ISO 10767-1:2015

Hydraulic fluid power — Determination of pressure ripple levels generated in systems and components — Part 1: Method for determining source flow ripple and source impedance of pumps

ISO 10767-1:2015 establishes a test procedure for measuring the source flow ripple and source impedance of positive-displacement hydraulic pumps. It is applicable to all types of positive-displacement pumps operating under steady-state conditions, irrespective of size, provided that the pumping frequency is in the range from 50 Hz to 400Hz. Source flow ripple causes fluid borne vibration (pressure ripple) and then airborne noise from hydraulic systems. This procedure covers a frequency range and pressure range that have been found to cause many circuits to emit airborne noise which presents a major difficulty in design of hydraulic fluid power systems. Once the source flow ripple and source impedance of hydraulic fluid power pump are known, the pressure ripple generated by the pump in the fluid power system can be calculated by computer simulation using the known ripple propagation characteristics of the system components. As such, this part of ISO 10767 allows the design of low noise fluid power systems to be realized by establishing a uniform procedure for measuring and reporting the source flow ripple and the source impedance characteristics of hydraulic fluid power pumps. In ISO 10767-1:2015, calculation is made for blocked acoustic pressure ripple as an example of the pressure ripple. An explanation of the methodology and theoretical basis for this test procedure is given in Annex B. The test procedure is referred to here as the two pressures/two systems method. Ratings are obtained as follows: a) source flow ripple (in the standard "Norton" model) amplitude, in cubic meter per second[m3/s], and phase, in degree, over 10 individual harmonics of pumping frequency; b) source flow ripple (in the modified model) amplitude, in cubic meter per second [m3/s], and phase, in degree, over 10 individual harmonics of pumping frequency; and its time history wave form, c) source impedance amplitude, in Newton second per meter to the power of five [(Ns)/m5]., and phase, in degree, over 10 individual harmonics of pumping frequency; d) blocked acoustic pressure ripple, in MPa (1 MPa = 106 Pa) or in bar (1 bar = 105 Pa), over 10 individual harmonics of pumping frequency; and the RMS average of the pressure ripple harmonic f1 to f10.

Transmissions hydrauliques — Détermination des niveaux d'onde de pression engendrés dans les circuits et composants — Partie 1: Méthode de détermination de l'onde de flux de la source et de l'impédance de la source des pompes

L'ISO 10767-1-1:2015 établit un mode opératoire d'essai pour le mesurage de l'onde d'écoulement de la source et de l'impédance de la source des pompes hydrauliques volumétriques. Elle s'applique à tous les types de pompes volumétriques fonctionnant dans des conditions de régime permanent, quelle que soit leur taille, à condition que la fréquence de pompage soit comprise entre 50 Hz et 400 Hz.

Fluidna tehnika - Hidravlika - Ugotavljanje tlačnih konic pri nihanju tlaka v sistemih in sestavinah - 1. del: Metoda za določevanje vira valovanja toka in impedance črpalk

Ta del standarda ISO 10767 določa preskusni postopek za merjenje vira valovanja toka in impedance hidravličnih črpalk z iztiskanjem. Uporablja se za vse vrste črpalk
z iztiskanjem, ki delujejo pri ustaljenih pogojih, ne glede na velikost, pod pogojem, da je frekvenca črpanja v obsegu od 50 Hz do 400 Hz.
Vir valovanja toka povzroča tresljaje v tekočini (tlačno valovanje) in posledično emisije hrupa hidravličnih sistemov. Ta postopek vključuje frekvenčni in tlačni razpon, ki dokazano povzročata emisije hrupa številnih krogotokov, kar predstavlja večjo težavo pri načrtovanju hidravličnih pogonskih sistemov. Ko sta vir valovanja toka in impedanca vira hidravlične pogonske črpalke znana, je z računalniško simulacijo in znanimi lastnostmi širjenja valovanja v sistemskih komponentah mogoče izračunati tlačno valovanje, ki ga ustvari črpalka v fluidnem pogonskem sistemu. Ta del standarda ISO 10767 kot tak omogoča načrtovanje tišjih fluidnih pogonskih sistemov z vzpostavitvijo enotnega postopka za merjenje in sporočanje lastnosti vira valovanja toka ter impedance vira hidravličnih pogonskih črpalk.
V tem delu standarda ISO 10767 se izračun opravi za blokirano valovanje zvočnega tlaka kot primer tlačnega valovanja. Razlaga metodologije in teoretične osnove za ta preskusni postopek je podana v dodatku B. Preskusni postopek se na tem mestu obravnava kot metoda z dvema tlakoma/sistemoma. Nazivne vrednosti so pridobljene, kot sledi:
a) amplituda vira valovanja toka (v standardnem »Nortonovem« modelu) v kubičnih metrih na sekundo (m3/s) in faza v stopnjah prek 10 ločenih harmonikov frekvence črpanja;
a) amplituda vira valovanja toka (v spremenjenem modelu) v kubičnih metrih na sekundo (m3/s) in faza v stopnjah prek 10 ločenih harmonikov frekvence črpanja ter valovna oblika v časovnem poteku;
c) amplituda impedance vira v newton-sekundah na meter na peto potenco ((Ns)/m5) in faza v stopnjah prek 10 ločenih harmonikov frekvence črpanja;
d) blokirano valovanje zvočnega tlaka v MPa (1 MPa = 106 Pa) ali v barih (1 bar = 105 Pa) prek 10 ločenih harmonikov frekvence črpanja in povprečje efektivne vrednosti harmonikov tlačnega valovanja od f1 do f10.

General Information

• Status: Published
• Publication Date: 28-Sep-2015
• ICS: 23.100.10 - Pumps and motors
• Technical Committee: ISO/TC 131/SC 8 - Product testing
• Drafting Committee: ISO/TC 131/SC 8/WG 1 - Hydraulic component and system sound measurement
• Current Stage: 9093 - International Standard confirmed
• Completion Date: 13-Apr-2021
• Ref Project: SIST ISO 10767-1:2016 - Hydraulic fluid power - Determination of pressure ripple levels generated in systems and components - Part 1: Method for determining source flow ripple and source impedance of pumps

Relations

• Revises: ISO 10767-1:1996 - Hydraulic fluid power — Determination of pressure ripple levels generated in systems and components — Part 1: Precision method for pumps
• Effective Date: 26-Feb-2011

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 10767-1
Second edition
2015-10-01
Hydraulic fluid power —
Determination of pressure ripple
levels generated in systems and
components —
Part 1:
Method for determining source flow
ripple and source impedance of pumps
Transmissions hydrauliques — Détermination des niveaux d’onde de
pression engendrés dans les circuits et composants —
Partie 1: Méthode de détermination de l’onde de flux de la source et
de l’impédance de la source des pompes
Reference number
ISO 10767-1:2015(E)
©
ISO 2015

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ISO 10767-1:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

