JP2012205444A - Stator core, method for manufacturing the same, and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator core that prevents laser penetration portions from extending over adjacent thin sheets in a direction of a rotating axis even if there are sheet thickness errors and laser positioning errors as in conventional stator cores and that maintains electric insulation between the adjacent thin sheets in the direction of the rotating axis.SOLUTION: A stator core 10 has thin sheets 12 that are laminated in a direction of a rotating axis 11 and joined together in a circumferential direction. On an outer or inner edge thereof, each of the thin sheets 12 has a set of laser welding portions 15 and 16 and non-welding portions 17 and 18 that allow laser to be defocused thereon. The laser welding portions 15 and 16 and the non-welding portions 17 and 18 are alternated in the direction of the rotating axis 11.

Description

  The present invention relates to a stator core used in a motor (rotary electric motor), a manufacturing method thereof, and a motor using the stator core.

  FIG. 10 shows a typical stator core 100 used in a PM motor. FIG. 10A is a plan view of the stator core 100, and FIG. 10B is a front view of the stator core 100. The stator core 100 is formed by laminating a T-shaped thin plate 102 made of a ferromagnetic material, in which a hollow disk is divided into a plurality of portions in the circumferential direction, laminated in the direction of the rotating shaft 101 and coupled in the circumferential direction. The horizontal bar portion of the T-shaped thin plate 102 is referred to as a yoke 104, and the vertical bar portion is referred to as a tooth 105. The thin plates 102 adjacent to each other in the circumferential direction are laser welded to the laser welded portion 103 at the division boundary on the outer periphery of the yoke 104. Since the surface of the thin plate 102 is covered with a thin insulating film, the laminated thin plates 102 are electrically insulated except for the laser welding portion 103.

  FIG. 11 is an enlarged view of the laser welded portion 103 when the conventional stator core 100 is ideally laser welded. FIG. 11A is a plan view of the stator core 100, and FIG. 11B is a front view of the stator core 100. As shown in FIG. 11B, the laser is spot-irradiated at the center of the laser welded portion 103 of the adjacent left and right thin plates 102. The center of the laser weld 103 is coincident with the center of the boundary of the thin plate 102. In this case, the laser penetration part 106 does not reach the thin plate 102 adjacent in the rotation axis direction.

  The purpose of laser welding is to mechanically couple the adjacent left and right thin plates 102 by the laser penetration 106. However, the adjacent left and right thin plates 102 are also electrically coupled. Considering the eddy current in the thin plate 102, it is not desirable that the left and right thin plates 102 are electrically coupled. However, when laser welding is used, it is difficult to electrically insulate the left and right thin plates 102 while mechanically connecting them.

  As shown in FIG. 11B, when laser welding is ideally performed, the laser penetration portion 106 does not reach the thin plate 102 adjacent in the rotation axis direction. Therefore, it is electrically insulated from the thin plate 102 adjacent in the rotation axis direction. This is desirable considering eddy currents.

  FIG. 12 is an enlarged view of the actual laser weld 103. FIG. 12A is a plan view of the laser welded portion 103, and FIG. 12B is a front view of the laser welded portion 103. The stator core 100 is obtained by laminating about 200 to 300 thin plates 102 having a thickness of about 0.3 mm to 0.5 mm. Therefore, in the stator core 100 as a whole, a slight thickness error of each thin plate 102 is accumulated, and the cumulative error in the thickness direction may exceed the thickness of one thin plate 102. There is also a laser positioning error.

  The thickness error of the thin plate 102 and the laser positioning error overlap, and in reality, as shown in FIG. 12B, the position of the laser melted portion 106 may vary in the rotation axis direction. If the position of the laser penetration part 106 varies in the rotation axis direction, the laser penetration part 106 may reach the thin plate 102 adjacent in the rotation axis direction as shown in FIG. As a result, the thin plates 102 adjacent in the rotation axis direction are electrically connected. This is not desirable considering eddy currents. Therefore, it is necessary to prevent the laser penetration part 106 from reaching the thin plate 102 adjacent in the rotation axis direction.

