METHOD FOR PRODUCING AN ACTIVE PART FOR A ROTARY ELECTRIC MACHINE, ACTIVE PART FOR A ROTARY ELECTRIC MACHINE, AND ROTARY ELECTRIC MACHINE

Abstract

A method for producing an active part (1) for a rotary electric machine (101), comprising the following steps: providing a core (2) for the active part (1) and shaped conductors (6) inserted into the core; joining together, in each case, two of the end areas (9) so that the two end areas (9) form a pair (10); and welding each pair (10) of the end areas (9) by means of a laser beam which is guided on the end areas (9) of the pair (10) along a first trajectory (13).

Claims

1. A method for producing an active part for a rotary electric machine, comprising: providing a core for the active part and shaped conductors inserted into the core, wherein the core has an end face, a further end face opposite the end face, and a plurality of slots which are arranged circumferentially and in which the shaped conductors are arranged, wherein the shaped conductors extend from the end face to the further end face and each have a free end which protrudes at the end face and has an end area; joining together, in each case, two of the end areas so that the two end areas form a pair; and welding each pair of the end areas by a laser beam which is guided on the end areas of the pair along a first trajectory and a second trajectory, wherein the first trajectory and the second trajectory each have a start point and an end point which is different from the start point, wherein the first trajectory and the second trajectory run concavely between the start point and the end point.

2. The method according to claim 1, wherein an edge of the end area of each shaped conductor consists of an inner edge portion and an outer edge portion, wherein the inner edge portion of one of the end areas of each pair runs along the inner edge portion of the other end area of the pair in question, and between the inner edge portions a boundary region, in particular formed by a gap between the inner edge portions or a contact of the inner edge portions, runs, formed by a gap between the inner edge portions or a contact of the inner edge portions, wherein each trajectory runs over an area at the edge of which the outer edge portions lie and which encloses the boundary region.

3. The method according to claim 2, wherein the midpoint of the first trajectory and of the second trajectory is closer to a midpoint of the area than the start point and the end point of the trajectory.

4. The method according to claim 2, wherein the area is subdivided into a first to fourth quadrant, wherein a common boundary line of the first and second quadrants and a common boundary line of the third and fourth quadrants lie on a first line and a common boundary line of the first and fourth quadrants and a common boundary line of the second and third quadrants lie on a second line intersecting the first line.

5. The method according to claim 4, wherein the start point and the end point of the first trajectory are located in two different quadrants lying on the same side of the first line, and the start point and the end point of the second trajectory are located in different quadrants lying on the other side of the first line.

6. The method according to claim 4, wherein the first line runs along the boundary portion.

7. The method according to claim 4, wherein the second line runs along the boundary portion.

8. The method according to claim 4, wherein the first trajectory and the second trajectory each run entirely within those quadrants in which the start point and the end point of the trajectory lie.

9. The method according to claim 4, wherein each quadrant is diagonally divided into two octants and a common boundary line of each two adjacent octants runs towards an intersection of the first line with the second line, wherein the first and second trajectories each extend over a greater distance within the non-adjacent octants of the quadrants in which the trajectory lies than within the adjacent octants of the quadrants in which the trajectory lies, and/or an energy input of the laser beam along the first and second trajectories within the non-adjacent octants of the quadrants in which the trajectory lies is greater than within the adjacent octants of the quadrants in which the trajectory lies.

10. The method according to claim 1, wherein the first and second trajectories each describe an arched curve, an arc of a circle, an arc of an ellipse, a parabola or a hyperbola, on the area or have or consist of first to third straight portions, wherein the first straight portion extends from the start point, the third straight portion extends towards the end point, and the second straight portion connects the first straight portion to the third straight portion.

11. The method according to claim 1, wherein the laser beam in the welding step is further guided along a third trajectory which lies, in particular without overlapping, between the first and second trajectories and has a start point and an end point which is different from the start point.

12. The method according to claim 1, wherein a laser device generating the laser beam is used, the laser device being operable in a deactivated state, in which the laser beam is switched off or has insufficient power for melting a material of the shaped conductors, and in an activated state, in which the laser beam can melt the material of the shaped conductors, wherein the step of welding comprises, for each trajectory: aligning the laser device with the start point of the trajectory in the deactivated state; guiding the laser beam in the activated state of the laser device from the start point along the trajectory to the end point of the trajectory, wherein, between the aligning and the guiding, the laser device is transferred from the deactivated state to the activated state when the laser device is aligned with the start point of the trajectory, and is transferred from the activated state to the deactivated state when the guiding has reached the end point of the trajectory.