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ISO 10767-1:2015(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Instrumentation . 3
4.1 Static measurements. 3
4.2 Dynamic measurements . 4
4.3 Frequency analysis of pressure ripple . 4
5 Pump installation . 4
5.1 General . 4
5.2 Drive vibration . 5
5.3 Reference signal . 5
6 Test conditions and setting . 5
6.1 General . 5
6.2 Mean flow . 5
6.3 Mean discharge pressure . 5
6.4 Pump shaft speed. 5
6.5 Fluid temperature . 5
6.6 Fluid property . 6
7 Test rig . 6
7.1 General . 6
7.2 Test pump . 6
7.3 Test fluid . 6
7.4 Inlet line . 6
7.5 Inlet pressure gauge (for static pressure) . 6
7.6 Pump discharge line . 7
7.6.1 General. 7
7.6.2 Pump discharge port connection . 8
7.6.3 Reference pipe . 8
7.6.4 Connecting pipe . 8
7.6.5 Extension pipe . 9
7.7 Pressure transducer . 9
7.7.1 Dynamic pressure transducer . 9
7.7.2 Static pressure transducer . 9
7.8 Loading valve . 9
7.9 Back pressure valve . 9
7.10 Safety valve . 9
8 Test procedure .10
8.1 General .10
8.2 Frequency analyses of pressure ripple.11
8.3 Evaluation of source flow ripple, Q , in the standard “Norton” model.11
s
8.4 Evaluation of source impedance, Z , in the standard “Norton” model .12
s
8.5 Evaluation of source flow ripple, Q *, in the modified model .12
s
8.6 Evaluation of blocked acoustic pressure ripple rating .13
9 Test report .13
9.1 General information and test conditions .13
9.2 Test results.13
10 Identification statement (Reference to this part of ISO 10767) .14
Annex A (normative) Test forms .15
© ISO 2015 – All rights reserved iii

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ISO 10767-1:2015(E)

Annex B (informative) Two pressures/two systems method .21
Bibliography .28
iv © ISO 2015 – All rights reserved

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ISO 10767-1:2015(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 131, Fluid power systems, Subcommittee SC 8,
Product testing.
This second edition cancels and replaces the first edition (ISO 10767-1:1996), which has been
technically revised.
ISO 10767 consists of the following parts, under the general title Hydraulic fluid power — Determination
of pressure ripple levels generated in systems and components:
— Part 1: Precision method for pumps
— Part 2: Simplified method for pumps
— Part 3: Method for motors
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ISO 10767-1:2015(E)

Introduction
The first edition of ISO 10767-1, published in 1996, was developed with a view to provide means for
measurement (experimental determination) of the set of two characteristic values consisting of source
flow ripple Q and source impedance Z of hydraulic pumps giving rise to pressure ripple (fluid born
s s
vibration) in the hydraulic power circuit., measurement of these two values for a given ripple source is
extremely important for design and development of low noise pumps and hydraulic power systems, and
for this reason, there is a valid need for such an international standard to experimental measurement
of source flow ripple Qs and source impedance Z .
s
However, as discussed in the paragraph below, the so-called “secondary source method” presented in
the first edition requires a very complex test system as well as signal processing technique, making
its implementation highly difficult; because of this, no country except for the UK, the proposer, has yet
adopted ISO 10767-1 as a national standard.
The difficulty can be explained as follows.
To determine the two characteristic values of the source flow ripple, Q , and source impedance, Z , a
s s
secondary ripple source is located in the test circuit to generate wide range ripples in the test system.
Frequency characteristics of Z , arising from the secondary source, are first determined, followed by
s
measurement of Q of the test pump on the basis of the test pump itself. This means that measurement
s
of the harmonics of the pressure ripple is made with both the test pump and the secondary source
in operation. As the result, the measurement accuracy of the harmonic component of the test pump
deteriorates significantly as we come close to harmonic frequency level, where differences between
the harmonic frequency of the test pump ripple and that of the secondary source become small. To
deal with the problem, very complicated signal processing such as compensation is performed, but
its practical effect is quite limited. In addition, the standard specifies use of a rotary valve for the
secondary source of wide range (50 Hz ~ 4k Hz) ripples, but there is no provision as to the design and
frequency characteristics.
These problems arise from the requirement for the secondary source, whereas the method proposed by
[2] [3]
Weddfelt and Kojima allows measurement of delivery ripple characteristics (Q ) and the internal
s
source (Z ) on the sole basis of pressure ripple generated by the test pump. This makes the test system
s
quite simple and allows superior accuracy to be achieved without complex processing of signals. The
method according to the approaches of Weddfelt and Kojima, respectively, is the same in principle, the
only difference between the two being the arrangement of the piping. The present proposal represents
[3] [2]
the method according to Kojima, while annexing that of Weddfelt for the purpose of reference.
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INTERNATIONAL STANDARD ISO 10767-1:2015(E)
Hydraulic fluid power — Determination of pressure ripple
levels generated in systems and components —
Part 1:
Method for determining source flow ripple and source
impedance of pumps
1 Scope
This part of ISO 10767 establishes a test procedure for measuring the source flow ripple and source
impedance of positive-displacement hydraulic pumps. It is applicable to all types of positive-
displacement pumps operating under steady-state conditions, irrespective of size, provided that the
pumping frequency is in the range from 50 Hz to 400Hz.
Source flow ripple causes fluid borne vibration (pressure ripple) and then airborne noise from
hydraulic systems. This procedure covers a frequency range and pressure range that have been found
to cause many circuits to emit airborne noise which presents a major difficulty in design of hydraulic
fluid power systems. Once the source flow ripple and source impedance of hydraulic fluid power pump
are known, the pressure ripple generated by the pump in the fluid power system can be calculated by
computer simulation using the known ripple propagation characteristics of the system components.
As such, this part of ISO 10767 allows the design of low noise fluid power systems to be realized by
establishing a uniform procedure for measuring and reporting the source flow ripple and the source
impedance characteristics of hydraulic fluid power pumps.
In this part of ISO 10767, calculation is made for blocked acoustic pressure ripple as an example of the
pressure ripple. An explanation of the methodology and theoretical basis for this test procedure is given
in Annex B. The test procedure is referred to here as the two pressures/two systems method. Ratings are
obtained as follows:
3
a) source flow ripple (in the standard “Norton” model) amplitude, in cubic meter per second[m /s],
and phase, in degree, over 10 individual harmonics of pumping frequency;
3
b) source flow ripple (in the modified model) amplitude, in cubic meter per second [m /s], and phase,
in degree, over 10 individual harmonics of pumping frequency; and its time history wave form,
5
c) source impedance amplitude, in Newton second per meter to the power of five [(Ns)/m ]., and
phase, in degree, over 10 individual harmonics of pumping frequency;
6 5
d) blocked acoustic pressure ripple, in MPa (1 MPa = 10 Pa) or in bar (1 bar = 10 Pa), over 10 individual
harmonics of pumping frequency; and the RMS average of the pressure ripple harmonic f to f .
1 10
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 5598, Fluid power systems and components — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.
© ISO 2015 – All rights reserved 1

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ISO 10767-1:2015(E)