  In the stator core described in Patent Document 1, protruding bent pieces and notches are provided at both ends of the yoke. When assembling the stator core, after laminating the thin plates, the protruding bent piece of the yoke is inserted into the notch portion of the adjacent yoke, the protruding bent piece is bent, and the yokes are fixed to each other. Since welding is not performed, the insulation between the thin plates adjacent in the rotation axis direction is maintained. However, 200 to 300 protruding bent pieces each having a thickness of about 0.3 mm to 0.5 mm are provided in 200 to 300 notch portions each having a gap of about 0.3 mm to 0.5 mm. It must be inserted securely without mistakes.

  In the stator core described in Patent Document 2, a connecting concave portion and a connecting convex portion are provided at both ends of the yoke. When assembling the stator core, after laminating the thin plates, the connecting projections of the yoke are fitted into the connecting recesses of the adjacent yoke, and the thin plates are fixed to each other. Since welding is not performed, the insulation between the thin plates adjacent in the rotation axis direction is maintained. However, the connecting projections at 200 to 300 must be securely fitted into the connecting recesses at 200 to 300 without any mistakes.

  In the stator cores described in Patent Documents 1 and 2, the insulation between the thin plates adjacent to each other in the rotation axis direction is maintained without welding. However, the stator cores described in Patent Documents 1 and 2 are likely to be difficult to mass-produce.

  In the stator core described in Patent Document 3, punching is performed without dividing the thin plate, with the yoke being connected linearly by a very thin connecting piece. After laminating linear thin plates and winding them, the laminated thin plates are bent into a circular shape to form a stator core. Both ends of the thin plate are joined by, for example, arc welding. When both ends of the sheet are arc welded, the electrical insulation between the laminated sheets is lost. Even if the connecting piece is very thin, when it is deformed, it swells in the thickness direction. Therefore, a gap is generated between the yokes in the direction of the rotation axis, and the magnetic characteristics of the stator core may be deteriorated.

JP 2000-295801 A JP 2001-238376 A JP 2000-184630 A

  In the conventional stator core 100, the thickness error of the thin plate 102 and the positioning error of the laser are accumulated, the position of the laser melting portion 106 varies in the rotation axis direction, and the laser melting portion 106 reaches the thin plate 102 adjacent in the rotation axis direction. Sometimes. As a result, the thin plates 102 adjacent in the rotation axis direction are electrically connected. This is not desirable considering eddy currents.

  The object of the present invention is to provide electrical insulation from a thin plate adjacent in the direction of the rotation axis, even if the thickness error of the thin plate and the positioning error of the laser are not different from the conventional case, the laser penetration portion does not reach the thin plate adjacent in the direction of the rotation axis. This is to realize a stator core that maintains its performance.

  (1) The present invention is a stator core in which a hollow disk is divided into a plurality in the circumferential direction, and a T-shaped thin plate having a yoke and teeth is laminated in the rotation axis direction and joined in the circumferential direction. The thin plate is provided with a laser welded portion at an outer peripheral or inner peripheral divided portion. The thin plate is provided with a non-welded portion that retreats or protrudes from the outer periphery or inner periphery at the non-divided portion at the outer periphery or inner periphery. Laser welded portions and non-welded portions are alternately arranged in the rotation axis direction.

  (2) In each thin plate of the stator core of the present invention, the penetration portion of laser welding does not reach the non-welded portion.

  (3) In the stator core of the present invention, the laser welded portion is formed by spot welding to each laminated thin plate.

  (4) In the stator core of the present invention, the laser welded portion is formed by continuous welding in the rotation axis direction.

  (5) In the stator core of the present invention, the laser welded portion is linear or arcuate around the rotation axis. The non-welded part has a concave shape with a smaller radius of curvature than the laser welded part.

  (6) In the stator core of the present invention, the width of the narrowest portion of the portion including the non-welded portion of the yoke is equal to or greater than the width of the narrowest portion of the portion not including the non-welded portion of the yoke.

  (7) In the stator core of the present invention, the laser welded portion has a linear shape or an arc shape centered on the rotation axis. The non-welded part has a convex shape with a smaller radius of curvature than the laser welded part.