13. The method according to claim 1, wherein the active part is a stator or a rotor.

14. An active part for a rotary electric machine obtained by a method according to claim 1 comprising: a core; and shaped conductors inserted into the core, wherein the core has an end face, a further end face opposite the end face, and a plurality of slots which are arranged circumferentially and in which the shaped conductors are arranged, wherein the shaped conductors extend from the end face to the further end face and each have a free end which protrudes at the end face and which in each case has an end area, wherein each two of the end areas are joined together in such a way that the two end areas form a pair, wherein each pair of the end areas of the pair are welded along a first trajectory and a second trajectory on the end areas, wherein the first trajectory and the second trajectory each have a start point and an end point which is different from the start point, wherein the first trajectory and the second trajectory run concavely between the start point and the end point.

15. A rotary electric machine comprising a first active part according to claim 14; and a second active part wherein the electric machine is configured to drive a vehicle.

Description

[0035] Further advantages and details of the present invention will become apparent from the exemplary embodiments described below and from the drawings. These are schematic representations and show:

[0036] FIG. 1 a schematic sketch of a first exemplary embodiment of the active part according to the invention;

[0037] FIG. 2 a detailed view of two shaped conductors in the region theft free ends according to the first exemplary embodiment;

[0038] FIG. 3 an end-face view of the end areas of one of the pairs;

[0039] FIGS. 4 to 8 in each case an end-face view of the end area of one of he pairs according to a further exemplary embodiment; and

[0040] FIG. 9 a schematic sketch of a vehicle with an exemplary embodiment of the electric machine according to the invention.

[0041] FIG. 1 is a schematic sketch of a first exemplary embodiment of active part 1 for a rotary electric machine 101 (cf. FIG. 9).

[0042] The active part 1 comprises a core 2, which can be formed in a generally known manner from a plurality of layered individual laminations (not shown) that are electrically insulated from one another and in this case can also be understood as a laminated core. The core 2 has an end face 3 and a further end face 4 opposite the end face 3. The core 2 also has a plurality of slots 5 arranged circumferentially which extend in the axial direction from the end face 3 to the further end face 4 and pass completely through the core 2 in the axial direction. Only two of the slots 5 are shown schematically in FIG. 1.

[0043] The active part 1 also comprises, inserted into the core 2, a plurality of shaped conductors 6, of which only one is shown in FIG. 1. The shaped conductors 6 extend from the end face 3 to the further end face 4 and each have a free end 7. In the present exemplary embodiment, the shaped conductor 6 is made of copper by way of example and is formed by a wire bent multiple times. In this case, the shaped conductor 6 extends from the free end 7 at the end face 3 in the axial direction to the further end face 4, has a 180-degree bend at the further end face 4 and extends back from the further end face 4 through another slot 5 to the end face 3. At the end face 3, the shaped conductor 6 has a further free end 7′. The shaped conductor 6 accordingly has a U-shape or V-shape and can also be understood as a conductor segment of a hair pin winding. At both end faces 3, 4 the shaped conductors form winding heads 8 as shown merely schematically.

[0044] FIG. 2 is a detailed view of two shaped conductors 6 in the region of heir free ends 7 according to the first exemplary embodiment.

[0045] The shaped conductors 6 protrude from the core 2 at its end face 3. The free ends 7 each have an end area 9 which extends substantially perpendicular to the axial direction or perpendicular to the direction in which the shaped conductors extend. The end areas 9 are joined together to form the pair 10. A gap between the end areas 9 or contact between the end areas 9 forms a boundary region 11.

[0046] Each pair 10 of end areas 9 is welded together by means of a laser beam so that the free ends 7 or the shaped conductors 6 are electrically conductive and mechanically connected to each other. By welding, one or more current paths are formed, which are configured to generate a magnetic field for producing an electromotive force of the rotary electric machine 101 (see FIG. 9) when a current is applied.

[0047] FIG. 2 also shows schematically, by hatching, an outer electrically insulating surface layer 12 of the shaped conductors 6. The surface layer 12 surrounds an electrically conductive material of the shaped conductors 6. Only at the free ends 7, T is the electrically conductive material exposed, and therefore the surface layer 12 is not damaged by the thermal energy input of the laser beam.

[0048] FIG. 3 is an end-face view of the end areas 9 of one of the pairs 10 according to the first exemplary embodiment.

[0049] Each pair 10 is welded on the end areas 9 along a first trajectory 13 and a second trajectory 14. The trajectories 13, 14 each have a start point 13a, 14a and an end point 13b, 14b. The first trajectory 13 is concave between its start point 13a and its end point 13b. Similarly, the second trajectory 14 is concave between its start point 14a and its end point 14b.

[0050] One edge 15 of the end area 9 of each shaped conductor 6 consists of an inner edge portion 16 and an outer edge portion 17. In FIG. 3, the start and end of the inner edge portion 16 are marked with arrows P1, P2. The inner edge portion 16 of one of the end areas 9 of each pair runs along the inner edge portion 16 of the other end area 9 of the pair 10 in question. The boundary region 11 runs between the inner edge portions 16. Each trajectory 13, 14 runs over an area 18, at the edge 19 of which the outer edge portions 17 lie. The area 18 also includes the boundary region 11. A midpoint 21 of each trajectory 13, 14 is closer to a midpoint 22 of the area 18 than the trajectory start point 13a, 14a and trajectory end point 14a, 14b.