3.1
source flow ripple
fluctuating component of flow-rate generated within the pump, which is independent of the
characteristics of the connected circuit
Note 1 to entry: Since there exist the following two definitions of the pump source flow ripple, it shall be used
with distinct discrimination:
—   source flow ripple in the standard “Norton” model, Q , is the source flow ripple implicitly assumed to be
s
generated at the pump outlet, as shown in Figure 1 a);
—   source flow ripple in the “modified” model, Q *, is the source flow ripple assumed to be generated at the
s
inner end of the discharge flow line, as shown in Figure 1 b).
Note 2 to entry: The theoretical pump source flow ripple which is calculated from computer simulation using the
dimensions and configuration of the pump, physical properties of the fluid and operating conditions corresponds
to the pump flow ripple (3.2) in the modified model, Q *.
s
3.2
flow ripple
fluctuating component of flow-rate of the hydraulic fluid, caused by interaction of source flow ripple
(3.1) with the system
3.3
pressure ripple
fluctuating component of pressure in the hydraulic fluid, caused by interaction of the source flow ripple
(3.1) with the system
3.4
blocked acoustic pressure ripple
pressure ripple (3.3) that would be generated at the pump discharge port when fluid is discharged into a
circuit of infinite impedance (3.5)
3.5
impedance
complex ratio of the pressure ripple (3.3) to the flow ripple (3.2) occurring at a given point in a hydraulic
system and at a given frequency
3.6
source impedance
impedance (3.5) of a pump at the discharge port in the standard “Norton” model
3.7
harmonic
sinusoidal component of the pressure ripple (3.3) or flow ripple (3.2) occurring at an integer multiple of
the pumping frequency (3.8)
Note 1 to entry: A harmonic can be represented by its amplitude and phase, or, alternatively, by its real and
imaginary components, provided that in this part of ISO 10767 the real and imaginary components are used in
the arithmetic calculations.
3.8
pumping frequency
frequency given by the product of the shaft rotational frequency (3.9) and the number of pumping
elements on that shaft
Note 1 to entry: It is expressed in hertz.
2 © ISO 2015 – All rights reserved

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ISO 10767-1:2015(E)

3.9
shaft rotational frequency
frequency (in hertz) given by the shaft rotational speed (in revolutions per minute) divided by 60
Note 1 to entry: Since the calculations in Clause 8 are all carried out using SI unit, all variables and constants
shall be expressed in SI units, except for reporting of the end results.
a) Standard “Norton” model
b) Modified model
Key
1 discharge passageway
2 discharge line
3 pump exit
Figure 1 — Modelling of pump pulsation source
4 Instrumentation
4.1 Static measurements
The instruments used to measure
a) shaft rotational speed,
b) mean pressure,
c) mean discharge flow-rate, and
d) fluid temperature
© ISO 2015 – All rights reserved 3

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ISO 10767-1:2015(E)

shall have an accuracy throughout each test within the limits specified in Table 1.
NOTE The percentage limits are the of the value of the quantity being measured and not the maximum test
values or the maximum reading of the instrument.
Table 1 — Permissible errors of static measurements
Shaft rotational Mean flow Mean pressure Temperature
frequency % % °C
%
±0,5 ±2,0 ±2,0 ±2,0
4.2 Dynamic measurements
The instruments used for measurement of pressure ripple shall have the following characteristics:
a) resonant frequency ≥ 30 kHz;
b) linearity ≤ ± 1 %.
The instruments need not respond to steady-state pressure. It can be advantageous to filter out any
steady-state signal component by using a high-pass filter. This filter shall not introduce additional
amplitude or phase error exceeding 1 % or 2°, respectively, at the pumping frequency.
4.3 Frequency analysis of pressure ripple
A suitable instrument shall be used to measure the harmonic amplitude and phase (or its real and
imaginary components) of pressure ripple, for individual harmonics of the pumping frequency up to
3,5 kHz. The instrument shall be capable of measuring the pressure ripple from two pressure transducers
simultaneously. The respective two pressure ripple signals of system 1 and system 2 shall be sampled in
an instrument using external trigger signal obtained from a fixed reference on the pump shaft.
This instrument shall have the following accuracy and resolution for harmonic measurements over the
frequency range from 50 Hz to 4 000 Hz:
a) amplitude within the range of ±1 %;
b) phase within the range of ±1°;
c) frequency within the range of ±0,5 %.
This can be achieved using a common type analysing recorder and then carrying out the spectral
analyses by calculating discrete Fourier transforms (DFTs) of the time history data on a post processing
digital computer. Annex B contains a tutorial explanation of this frequency analysis method.
NOTE In order to improve the accuracy of Fourier transformation, pump speed shall be adjusted minutely
while observing the monitor of the analysing recorder so that the higher (e.g. 10th) harmonic amplitude peak
appears nearly at the assigned higher (e.g. 10th) harmonic frequency (i.e. in case of f being 225 Hz, f = 2,25 kHz)
1 10
of the pumping frequency.
5 Pump installation
5.1 General
The pump shall be installed in the attitude recommended by the manufacture and mounted in such a
manner that the response of the mounting-to-pump vibration is minimized.
4 © ISO 2015 – All rights reserved

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ISO 10767-1:2015(E)

5.2 Drive vibration
The electric motor and associated drive coupling shall not generate torsional vibration in the pump
shaft. If necessary, the pump and the driving unit shall be isolated from each other to eliminate vibration
generated by the electric motor.
5.3 Reference signal
A means of producing a reference signal relative to the pump shaft rotation shall be included, as one of
essential elements in measurement according to this part of ISO 10767. The signal shall be an electrical
pulse occurring once per revolution, with sharply defined rising and falling edges. This signal is used
as an external trigger signal of analysing recorder, as well as for measurement of the shaft rotational
speed. A magnetic gap detector (or a photo sensor) a satisfactory means of providing the required
characteristics of reference signal mentioned above.
6 Test conditions and setting
6.1 General
Pump shaft speed, mean discharge pressure and fluid temperature are set to the values of required
test conditions. These operating conditions shall be maintained throughout each test within the limits
specified in Table 2.
Table 2 — Permissible variations in test conditions
Test parameter Permissible variation
Mean flow ±2,0 %
Mean pressure ±2,0 %
Shaft rotational speed ±0,5 %
Temperature ±2,0 °C
6.2 Mean flow
Mean flow is measured by the positive-displacement type flow meter installed on the outlet line of
loading valve 2.
6.3 Mean discharge pressure
Mean discharge pressure shall be measured electrically using a piezoresistance type transducer or a
strain gauge type transducer mounted in the adapter before loading valve 1.
A bourdon type pressure gauge shall not be used for measurement of the mean discharge pressure.
6.4 Pump shaft speed
Pump shaft speed is measured by the magnetic gap detector (or photo sensor) installed on the pump
shaft. Shaft rotational frequency (Hz) is given by the shaft rotational speed (rev/min) divided by 60.
6.5 Fluid temperature
Temperature of the fluid shall be that measured at the pump inlet.
© ISO 2015 – All rights reserved 5

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ISO 10767-1:2015(E)

6.6 Fluid property
Density, viscosity and bulk modulus of the test fluid shall be known to an accuracy within the limits
specified in Table 3.
NOTE The percentage limits are of the error of the estimated quantity to the real value
Table 3 — Required accuracy of fluid property data
Property Required accuracy
Density ±2,0 %
Viscosity ±5,0 %
Bulk modulus ±5,0 %
7 Test rig
7.1 General
The test rig shall be installed as shown in Figure 2. The test rig shall include all fluid filters, fluid
coolers, reservoir, loading valves and any ancillary pumps required to meet operating conditions of the
hydraulic pump. Specific features are described in 7.2 to 7.10.
7.2 Test pump
The test pump shall be installed in the “as-delivered” condition.
7.3 Test fluid
Type of the test hydraulic fluid and the quality of filtration shall be in accordance with the pump
manufacturer’s recommendations.
7.4 Inlet line
Internal diameter of the inlet line to the pump shall be in accordance with the pump manufacturer’s
recommendations. Care shall be exercised when assembling the inlet line to prevent air leakage into the
circuit. The supply pressure shall be in accordance with the pump manufacturer’s recommendations
and, if necessary, a boost pump shall be used. If a boost pump is used, the pressure and flow ripple of
the boost pump shall be taken into account, so that they do not affect the test results.
7.5 Inlet pressure gauge (for static pressure)
The inlet pressure gauge of Bourdon tube type shall be mounted at the same height as the inlet fitting.
Otherwise, the gauge shall be calibrated for any height difference therefrom.
6 © ISO
...

