Stator with coplanar tapered conductors

Abstract

The torque produced by an electric machine of the axial air gap type is increased by pressing or forming the active sectors of the radial coil sections, essentially coplanar, and by using nonuniform cross-section conductors for the radial active sectors of the coils. One of the active sectors of a leading radial coil section and one of the active sectors of a trailing radial coil section are confined within the central open area formed in a first coil. The gap required between the permanent magnets of rotors, necessary to accommodate the axial thickness of a stator, is reduced to little more than the axial thickness of a single radial section of a stator coil in the active area of the coil. The stator coils can be made by joining winding sheets together. The winding sheets can be made by forming coils from flat, thin conductor coils on carrier films. Two of the winding sheets thus formed can be superimposed, aligned, pressed and laminated together to form the desired stator laminate, with or without further treatment. By forming the radial coil sections active sectors of radially increasing conductor widths, almost all of the lines of force passing between the rotating permanent magnets will be cut by the radial sectors of the stator coils, thereby fully utilizing the magnetic field created by permanent magnets to produce torque.