Electric motor and electric power steering apparatus equipped with the motor

An electric power steering apparatus comprising:

• an electric motor driven by three-phase electric power to provide steering assist force to a steering system;
• steering torque detecting means for detecting steering torque applied to a steering wheel;
• and
• a control device for controlling said electric motor in accordance with at least a signal generated by said steering torque detection means,
• said electric motor comprising:
• a rotor including a rotation shaft and a plurality of permanent magnets arranged circumferentially on an outer periphery of said rotation shaft;
• and
• armature windings disposed adjacent to an outer periphery of said rotor, said armature windings being connected in series, via an armature-winding connecting line, for each of a plurality of groups of three or N circumferentially-adjoining poles, to thereby provide three-phase armature windings, wherein N is an arbitrary number equal to a multiple of three,
• wherein the armature-winding connecting line, connecting in series said armature windings, is positioned so as not to substantially straddle a relatively great part of an outer periphery of any of adjoining ones of the armature windings, and wherein the armature-winding connecting line connects the adjoining armature windings of each of the three phases at one longitudinal end of the adjoining armature windings.

An electric motor driven by three-phase electric power, comprising:

• a rotor including a rotation shaft and a plurality of permanent magnets arranged circumferentially on an outer periphery of the rotation shaft;
• and
• armature windings disposed adjacent to an outer periphery of the rotor, the armature windings being connected in series, via an armature-winding connecting line, for each of a plurality of groups of three or N circumferentially-adjoining poles, to thereby provide three-phase armature windings, wherein N is an arbitrary number equal to a multiple of three,
• wherein for each group, the armature-winding connecting line, connecting in series the armature windings, does not intersect itself, and
• a neutral-point connecting line connecting respective neutral points of the three phases, and wherein the armature-winding connecting line and the neutral-point connecting line are positioned at opposite longitudinal ends of the armature windings.