SLOVENSKI STANDARD
SIST ISO 10767-1:2016
01-maj-2016
1DGRPHãþD
SIST ISO 10767-1:1998
)OXLGQDWHKQLND+LGUDYOLND8JRWDYOMDQMHWODþQLKNRQLFSULQLKDQMXWODNDYVLVWHPLK
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þUSDON
Hydraulic fluid power - Determination of pressure ripple levels generated in systems and
components - Part 1: Method for determining source flow ripple and source impedance of
pumps
Transmissions hydrauliques - Détermination des niveaux d'onde de pression engendrés
dans les circuits et composants - Partie 1: Méthode de détermination de l'onde de flux de
la source et de l'impédance de la source des pompes
Ta slovenski standard je istoveten z: ISO 10767-1:2015
ICS:
23.100.10 +LGUDYOLþQHþUSDONHLQPRWRUML Pumps and motors
SIST ISO 10767-1:2016 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 10767-1:2016

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SIST ISO 10767-1:2016
INTERNATIONAL ISO
STANDARD 10767-1
Second edition
2015-10-01
Hydraulic fluid power —
Determination of pressure ripple
levels generated in systems and
components —
Part 1:
Method for determining source flow
ripple and source impedance of pumps
Transmissions hydrauliques — Détermination des niveaux d’onde de
pression engendrés dans les circuits et composants —
Partie 1: Méthode de détermination de l’onde de flux de la source et
de l’impédance de la source des pompes
Reference number
ISO 10767-1:2015(E)
©
ISO 2015

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SIST ISO 10767-1:2016
ISO 10767-1:2015(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

---------------------- Page: 4 ----------------------

SIST ISO 10767-1:2016
ISO 10767-1:2015(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Instrumentation . 3
4.1 Static measurements. 3
4.2 Dynamic measurements . 4
4.3 Frequency analysis of pressure ripple . 4
5 Pump installation . 4
5.1 General . 4
5.2 Drive vibration . 5
5.3 Reference signal . 5
6 Test conditions and setting . 5
6.1 General . 5
6.2 Mean flow . 5
6.3 Mean discharge pressure . 5
6.4 Pump shaft speed. 5
6.5 Fluid temperature . 5
6.6 Fluid property . 6
7 Test rig . 6
7.1 General . 6
7.2 Test pump . 6
7.3 Test fluid . 6
7.4 Inlet line . 6
7.5 Inlet pressure gauge (for static pressure) . 6
7.6 Pump discharge line . 7
7.6.1 General. 7
7.6.2 Pump discharge port connection . 8
7.6.3 Reference pipe . 8
7.6.4 Connecting pipe . 8
7.6.5 Extension pipe . 9
7.7 Pressure transducer . 9
7.7.1 Dynamic pressure transducer . 9
7.7.2 Static pressure transducer . 9
7.8 Loading valve . 9
7.9 Back pressure valve . 9
7.10 Safety valve . 9
8 Test procedure .10
8.1 General .10
8.2 Frequency analyses of pressure ripple.11
8.3 Evaluation of source flow ripple, Q , in the standard “Norton” model.11
s
8.4 Evaluation of source impedance, Z , in the standard “Norton” model .12
s
8.5 Evaluation of source flow ripple, Q *, in the modified model .12
s
8.6 Evaluation of blocked acoustic pressure ripple rating .13
9 Test report .13
9.1 General information and test conditions .13
9.2 Test results.13
10 Identification statement (Reference to this part of ISO 10767) .14
Annex A (normative) Test forms .15
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Annex B (informative) Two pressures/two systems method .21
Bibliography .28
iv © ISO 2015 – All rights reserved

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SIST ISO 10767-1:2016
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Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 131, Fluid power systems, Subcommittee SC 8,
Product testing.
This second edition cancels and replaces the first edition (ISO 10767-1:1996), which has been
technically revised.
ISO 10767 consists of the following parts, under the general title Hydraulic fluid power — Determination
of pressure ripple levels generated in systems and components:
— Part 1: Precision method for pumps
— Part 2: Simplified method for pumps
— Part 3: Method for motors
© ISO 2015 – All rights reserved v

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SIST ISO 10767-1:2016
ISO 10767-1:2015(E)

Introduction
The first edition of ISO 10767-1, published in 1996, was developed with a view to provide means for
measurement (experimental determination) of the set of two characteristic values consisting of source
flow ripple Q and source impedance Z of hydraulic pumps giving rise to pressure ripple (fluid born
s s
vibration) in the hydraulic power circuit., measurement of these two values for a given ripple source is
extremely important for design and development of low noise pumps and hydraulic power systems, and
for this reason, there is a valid need for such an international standard to experimental measurement
of source flow ripple Qs and source impedance Z .
s
However, as discussed in the paragraph below, the so-called “secondary source method” presented in
the first edition requires a very complex test system as well as signal processing technique, making
its implementation highly difficult; because of this, no country except for the UK, the proposer, has yet
adopted ISO 10767-1 as a national standard.
The difficulty can be explained as follows.
To determine the two characteristic values of the source flow ripple, Q , and source impedance, Z , a
s s
secondary ripple source is located in the test circuit to generate wide range ripples in the test system.
Frequency characteristics of Z , arising from the secondary source, are first determined, followed by
s
measurement of Q of the test pump on the basis of the test pump itself. This means that measurement
s
of the harmonics of the pressure ripple is made with both the test pump and the secondary source
in operation. As the result, the measurement accuracy of the harmonic component of the test pump
deteriorates significantly as we come close to harmonic frequency level, where differences between
the harmonic frequency of the test pump ripple and that of the secondary source become small. To
deal with the problem, very complicated signal processing such as compensation is performed, but
its practical effect is quite limited. In addition, the standard specifies use of a rotary valve for the
secondary source of wide range (50 Hz ~ 4k Hz) ripples, but there is no provision as to the design and
frequency characteristics.
These problems arise from the requirement for the secondary source, whereas the method proposed by
[2] [3]
Weddfelt and Kojima allows measurement of delivery ripple characteristics (Q ) and the internal
s
source (Z ) on the sole basis of pressure ripple generated by the test pump. This makes the test system
s
quite simple and allows superior accuracy to be achieved without complex processing of signals. The
method according to the approaches of Weddfelt and Kojima, respectively, is the same in principle, the
only difference between the two being the arrangement of the piping. The present proposal represents
[3] [2]
the method according to Kojima, while annexing that of Weddfelt for the purpose of reference.
vi © ISO 2015 – All rights reserved

