BS 1807(1981) : 1981

Foreword
Cooperating organizations
Specification
1 Scope
2 References
3 Terminology
4 Basic rack tooth profile
5 Standard normal modules
6 Accuracy requirements for gear blanks
7 Accuracy requirements for gears
8 Accuracy of assembly
Tables
1 Standard normal modules
2 Maximum permitted surface roughness of tooth flanks
3 Tooth contact marking
4 Tooth contact marking after load test
Figures
1 Tandem gear train
2 Dual tandem gear train
3 Split secondary gear train
4 Split primary gear train
5 Epicyclic primary gear train
6 Epicyclic secondary gear train
7 Double epicyclic gear train
8 20 deg pressure angle basic rack tooth profile in
    terms of unit normal metric module
9 16 deg pressure angle basic rack tooth profile in
    terms of unit normal metric module
10 Position of marking on reference surfaces on a wheel
11 Position of marking on reference surfaces on a
    pinion
12 Maximum permissible undulation amplitude
13 Cumulative, short span and single pitch errors
14 Permissible consecutive errors
15 Matching of cumulative pitch errors
16 Base pitch error
17 Profile and alignment errors
18 Permissible backlash
19 Maximum permissible journal errors

Describes tooth forms, modules and accuracy requirements for high-grade gears. Applicable to marine main propulsion gears and similar drives in the range 2 to 25 normal module. Accuracy requirements refer to gears supplied as mating pairs or sets with or without gearbox. Individual gears in isolation are not covered. Four classes of gear are specified, designated Class AO, A1, A2 and A3. Requirements for tooth contact marking following service load test running are included.