An electric motor polyphase winding pack includes a plurality of coiled conductors, each of the coiled conductors corresponding to a phase of a plurality of phases. Each of the coiled conductors has a first side and a second side. The coiled conductors are arranged in a sequence in which all of the first sides are disposed sequentially in a first layer, and all of the second sides are arranged in second layer disposed adjacent to the first layer, such that some of the first sides in the first layers and some of the second sides in the second layer correspond to each phase of the plurality of phases.

The invention relates to a roller casting method for producing a spiral structure, in particular a spiral structure for use in electric machines. Molten metal is supplied between a first roller and a second roller miming opposite thereto, wherein the first roller has first teeth, and the second roller has second teeth, said first and/or second teeth having tooth flanks with cavities for receiving the supplied molten metal. The teeth are designed and aligned such that the cavity of at least one tooth is at least temporarily delimited by the surface of a tooth of the other roller when the rollers are rotating such that the supplied molten metal is molded between the teeth while cooling and is molded into a section of the spiral structure.

The invention relates to a method for producing a coil (6), in which, by means of casting, a semi-finished product (5) in the form of an elongate conductor is formed in a cavity (2) of a casting tool and the coil (6) is formed following a demolding of the semi-finished product (5) by shaping this semi-finished product (5), wherein the form of the semi-finished product (5) may be derived from a shape of the finished coil (6) by stretching along a longitudinal axis of the coil (6) and/or by bending this longitudinal axis, and wherein the semi-finished product (5), during the shaping, is bent and compressed so that windings of the coil (5) already present in the semi-finished product (5) are brought closer to one another at least in some regions during the shaping and are brought into an arrangement along the longitudinal axis of the finished coil (6), wherein the conductor, whilst being shaped, is twisted or bent by no more than a right angle over the course of each individual turn. The invention also relates to a coil (6) produced in this way and to a casting tool which may be used to carry out the described method.

The present application creates a roller molding method for producing a spiral structure or a coil, in particular a spiral structure for use in electric machines, wherein material is supplied between a first roller and a second roller running opposite thereto, wherein the first roller has first teeth, and the second roller has second teeth, said first and/or second teeth having tooth flanks with cavities for receiving the supplied material, wherein the teeth are designed and aligned such that the cavity of at least one tooth is at least temporarily delimited by the surface of a tooth of the other roller when the rollers are rotating such that the supplied material is molded between the teeth into a portion of the spiral structure or the coil.

A method for making a poly-phase field winding for a slotless stator includes: forming the first coil group by winding an insulated wire for each coil winding in a first direction around a mandrel; axially shifting along the mandrel the insulated wire from a trailing edge of each coil winding a distance substantially equal to one half of twice the number of coil groups multiplied by the number of coil windings minus one times the width of one of the completed windings to position the wires at a leading edge of each of coil winding in the second coil group; forming the second coil group by winding the insulated wire for each coil winding in the first direction; removing the mandrel from the wound coil groups; collapsing the wound coil groups to a single layer web, and wrapping the single layer web into a cylinder to form the field winding.