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SIST ISO 10767-1:2016
INTERNATIONAL STANDARD ISO 10767-1:2015(E)
Hydraulic fluid power — Determination of pressure ripple
levels generated in systems and components —
Part 1:
Method for determining source flow ripple and source
impedance of pumps
1 Scope
This part of ISO 10767 establishes a test procedure for measuring the source flow ripple and source
impedance of positive-displacement hydraulic pumps. It is applicable to all types of positive-
displacement pumps operating under steady-state conditions, irrespective of size, provided that the
pumping frequency is in the range from 50 Hz to 400Hz.
Source flow ripple causes fluid borne vibration (pressure ripple) and then airborne noise from
hydraulic systems. This procedure covers a frequency range and pressure range that have been found
to cause many circuits to emit airborne noise which presents a major difficulty in design of hydraulic
fluid power systems. Once the source flow ripple and source impedance of hydraulic fluid power pump
are known, the pressure ripple generated by the pump in the fluid power system can be calculated by
computer simulation using the known ripple propagation characteristics of the system components.
As such, this part of ISO 10767 allows the design of low noise fluid power systems to be realized by
establishing a uniform procedure for measuring and reporting the source flow ripple and the source
impedance characteristics of hydraulic fluid power pumps.
In this part of ISO 10767, calculation is made for blocked acoustic pressure ripple as an example of the
pressure ripple. An explanation of the methodology and theoretical basis for this test procedure is given
in Annex B. The test procedure is referred to here as the two pressures/two systems method. Ratings are
obtained as follows:
3
a) source flow ripple (in the standard “Norton” model) amplitude, in cubic meter per second[m /s],
and phase, in degree, over 10 individual harmonics of pumping frequency;
3
b) source flow ripple (in the modified model) amplitude, in cubic meter per second [m /s], and phase,
in degree, over 10 individual harmonics of pumping frequency; and its time history wave form,
5
c) source impedance amplitude, in Newton second per meter to the power of five [(Ns)/m ]., and
phase, in degree, over 10 individual harmonics of pumping frequency;
6 5
d) blocked acoustic pressure ripple, in MPa (1 MPa = 10 Pa) or in bar (1 bar = 10 Pa), over 10 individual
harmonics of pumping frequency; and the RMS average of the pressure ripple harmonic f to f .
1 10
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 5598, Fluid power systems and components — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.
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3.1
source flow ripple
fluctuating component of flow-rate generated within the pump, which is independent of the
characteristics of the connected circuit
Note 1 to entry: Since there exist the following two definitions of the pump source flow ripple, it shall be used
with distinct discrimination:
—   source flow ripple in the standard “Norton” model, Q , is the source flow ripple implicitly assumed to be
s
generated at the pump outlet, as shown in Figure 1 a);
—   source flow ripple in the “modified” model, Q *, is the source flow ripple assumed to be generated at the
s
inner end of the discharge flow line, as shown in Figure 1 b).
Note 2 to entry: The theoretical pump source flow ripple which is calculated from computer simulation using the
dimensions and configuration of the pump, physical properties of the fluid and operating conditions corresponds
to the pump flow ripple (3.2) in the modified model, Q *.
s
3.2
flow ripple
fluctuating component of flow-rate of the hydraulic fluid, caused by interaction of source flow ripple
(3.1) with the system
3.3
pressure ripple
fluctuating component of pressure in the hydraulic fluid, caused by interaction of the source flow ripple
(3.1) with the system
3.4
blocked acoustic pressure ripple
pressure ripple (3.3) that would be generated at the pump discharge port when fluid is discharged into a
circuit of infinite impedance (3.5)
3.5
impedance
complex ratio of the pressure ripple (3.3) to the flow ripple (3.2) occurring at a given point in a hydraulic
system and at a given frequency
3.6
source impedance
impedance (3.5) of a pump at the discharge port in the standard “Norton” model
3.7
harmonic
sinusoidal component of the pressure ripple (3.3) or flow ripple (3.2) occurring at an integer multiple of
the pumping frequency (3.8)
Note 1 to entry: A harmonic can be represented by its amplitude and phase, or, alternatively, by its real and
imaginary components, provided that in this part of ISO 10767 the real and imaginary components are used in
the arithmetic calculations.
3.8
pumping frequency
frequency given by the product of the shaft rotational frequency (3.9) and the number of pumping
elements on that shaft
Note 1 to entry: It is expressed in hertz.
2 © ISO 2015 – All rights reserved

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SIST ISO 10767-1:2016
ISO 10767-1:2015(E)

3.9
shaft rotational frequency
frequency (in hertz) given by the shaft rotational speed (in revolutions per minute) divided by 60
Note 1 to entry: Since the calculations in Clause 8 are all carried out using SI unit, all variables and constants
shall be expressed in SI units, except for reporting of the end results.
a) Standard “Norton” model
b) Modified model
Key
1 discharge passageway
2 discharge line
3 pump exit
Figure 1 — Modelling of pump pulsation source
4 Instrumentation
4.1 Static measurements
The instruments used to measure
a) shaft rotational speed,
b) mean pressure,
c) mean discharge flow-rate, and
d) fluid temperature
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SIST ISO 10767-1:2016
ISO 10767-1:2015(E)

shall have an accuracy throughout each test within the limits specified in Table 1.
NOTE The percentage limits are the of the value of the quantity being measured and not the maximum test
values or the maximum reading of the instrument.
Table 1 — Permissible errors of static measurements
Shaft rotational Mean flow Mean pressure Temperature
frequency % % °C
%
±0,5 ±2,0 ±2,0 ±2,0
4.2 Dynamic measurements
The instruments used for measurement of pressure ripple shall have the following characteristics:
a) resonant frequency ≥ 30 kHz;
b) linearity ≤ ± 1 %.
The instruments need not respond to steady-state pressure. It can be advantageous to filter out any
steady-state signal component by using a high-pass filter. This filter shall not introduce additional
amplitude or phase error exceeding 1 % or 2°, respectively, at the pumping frequency.
4.3 Frequency analysis of pressure ripple
A suitable instrument shall be used to measure the harmonic amplitude and phase (or its real and
imaginary components) of pressure ripple, for individual harmonics of the pumping frequency up to
3,5 kHz. The instrument shall be capable of measuring the pressure ripple from two pressure transducers
simultaneously. The respective two pressure ripple signals of system 1 and system 2 shall be sampled in
an instrument using external trigger signal obtained from a fixed reference on the pump shaft.
This instrument shall have the following accuracy and resolution for harmonic measurements over the
frequency range from 50 Hz to 4 000 Hz:
a) amplitude within the range of ±1 %;
b) phase within the range of ±1°;
c) frequency within the range of ±0,5 %.
This can be achieved using a common type analysing recorder and then carrying out the spectral
analyses by calculating discrete Fourier transforms (DFTs) of the time history data on a post processing
digital computer. Annex B contains a tutorial explanation of this frequency analysis method.
NOTE In order to improve the accuracy of Fourier transformation, pump speed shall be adjusted minutely
while observing the monitor of the analysing recorder so that the higher (e.g. 10th) harmonic amplitude peak
appears nearly at the assigned higher (e.g. 10th) harmonic frequency (i.e. in case of f being 225 Hz, f = 2,25 kHz)
1 10
of the pumping frequency.
5 Pump installation
5.1 General
The pump shall be installed in the attitude recommended by the manufacture and mounted in such a
manner that the response of the mounting-to-pump vibration is minimized.
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5.2 Drive vibration
The electric motor and associated drive coupling shall not generate torsional vibration in the pump
shaft. If necessary, the pump and the driving unit shall be isolated from each other to eliminate vibration
generated by the electric motor.
5.3 Reference signal
A means of producing a reference signal relative to the pump shaft rotation shall be included, as one of
essential elements in measurement according to this part of ISO 10767. The signal shall be an electrical
pulse occurring once per revolution, with sharply defined rising and falling edges. This signal is used
as an external trigger signal of analysing recorder, as well as for measurement of the shaft rotational
speed. A magnetic gap detector (or a photo sensor) a satisfactory means of providing the required
characteristics of reference signal mentioned above.
6 Test conditions and setting
6.1 General
Pump shaft speed, mean discharge pressure and fluid temperature are set to the values of required
test conditions. These operating conditions shall be maintained throughout each test within the limits
specified in Table 2.
Table 2 — Permissible variations in test conditions
Test parameter Permissible variation
Mean flow ±2,0 %
Mean pressure ±2,0 %
Shaft rotational speed ±0,5 %
Temperature ±2,0 °C
6.2 Mean flow
Mean flow is measured by the positive-displacement type flow meter installed on the outlet line of
loading valve 2.
6.3 Mean discharge pressure
Mean discharge pressure shall be measured electrically using a piezoresistance type transducer or a
strain gauge type transducer mounted in the adapter before loading valve 1.
A bourdon type pressure gauge shall not be used for measurement of the mean discharge pressure.
6.4 Pump shaft speed
Pump shaft speed is measured by the magnetic gap detector (or photo sensor) installed on the pump
shaft. Shaft rotational frequency (Hz) is given by the shaft rotational speed (rev/min) divided by 60.
6.5 Fluid temperature
Temperature of the fluid shall be that measured at the pump inlet.
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SIST ISO 10767-1:2016
ISO 10767-1:2015(E)

