From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Technical document detailing the principles and calculations for Lap Windings.
| Identifier | ExFiles\Box 68\4\ scan0169 | |
| Date | 15th February 1916 | |
| (3) (2) Lap Windings Let number of conductors = n " " " poles = p Then both n and p must be even. The forward and backward pitches z1 and z2 must both be odd, and must differ by 2. Hence the mean pitch must be even. or z = 2k z₁ = 2K + 1 z₂ = 2K - 1 The mean pitch must be approximately the number of conductors divided by the number of poles i.e. n/p. If this quotient is not a whole even number the nearest whole even number to the result may be taken as the pitch z. Mean pitches of z - 2, z - 4, or z - 6 etc. may be used according to the extent of "short-chording" allowable. Example 1. n = 110, p = 6 n/p = 18 1/3, z = 18 z₁ = 19, z₂ = 17 or z₁ = 17, z₂ = 19. Example 2. R.R. S.S. Motor Armature. n = 96 p = 4 z = 24 z₁ = 25, z₂ = 23. Example 3. R.R. Speedometer Magnets Armature. | ||