ISO TR 10686-2013 Hydraulic fluid power - Method to relate the cleanliness of a hydraulic system to the cleanliness of the components and hydraulic fluid that m.pdf

1、 ISO 2013 Hydraulic fluid power Method to relate the cleanliness of a hydraulic system to the cleanliness of the components and hydraulic fluid that make up the system Transmissions hydrauliques Mthode de relation entre propret dun systme hydraulique et propret des composants et du fluide hydrauliqu

2、e qui composent le systme TECHNICAL REPORT ISO/TR 10686 First edition 2013-07-01 Reference number ISO/TR 10686:2013(E) ISO/TR 10686:2013(E)ii ISO 2013 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2013 All rights reserved. Unless otherwise specified, no part of this publication may be reprodu

3、ced 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 ISOs member body in the country of the requester.

4、ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO/TR 10686:2013(E) ISO 2013 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T

5、erms and definitions . 1 4 Symbols and units . 2 5 Basic considerations . 3 5.1 Particulate contamination . 3 5.2 System knowledge requirements 5 6 Prediction from component cleanliness to system cleanliness (the bottom-up approach) 6 6.1 Principles . 6 6.2 Determination of the cleanliness level of

6、a component. 6 6.3 Prediction of cleanliness level of an assembled system 7 6.4 Prediction of cleanliness level of a new system upon its release from the manufacturing area . 7 6.5 Practical predictions 8 7 Specifying the cleanliness requirements from system cleanliness level to component cleanlines

7、s level (the top-down approach) . 9 7.1 Principle 9 7.2 Specification of identical requirements . 9 7.3 Specification of different requirements . 9 8 Relationship between cleanliness levels per unit volume and cleanliness levels per unit surface area.10 8.1 V/A ratio 10 8.2 Impact of surface cleanli

8、ness level on fluid cleanliness level 10 Annex A (informative) Determination of geometrical characteristics of components .11 Annex B (informative) Example of calculation of the cleanliness of an assembled system from the cleanliness of individual components .12 Annex C (informative) Impact of surfa

9、ce cleanliness level on fluid cleanliness level 17 Annex D (informative) Relating volume to surface area .20 Annex E (informative) Relating the cleanliness of parts to the cleanliness of components 21 Bibliography .24 ISO/TR 10686:2013(E) Foreword ISO (the International Organization for Standardizat

10、ion) 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 r

11、epresented 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

12、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

13、 ISO/IEC Directives, Part 2. 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 th

14、e development of the document will be in the Introduction and/or on the ISO list of patent declarations received. 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. The committee responsible for this docu

15、ment is ISO/TC 131, Fluid power systems, Subcommittee SC 6, Contamination control.iv ISO 2013 All rights reserved ISO/TR 10686:2013(E) Introduction The initial cleanliness level of a hydraulic system can affect its performance and useful life. Unless removed, particulate contaminants present after m

16、anufacture and assembly of a system can circulate through the system and cause damage to the systems components. To reduce the probability of such damage, the fluids and the internal surfaces of the hydraulic fluid power system and of its components should be cleaned to a specified level. T he f ina

17、 l clea n l iness level of t he complet e s ys t em c a n be t heoret ic a l ly pred ic t ed a s t he su m of t he pa r t ic u lat e contamination brought in by both the components that make up the system and the filling fluid. As a reciprocal, the required cleanliness level of each individual compo

18、nent and of the filling fluid can be predicted from the required cleanliness level of the final system. This Technical Report explains the theoretical basis for such predictions. ISO 2013 All rights reserved v Hydraulic fluid power Method to relate the cleanliness of a hydraulic system to the cleanl

19、iness of the components and hydraulic fluid that make up the system 1 Scope This Technical Report describes methods that can be used to: relate the cleanliness of a hydraulic system to the cleanliness of its components and the hydraulic fluid belonging to the system; estimate the final cleanliness l