6.6 Fluid property
Density, viscosity and bulk modulus of the test fluid shall be known to an accuracy within the limits
specified in Table 3.
NOTE The percentage limits are of the error of the estimated quantity to the real value
Table 3 — Required accuracy of fluid property data
Pr
...

NORME ISO
INTERNATIONALE 10767-1
Deuxième édition
2015-10-01
Transmissions hydrauliques —
Détermination des niveaux d’onde de
pression engendrés dans les circuits
et composants —
Partie 1:
Méthode de détermination de l’onde
de flux de la source et de l’impédance
de la source des pompes
Hydraulic fluid power — Determination of pressure ripple levels
generated in systems and components —
Part 1: Method for determining source flow ripple and source
impedance of pumps
Numéro de référence
ISO 10767-1:2015(F)
©
ISO 2015

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ISO 10767-1:2015(F)

DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2015, Publié en Suisse
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni utilisée
sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie, l’affichage sur
l’internet ou sur un Intranet, sans autorisation écrite préalable. Les demandes d’autorisation peuvent être adressées à l’ISO à
l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – Tous droits réservés

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ISO 10767-1:2015(F)

Sommaire Page
Avant-propos .v
Introduction .vi
1 Domaine d’application . 1
2 Référence normative . 2
3 Termes et définitions . 2
4 Instrumentation . 4
4.1 Mesurages statiques . 4
4.2 Mesurages dynamiques . 4
4.3 Analyse de fréquence de l’onde de pression . 4
5 Installation de la pompe . 5
5.1 Généralités . 5
5.2 Vibration de l’entraînement . 5
5.3 Signal de référence . 5
6 Conditions d’essai et réglage . 5
6.1 Généralités . 5
6.2 Écoulement moyen . 5
6.3 Pression de refoulement moyenne . 6
6.4 Vitesse de l’arbre de la pompe. 6
6.5 Température du fluide . 6
6.6 Propriétés du fluide . 6
7 Montage d’essai . 6
7.1 Généralités . 6
7.2 Pompe d’essai. 6
7.3 Fluide d’essai . 6
7.4 Conduite d’aspiration . 6
7.5 Manomètre à l’aspiration (pour la pression statique) . 7
7.6 Conduite de refoulement de la pompe . 7
7.6.1 Généralités . 7
7.6.2 Raccordement à l’orifice de refoulement de la pompe . 8
7.6.3 Tuyauterie de référence . 8
7.6.4 Tuyauterie de raccordement . 8
7.6.5 Tuyauterie d’extension . 9
7.7 Capteur de pression . 9
7.7.1 Capteur de pression dynamique . 9
7.7.2 Capteur de pression statique . 9
7.8 Soupape de charge . 9
7.9 Soupape de retenue . 9
7.10 Soupape de sûreté . 9
8 Mode opératoire d’essai.10
8.1 Généralités .10
8.2 Analyses de fréquence de l’onde de pression .11
8.3 Évaluation de l’onde d’écoulement de la source, Qs, dans le modèle «Norton» normalisé 11
8.4 Évaluation de l’impédance de la source, Z , dans le modèle «Norton» normalisé .12
s
8.5 Évaluation de l’onde d’écoulement de la source, Q *, dans le modèle modifié .12
s
8.6 Évaluation de la valeur nominale de l’onde de pression acoustique de court-circuit .13
9 Rapport d’essai .13
9.1 Informations générales et conditions d’essai .13
9.2 Résultats d’essai .14
10 Phrase d’identification (Référence à la présente partie de l’ISO 10767) .14
Annexe A (normative) Formulaires d’essai .15
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ISO 10767-1:2015(F)

Annexe B (informative) Méthode des deux pressions/deux systèmes .22
Bibliographie .29
iv © ISO 2015 – Tous droits réservés

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ISO 10767-1:2015(F)

Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www.
iso.org/directives).
L’attention est appelée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www.iso.org/brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer
un engagement.
Pour une explication de la signification des termes et expressions spécifiques de l’ISO liés à
l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion de l’ISO aux principes
de l’OMC concernant les obstacles techniques au commerce (OTC), voir le lien suivant: Avant-propos —
Informations supplémentaires.
Le comité chargé de l’élaboration du présent document est l’ISO/TC 131, Transmissions hydrauliques et
pneumatiques, sous-comité SC 8, Essais des produits.
Cette deuxième édition annule et remplace la première édition (ISO 10767-1:1996), dont elle constitue
une révision technique.
L’ISO 10767 comprend les parties suivantes, présentées sous le titre général Transmissions
hydrauliques — Détermination des niveaux d’onde de pression engendrés dans les circuits et composants:
— Partie 1: Méthode de précision pour les pompes
— Partie 2: Méthode simplifiée pour les pompes
— Partie 3: Méthode pour les moteurs
© ISO 2015 – Tous droits réservés v

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ISO 10767-1:2015(F)

