Stator, bus bar unit, motor, and power steering device

A stator comprising:

• a ring portion;
• a core including a teeth portion which includes twelve teeth portions projecting from an inside of the ring portion toward a center thereof;
• and
• a coil group including twelve coils respectively provided in each one of the teeth portions;
• wherein
• the core includes twelve cores coupled to each other and each of which respectively includes one of the teeth portions;
• the coil group includes six coil pairs each including two of the twelve coils joined to each other by a conductive line;
• and
• when the core is divided into a phase region and a neutral region equally along an axial direction, one coil in each of the six coil pairs is arranged in the phase region, and the other coil in each of the six coil pairs is arranged in the neutral region.

A bus bar unit comprising:

• a plurality of bus bars;
• and
• an insulating holder in which the plurality of bus bars are arranged;
• wherein
• the insulating holder includes a ring-shaped bus bar supporting portion;
• the bus bar includes a first bus bar being in the shape of an approximate semicircle and at least one second bus bar, a third bus bar, and a fourth bus bar being in the shape of a minor arc;
• and
• when the bus bar supporting portion is viewed from its axial direction and is divided into a phase side region and a neutral side region, the first bus bar is arranged in the neutral side region, and the at least one second bus bar, the third bus bar, and the fourth bus bar are arranged in the phase side region to overlap with each other.

A motor comprising:

• a stator including:
• a ring portion;
• a core including a teeth portion which includes twelve teeth portions projecting from an inside of the ring portion toward a center thereof;
• and
• a coil group which includes twelve coils respectively provided in each one of the teeth portions;
• wherein
• the core includes twelve cores coupled to each other and each of which includes one of the teeth portions;
• the coil group includes six coil pairs each including two of the twelve coils joined to each other by a conductive line;
• when the core is divided into a phase region and a neutral region equally along the axial direction, one coil in each of the six coil pairs is arranged in the phase region, and the other coil in each of the six coil pairs is arranged in the neutral region;
• each of the coil pairs is connected in a star connection;
• and
• all of the conductive lines derived from the neutral region are connected to a neutral point;
• and
• a bus bar unit including:
• a plurality of bus bars;
• and
• an insulating holder in which the plurality of bus bars are arranged;
• wherein
• the insulating holder includes a bus bar supporting portion being in the shape of a ring;
• the bus bar includes a first bus bar being in the shape of an approximate semicircle and at least a second bus bar, a third bus bar, and a fourth bus bar being in the shape of a minor arc;
• when the bus bar supporting portion is viewed from its axial direction and is divided into a phase side region and a neutral side region, the first bus bar is arranged in the neutral side region, and the at least the second bus bar, the third bus bar, and the fourth bus bar are arranged in the phase side region to overlap with each other;
• and
• the first bus bar is arranged such that the star connection is connected to a neutral point.