An improved airgap armature for use in brushless rotary electrical machines is constructed with multiple phase windings comprised of wires that are wound onto and bonded to a supporting form constructed from nonmagnetic and electrically nonconductive material. The form has two ends, each with features for holding end turns of the multiple phase windings. The multiple phase windings have active lengths and end turns, with the active lengths being located on one side of the form and the end turns located on the opposite side of the form. The active lengths, which are located in the armature airgap of the electrical machine, lie flat against the form for minimal thickness, and the airgap armature can achieve maximum winding density. The form provides an easy method for winding as well as increased structural integrity in the final armature to enable it to transfer torque between the rotor and stationary housing.

A three-phase motor allows connection of neutral end portions of the coil conductors without substantially increasing the axial length of the motor. The neutral end portions of the coil conductors extend in parallel arrangement over end portions of the coil assemblies to the peripheral outer side of the coil assemblies where neutral end portions of the coil conductors are connected to spaced points on a bus bar to form a neutral for the three phases of the coils.

A full levitation magnetic bearing system with passive magnetic bearings that affords increased radial stiffness and load capacity includes two passive permanent magnet magnetic bearings, one each located on each side of the center of mass of the rotor to be levitated. An active axial magnetic bearing provides control for stable levitation. The magnetic bearing system provides increased radial stiffness and load capacity by the reduction or elimination of the unstable tilting moments generated by the individual passive permanent magnet magnetic bearings. The bearings are constructed so that they are concave toward the center of the rotor, with a radius approximately equal to the distance between the magnetic bearing and the central point about which tilt rotation would tend to occur. The individual magnetic air gaps are preferably constructed to be perpendicular to the axis of rotation.

A bus bar secured to a stator in an electric motor in a preferred embodiment according to the invention includes four wiring boards, which are arranged perpendicularly to a center axis at intervals in a direction toward the center axis, and a resin portion for covering the surroundings of the four wiring boards by injection molding. Resin passing holes, through which a resin flows when the resin portion is molded, are formed at each of the wiring boards. When the bus bar is molded, the resin is injected into a resin molding die in a state in which the four wiring boards are supported by supporting pins disposed inside of the die. The resin flows to and fro between a space defined between the die and the wiring board and a space defined between the adjacent wiring boards.

A centralized power distribution unit for a vehicular thin brushless motor includes a plurality of bus bars, a resin insulation layer that covers the bus bars, and an insulating holder having a plurality of holding grooves that hold the bus bars. The bus bars are pre-bent in a thickness direction to be formed into a substantially annular shape. Each of the bus bars is provided correspondingly with a phase of the motor. The holding grooves are formed in parallel extending along a circumferential direction of the centralized power distribution unit. The bus bars are respectively inserted into the holding grooves, and are thus stacked in a radial direction of the centralized power distribution unit. The insulating holder and the bus bars are covered by the resin insulation layer.