An assembly and insertion system (1000,2000) for assembling and inserting into a stator pack a stator winding comprising one or more layers, each layer consisting of a circumferential arrangement of basic conductors (255, 255-R, 255-IP, 255-IVP), the basic conductors comprising a head end and one or more legs with a respective free insertion end, the assembly and insertion system (1000,2000) comprising: - circumferential containment means (500,540,580) of the basic conductors (255, 255-R, 255-IP, 255-IVP) for the assembling the winding, the circumferential containment means defining a set of spaces or slots into which inserting the legs of the basic conductors, the angular distance between two slots being referred to as a slot pitch; - removable insertion means (210,220,230) for inserting the basic conductors (255, 255-R, 255-IP, 255-IVP) into said circumferential containment means (500,540,580); and - rotating means for rotating the circumferential containment means (500,540,580) about the winding axis, said rotating means being configured to perform rotations of one or more slot pitches about the winding axis; the assembly and transfer system (1000,2000) further comprising a rotary table with a first housing hole housing the circumferential containment means, wherein - the rotary table has a first table surface and a second table surface axially opposite to said first surface; - the circumferential containment means (500,540,580) are configured to receive said basic conductors starting from said free ends, on the side of said first table surface in the assembly position; the assembly and transfer system (1000,2000) being characterized in that: - the rotary table is configured to rotate about a table axis so as to bring the circumferential containment means (500,540,580) from a winding assembly position to a winding insertion position for the insertion of the winding into the stator pack; - feeding means of a stator pack from the side of said second table surface at the insertion position are included, said stator pack comprising a set of stator pack slots; and - relative introduction means for the relative introduction of said winding into said stator pack with relative approaching motion between the winding and the stator pack in said insertion position are included; wherein the circumferential containment means (500,540,580) comprise a set of positioners arranged circumferentially and configured to slide radially, wherein a space or slot of said set of spaces or slots is defined between each successive pair of positioners. - circumferential containment means (500,540,580) of the basic conductors (255, 255-R, 255-IP, 255-IVP) for the assembling the winding, the circumferential containment means defining a set of spaces or slots into which inserting the legs of the basic conductors, the angular distance between two slots being referred to as a slot pitch; - removable insertion means (210,220,230) for inserting the basic conductors (255, 255-R, 255-IP, 255-IVP) into said circumferential containment means (500,540,580); and - rotating means for rotating the circumferential containment means (500,540,580) about the winding axis, said rotating means being configured to perform rotations of one or more slot pitches about the winding axis; the assembly and transfer system (1000,2000) further comprising a rotary table with a first housing hole housing the circumferential containment means, wherein - the rotary table has a first table surface and a second table surface axially opposite to said first surface; - the circumferential containment means (500,540,580) are configured to receive said basic conductors starting from said free ends, on the side of said first table surface in the assembly position; - the rotary table has a first table surface and a second table surface axially opposite to said first surface; - the circumferential containment means (500,540,580) are configured to receive said basic conductors starting from said free ends, on the side of said first table surface in the assembly position; the assembly and transfer system (1000,2000) being characterized in that: - the rotary table is configured to rotate about a table axis so as to bring the circumferential containment means (500,540,580) from a winding assembly position to a winding insertion position for the insertion of the winding into the stator pack; - feeding means of a stator pack from the side of said second table surface at the insertion position are included, said stator pack comprising a set of stator pack slots; and - relative introduction means for the relative introduction of said winding into said stator pack with relative approaching motion between the winding and the stator pack in said insertion position are included; - the rotary table is configured to rotate about a table axis so as to bring the circumferential containment means (500,540,580) from a winding assembly position to a winding insertion position for the insertion of the winding into the stator pack; - feeding means of a stator pack from the side of said second table surface at the insertion position are included, said stator pack comprising a set of stator pack slots; and - relative introduction means for the relative introduction of said winding into said stator pack with relative approaching motion between the winding and the stator pack in said insertion position are included; wherein the circumferential containment means (500,540,580) comprise a set of positioners arranged circumferentially and configured to slide radially, wherein a space or slot of said set of spaces or slots is defined between each successive pair of positioners.