Introduction
La première édition de l’ISO 10767-1, publiée en 1996, a été élaborée en vue d’offrir un moyen de
mesurer (détermination expérimentale) le jeu de deux valeurs caractéristiques composé de l’onde
d’écoulement de la source, Qs, et de l’impédance de la source, Zs, des pompes hydrauliques engendrant
l’onde de pression (vibration transmise par le fluide) dans le circuit de transmissions hydrauliques. Le
mesurage de ces deux valeurs pour une source d’onde donnée est très important pour la conception et
la mise au point de systèmes de transmissions hydrauliques et de pompes à bruit réduit; c’est pourquoi
l’établissement d’une telle Norme internationale traitant de la détermination expérimentale de l’onde
d’écoulement de la source, Qs, et de l’impédance de la source, Zs, répond à un besoin légitime.
Toutefois, comme évoqué dans le paragraphe ci-dessous, la « méthode de la source secondaire »
présentée dans la première édition nécessite le recours à un système d’essai et à une technique de
traitement de signaux extrêmement complexes, ce qui rend sa mise en œuvre particulièrement difficile;
de ce fait, aucun pays, à l’exception du Royaume-Uni, qui est à l’origine de sa proposition, n’a jusqu’ici
adopté l’ISO 10767-1 comme norme nationale.
Cette difficulté peut s’expliquer par ce qui suit.
Pour déterminer les deux valeurs caractéristiques de l’onde d’écoulement de la source Qs et Zs
de l’impédance de la source, on place une source d’onde secondaire dans le circuit d’essai afin
d’engendrer des ondes longue période dans le système d’essai. On commence alors par déterminer les
caractéristiques de fréquence de l’impédance de la source, Zs, provenant de la source secondaire, avant
de mesurer l’onde d’écoulement de la source, Qs, de la pompe d’essai sur la base de la pompe d’essai elle-
même. Cela signifie que le mesurage de l’harmonique de l’onde de pression est réalisé alors que la pompe
d’essai et la source secondaire sont en fonctionnement; par conséquent, la précision de mesurage de la
composante harmonique de la pompe d’essai diminue de façon significative à mesure que l’on approche
du niveau de fréquence harmonique où les différences entre la fréquence harmonique de l’onde de la
pompe d’essai et celle de la source secondaire sont faibles. Pour régler ce problème, on a recours à des
techniques de traitement de signaux extrêmement complexes, comme la compensation, qui s’avèrent
avoir peu d’effet dans la pratique. En outre, cette norme prescrit l’utilisation d’un tiroir rotatif pour la
source secondaire d’ondes longue période (50 Hz~4 kHz), mais ne prévoit aucune disposition en ce qui
concerne les caractéristiques de conception et de fréquence.
Les problèmes résultent tous de la nécessité de la source secondaire, alors que les méthodes proposées
[2] [3]
par Weddfelt et Kojima permettent de mesurer les caractéristiques de l’onde fournie (Qs) et la
source interne (Zs) en se basant uniquement sur l’onde de pression engendrée par la pompe d’essai. Leur
emploi permet de simplifier le système d’essai, et d’obtenir une plus grande précision sans passer par
un traitement complexe des signaux. La méthode basée respectivement sur les approches de Weddfelt
et Kojima, sont identiques dans leur principe, la seule différence entre elles concernant la disposition de
[3]
la tuyauterie. La présente proposition correspond à la méthode proposée par Kojima , tandis que la
[2]
méthode de Weddfelt est incluse en annexe à titre de référence.
vi © ISO 2015 – Tous droits réservés

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NORME INTERNATIONALE ISO 10767-1:2015(F)
Transmissions hydrauliques — Détermination des
niveaux d’onde de pression engendrés dans les circuits
et composants —
Partie 1:
Méthode de détermination de l’onde de flux de la source et
de l’impédance de la source des pompes
1 Domaine d’application
La présente partie de l’ISO 10767 établit un mode opératoire d’essai pour le mesurage de l’onde
d’écoulement de la source et de l’impédance de la source des pompes hydrauliques volumétriques.
Elle s’applique à tous les types de pompes volumétriques fonctionnant dans des conditions de régime
permanent, quelle que soit leur taille, à condition que la fréquence de pompage soit comprise entre
50 Hz et 400 Hz.
L’onde d’écoulement de la source provoque la vibration transmise par le fluide (onde de pression)
puis des bruits aériens émis par les systèmes hydrauliques. Le mode opératoire couvre une gamme
de fréquences et de pressions connues pour provoquer l’émission, par de nombreux circuits, de
bruits aériens constituant une difficulté majeure dans la conception de systèmes de transmissions
hydrauliques. Si l’onde d’écoulement de la source et l’impédance de la source de la pompe de
transmissions hydrauliques sont connues, l’onde de pression engendrée par la pompe dans le système
de transmissions hydrauliques peut être calculée au moyen d’une simulation sur ordinateur, à partir
des caractéristiques connues de propagation d’onde des composants du système. La présente norme
permet ainsi de concevoir des systèmes de transmissions hydrauliques à bruit réduit, en établissant un
mode opératoire uniforme pour le mesurage et la consignation des caractéristiques d’onde d’écoulement
de la source et d’impédance de la source des pompes de transmissions hydrauliques.
Dans la présente partie de l’ISO 10767, le calcul est réalisé pour l’onde de pression acoustique de
court-circuit, qui constitue un exemple d’onde de pression. Une explication de la méthodologie et des
fondements théoriques du mode opératoire d’essai est donnée en Annexe B. Dans ce texte, le mode
opératoire d’essai est appelé méthode des deux pressions/deux systèmes. Les valeurs nominales sont
obtenues sous les formes suivantes:
a) l’amplitude de l’onde d’écoulement de la source (dans le modèle « Norton » normalisé), en
3
mètres cubes par seconde [m /s], et sa phase, en degrés, sur 10 harmoniques individuelles de la
fréquence de pompage;
b) l’amplitude de l’onde d’écoulement de la source (dans le modèle modifié), en mètres cubes par
3
seconde [m /s], et sa phase, en degrés, sur 10 harmoniques individuelles de la fréquence de
pompage, et l’historique de sa forme d’onde;
c) l’amplitude de l’impédance de la source, en Newtons secondes par mètre à la puissance cinq [(Ns)/
5
m ], et sa phase, en degrés, sur 10 harmoniques individuelles de la fréquence de pompage;
6 5
d) l’onde de pression acoustique de court-circuit, en MPa (1 MPa = 10 Pa) ou en bar (1 bar = 10 Pa),
sur dix harmoniques individuelles de la fréquence de pompage, et la moyenne efficace des
harmoniques f à f de l’onde de pression.
1 10
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ISO 10767-1:2015(F)

2 Référence normative
La présente partie de l’ISO 10767 s’applique à tous les types de pompes volumétriques fonctionnant
dans des conditions de régime permanent, quelle que soit leur taille, à condition que la fréquence de
pompage soit comprise entre 50 Hz et 400 Hz.
ISO 5598, Transmissions hydrauliques et pneumatiques — Vocabulaire
3 Termes et définitions
Pour les besoins de la présente partie de l’ISO 10767, les termes et définitions donnés dans l’ISO 5598
ainsi que les suivants s’appliquent.
3.1
onde d’écoulement de la source
composant fluctuant de débit engendré à l’intérieur de la pompe, qui est indépendant des caractéristiques
du circuit relié
Note 1 à l’article: Étant donné qu’il existe deux définitions (voir ci-dessous) pour l’onde d’écoulement de la source
de la pompe, celle-ci doit être clairement identifiée:
— onde d’écoulement de la source dans le modèle «Norton» normalisé, Qs: onde d’écoulement de la source que
l’on suppose implicitement être engendrée au refoulement de la pompe, comme illustré à la Figure 1(a);
— onde d’écoulement de la source dans le modèle «modifié», Qs*: onde d’écoulement de la source que l’on suppose
être engendrée à l’extrémité intérieure de la conduite de refoulement, comme illustré à la Figure 1(b).
Note 2 à l’article: L’onde d’écoulement théorique de la source de la pompe, calculée au moyen d’une simulation sur
ordinateur à partir des dimensions et de la configuration de la pompe, des propriétés physiques du fluide, et des
conditions de fonctionnement correspond à l’onde d’écoulement de la pompe dans le modèle modifié, Qs*.
3.2
onde d’écoulement
composant fluctuant de débit du fluide hydraulique, provoqué par l’interaction entre l’onde d’écoulement
de la source et le système
3.3
onde de pression
composant fluctuant de pression dans le fluide hydraulique, provoqué par l’interaction entre l’onde
d’écoulement de la source et le système
3.4
onde de pression acoustique de court-circuit
onde de pression qui serait engendrée à l’orifice de refoulement de la pompe en cas de refoulement du
fluide dans un circuit d’impédance infinie
3.5
impédance
rapport complexe entre l’onde de pression et l’onde d’écoulement se produisant à un point donné d’un
système hydraulique et à une fréquence donnée
3.6
impédance de la source
impédance d’une pompe à l’orifice de refoulement dans le modèle «Norton» normalisé
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ISO 10767-1:2015(F)

