Electric machine wedges and method for insertion of wedges

An electric machine comprising:

• a rotor;
• and
• a stator separated from the rotor by an airgap and defining an axial direction, the stator comprising:
• a stator core including a plurality of slots, each slot including an opening;
• a winding arrangement formed by conductors extending through the slots of the stator core;
• a plurality of slot liners positioned in the plurality of slots, each slot liner including a first side positioned on one side of an associated slot and a second side positioned on a second side of the associated slot such that the conductors in the associated slot are positioned between the first side and the second side of the slot liner;
• and
• a plurality of wedges positioned in the slots of the stator core, wherein at least a portion of each wedge is positioned radially outward from an opening of the associated slot, wherein each wedge includes a first leg positioned between the first side of the slot liner and a radially innermost conductor in the associated slot, a second leg positioned between the second side of the slot liner and the radially innermost conductor in the associated slot, and a bridge extending between the first leg and the second leg, wherein the bridge blocks an opening to the associated slot, and wherein each wedge is friction fit in the slot with the first leg wedged between the first side of the slot liner and a first side of the radially innermost conductor on one side of said slot and the second leg wedged between the second side of the slot liner and a second side of the radially innermost conductor on an opposite side of said slot.

A method of making a stator for an electric machine comprising:

• inserting conductors into slots of a stator core, the stator core defining an axial direction, a circumferential direction, and a radial direction, the stator core including an outer diameter wall and teeth extending radially inward from the outer diameter wall with minicaps positioned at radially inward ends of the teeth and extending in the circumferential direction, wherein the slots are formed between the teeth, each of the slots defining a slot opening on a radially inward portion of the stator core between a pair of the minicaps, wherein a width of each slot opening is less than a width of each slot radially outward from said slot opening, wherein the conductors are inserted into the slots of the stator core through the slot openings;
• inserting slot liners into the slots such that, for each slot liner, a first side of said slot liner is positioned on one side of an associated slot, a second side of said slot liner is positioned on an opposite side of the associated slot, and the conductors in the associated slot are positioned between the first side and the second side of the slot liner;
• and
• inserting wedges through the slot openings in a radial direction and into the slots such that in each slot:
• a first leg of a wedge is positioned between the one side of the slot liner and a radially innermost conductor in the slot,
• a second leg of the wedge is positioned between the opposite side of the slot liner and the radially innermost conductor in the slot,
• a bridge of the wedge blocks the slot opening, and
• the wedge is friction fit in the slot with the first leg wedged between the first side of the slot liner and a first side of the radially innermost conductor on the one side of said slot and the second leg wedged between the second side of the slot liner and the second side of the radially innermost conductor on the opposite side of said slot.