gearing, matched in form by the rotation of the drive shaft, results in the parabolic flow characteristic shown here on the left. In a standard pump, this characteristic is repeated each time a gear tooth meshes. With their dual-flank system, the flow pulsation of SILENCE pumps is reduced by 75 % – with correspondingly lower excitation of downstream system components – at double the fundamental frequency. During this process, the gear pair exhibits an extremely reduced rear flank backlash, so that hydraulic ­sealing is provided not just by the front flank of the driven gear, but also by the rear flanks. In this way, the front and rear flanks ­alternately contribute to flow displacement. And by adapting the shape of the metering notches, the expansion of the ­hydraulic line of action is half that of the standard pump.

Construction

The external gear pump consists essentially of a pair of gear wheels supported in bearing bushings and the housing with a front cover and an end cover.

The drive shaft protrudes from the front cover where it is usually sealed by the shaft seal. The bearing forces are absorbed by slide bearings. These bearings were designed for high pressures and have excellent emergency running properties, especially at low rotational speeds.

The gear wheels have 12 teeth. This keeps both flow pulsation and noise emission to a minimum. The sealing of the pressure chambers is achieved by forces depending on the working pressure. This ensures optimum efficiency. The working pressure generated in the gear chambers is transferred to the outside of the bearing bushings in specifically designed pressure fields in such a way that they are pressed against the gears and seal them up. The pressurized compression areas are limited by special seals. The seal in the area between the gear teeth and the housing is ensured by the smallest of gaps that are set depending on the pressure between the gear teeth and housing.

External gear pump layout

Gear pumps with integrated valves

In order to reduce piping complexity, a flow control valve or pressure-relief valve can be integrated in the cover of the gear pump. Such solutions are used, for instance, for the hydraulic oil supply of power steering systems. The pump delivers a constant flow or maximum

pressure irrespective of the rotational speed. The residual flow distributed externally to other consumers.

Pressure relief valve, external pressure discharge

p1 = 5 to 250 bar

Pressure relief valve, pressure discharge into suction line

p1 = 5 to 250 bar

3-way flow control valve, residual flow distributed externally, loadable

qconst = 2 to 30 l/min

3-way flow control valve, residual flow returned in suction line

qconst = 2 to 30 l/min

3-way flow control valve with pressure relief valve, residual flow returned in suction line

qconst = 2 to 30 l/min; p1 = 100 to 180 bar

Type code

Type code single pump

Note

• Not all of the variants according to the type code are possible.

• Please select the desired pump with the help of the selection table (preferred types ) or after consultation with Bosch Rexroth.

• Special options are available on request.

Type code multiple pump

Example 4-way pump:

AZPG…032… + AZPG…022… + AZPJ…016… + AZPJ…012…

Technical data

Table of values

General technical data

Corrosion protection

Note

• Safety requirements pertaining to the whole systems are to be observed.

• Please contact us for applications with frequent load changes.

Pressure definition

Determining the operating characteristics
Flow		[l/min]
Torque		[Nm]
Power		[kW]

Note

You can find diagrams for a rough calculation in chapter "Diagrams / Characteristic curves".

Hydraulic fluids

The external gear unit is designed for operation with HLP mineral oil according to DIN 51524, 1-3. Under higher load, however, Bosch Rexroth recommends at least HLP compliant with DIN 51524 Part 2.

See the following data sheet for application instructions and requirements for selecting hydraulic fluid, behavior during operation as well as disposal and environmental protection before you begin project planning:

• 90220: Hydraulic fluids based on mineral oils and related hydrocarbons

Other hydraulic fluids on request.

Selection of hydraulic fluid

Bosch Rexroth evaluates hydraulic fluids on the basis of the Fluid Rating according to the technical data sheet 90235.

Hydraulic fluids with positive evaluation in the Fluid Rating are provided in the following technical data sheet:

• 90245: Bosch Rexroth Fluid Rating List for Rexroth hydraulic components (pumps and motors)

The hydraulic fluid should be selected so that the operating viscosity in the operating temperature range is within the optimum range (νopt; see selection diagram).

Viscosity and temperature of hydraulic fluids

Observe the instructions for the filtration of the hydraulic fluid (see chapter Project planning information).

Direction of rotation

The dimensional drawings in the chapter Dimensions represent pumps for clockwise rotation. The position of the drive shaft or the position of suction and pressure port changes for counter-clockwise rotation.

