BS ISO 6336-3:2019
$198.66
Calculation of load capacity of spur and helical gears – Calculation of tooth bending strength
| Published By | Publication Date | Number of Pages |
| BSI | 2019 | 66 |
This document specifies the fundamental formulae for use in tooth bending stress calculations for involute external or internal spur and helical gears with a rim thickness sR > 0,5 ht for external gears and sR > 1,75 mn for internal gears. In service, internal gears can experience failure modes other than tooth bending fatigue, i.e. fractures starting at the root diameter and progressing radially outward. This document does not provide adequate safety against failure modes other than tooth bending fatigue. All load influences on the tooth root stress are included in so far as they are the result of loads transmitted by the gears and in so far as they can be evaluated quantitatively.
This document includes procedures based on testing and theoretical studies such as those of Hirt[ 11], Strasser[ 14] and Brossmann[ 10]. The results are in good agreement with other methods (References [5], [6], [7] and [12]). The given formulae are valid for spur and helical gears with tooth profiles in accordance with the basic rack standardized in ISO 53. They can also be used for teeth conjugate to other basic racks if the virtual contact ratio ??n is less than 2,5.
The load capacity determined on the basis of permissible bending stress is termed “tooth bending strength”. The results are in good agreement with other methods for the range, as indicated in the scope of ISO 6336-1.
If this scope does not apply, refer to ISO 6336-1:2019, Clause 4.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 7 | Foreword |
| 8 | Introduction |
| 11 | 1 Scope 2 Normative references |
| 12 | 3 Terms, definitions, symbols and abbreviated terms 3.1 Terms and definitions 3.2 Symbols and abbreviated terms |
| 17 | 4 Tooth breakage and safety factors 5 Basic formulae 5.1 General |
| 18 | 5.2 Safety factor for bending strength (safety against tooth breakage), SF 5.3 Tooth root stress, σF 5.3.1 General 5.3.2 Method A 5.3.3 Method B |
| 20 | 5.4 Permissible bending stress, σFP 5.4.1 General 5.4.2 Methods for determination of permissible bending stress, σFP — Principles, assumptions and application |
| 21 | 5.4.3 Permissible bending stress, σFP: Method B |
| 22 | 5.4.4 Permissible bending stress, σFP, for limited and long life: Method B |
| 24 | 6 Form factor, YF 6.1 General |
| 25 | 6.2 Calculation of the form factor, YF: Method B 6.2.1 General |
| 27 | 6.2.2 Parameters of virtual gears |
| 28 | 6.2.3 Tooth root normal chord, sFn, radius of root fillet, ρF, bending moment arm, hFe for external gears generated with a hob |
| 29 | 6.2.4 Tooth root normal chord, sFn , radius of root fillet, ρF , bending moment arm, hFe for external gears generated with a shaper cutter2) |
| 34 | 6.2.5 Tooth root normal chord, sFn, radius of root fillet, ρF, bending moment arm, hFe for internal gears generated with a shaper cutter2) 7 Stress correction factor, YS 7.1 Basic uses 7.2 Stress correction factor, YS: Method B |
| 35 | 7.3 Stress correction factor for gears with notches in fillets 7.4 Stress correction factor, YST, relevant to the dimensions of the standard reference test gears |
| 36 | 8 Helix angle factor, Yβ 8.1 General 8.2 Graphical value 8.3 Determination by calculation |
| 37 | 9 Rim thickness factor, YB 9.1 General 9.2 Graphical values 9.3 Determination by calculation 9.3.1 External gears |
| 38 | 9.3.2 Internal gears 10 Deep tooth factor, YDT 10.1 General 10.2 Graphical values |
| 39 | 10.3 Determination by calculation 11 Reference stress for bending 11.1 General 11.2 Reference stress for Method A 11.3 Reference stress, with values σF lim and σFE for Method B 12 Life factor, YNT 12.1 General |
| 40 | 12.2 Life factor, YNT: Method A 12.3 Life factor, YNT: Method B 12.3.1 General 12.3.2 Graphical values |
| 41 | 12.3.3 Determination by calculation |
| 42 | 13 Notch sensitivity factor, YδT, and relative notch sensitivity factor, Yδ rel T 13.1 Basic uses 13.2 Determination of the notch sensitivity factors 13.2.1 General 13.2.2 Method A 13.2.3 Method B 13.3 Relative notch sensitivity factor, Yδ rel T: Method B 13.3.1 Graphical values |
| 43 | 13.3.2 Determination by calculation |
| 48 | 14 Surface factors, YR, YRT, and relative surface factor, YR rel T 14.1 Influence of surface condition |
| 49 | 14.2 Determination of surface factors and relative surface factors 14.2.1 General 14.2.2 Method A 14.2.3 Method B 14.3 Relative surface factor, YR rel T: Method B 14.3.1 Graphical values |
| 50 | 14.3.2 Determination by calculation |
| 51 | 15 Size factor, YX 15.1 General 15.2 Size factor, YX: Method A 15.3 Size factor, YX: Method B 15.3.1 General 15.3.2 Graphical values for reference stress and static stress |
| 52 | 15.3.3 Determination by calculation |
| 54 | Annex A (normative) Permissible bending stress, σFP, obtained from notched, flat or plain polished test pieces |
| 62 | Annex B (informative) Guide values for mean stress influence factor, YM |
| 64 | Annex C (informative) Derivations of determinant normal tooth load of spur gears |
| 65 | Bibliography |
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