ANGLED WELD END TURNS FOR COOLANT ACCESS
An electric machine includes a stator core having a plurality of circumferentially-oriented slot positions, each slot position having a plurality of radially-oriented slots, each slot extending longitudinally through the core. The stator core has a plurality of conductor segments each extending through at least one of the slots. When a slot position is populated with at least two conductor segments, at least two exterior conductor portions exiting the slot position are angled radially apart from one another by more than one degree. A method of cooling an electric machine includes providing coolant access to embedded conductor end turn portions of a stator having circumferentially spaced slot positions by radially spreading exterior conductor portions exiting populated ones of the slot positions.
1 . An electric machine, comprising:
a stator core having a plurality of circumferentially-oriented slot positions, each slot position having a plurality of radially-oriented slots, each slot extending longitudinally through the core;
a plurality of conductor segments each extending through at least one of the slots;
wherein when a slot position is populated with at least two conductor segments, at least two conductor portions protruding from the slot position are angled radially apart from one another by more than one degree.
2 . The electric machine of claim 1 , wherein at least one exterior conductor portion protruding from the slot position is angled radially outward of the axial direction of the stator core by more than one degree.
3 . The electric machine of claim 1 , wherein a plurality of the slot positions are each populated with at least three conductor segments.
4 . The electric machine of claim 1 , wherein a plurality of the slot positions are each populated with at least four conductor segments, and wherein conductor portions of the radially outer two conductor segments exiting each populated slot position are angled radially outward by more than one degree.
5 . The electric machine of claim 1 , wherein, for each populated slot position, each external axial end of at least one radially outermost conductor segment is angled radially outwardly by more than one degree.
6 . The electric machine of claim 5 , wherein each conductor segment is a hairpin having an apex and having two legs respectively extending through two of the slots, the apex and ends of the legs extending from opposite axial ends of the stator core.
7 . The electric machine of claim 6 , wherein at least one pair of leg portions exiting each populated slot position is angled radially outwardly by more than one degree.
8 . The electric machine of claim 7 , wherein end portions of the pair are welded to one another.
9 . The electric machine of claim 6 , wherein respective protruding portions of the apex and the legs are angled radially outwardly by more than one degree.
10 . A method of forming an electric machine, comprising:
providing a stator core having a plurality of circumferentially-oriented slot positions, each slot position having a plurality of radially aligned slots, each slot extending longitudinally through the core;
placing a plurality of conductor segments through the slots so that at least two legs of the segments protrude from an axial end of the stator core at each populated slot position; and
at each populated slot position, radially angling the protruding portion of at least one of the legs by more than one degree.
11 . The method of claim 10 , wherein the angling includes axially forcing a wedge between adjacent external conductor portions.
12 . The method of claim 10 , wherein the wedging includes a plurality of individual wedging events performed sequentially about a circumference of the stator.
13 . The method of claim 10 , further comprising welding pairs of the protruding legs.
14 . The method of claim 13 , wherein the angling includes bending the protruding leg pairs prior to the welding.
15 . A method of cooling an electric machine, comprising providing coolant access to embedded conductor end turn portions of a stator having circumferentially spaced slot positions by radially spreading conductor portions protruding from populated ones of the slot positions.
16 . The method of claim 15 , wherein the radially outermost protruding conductor portion at each populated slot position is angled radially outward by more than one degree.
17 . The method of claim 15 , further comprising welding pairs of the protruding conductor portions together, wherein the radial spreading includes bending radially outermost ones of the welded pairs radially outward by more than one degree.
18 . The method of claim 15 , further comprising applying coolant to the embedded conductor end turn portions via the access provided therefor.
19 . The method of claim 15 , wherein the radial spreading includes forming more than one radial bend in radial outermost conductor portions protruding from respective selected ones of the populated slot positions.
20 . The method of claim 15 , wherein the radial spreading is performed for protruding conductor portions at each axial end of the stator.