[0051] The area 18 is further divided into first to fourth quadrants 23a, 23b, 23c, 23d. A common boundary line of the first quadrant 23a and the second quadrant 23b lies on a first line 24a. A common boundary line of the third quadrant 23c and the fourth quadrant 23d further lies on the first line 24a. On a second line 24b lies a common boundary line of the first and fourth quadrants 23a, 23d and a common boundary line of the second and third quadrants 23b, 23c. The quadrants 23a-d are named according to their order in a counter-clockwise sense when looking at the end areas 9 from the end face, The first line 24a intersects the second line 24b perpendicularly and runs along the boundary portion 11.

[0052] The start point 13a and the end point 13b of the first trajectory 13 are located in two different quadrants lying on the same side of the first line 24a, namely in the second and third quadrants 23b, 23c. The start point 14a and the end point 14b of the second trajectory 14 lie in different quadrants located on the other side of the first line 24b, namely in the first and fourth quadrants 23a, 23b. In this case, the first trajectory 13 and the second trajectory 14 run entirely within those quadrants 23a-d in which their start point 13a, 14a and their end point 13b, 14b lie.

[0053] It can also be seen that an intersection point 25 of the first trajectory 13 with the second line 24b is closer to the first line 24a than an intersection point 26 of an imaginary straight line 27 through the start point 13a and the end point 13b with the second line 24b. Likewise, an intersection point of the second trajectory 14 with the second line 24b is closer to the first line 24a than an intersection point of an imaginary straight line through the start point 14a and the end point 14b with the second line 24b, wherein in FIG. 3, for the sake of clarity, the intersection points and the straight line with respect to the second trajectory 14 have not been marked.

[0054] FIG. 3 further shows that each quadrant 23a-d is diagonally divided into two octants 23a1, 23a2, 23b1, 23b2, 23c1, 23c2, 23d1, 23d2. A common boundary line of two adjacent octants 23a1 to 23d2 runs towards an intersection point 28 of the first line 24a with the second line 24b. The first trajectory 13 lies over a greater distance within the non-adjacent octants 23b1, 23c2 of the quadrants 23b, 23c than within the adjacent octants 23b2, 23c1 of the quadrants 23b, 23c. The second trajectory 14 lies over a greater distance within the non-adjacent octants 23a2, 23d1 of the quadrants 23a, 23d than within the adjacent octants 23a1, 23d2 of the quadrants 23a, 23d.

[0055] According to the first exemplary embodiment, the first trajectory 13 and the second trajectory 14 each comprise a first straight portion 29a, a second straight portion 29b and a third straight portion 29c, which are only drawn for the second trajectory 14 in FIG. 3 for clarity. The first straight portion 29a extends from the start point 13a, 14a. The third straight portion 29c extends towards the end point 13b, 14b. The second straight portion 29b connects the first straight portion 29a to the third straight portion 29c. Further, the first straight portion 29a forms a right angle with the second straight portion 29b, and the second straight portion 29b forms a right angle with the third straight portion 29c.

[0056] According to the first exemplary embodiment, the first trajectory 13 and the second trajectory 14 further run mirror-symmetrically with respect to the first line 24a and with respect to the boundary portion 11, respectively.

[0057] The active part 1 can be formed as a stator 102 or as a rotor 103 (cf. FIG. 9).

[0058] Further exemplary embodiments of the active part 1 are described below. Like or equivalent components are provided with identical reference signs.

[0059] FIG. 4 is an end-face view of the end areas 9 of one of the pairs 10 according to a second exemplary embodiment of the active part 1 to which all explanations regarding the first exemplary embodiment can be transferred except for the deviations described below. In the second exemplary embodiment, instead of the straight portions 29a-c (see FIG. 3), the trajectories 13, 14 each describe an arched curve, for example an arc of a circle, an arc of an ellipse, a parabola or a hyperbola on the area 18.

[0060] FIG. 5 is an end-face view of the end areas 9 of one of the pairs 10 according to a third exemplary embodiment of the active part 1, to which all explanations regarding the second exemplary embodiment can be transferred except for the deviations described below. In the third exemplary embodiment, the first trajectory 13 and the second trajectory 14 do not run mirror-symmetrically with respect to the first line 24a or with respect to the boundary portion 11, but mirror-symmetrically with respect to a straight line 30 that is shifted in parallel in relation to the first line 24a or the boundary portion 11.

