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).
The mathematical formulas and principles for armature wave windings.
| Identifier | ExFiles\Box 68\4\ scan0167 | |
| Date | 9th October 1918 | |
| EFC/L.9.10.18. ARMATURE WINDINGS. (1) Wave Windings. Let number of conductors = n (virtual) " " " poles = p Then both n and p must be even. In n ± 2 conductors there must be p steps. (+ means progressive) (- means retrogressive) Hence pitch z = (n ± 2) / p The pitch must be odd. Hence (n ± 2) / p = 2k + 1 where k is an integer representing step of winding. n ± 2 = (2K + 1)p n = (2K + 1)p ∓ 2. (-means progressive) (+means retrogressive) z = 2k + 1 No of coils = n/2 = (2K + 1) p/2 ∓ 1 (so must be odd for 4 pole machine. If with 4 pole machine, winding is retrogressive n/2 = 4(k+1) - 1 contd. | ||