  (8) In the stator core of the present invention, except for the vicinity of the laser welded portion, the divided boundary surfaces of the laminated thin plates are flush with the rotation axis direction.

  (9) The stator core of the present invention has a dividing boundary in the circumferential direction of the thin plate in the yoke.

  (10) The stator core of the present invention has a laser welded portion and a non-welded portion on the outer periphery of the yoke.

  (11) The stator core of the present invention has a welding heat blocking gap between the laser weld and the slot.

  (12) The stator core of the present invention has a laser welded portion and a non-welded portion on the inner periphery of the yoke.

  (13) In the stator core of the present invention, after winding, the laser weld is welded from the slot open.

  (14) The stator core of this invention has the division | segmentation boundary of the circumferential direction of a thin plate in a teeth part.

  (15) The stator core of the present invention has a laser welded portion on the inner peripheral portion of the teeth.

  (16) A motor of the present invention includes the stator core described above.

(17) A method for manufacturing a stator core of the present invention includes:
A plurality of hollow discs in the circumferential direction having laser welded portions on the outer peripheral or inner peripheral portion, non-split portions on the outer peripheral or inner periphery, and non-welded portions that are retracted or protruded from the outer peripheral or inner periphery. Preparing a T-shaped thin plate having divided yokes and teeth;
Laminating the thin plates such that the laser welded portions and non-welded portions are alternately arranged in the rotation axis direction;
Coupling the laminated thin plates in the circumferential direction;
Spot welding the laser weld.

(18) A method for manufacturing a stator core of the present invention includes:
A plurality of hollow discs in the circumferential direction having laser welded portions on the outer peripheral or inner peripheral portion, non-split portions on the outer peripheral or inner periphery, and non-welded portions that are retracted or protruded from the outer peripheral or inner periphery. Preparing a T-shaped thin plate having divided yokes and teeth;
Laminating the thin plates such that the laser welded portions and non-welded portions are alternately arranged in the rotation axis direction;
Coupling the laminated thin plates in the circumferential direction;
Continuously welding the laser weld.

  According to the present invention, even when the thickness error of the thin plate and the positioning error of the laser are not different from the conventional one, the laser penetration portion does not reach the thin plate adjacent in the rotation axis direction, and the electrical insulation with the thin plate adjacent in the rotation axis direction is achieved. A maintained stator core is realized.

(A) Plan view of stator core of the present invention, (b) Front view of stator core of the present invention (A) An enlarged plan view of a thin plate of the first layer of the stator core of the present invention, (b) An enlarged plan view of a thin plate of the second layer of the stator core of the present invention, (c) An enlarged front view of the stator core of the present invention. (A) Plan view when the stator core of the present invention is ideally laser welded, (b) Front view when the stator core of the present invention is ideally laser welded (A) Plan view of the stator core of the present invention laser-welded to the reality, (b) Front view of the stator core of the present invention laser-welded to the reality (A) The top view of the stator core of the present invention continuously laser-welded in the direction of the rotation axis, (b) The front view of the stator core of the present invention continuously laser-welded in the direction of the rotation axis (A) Plan view of stator core of the present invention, (b) Front view of stator core of the present invention Plan view of the stator core of the present invention Plan view of the stator core of the present invention Plan view of the stator core of the present invention (A) Plan view of conventional stator core, (b) Front view of conventional stator core (A) Plan view when the conventional stator core is ideally laser welded, (b) Front view when the conventional stator core is ideally laser welded (A) Plan view of the conventional stator core laser-welded, (b) Front view of the conventional stator core laser-welded

  The stator core of the present invention is formed by dividing a hollow disk into a plurality of parts in the circumferential direction, and a T-shaped thin plate having a yoke and teeth is laminated in the direction of the rotation axis and joined in the circumferential direction. The thin plate is provided with a laser welded portion at an outer peripheral or inner peripheral divided portion. The thin plate is provided with a non-welded portion that retreats or protrudes from the outer periphery or the inner periphery in the non-divided portion on the outer periphery or the inner periphery. Laser welded portions and non-welded portions are alternately arranged in the rotation axis direction.