3.7
harmonique
composant sinusoïdal de l’onde de pression ou de l’onde d’écoulement se produisant à un multiple entier
de la fréquence de pompage
Note 1 à l’article: Une harmonique peut être représentée par son amplitude et sa phase, ou bien par ses composants
réel et imaginaire, à condition que pour la présente partie de l’ISO 10767, les composants réel et imaginaire soient
utilisés dans les calculs arithmétiques.
3.8
fréquence de pompage
fréquence donnée par le produit de la fréquence de rotation de l’arbre et le nombre d’éléments de
pompage présents sur cet arbre
Note 1 à l’article: Elle est exprimée en hertz.
3.9
fréquence de rotation de l’arbre
fréquence, en hertz, donnée par la vitesse de rotation de l’arbre, en tours par minute, divisée par 60
Note 1 à l’article: Tous les calculs de l’Article 7 étant effectués à l’aide d’unités SI, l’ensemble des variables et des
constantes doivent être exprimées en unités SI, excepté pour la consignation des résultats finaux.
(a) Modèle «Norton» normalisé
(b) Modèle modifié
Légende
1 passage de refoulement
2 conduit de refoulement
3 sortie de la pompe
Figure 1 — Modélisation de la source de pulsation de la pompe
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ISO 10767-1:2015(F)

4 Instrumentation
4.1 Mesurages statiques
Les instruments utilisés pour mesurer
a) la vitesse de rotation de l’arbre,
b) la pression moyenne,
c) le débit de refoulement moyen et
d) la température du fluide
doivent garder une précision contenue dans les limites spécifiées dans le Tableau 1 tout au long de
chaque essai.
NOTE Les limites en pourcentage s’appliquent à la valeur de la grandeur mesurée et non aux valeurs
maximales de l’essai ou à l’indication maximale de l’instrument.
Tableau 1 — Erreurs admissibles des mesurages statiques
Fréquence de rota-
Écoulement moyen Pression moyenne Température
tion de l’arbre
% % °C
%
± 0,5 ± 2,0 ± 2,0 ± 2,0
4.2 Mesurages dynamiques
Les instruments utilisés pour mesurer l’onde de pression doivent présenter les caractéristiques suivantes:
a) fréquence de résonance ≥ 30 kHz;
b) linéarité ≤ ± 1 %.
Il est inutile que les instruments réagissent à la pression de régime permanent. Il peut être avantageux
de filtrer tout composant de signal de régime permanent en utilisant un filtre passe-haut. Ce filtre ne doit
pas introduire d’amplitude ou d’erreur de phase supplémentaire dépassant 1 % ou 2°, respectivement,
à la fréquence de pompage.
4.3 Analyse de fréquence de l’onde de pression
Un instrument approprié doit être utilisé pour mesurer l’amplitude et la phase d’harmonique (ou
des composants d’harmonique réels et imaginaires) de l’onde de pression, pour des harmoniques
individuelles de la fréquence de pompage jusqu’à 3,5 kHz. L’instrument doit pouvoir mesurer l’onde de
pression depuis deux capteurs de pression simultanément. Les signaux d’onde de pression respectifs
du système 1 et du système 2 doivent être échantillonnés dans un instrument à l’aide du signal de
déclenchement externe provenant d’une référence fixe située sur l’arbre de la pompe.
Cet instrument doit présenter une précision et une résolution conformes à ce qui suit pour les mesurages
d’harmoniques, sur la gamme de fréquences comprise entre 50 Hz et 4 000 Hz:
a) amplitude: ± 1 %;
b) phase: ± 1°;
c) fréquence: ± 0,5 %.
Il est possible d’obtenir cela en utilisant un enregistreur-analyseur de type courant, puis en effectuant
les analyses spectrales en calculant les transformées de Fourier discrètes (TFD) des données historiques
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ISO 10767-1:2015(F)

sur un calculateur numérique de post-traitement. L’Annexe B comporte une explication pratique de
cette méthode d’analyse de fréquence.
NOTE Pour améliorer la précision de la transformation de Fourier, il faut régler minutieusement la
vitesse de la pompe tout en observant le moniteur de l’enregistreur-analyseur, de telle sorte que la pointe de
ème
l’amplitude d’harmonique la plus élevée (par exemple, la 10 ) apparaisse quasiment au niveau de la fréquence
ème
harmonique la plus élevée (par exemple, la 10 ) assignée (c’est-à-dire que si f = 225 Hz, f = 2,25 kHz) de la
1 10
fréquence de pompage.
5 Installation de la pompe
5.1 Généralités
La pompe doit être installée dans la position recommandée par le fabricant, et montée de sorte à
minimiser la réaction du montage à sa vibration.
5.2 Vibration de l’entraînement
Le moteur électrique et l’accouplement d’entraînement associé ne doivent pas engendrer de vibration
torsionnelle de l’arbre de la pompe. Si nécessaire, la pompe et l’unité d’entraînement doivent être isolées
l’une de l’autre pour éliminer la vibration engendrée par le moteur électrique.
5.3 Signal de référence
Un moyen de produire un signal de référence correspondant à la rotation de l’arbre de la pompe doit
être inclus, comme il s’agit d’un des éléments essentiels du mesurage selon la présente partie de
l’ISO 10767. Le signal doit être une impulsion électrique se produisant une fois par tour, et présentant
des flancs montant et descendant bien définis. Ce signal est utilisé comme signal de déclenchement
externe de l’enregistreur-analyseur, ainsi que pour le mesurage de la vitesse de rotation de l’arbre. Un
détecteur magnétique (ou un capteur photo-électrique) constitue un moyen satisfaisant pour fournir
les caractéristiques exigées pour le signal de référence, telles que mentionnées ci-dessus.
6 Conditions d’essai et réglage
6.1 Généralités
La vitesse de l’arbre de la pompe, la pression de refoulement moyenne et la température du fluide sont
réglées sur les valeurs correspondant aux conditions d’essai exigées. Ces conditions de fonctionnement
doivent être conservées, tout au long de chaque essai, dans les limites spécifiées dans le Tableau 2.
Tableau 2 — Écarts admissibles dans les conditions d’essai
Paramètre d’essai Écart admissible
Écoulement moyen ± 2,0 %
Pression moyenne ± 2,0 %
Vitesse de rotation de l’arbre ± 0,5 %
Température ± 2,0 °C
6.2 Écoulement moyen
L’écoulement moyen est mesuré par le débitmètre de type volumétrique installé sur la conduite de
refoulement de la soupape de charge 2.
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ISO 10767-1:2015(F)

6.3 Pression de refoulement moyenne
La pression de refoulement moyenne doit être déterminée pa
...