Direction of rotation, viewed on drive shaft

Drives

1. Elastic couplings

• The coupling must not transfer any radial and axial forces onto the pump.

• The maximum admissible radial run-out deviation from the shaft to the fitting slot is 0.2 mm.

• Admissible shaft shifting see installation information of the coupling manufacturers.

2. Coupling sleeve

• To be used on splined shaft profile according to DIN and SAE.

• Attention: No radial or axial forces are permitted on the pump shaft or coupling sleeve. The coupling sleeve must be free to move axially.

• The distance between the pump drive shaft and drive shaft on the customer side must 2+1 mm.

• Provide installation space for the snap ring.

• Oil-bath or oil-mist lubrication is required.

3. Tang drive coupling

• For attaching the pump directly to an electric motor or combustion engine, gear, etc.

• The pump shaft has a special tang drive and driver (3) (scope of delivery see offer drawing)

• There is no shaft sealing

• Drive-side installation and sealing according to the following recommendations and dimensions

• Drive shaft on the customer side (1)
  • Case-hardening steel DIN EN 10084 e.g. 20MnCrS5 case-hardened 0.6 mm deep; HRC 60±3
  • Seal ring running surface ground without rifling Rt ≤ 4 μm

• Radial shaft seals on the customer side (2)
  • Provide with rubber cover (see DIN 3760, type AS or double-lipped ring)
  • Provide installation edge with 15° slant or install shaft seal with protection sleeve

AZPS-1x (sizes 4 … 16)

AZPS-2x (sizes 19 … 28)

4. V-belts and straight gear wheels or helical toothed gear drives without outrigger bearing

For V-belt or gear wheel drives, please contact us specifying the application and mounting conditions (dimensions a, dm, dw and angle α). For helical toothed gear drives, details of the helix angle β are also required.

5. Outrigger bearing

Outrigger bearing are offered to eliminate possible problems when the pumps are driven by V-belts or gear wheels. The diagrams show the radial and axial load capacity in relation to a bearing service life of LH = 1000 h.

Front cover A (type 1)

Maximum transferable drive torques

Splined shafts

Tapered shafts

Parallel keyed shafts

Tang drive

With outrigger bearing

Multiple gear pumps

Gear pumps are well-suited to multiple arrangements, whereby the drive shaft of the first pump stage is extended to a second and possibly third pump stage. The shaft of the individual pump sections are normally connected via a driver or via a splined coupling (reinforced

through drive).

The individual pump stages are usually hydraulically isolated and have separate suction ports. On request a common suction port or separated but hydraulically connected suction ports are available.

For the configuration of multiple pumps, Bosch Rexroth recommends arranging the pump stage with the largest displacement on the drive side.

Note

Basically, the parameters of the single pumps apply, however certain restrictions need to be observed:

• Maximum rotational speed: This is determined by the largest pump stage used.

• Pressures: These are restricted by the maximum transmissible torques of the drive shaft, the through drive and the driver.

Addition of drive torques

Please note, that in multiple pump arrangements the drive torques of the single pumps stages will add up according to the following formula:

This may result in pressure restrictions for the respective pump stages.

Standard through drive (tang drive coupling)

In the case of AZPS pumps the driver for the following pump stage can carry a load of up to Mmax = 65 Nm (AZPS-1x) resp. Mmax = 85 Nm (AZPS-2x).

Please note possibly resulting pressure restrictions for the following pump stages. Subsequent pumps of a smaller series determine the max. transmissible torque.

Reinforced through drives

For applications with higher transfer torques or torsional vibrations reinforced through drives up to Mmax = 160 Nm are available. Lay out design on request.

Diagrams/characteristic curves

Flow characteristic curves

Note

• Characteristic curves measured at ν = 32 mm²/s and t = 50 °C.

Power diagrams

Size 4

Size 5

Size 8

Size 11

Size 14

Size 16

Size 19

Size 22

Size 25

Size 28

Noise charts

Noise levels dependent on the rotational speed, pressure range between 10 bar and pressure value p2 (see chapter "Technical data").

These are typical characteristic values for the respective size. They describe the airborne sound emitted solely by the pump.

Ambient influences (installation site, piping, other system components) were not taken into account.

The values refer to one individual pump.

Note

• Characteristic curves measured at ν = 32 mm²/s and t = 50 °C.

