1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58ICS 21.200Bevel gears ISO system of accuracyBRITISH STANDARDBS ISO 17485:2006BS ISO 17485:2006This
2、British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2006 BSI 2006ISBN 0 580 48576 5Cross-referencesThe British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the sectio
3、n entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Comp
4、liance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 32, an inside back cover and a back cover.The BSI copyright notice displa
5、yed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this subcommittee can be obtained on request to its secretary. present to the responsible international/European committee any enquiries on
6、 the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 17485:2006 and implements it as the UK national standard. The UK particip
7、ation in its preparation was entrusted by Technical Committee MCE/5, Gears, to Subcommittee MCE/5/-/2, Gear accuracy, which has the responsibility to: aid enquirers to understand the text;Reference numberISO 17485:2006(E)INTERNATIONAL STANDARD ISO17485First edition2006-06-15Bevel gears ISO system of
8、 accuracy Engrenages coniques Systme ISO dexactitude BS ISO 17485:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 2 3 Terms, definitions and symbols 2 3.1 Terms and definitions. 2 3.2 Fundamental terms and symbols 6 4 Application of classification system. 7 4.
9、1 General. 7 4.2 Accuracy grade classification . 7 4.3 Tolerance direction. 8 4.4 Additional characteristics 8 5 Tolerances . 8 5.1 Tolerance values. 8 5.2 Step factor . 8 5.3 Rounding rules 9 5.4 Tolerance equations. 9 6 Application of measuring methods. 11 6.1 Methods of measurement 11 6.2 Recomme
10、nded measurement control methods 12 6.3 Measurement data filtering 12 6.4 Tooth contact pattern inspections 12 Annex A (informative) Example tolerance tables 14 Annex B (informative) Single-flank composite measuring method 16 Annex C (informative) Accuracy of small module bevel gears 21 Annex D (inf
11、ormative) Interpretation of composite data 24 Bibliography . 32 BS ISO 17485:2006iv 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 thro
12、ugh 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 collabor
13、ates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standa
14、rds. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of t
15、his document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 17485 was prepared by Technical Committee ISO/TC 60, Gears. BS ISO 17485:2006vIntroduction The measurement and tolerance specification of bevel gears are very comple
16、x subjects that were in need of international standardization. For these and other reasons, ISO/TC 60 approved the project based on a proposed document, ANSI/AGMA 2009-B01, Bevel Gear Classification, Tolerances, and Measuring Methods. At an early stage it was decided to develop two documents: this I
17、nternational Standard, with accuracy grades and definitions, and a separate Technical Report, ISO/TR 10064-6, containing inspection practice and measuring methods. These practices and measuring methods include topics such as manufacturing considerations, CMM measurements, contact pattern checking, a
18、nd advanced topics such as bevel gear flank form analysis. Prior to the development of this International Standard, the accuracy grades described in ISO 1328, for cylindrical gears, were often used for bevel gears. However, this use was not always consistent with the specific requirements and genera
19、l practices followed within the bevel gear industry. This International Standard contains items that are distinctly different from ISO 1328-1:1995: the definitions, tolerance diameter and measuring directions are specifically for bevel gears; accuracy grade tolerances are based on equations and not
20、on tables; there is approximately one grade difference in tolerance level between bevel and cylindrical gears, similar to that used by the DIN system of tolerances. The use of the definitions and accuracy grades within this International Standard should improve the consistent application of bevel ge
21、ar geometrical tolerances for the general benefit of industry. BS ISO 17485:2006blank1Bevel gears ISO system of accuracy 1 Scope This International Standard establishes a classification system that can be used to communicate geometrical accuracy specifications of unassembled bevel gears, hypoid gear
22、s, and gear pairs. It defines gear tooth accuracy terms and specifies the structure of the gear accuracy grade system and allowable values. This International Standard provides the gear manufacturer and the gear buyer with a mutually advantageous reference for uniform tolerances. Ten accuracy grades
23、 are defined, numbered 2 to 11 in order of decreasing precision. Equations for tolerances and their ranges of validity are provided in 5.4 for the defined accuracy of gearing. In general, these tolerances cover the following ranges: 1,0 mm u mmnu 50 mm 5 u z u 400 5 mm u dTu 2 500 mm where dTis the
24、tolerance diameter; mmnis the mean normal module; z is the number of teeth. See Clause 6 for required and optional measuring methods. As tolerances are calculated from the actual dimensions of a bevel gear, tolerance tables are not provided. In order to provide an overview, example values of toleran
25、ces and graphs are given in Annex A. This International Standard does not apply to enclosed gear unit assemblies, including speed reducers or increasers, gear motors, shaft mounted reducers, high speed units, or other enclosed gear units manufactured for a given power, speed, ratio or application. G
26、ear design is beyond the scope of this International Standard. The use of the accuracy grades for the determination of gear performance requires extensive experience with specific applications. Therefore, the users of this International Standard are cautioned against the direct application of tolera
27、nce values to a projected performance of unassembled (loose) gears when they are assembled. Tolerance values for gears outside the limits stated in this International Standard will need to be established by determining the specific application requirements. This could require the setting of a tolera
28、nce other than that calculated by the formulas in this International Standard. BS ISO 17485:20062 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest
