Patent ID: 8487499
Filing Date: 2013-07-16
Classification: H02K

Abstract:
1. An electric rotating machine comprising: a stator including a hollow cylindrical stator core and a stator coil, the stator core having a plurality of stator core teeth that are formed at a predetermined pitch in a circumferential direction of the stator core, the stator coil having three terminals via which three-phase AC current is input to or output from the stator coil; and a rotor disposed radially inside of the stator core, the rotor having a plurality of magnetic poles the polarities of which alternate between north and south in the circumferential direction of the stator core, wherein the number of the stator core teeth is equal to 12×n, and the number of the magnetic poles of the rotor is equal to 10×n or 14×n, where n is a natural number, the stator coil is comprised of first and second winding groups, the first winding group including 2×n X-phase windings, 2×n Y-phase windings, and 2×n Z-phase windings, the second winding group including 2×n U-phase windings, 2×n V-phase windings, and 2×n W-phase windings, each of the windings of the first and second winding groups includes a first section and a second section, the stator coil is wound around the stator core in a concentrated winding manner so that each of the first and second sections of the windings of the first and second winding groups is wound around a corresponding one of the stator core teeth, for each of the windings of the first and second winding groups, the first and second sections of the winding are wound in opposite directions, the windings of the first and second winding groups are connected to form 2×n Δ-Y connections that are arranged one after another in the circumferential direction of the stator core, each of the Δ-Y connections is formed of six different-phase windings including one X-phase winding, one Y-phase winding, and one Z-phase winding of the first winding group and one U-phase winding, one V-phase winding, and one W-phase winding of the second winding group, wherein for each of the Δ-Y connections: the first and second sections of the three different-phase windings of the first winding group are arranged in the circumferential direction of the stator core in a sequence of the first section of the X-phase winding, the second section of the X-phase winding, the first section of the Y-phase winding, the second section of the Y-phase winding, the first section of the Z-phase winding, and the second section of the Z-phase winding; the first and second sections of the three different-phase windings of the second winding group are arranged in the circumferential direction of the stator core in a sequence of the first section of the U-phase winding, the second section of the U-phase winding, the first section of the V-phase winding, the second section of the V-phase winding, the first section of the W-phase winding, and the second section of the W-phase winding; the first section of the U-phase winding and the second section of the X-phase winding are wound around the same stator core tooth, the second section of the U-phase winding and the first section of the Y-phase winding are wound around the same stator core tooth, the first section of the V-phase winding and the second section of the Y-phase winding are wound around the same stator core tooth, the second section of the V-phase winding and the first section of the Z-phase winding are wound around the same stator core tooth, and the first section of the W-phase winding and the second section of the Z-phase winding are wound around the same stator core tooth; and the first sections of the U-phase and X-phase windings are wound in opposite directions, the second sections of the U-phase and X-phase windings are wound in opposite directions, the first sections of the V-phase and Y-phase windings are wound in opposite directions, the second sections of the V-phase and Y-phase windings are wound in opposite directions, the first sections of the W-phase and Z-phase windings are wound in opposite directions, the second sections of the W-phase and Z-phase windings are wound in opposite directions, and wherein each of the Δ-Y connections is a combination of a Δ connection and a Y connection, the Δ connection being formed by Δ-connecting the three different-phase windings of one of the first and second winding groups, the Y connection being formed by Y-connecting the three different-phase windings of the other winding group, the Δ and Y connections being combined by connecting opposite ends of each of the Y-connected windings respectively to a corresponding one of nodes between the Δ-connected windings and a corresponding one of the three terminals of the stator coil.