[0061] FIG. 6 is an end-face view of the end areas 9 of one of the pairs 10 according to a fourth exemplary embodiment of the active part 1, to which all explanations regarding the first exemplary embodiment can be transferred except for the deviations described below. In the fourth exemplary embodiment, an angle greater than 90° is formed between the first straight portion 29a forms and the second straight portion 29b and also between the second straight portion 29b and the third straight portion 29c. In the present case, the angle is 135°. The first and third straight portions 29a, 29c also run along the boundary lines of adjacent octants 23a1 to 23d2.

[0062] FIG. 7 is an end-face view of the end areas 9 of one of the pairs 10 according to a fifth exemplary embodiment of the active part 1, to which all explanations regarding the first exemplary embodiment can be transferred except for the deviations described below. In the fifth exemplary embodiment, the second line 24b runs along the boundary portion 11. As a result, the trajectories 13, 14 extend over the boundary portion and the naming of the quadrants 23a-d is rotated by 90°—in this example counter-clockwise—compared to FIG. 1.

[0063] FIG. 8 is an end-face view of the end areas 9 of one of the pairs 10 according to a sixth exemplary embodiment of the active part 1, to which all explanations regarding the second exemplary embodiment can be transferred except for the deviations described below. In the sixth exemplary embodiment, a third trajectory 31 is provided which lies between the first and second trajectories 13, 14 without overlapping and has a start point 31a and an end point 31b different from the start point. In this example, the third trajectory 31 runs straight and intersects the boundary region 11.

[0064] According to further exemplary embodiments of the active part 1, the mirror symmetry of the third exemplary embodiment is applied to the trajectories according to the first, fourth, fifth or sixth exemplary embodiment.

[0065] According to further exemplary embodiments of the active part 1, the second line 24b runs along the boundary region 11 as described in the fifth exemplary embodiment and the trajectories 13, 14, 31 run according to the second, third, fourth or sixth exemplary embodiment.

[0066] According to further exemplary embodiments of the active part 1, a third trajectory 31 corresponding to the sixth exemplary embodiment is provided in an active part 1 according to the first to fifth exemplary embodiments.

[0067] In the following, exemplary embodiments of a method for producing the active part 1 according to the preceding exemplary embodiments are described:

[0068] The method comprises a first step of providing the core 2 and the shaped conductors 6 inserted into the core 2. In a subsequent second step, two end areas 9 are joined together so that the two end areas 9 form a pair 10.

[0069] In a subsequent third step, each pair 10 is welded by means of a laser beam guided on the end areas 9 of the pair along the first trajectory 13 and the second trajectory and, if necessary, along the third trajectory 31 according to one of the previously described exemplary embodiments. A laser device generating the laser beam is used for this purpose. The laser device is operable in a deactivated state, in which the laser beam is switched off or has insufficient power to melt a material of the shaped conductors 6. The laser device is further operable in an activated state in which the laser beam can melt the material of the shaped conductor 6.

[0070] The third step of welding further comprises the following steps for each trajectory 13, 14, 31: aligning the laser device with the start point 13a, 14a, 31a of the trajectory 13, 14, 31 in the deactivated state; and guiding the laser beam in the activated state of the laser device from the start point 13a, 14a, 31a along the trajectory 13, 14, 31 to the end point of the trajectory 13b, 14b, 31b. Here, between the aligning and the guiding, the laser device is transferred from the deactivated state to the activated state when the laser device is aligned with the start point 13a, 14a, 31a of the trajectory 13, 14, 31, and is transferred from the activated state to the deactivated state when the guiding has reached the end point 13b, 14b, 31b of the trajectory.

[0071] Optionally, it can be provided that an energy input of the laser beam along the first trajectory 13 within the non-adjacent octants 23b1, 23c2 of the quadrants 23b, 23c in which the first trajectory 13 is located is greater than within the adjacent octants 23b2, 23c1 of the quadrants 23b, 23c in which the first trajectory 13 is located.

[0072] Accordingly, it can be provided that an energy input of the laser beam along the second trajectory 14 is greater within the non-adjacent octants 23a2, 23d1 of the quadrants 23a, 23d in which the second trajectory 14 lies than within the adjacent octants 23a1, 23d2 of the quadrants 23a, 23d in which the second trajectory 14 lies.

[0073] It should be noted that the active part 1 obtained by carrying out the method—depending on the parameterization of the welding process—does not necessarily have to have weld seams in the form of the trajectories.

[0074] FIG. 9 is a schematic sketch of a vehicle 100 with an exemplary embodiment of a rotary electric machine 101. The electric machine 101 comprises a stator 102 and a rotor 103. The stator 102 and/or the rotor 103 are formed as an active part 1 according to one of the previously described exemplary embodiments or are obtained by one of the previously described exemplary embodiments of the method.

[0075] The electric machine 101 is configured to drive the vehicle 100. Accordingly, the vehicle 100 is a battery electric vehicle (BEV) or a hybrid vehicle.