Joining method and joining apparatus for inserting a coil winding into a component of an electrical machine

A method for inserting a coil winding into a component of an electrical machine, the method comprising:

• a) providing the component with an annular arrangement of inwardly opening slots which are bounded by inwardly projecting slot boundaries,
• b) providing the coil winding wound with a coil diameter which is equal to or smaller than an inner diameter of the annular arrangement inside the annular arrangement, the coil winding having a plurality of straight conductor sections which are connected by winding heads,
• c) providing radially movable support fingers axially adjacent the slot boundaries,
• d) expanding the coil winding outwards while inserting the straight conductor sections of the coil winding into the inwardly opening slots, and
• e) moving the radially movable support fingers radially along with the coil winding to guide the straight conductor sections, or the winding heads, or both during insertion of the straight conductor sections of the coil winding into the inwardly opening slots, wherein step e) comprises:
• e1) during insertion of the straight conductor sections of the coil winding into the inwardly opening slots, moving the radially movable support fingers along with the coil winding from a home position over a partial distance to a radial intermediate position between a radially inwardly open mouth and a radially outwardly located slot base of the associated inwardly opening slot, wherein the home position is located radially inwardly of the intermediate position, and, in the home position, the radially moveable support fingers each cover one of the slot boundaries which points in an axial direction,
• e2) during insertion of the straight conductor sections of the coil winding into the inwardly opening slots, returning the radially movable support fingers from the radial intermediate position to the home position or to a further intermediate position closer to the home position, and
• e3) repeating steps e1) and e2) during insertion of the straight conductor sections of the coil winding into the inwardly opening slots.