20、evel of an assembled hydraulic system filled with the hydraulic fluid, upon its release from the manufacturing area. The estimation of the final cleanliness level is based on the cleanliness level of each component in the system and on the cleanliness level of the filling fluid; calculate and manage

21、 cleanliness requirements of components and subassemblies that make up a system and of the fluid filling it so as to achieve a required cleanliness level (RCL) for the final system. These methods can apply whatever the particle size considered and can also be used for other types than hydraulic flui

22、d power. 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

23、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. 3.1 wetted surface area A surface area of the component or system that is exposed to the sy

24、stem liquid in normal operation, as agreed between parties Note 1 to entry: Subscripts C or S are added to the symbol A when it refers to the wetted surface area of, respectively, a component or a system. EXAMPLE Consider a hydraulic gear pump with two gears (see Figure 1). The wetted surface area c

25、an be calculated as the sum of the internal surfaces of the pump body (two plates and one flange with two ports) plus the external surface of the two gears. TECHNICAL REPORT ISO/TR 10686:2013(E) ISO 2013 All rights reserved 1 ISO/TR 10686:2013(E) A + + c= Figure 1 Wetted surface of an external gear

26、hydraulic pump 3.2 wetted volume contained volume V volume of a component or system in which the system liquid is to be found in end-use operating conditions, as agreed between parties Note 1 to entry: Subscripts C or S are added to the symbol V when it refers to the wetted volume of, respectively,

27、a component or a system. EXAMPLE Consider a hydraulic gear pump with two gears (see Figure 2). The wetted volume can be calculated as the volume of the body minus the volume of the two gears or measured as the filling volume of the complete pump. V c= Figure 2 Wetted volume of an external gear hydra

28、ulic pump 4 Symbols and units The symbols and units related to the cleanliness of fluids, systems and components used in this Technical Report are given in Table 1. Table 1 Symbols and units Symbol Description or explanation Unit N A Number of particles of a given size introduced during assembly num

29、ber of particles N C Number of particles of a given size in a component number of particles N Ci Number of particles of a given size in component i number of particles N S Number of particles of a given size in an empty system (without fluid) number of particles N F Number of particles of a given si

30、ze in a fluid used to fill system number of particles N SF Number of particles of a given size in a system filled with system fluid number of particles N X Number of particles of a given size in an item X number of particlesa If the relevant particle sizes are those covered in ISO 4406 i.e. 4 m(c),

31、6 m(c), 14 m(c) for automatic counting, 5 m or 15 m for microscopic counting, the cleanliness level can be expressed using the code system specified in ISO 4406.2 ISO 2013 All rights reserved ISO/TR 10686:2013(E) Symbol Description or explanation Unit A C Wetted surface area of a component cm 2 A S

32、Wetted surface area of an empty system (without fluid) cm 2 V C Wetted volume of a component cm 3or ml V Ci Wetted volume of component i cm 3or ml V S Wetted volume of an empty system (without fluid) cm 3or ml V F Volume of fluid used to fill system cm 3or ml V SF Wetted volume of a system upon its

33、release from the manufacturing area cm 3or ml V X Wetted volume of an item cm 3or ml C C Cleanliness level of a component N C/ V C number of particles per cm 3or ml C Ci Cleanliness level of component i number of particles per cm 3or ml C S Cleanliness level of an empty system (without fluid) N S/ V

34、 S number of particles per cm 3or ml C F Cleanliness level of fluid used to fill system N F/ V F number of particles per cm 3or ml a C SF Cleanliness level of a system upon its release from the manufacturing area N SF/ V SF number of particles per cm 3or mla If the relevant particle sizes are those

35、covered in ISO 4406 i.e. 4 m(c), 6 m(c), 14 m(c) for automatic counting, 5 m or 15 m for microscopic counting, the cleanliness level can be expressed using the code system specified in ISO 4406. 5 Basic considerations 5.1 Particulate contamination 5.1.1 Basic principles The physical and chemical pri