29、 edition of the referenced document (including any amendments) applies. ISO 1122-1:1998, Vocabulary of gear terms Part 1: Definitions related to geometry ISO 235091), Bevel and hypoid gear geometry 3 Terms, definitions and symbols For the purposes of this document, the terms and definitions given in
30、 ISO 1122-1, ISO 23509 and the following terms, definitions and symbols apply. Some of the symbols and terminology contained in this document could differ from those used in other documents and standards. Users of this International Standard should assure themselves that they are using the symbols,
31、terminology and definitions in the manner indicated herein. 3.1 Terms and definitions 3.1.1 index deviation Fxdisplacement of any tooth flank from its theoretical position, relative to a datum tooth flank 3.1.2 mean normal module mmnratio of the mean pitch diameter in millimetres to the number of te
32、eth in a normal plane at the mean cone distance mmmn m et mecos cosdRmmzR = (1) where dmis the mean pitch diameter, z is the number of teeth, mis the mean spiral angle, Rmis the mean cone distance, Reis the outer cone distance, and metis the outer transverse module 3.1.3 reference gear gear of known
33、 accuracy that is designed specifically to mesh with the gear to be inspected for composite deviation and contact marking tests 1) To be published. BS ISO 17485:200633.1.4 total runout deviation Frdifference between the maximum and minimum distance perpendicular to the pitch cone, of a probe (ball o
34、r cone) placed successively in each tooth space, with the probe contacting both the right and left flanks at the tolerance circle approximately mid tooth-depth NOTE Tolerances are provided in 5.4.4. 3.1.5 tooth mesh component single-flank composite deviation fisvalue of the greatest single-flank com
35、posite deviation over any one pitch (360/z), after removal of the long-term component (sinusoidal effect of eccentricity), during a single-flank composite test, when the wheel is moved through one revolution NOTE This International Standard specifies the tolerance direction for tooth mesh component
36、single-flank composite deviation to be along the arc of the tolerance diameter circle in a transverse section. Tolerances are provided in 5.4.5. 3.1.6 total single-flank composite deviation Fistotal deviation, measured from minimum to maximum, during a single-flank composite test, when the wheel is
37、moved through one revolution NOTE This International Standard specifies the tolerance direction for total single-flank composite deviation to be along the arc of the tolerance diameter circle in a transverse section. See Annex B. Tolerances are provided in 5.4.6. 3.1.7 single pitch deviation fptdisp
38、lacement of any tooth flank from its theoretical position relative to the corresponding flank of an adjacent tooth, measured by a probe from a point on a flank, to a point on the adjacent flank, on the same measurement circle See Figure 1. NOTE 1 Distinction is made as to the algebraic sign of the m
39、easured value. Thus, a condition wherein the actual tooth flank position was nearer to the adjacent tooth flank than the theoretical position would be considered a minus () deviation. A condition wherein the actual tooth flank position was farther from the adjacent tooth flank than the theoretical p
40、osition would be considered a plus (+) deviation. NOTE 2 This International Standard specifies the tolerance direction of measurement for single pitch deviation to be along the arc of the tolerance diameter circle in the transverse section. Tolerances are provided in 5.4.2. BS ISO 17485:20064 Key 1
41、theoretical tooth flank position 2 actual tooth flank position 3 theoretical circular pitch 4 measurement circle Figure 1 Pitch deviations 3.1.8 tolerance diameter dTdiameter where the mean cone distance, Rm, and the midpoint of the working depth intersect See Figure 2. NOTE The midpoint of the mean
42、 working depth is one half the depth of engagement of the two gears at the mean cone distance. The value of dTcan be determined by Equations (2) or (3). ( ) ( )T1 m1 mw am2 1 m1 am1 am2 120,5 cos cosdd h h d h h =+ =+ (2) ( ) ( )T2 m2 mw am2 2 m2 am2 am1 220,5 cos cosdd h h d h h = =+ (3) where dm1,
43、 2is the mean pitch diameter (pinion, wheel); hmwis the mean working depth; ham1, 2is the mean addendum; 1, 2is the pitch angle (pinion, wheel). These values can be obtained from manufacturing summary sheets or by calculations shown in ISO 10300 or in ISO 23509. BS ISO 17485:20065Figure 2 Tolerance
44、diameter 3.1.9 total cumulative pitch deviation Fplargest algebraic difference between any two index deviation values for a specified flank (left or right), without distinction as to the direction or algebraic sign of this reading See Figure 3. NOTE This International Standard specifies the toleranc
45、e direction of for total cumulative pitch deviation to be along the arc of the tolerance diameter circle in the transverse section. Tolerances are provided in 5.4.2. Fx= index deviation fpt = single pitch deviation Fp = total cumulative pitch deviation z = tooth number Figure 3 Pitch data from singl
46、e probe device BS ISO 17485:20066 3.1.10 transmission error edeviation of the position of the driven gear, for a given angular position of the driving gear, from the position that the driven gear would occupy if the gears were geometrically perfect NOTE See Annex B for discussion of transmission err
47、or and single flank composite deviations. 3.2 Fundamental terms and symbols The terminology and symbols used in this International Standard are listed alphabetically by symbol in Table 1, and alphabetically by term in Table 2. To convey the maximum amount of information, however, the names of a numb
48、er terms have been rearranged in order to group principle characteristics. Table 1 Alphabetical table of symbols, by symbol Symbol Term Where first used (clause/subclause/figure) dm1, 2Mean pitch diameter (pinion or wheel) 3.1.8 dTTolerance diameter 1 FisSingle-flank composite deviation, total 3.1.6
49、 FisTSingle-flank composite tolerance, total 5.4.6 FpCumulative pitch deviation, total 3.1.9 FpTCumulative pitch tolerance, total 5.4.3 FrRunout deviation, total 3.1.4 FrTRunout tolerance 5.4.4 FxIndex deviation 3.1.1 fisSingle-flank composite deviation, tooth mesh component 3.1.6 fis(design)Single-flank composite deviation, design tooth mesh component 5.4.5 fisTSingle-flank composite tolerance, tooth mesh component 5.4.5 fptSingle pitch deviation 3.1.7 fptTSingle pitch tolerance 5.4.2 hamAddendum, mean
