| 摘要 |
<p>584,831. A.C. commutator machines. BRITISH THOMSONHOUSTON CO., Ltd., and MAGGS, A. H. Jan. 26, 1945, No. 2120. [Class 35] In a variable speed A.C. commutator motor having an unbalanced polyphase stator winding producing an elliptical rotating field, the speed variation is achieved by movement of the axis of the shortcircuited brushes. In a two-phase motor, Fig. 1, the main phase 5 has fewer turns of heavier wire than phase 6 so that the flux has major and minor axes 10, 11 respectively. Movement of the brushes 2, 3 from the major towards the minor axis reduces the speed through synchronism. In Fig. 3 (not shown) a three-phase modification is shown in which the unbalanced phase is coincident with the minor axis and has an increased number of turns.</p> |
