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).
Analysis and comparison of different armature designs based on core losses and volt excitation curves.
| Identifier | ExFiles\Box 34\3\ Scan124 | |
| Date | 15th May 1916 | |
| -10- From the foregoing, we deduce the following: As regards core losses pure and simple there is not much to choose between the wound armatures. The 24 slot wire wound armature would seem to have rather smaller eddy current losses in the conductors. Both the unwound armatures have greater hysteresis losses than similar wound armatures, due to either the difference of material or construction. Considering the complete armatures, it appears that of these the 45 slot is the best, the 24 slot a near equal, and the 17 slot a bad one. But 17A is better than 17B for some unexplained reason. This order 45, 24, 17A, 17B, is borne out by the volt excitation. curves, when the number of conductors is taken into account, (see flux figures on page 8). (We took a volt excitation curve of 17B, and it came somewhat lower than that for 17A). It is borne out again by the volt excitation curves which we took with standard brushes, which lay above one another in exactly this order. And it is still further borne out to by the curves of brush-short- circuited currents. With reference to Mr. Royce's memo R1/IB24315, we could carry out experiment there suggested, of allowing armature to generate current and measuring power to drive, and electrical power delivered, for the three (Contd) | ||