• Sound pressure level calculated from noise measurements made in the low reflection measuring room according to DIN 45635, Part 26.

• Distance from measuring sensor to pump: 1 m.

Size 4

Size 5

Size 8

Size 11

Size 14

Size 16

Size 19

Size 22

Size 25

Size 28

Dimensions

Drive shafts

Tapered shaft 1:5

(for front cover B, P, N)

Tapered shaft 1:5

(for outrigger bearing A, G)

Tapered shaft 1:8

Splined shaft (SAE J744 16-4 9T)

Splined shaft (SAE J744 19-4 11T)

Splined shaft (DIN 5482 B17 x 14)

Tang drive

Parallel keyed shaft (SAE J744 16-1 A)

Front cover

Rectangular flange ⌀80 mm

Rectangular flange ⌀36.47mm

2-bolt flange ⌀82.55 mm, SAE J744 82-2 (A)

2-bolt flange ⌀101.6mm, SAE J744 101-2 (B)

2-bolt mounting ⌀52mm, with O-ring

2-bolt mounting ⌀50mm, connection variant 1

4-bolt mounting ⌀52 mm, with O-ring

Outrigger bearing ⌀80 mm, type 1

Line connections

Pipe thread according to ISO 228-1

Metric threads according to ISO 6149, O-ring

UN-thread according to ISO 11926-1 / ASME B 1.1, O-ring

Note

Depending on the design variant, the size of the threaded connections may differ from the sizes specified in the table.

See information in the dimensional drawings.

Square flange

Square flange

Preferred program

Tang drive with 2-bolt mounting ⌀52 mm

AZPS – XX – … NM20MB

Tapered shaft 1:5 with 2-bolt mounting ⌀50 mm

AZPS – XX – … CP20KB – S0007

Splined shaft (DIN 5482 B17 x 14) with 2-bolt mounting ⌀50 mm

AZPS – XX – … FN20KB

Tapered shaft 1:5 with rectangular flange ⌀80 mm

AZPS – XX – … CB20MB

Splined shaft (SAE J744 16-4 9T) with 2-bolt flange ⌀82.55 mm, SAE J744 82-2 (A)

AZPS – XX – … RR20MB

Parallel keyed shaft (SAE J744 16-1 A) with 2-bolt flange ⌀82.55 mm, SAE J744 82-2 (A)

AZPS – XX – … QR12MB

Splined shaft (SAE J744 16-4 9T) with 2-bolt flange ⌀101,6 mm

AZPS – XX – … RC20KB

Tapered shaft 1:5 with rectangular flange ⌀80 mm

AZPSS – XX – … CB2020MB

Splined shaft (SAE J744 16-4 9T) with 2-bolt flange ⌀82.55 mm, SAE J744 82-2 (A)

AZPSS – XX – … RR2020MB

Project planning information

Technical data

All mentioned technical data are dependent on manufacturing tolerances and are applicable for certain boundary conditions.

Note that certain deviations are therefore possible and that technical data may vary when certain boundary conditions (e.g., viscosity) change.

Pumps delivered by Bosch Rexroth are tested for function and performance.

The pump may only be operated with the permissible data (see chapter "Technical data").

Characteristic curves

When dimensioning the gear pump, observe the maximum possible application data on the basis of the characteristic curves shown.

Application information

External gear units are not approved in on-highway vehicles for safety-relevant functions, as well as functions in the drive train, for steering, braking and level regulation.

Classified as on-highway vehicles are e.g. vehicles such as motorbikes, private cars, trucks, vans, freight cars, buses and trailers. The European vehicle classes L (motorbikes), M (private cars), N (vehicles for transporting goods such as trucks and vans) and O (trailers and semi-trailers) serve as reference.

Filtration of the hydraulic fluid

Since the majority of premature failures in gear pumps occur due to contaminated hydraulic fluid, filtration should maintain a cleanliness level of 20/18/15 as defined by ISO 4406. Thus contamination can be reduced to an acceptable degree in terms of particle size and concentration.

Bosch Rexroth generally recommends full-flow filtration. The basic contamination of the hydraulic fluid filled in should not exceed class 20/18/15 as defined by ISO 4406. New fluids are often above this value. In such instances, a filling device with a special filter should be used.

Bosch Rexroth is not liable for wear due to contamination.

For hydraulic systems or devices with function-related, critical failure effects, such as steering and brake valves, the type of filtration selected must be adapted to the sensitivity of these devices.

