Polyphase armature for a rotary electrical machine, and its method of manufacture

A polyphase armature (13) for a rotary electrical machine, comprising a body (14) carrying a plurality of phases (20 to 25), each of which comprises, firstly, an input (E1 to E′3) and an output (S1 to S′3), each of which is part of an electrically conductive input element and output element respectively, and, secondly, electrically conductive elements (37) for connecting the input of a phase to the output of a phase and constituting a winding having at least two coils per phase, together with at least one first electrically conductive inversion element (38, 338) for reversing the circumferential direction of the current in the winding, the said first inversion element being interposed electrically between the two coils, and at least one phase winding is provided with at least one electrically conductive second inversion element (138, 238) for reversing the circumferential direction of the current in the said phase winding, wherein the electrically conductive output element of the said winding is connected in the electrical circuit that includes the two coils and the two electrically conductive inversion elements,

• wherein the electrically conductive elements consist of electrically conductive bars (37, 38, 138, 238, 338), which are arranged on either side of the body (14) of the armature (13) so as to constitute a first chignon (12) and a second chignon (12′), and which extend through said body (14), in that the electrically conductive bars (37, 38, 338) comprise bars made in the form of standard hairpins (37), which are joined together so as to connect the input of one phase with the output of one phase to form the winding having at least two coils per phase, and wherein each of the standard hairpins (37) comprises, firstly, at least two branches spaced apart circumferentially from each other and carried by the body (14) of the armature (13), and, secondly, a head which joins together the two branches of the hairpin concerned and which is part of one of the chignons (12, 12′), and
• wherein the first and the second electrically conductive inversion elements consist of bars made in the form of hairpins, each of which comprises, firstly, at least two branches spaced apart circumferentially from each other and carried by the body (14) of the armature (13), and, secondly, a head which joins together the two branches of the hairpin concerned and which is part of one of the chignons (12, 12′), and
• wherein each of the said heads including a summit portion which joins together the two connecting arms of that head, and wherein the summit portion of the first inversion hairpin (38, 338) is offset circumferentially and radially with respect to the summit portion of the second inversion hairpin (138, 238).