JPS55160964A - Dc motor - Google Patents

Abstract

PURPOSE:To dispense with a commutator and to enable stable rotation with no torque fluctuation, by making one torque of an armature having a toroidal conductor, much smaller than the other torque. CONSTITUTION:A dense winding 112 is provided around an annular core 111. Intervals 111a are almost regularly provided between the portions of the winding 112 so that the width of each interval increases outward. The first magnetic flux guide passages 113 are provided on the intervals. The annular second magnetic guide passage 114 is provided around the first guide passages. Air gaps 116 are thus assured. The field flux B1 of a magnet 124 is conducted through a closed circuit comprising an armature 110, the guide passages 113, 114 and the magnet 124. Similar conduction is also effected as to another magnet 125. When a current is caused to flow through the winding 112 in the direction of an arrow, the magnetic fluxes B1, B2 intersect the winding on both the top and bottom of the core 111 but hardly intersect the winding on the right side 111k because the gap is large and on the left side 111n because the magnetic fluxes proceed toward the guide passages 113, 114. For this reason, one torque is much larger than the other and stable rotation is enabled.