BSISO21771-1:2024 BSl Standards Publication Cylindrical involute gears and gear pairs Part1:Concepts andgeometry bsi.
BS ISO 21771-1:2024 International ISO Standard ISO21771-1 Cylindricalinvolutegearsand Firstedition gear pairs -- 2024-10 Part 1: Conceptsandgeometry Rouesetengrenagescylindriquesendeveloppantedecercle- Partie1:Conceptsetgeometrie Referencenumber ISO 21771-1:2024(en) ISO 2024
BSISO21771-1:2024 ISO 21771-1:2024(en) COPYRIGHTPROTECTEDDOCUMENT ISO 2024 All rightsreserved.Unlessotherwisespecifiedorrequiredinthecontextof isimplementationopartf thispublicationmay 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. ISOcopyright office CP401Ch.de Blandonnet 8 CH-1214 Vernier Geneva Phone: 41 22 749 01 11 Email:copyright@iso.org Website:.iso.org Published in Switzerland ISO 2024 All rights reserved ii
BSISO21771-1:2024 ISO 21771-1:2024(en) Contents Page Foreword. vii 1 Scope. 1 2 Normativereferences. 1 3 Terms definitionssymbols subscriptsandunit 1 3.1 Terms and definitions. .1 3.2 Symbols. 2 3.3 Subscripts. ..9 3.4 Units and conventions... 10 3.4.1 Units. 10 3.4.2 Conventions. 10 Individual cylindricalgears. 10 4.1 General. 10 4.2 Conceptsforanindividualgear. 11 4.2.1 Gear cylindricalgear externalgearandinternalgear. 11 4.2.2 Toothsystem externaltethandinternalteeth. 11 4.2.3 Tooth and tooth space. 11 4.2.4 Tooth system parameters. 11 4.2.5 Number of teeth and signof number of teeth. 11 4.2.6 Tooth number. 12 4.2.7 Topland and bottomland. 12 4.2.8 Tooth flanks and flank sections. 12 4.3 Reference surfaces datumlines andreferencequantities. 13 4.3.1 Reference surface and datumface. 13 4.3.2 Referencerack. 13 4.3.3 Basicracktoothprofileforinvolutegear teeth. 14 4.3.4 Reference cylinder reference circle and reference diameter. 15 4.3.5 Gear axis. 15 4.3.6 Sections through a cylindrical gear. 15 4.3.7 Module. 16 4.3.8 Diametral pitch. 16 4.3.9 Facewidth. 16 4.3.10 Profilehiftrofilehiftcoefficientandsigfprofileshf. .17 4.4 Involutehelicoids. 18 4.4.1 Generatorofinvolute helicoids. 18 4.4.2 Base cylinder base circle and base diameter. 19 4.4.3 Transverse pressure angleat apoint and transverse pressure angle. 19 4.4.4 20 4.4.5 Involute function. 20 4.4.6 Lead.. .21 4.4.7 Helix angle and lead angle.. 21 4.4.8 Hand of helix. 22 4.4.9 Roll angleof the involute.. 23 4.4.10 Radiusof curvature of theinvolute andlengthof roll. Lengthfinvlprofl 23 4.4.11 23 4.5 Angular pitch and pitches. 23 4.5.1 Angular pitch. 23 4.5.2 Pitches on the reference cylinder. 23 4.5.3 Pitches on any cylinder.. .24 4.5.4 Axial pitch. 25 4.5.5 Base pitch. 25 4.6 Diameters of gearteeth. 25 4.6.1 General 25 4.6.2 V-cylinder andV-circle diameter. 26 4.6.3 y-cylinder andy-circle diameter. 26 ISO 2024 A1l rights reserved i
BSISO21771-1:2024 ISO 21771-1:2024(en) 4.6.4 Tip alteration coefficient. 26 4.6.5 Tipcylinder tipcircle andtipdiameter. 26 4.6.6 Profilecontroldiameter d 26 4.6.7 Root cylinder root circle androot diameter. 26 4.7 Gear tooth depth.. .27 4.7.1 Tooth depth. 27 4.7.2 Addendum working addendum dedendum and working dedendum. .27 4.8 Tooth thickness and space width. 27 4.8.1 General. .27 4.8.2 Transverse tooth thickness. .27 4.8.3 Transverse tooth thickness half angle. 28 4.8.4 Transverse space width. 29 4.8.5 Transversespacewidth half angle. 29 4.8.6 Normal tooth thickness. 29 4.8.7 Normal spacewidth.. 29 4.9 Radi of curvature of the tooth flanks in different planes. 30 4.10 Tilt angle of contact line. .31 5 Parallel axiscylindricalgear pairs. 32 5.1 General. .32 5.2 Concepts fora gear pair. .32 5.2.1 Matinggearandmatingflank. .32 5.2.2 Workingflankand non-workingflank. .32 5.2.3 External gear pair. 32 5.2.4 Internalgear pair. 33 5.3 Mating quantities. 33 5.3.1 Gearratio 33 5.3.2 Driving gear driven gear and transmissionratio. 33 5.3.3 Lineof centres and centre distance. 33 5.3.4 Working transverse pressure angle.. 34 5.3.5 Workingitchpoint pitchcyliners pitchcirclespitchdiameterandpitchaxis. 34 5.3.6 Workinghelix angles. 36 5.3.7 Working depth. 36 5.3.8 Tip clearance.. 36 5.3.9 Calculation of tipalterationcoefficientk(forparallelaxisgear) 37 5.4 Calculation of thesum of theprofile shiftcoefficients. 38 5.5 Tooth engagement. 38 5.5.1 General. 38 5.5.2 Active area of the toothflanks start of active profile and active tip diameters. 38 5.5.3 Plane of action zoneof actionandcontact line 40 5.5.4 Lineofaction pathofcontactandpointofcontat. 41 5.5.5 Form over dimension. 41 5.5.6 Designations andvaluesrelating to theline of action. 41 5.5.7 Radii of curvature of the toothflanksin a transverseplane. 42 5.5.8 Tooth interference.. 43 5.5.9 Meshgeometry parameters. 45 5.5.10 Contactlineandsumof the contact linelengths. 47 5.6 Backlash. 49 5.6.1 General. 49 5.6.2 Transverse backlash 49 5.6.3 Circumferential backlash. 49 5.6.4 Normal backlash. 49 5.6.5 Radial backlash. 50 5.6.6 Angular backlash 50 5.7 Velocities andslidingconditions at thetoothflanks. 51 5.7.1 Angular velocity. 51 5.7.2 Circumferential velocity. 51 5.7.3 Normal velocity 51 5.7.4 Rolling velocity. .52 ISO 2024 All rights reserved iv
英文原版 BS ISO 21771-1-2024 圆柱渐开线齿轮和齿轮对 第一部分 概念和几何.pdf
