BS 436-3:1986

Foreword
Committees responsible
Method
Section one: General
1. Scope and field of application
2. Definitions and symbols
3. Guide to using the calculation procedure
Section two: Contact stress calculations
4. Basic equations for contact stress calculations
5. Nominal tangential force for contact stress, FHt
6. Zone factor for contact stress, ZH
7. Contact ratio factor for contact stress, Z epsilon
8. Elasticity factor for contact stress, ZE
9. Basic endurance limit for contact stress,
     sigma H lim
10. Material quality for contact stress, ZM
11. Lubricant influence, roughness and speed factors
     for contact stress, ZL, ZR and Zv
12. Work hardening factor for contact stress, ZW
13. Size factor for contact stress, ZX
14. Life factor for contact stress, ZN
15. Application factor, KA
16. Dynamic factor, Kv
17. Load distribution factors, KH alpha and KH beta
18. Minimum demanded and actual safety factors on
     contact stress, SHmin and SH
Section three: Bending stress calculations
19. Basic equations for tooth root bending stress
20. Nominal tangential force for bending stress, FFt
21. Geometry factors for bending stress, YF, YS, Y beta
22. Basic endurance limit for bending stress sigma F
     omicron
23. Material quality factor for bending stress, YM
24. Sensitivity factor for bending stress, Y delta
25. Surface condition factor for bending stress, YR
26. Size factor for bending stress, YX
27. Life factor for bending stress, YN
28. Load factors for bending stress, KF alpha and
     KF beta
29. Minimum demanded and actual safety factors on
     tooth root stress, SFmin and SF
Appendices
A. Variable duty calculations
B. Gearing equations
C. Design guidance on tooth modifications
D. Typical residual stresses
E. Tooth and mesh stiffness c' and c gama
F. Definition of material quality
G. Examples of calculations
H. Equations of graphs
Tables
1. Value of ZE for some material combinations
2. Limiting casedepth
3. Values of ZM
4. Values of application factor, KA
5. Examples of prime mover with different working
     characteristics
6. Examples of driven machines with different working
     characteristics
7. Values of X
8. Auxiliary value, A
9. Minimum and maximum values of KH alpha
10. Value of YM
11. Values of p'
12. Default values for contact stress S/N curve
     parameters
13. Typical values of residual stress, sigma R
14. Change in residual stress due to post-hardening
     operations
15. Variable duty calculation example
16. Values of Kv350 beta at discontinuities
17. Kv350 beta termination points
18. Values of Kv350 alpha discontinuities
19. Kv350 alpha termination points
Figures
1. Yield strength for contact stress, sigma HY
2. Values of sigma HD
3. Values of ZG2
4. Casedepth factor, Zc
5. Combined speed and lubricant factors, ZLZv
6. Roughness factor, ZR
7. Values of ZW
8. Life factor for contact stress, ZN
9. Constituent parts of typical gear load
10. Kv350 beta for helical gears, epsilon beta >1
11. Kv350 alpha for spur gears
12. Constant K for calculation of fsh
13. Values of qy
14. Dimensions of the basic rack of the gearing
15. Values of sigma FO
16. Values of YR
17. Values of YX
18. YN for through hardened steel
19. YN for thick case surface hardened steel and
     cast iron
20. YN for thin case surface hardened steel, grey
     cast iron and bronze
21. Typical S/N curve
22. Height and length of end relief
23. Height of crowning

Methods for determining load capacity for spur and helical external and internal gears of accuracy Grade 3 to 10 operating at any pitch line speed.