Notice

When used as an auxiliary steering pump, the vehicle manufacturer should make sure that the steering system continues to operate safely as per ECE R-79 even if the auxiliary steering pump fails.

Further information

Installation drawings and dimensions are valid at date of publication, subject to modifications.

Further information and notes on project planning can be found in the “General instruction manual for external gear units” (07012-B, chapter 5.5).

Information

AZ configurator

With our practical product selector, it will take you next to no time to find the right solution for your applications, no matter whether it is SILENCE PLUS or another external gear unit.

The selector guides you through a selection of features to all of the products available for order. By clicking on the order number, you can view and download the following product information: Data sheet, dimension sheet, operating conditions, and tightening torques.

You can order your selection directly via our online shop and at the same time benefit from an additional discount of 2%. And if you need something really quickly, simply use our fast delivery and preferred programs (GoTo). Then the goods will be sent within 10 working days.

You also have the possibility to easily and conveniently configure your individual external gear unit with our AZ configurator. All the necessary data that you need for the project planning of external gear units is requested by means of the menu navigation.

For an already existing configuration you receive as a result the order number, the type code, as well as further information. If your configuration does not lead to a product that is available for order, our online tools provide you with the possibility of sending a project request directly to Bosch Rexroth. We will then get in contact with you.

Link: www.boschrexroth.com/az-configurator

Spare parts

Spare parts can be found online at www.boschrexroth.com/eshop

Select "Spare parts and accessories" and enter the material number of the external gear units into the search field.

Example:

Material number: 0 517 215 301

Type designation: AZPS-11-004LNT20MB-S0002

All available spare parts are listed under "Spare parts" and can be ordered via the shopping basket.

Further information

• Extensive notes and suggestions can be found in the Hydraulic Trainer, volume 3: “Planning and Design of Hydraulic Power Systems”, order number R900018547.

Accessories

Straight flange, for square flange 20

90° angle flange, for square flange 20

90° angle flange, 3-hole, for square flange 30

Note

Permissible tightening torques can be found in the “General Operating Instructions for External Gear Units” (07012-B).

Ordering codes

Downloads

	General instruction manual for external gear units Manual | RE07012-B | 2020-11-18 | English | PDF | 713k Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Instruction manual
	Manuel d'utilisation général pour unités à engrenages extérieurs Manual | RF07012-B | 2020-11-18 | French | PDF | 734k Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Manuel d'utilisation
	Manuale d’uso generale per unità a ingranaggi esterni Manual | RI07012-B | 2020-11-18 | Italian | PDF | 730k Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Manuale d’uso
	Общее руководство по эксплуатации шестеренных агрегатов с внешним зацеплением Manual | R-RS07012-B | 2020-11-18 | Russian | PDF | 753k Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Инструкция по эксплуатации
	Manual de instrucciones generales para unidades a engranajes con dentado exterior Manual | RS07012-B | 2020-11-18 | Spanish | PDF | 726k Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Manual de instrucciones
	Allgemeine Betriebsanleitung für Außenzahnradeinheiten Manual | RD07012-B | 2020-11-18 | German | PDF | 705k Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Betriebsanleitung
	Ogólna instrukcja obsługi jednostek o zazębieniu zewnętrznym Manual | R-PL07012-B | 2020-11-18 | Polish | PDF | 1.3MB Product Groups: External gear pumps, External gear pumps, External gear motors, External gear motors Instrukcja obsługi
	Шестеренный насос с внешним зацеплением SILENCE AZPS Data Sheet | R-RS10095 | 2021-11-24 | Russian | PDF | 1.5MB Product Groups: External gear pumps Платформа F
	Bomba a engranajes con dentado exterior SILENCE AZPS Data Sheet | RS10095 | 2021-11-24 | Spanish | PDF | 1.1MB Product Groups: External gear pumps Plataforma F
	Außenzahnradpumpe SILENCE AZPS Data Sheet | RD10095 | 2021-11-24 | German | PDF | 1.2MB Product Groups: External gear pumps Plattform F
	External gear pump SILENCE AZPS Data Sheet | RE10095 | 2021-11-24 | English | PDF | 1.1MB Product Groups: External gear pumps Platform F
	Pompe à engrenages extérieurs SILENCE AZPS Data Sheet | RF10095 | 2021-11-24 | French | PDF | 1.4MB Product Groups: External gear pumps Plateforme F