Foreword

Introduction

1Scope

2Normative references

3Terms and definitions

3.1Terms and definitions

3.2Symbols and units

4Scuffing and wear

4.1Occurrence of scuffing and wear

4.2Transition diagram

4.3Friction at incipient scuffing

5Basic formulae

5.1Contact temperature

5.2Flash temperature formula

5.3Transverse unit load

5.4Distribution of overall bulk temperatures

5.5Rough approximation of a bulk temperature

6Coefficient of friction

6.1General

6.2Mean coefficient of friction, method A

6.3Mean coefficient of friction, method B

6.4Mean coefficient of friction, method C

7Parameter on the line of action

8Approach factor

9Load sharing factor, X

9.1General

9.2Spur gears with unmodified profiles

9.3Spur gears with profile modification

9.4Buttressing factor, X

9.5Helical gears with ε ≤ 0,8 and unmodified profiles

9.6Helical gears with ε ≤ 0,8 and profile modification

9.7Helical gears with ε ≥ 1,2 and unmodified profiles

9.8Helical gears with ε ≥ 1,2 and profile modification

9.9Helical gears with 0,8 < ε < 1,2

10Scuffing temperature and safety

10.1Scuffing temperature

10.2Structural factor

10.3Contact exposure time

10.4Scuffing temperature in gear tests

10.5Safety range

Annex AFlash temperature formula presentation (informative)

A.1General

A.2General case

A.3Cylindrical gears

A.4Thermo-elastic factor

Annex BOptimal profile modification (informative)

Bibliography