Method and apparatus for assembling a winding of hairpins

A method of assembling basic conductors in a winding set for an electric machine stator or rotor, comprising use of:

• one or more basic conductor feeding stations, each basic conductor comprising one or more legs and a bridge connection having a bending direction and connecting the one or more legs;
• N handling units for handling the basic conductors, each handling unit being provided with a respective gripper for gripping and transporting the basic conductors along a respective path about a predetermined axis, wherein said handling units have N handling arms to hold the basic conductors, the N handling arms being rotatable with respect to said predetermined axis, wherein N=1 or N is either greater than or equal to 2, wherein for N being either greater than or equal to 2 the N handling arms are:
• angularly arranged uniformly about the predetermined axis;
• configured to rotate integrally on a predetermined plane about the predetermined axis;
• the gripper sliding along the handling arms by actuating gripper sliding means;
• one or more basic conductor assembly stations for one or more winding sets, comprising:
• an assembly drum rotatable about a drum axis arranged perpendicular to said predetermined axis and comprising a series of slots arranged circumferentially on an outer cylindrical surface of the assembly drum at a sequential spacing of one slot pitch, each slot having a gap extending in radial direction and along the drum axis, the gap being open in an outward radial direction from the assembly drum and passing through parallelly to the drum axis;
• a basic conductor sliding guide with a first side facing a circumference arc of said assembly drum and a second side opposite to said first side, and with a circumferential exit end wherefrom the basic conductors exit, upon rotation of said assembly drum, at one end of said circumference arc;
• the method comprising the following steps:
• F1. when one of the N handling units is in a position corresponding to one of said one or more basic conductor feeding stations, actuating said gripper to grip a leg of a basic conductor;
• F2. displacing said handling unit with respect to the predetermined axis to move the basic conductors to said one or more basic conductor assembly stations;
• F3. in the position reached in step F2, displacing said gripper in a direction perpendicular to said predetermined axis towards said assembly drum, until alternately:
• inserting, by said gripper, the leg gripped by said gripper into the gap of a slot parallel to the drum axis, or
• inserting, by said gripper, a leg not gripped by the gripper into the gap of a slot parallel to the drum axis wherein the leg gripped by said gripper remains facing said second side of the basic conductor sliding guide;
• F4. after step F3, releasing the basic conductor by the gripper;
• F5. displacing said handling unit of steps F1 to F4 with respect to the predetermined axis until positioning the handling unit at one of said one or more basic conductor feeding stations;
• F6. repeating steps F1 to F5, with concurrent rotation of the assembly drum by at least one slot pitch in a direction towards said circumferential exit end of the basic conductor sliding guide;
• and
• F7. further rotating the assembly drum until all of the basic conductors on said basic conductor sliding guide exit.