36、nciples that explain the presence and the behaviour of particulate contaminants in a hydraulic system are numerous and complex. This subclause covers some basic principles on which this Technical Reports approach to cleanliness is based. 5.1.2 Homogeneity of distribution of contamination in the syst

37、em In the absence of a system or flushing filter when the system is operated for the first time and stabilized, particulate contaminants are considered to be distributed homogeneously in the whole system, i.e. particulate contamination is in the fluid everywhere in the components and the system and

38、on the wetted surfaces of the components. This assumes that all of the fluid and all the surfaces on which it flows are at the same cleanliness level. 5.1.3 Actual location of contaminants in items and fluid Particulate contaminants are either deposited on the surface area of the components or suspe

39、nded in the hydraulic fluid (see Figure 3). Even if particles are deposited on the entire surface of a component, only those deposited on the wetted surface are taken into consideration because they are the only ones likely to move into the fluid and potentially to damage the system.Table 1 (continu

40、ed) ISO 2013 All rights reserved 3 ISO/TR 10686:2013(E) 5.1.4 Theoretical location of contaminants in items To apply the cleanliness prediction method described in this Technical Report, it is necessary to consider that the particulate contaminants deposited on the wetted surface areas of hollow com

41、ponents and assemblies are in suspension in the void volume of the items see Figure 3 b). This concept applies because only particulate contaminants moving from the surface of the component into the hydraulic fluid add to the fluid contamination and become capable of damaging the system. a) Actual s

42、ituation Contaminants on the sur- face b) Cleanliness concept Contaminants in the volume Figure 3 Concept of cleanliness per unit volume The cleanliness level of hollow components, subassemblies and systems can be compared to the cleanliness level of fluids. 5.1.5 Overall cleanliness approach 5.1.5.

43、1 Cleanliness level of assembled components In the majority of hydraulic circuit configurations, the following statements apply. When components are assembled in subassemblies and when subassemblies are assembled in a system, the numbers of their contaminant particles are summed and their wetted vol

44、umes are also summed. The cleanliness level of an empty assembled system not yet filled with fluid is the ratio of the sum of the numbers of contaminant particles in or on each component to the sum of the wetted volume of all components. The cleanliness level of an empty assembled system is neither

45、the sum nor the average of the cleanliness levels of the components it is made of. See Table 2 for an illustration of these concepts.4 ISO 2013 All rights reserved ISO/TR 10686:2013(E) Table 2 Illustration of how cleanliness levels can and cannot be used in calculations Item Number (N i ) of con- ta

46、minant particles Volume, V i Cleanliness level, C i ml N/ml Component 1: 5 10 5/10 = 0,5 Component 2: 5 2 5/2 = 2,5 Component 3: 2 1 2/1 = 2 Assembly 4: N 4= N i N 4= 12 V 4= V i V 4= 13 C 4= N i/ V i 12/13 = 0,92Note C 4 C 1+ C 2+ C 3and C 4 (C 1+ C 2+ C 3 ) / 3 5.1.5.2 Cleanliness level of items f

47、illed with fluid When a hollow item of volume V Xcontaminated with N Xparticles of a given size per ml is fully filled in with a fluid contaminated with N Fparticles of the same size per ml, the resulting cleanliness level of the item filled with fluid is (N X+ N F ) / V F . 5.2 System knowledge req

48、uirements 5.2.1 System structure It is necessary to know precisely the components located upstream and downstream of the component being considered, as well as the subassembly the components are part of and the whole system the subassemblies are part of. It is necessary to know how to manage the cle

49、anliness of each part (i.e. make items cleaner to allow a relaxation in the cleanliness of other items), so that the overall cleanliness complies with the RCL. 5.2.2 Geometrical characteristics 5.2.2.1 Wetted volume (V X ) The wetted volume of the item can be either measured experimentally or calculated using computerised engineering drawing tools or from the ratio V/A of the complete system. See Annex A for further details. 5.2.2.2 Wetted surface area (A X ) The wetted surface ar