  In the stator core of the present invention, even if the laser irradiation position varies in the rotation axis direction, the laser penetration portion does not reach the thin plate adjacent in the rotation axis direction. For example, when the laser irradiation position is shifted downward and the laser penetration portion of the first layer thin plate is shifted downward, the second layer thin plate is also irradiated with laser simultaneously. Since the laser is focused on the laser welded portion of the first thin plate, the laser melted portion is formed by melting. However, the laser irradiation portion of the thin plate of the second layer is a concave non-welded portion (or a protruding convex shape) retreated from the outer periphery or inner periphery of the stator core, so that the laser is not focused. For this reason, even if a non-welded part is irradiated with a laser, it does not melt. Therefore, even if the laser irradiation position is shifted downward, the laser penetration portion is formed only on the thin plate of the first layer. As a result, the electrical insulation between the thin plate of the first layer and the thin plate of the second layer is maintained.

  The laser welded portion is the outer circumference (arc shape centered on the rotation axis) or inner circumference (arc shape centered on the rotation axis), the outer tangent line (straight line), or the inner circumference tangent line (linear shape). ) Is appropriate. Since the non-welded portion does not have to be focused on the laser, it may have a concave shape that is recessed from the outer periphery or inner periphery of the stator core, or may be a convex shape that protrudes from the outer periphery or inner periphery of the stator core. The shape of the non-welded portion includes an arc shape and a rectangular shape, and is not particularly limited. When the non-welded part has an arc shape (including a shape close to an arc), the radius of curvature of the arc is preferably smaller than the radius of curvature of the laser welded part.

  FIG. 1 shows a stator core 10 according to an example of the present invention. FIG. 1A is a plan view of the stator core 10, and FIG. 1B is a front view of the stator core 10. In the stator core 10 of the present invention, a T-shaped thin plate 12 made of a ferromagnetic material and divided into a plurality of hollow discs in the circumferential direction is laminated in the direction of the rotating shaft 11. The horizontal bar portion of the T-shaped thin plate 12 is referred to as a yoke 13, and the vertical bar portion is referred to as a tooth 14. In the stator core 10, the thin plate 12 is divided at the yoke portion. In FIG. 1A, the dividing line is a combination of a plurality of straight lines (broken line), but the dividing line may be an appropriate curve.

  Since the surfaces of the thin plates 12 are covered with a thin insulating film, the thin plates 12 adjacent to each other in the rotation axis direction are electrically insulated. The laser welds 15 and 16 of the thin plate 12 are laser welded.

  FIG. 2 is an enlarged view of a portion of the stator core 10 of the present invention that is laser welded. 2A is a plan view of the first layer 12a, FIG. 2B is a plan view of the second layer 12b, and FIG. 2C is a front view of the stator core 10. FIG. The third layer 12c has the same shape as the first layer 12a, and the fourth layer 12d has the same shape as the second layer 12b. Even after the fifth layer, the odd layer has the same shape as the thin plate 12a of the first layer, and the even layer has the same shape as the thin plate 12b of the second layer.

  The first-layer thin plate 12 a includes a laser welded portion 15 and a non-welded portion 17. The second layer thin plate 12 b includes a laser welded portion 16 and a non-welded portion 18. In the third and subsequent thin plates 12c, 12d,..., The odd-numbered layer includes the laser welded portion 15 and the non-welded portion 17, and the even-numbered layer includes the laser welded portion 16 and the non-welded portion 18.

  The non-welded portions 17 and 18 have a concave shape that is recessed from the outer periphery of the stator core 10. The dent amount h1 of the non-welded portion 17 and the dent amount h2 of the non-welded portion 18 are set so as not to melt even when the laser is defocused by the dent and the inside of the dent is irradiated with the laser. The dent amount h1 of the non-welded portion 17 and the dent amount h2 of the non-welded portion 18 are desirably set to the same value. As a result, the odd-numbered thin plates 12a, 12c,... And the even-numbered thin plates 12b, 12d,. Therefore, when the thin plates 12 having the same shape are laminated on the front, back, front, back,..., The stator core 10 is formed. In this way, only one type of punching die is required.

  The center of the laser welded portion 15 of the first thin plate 12a and the center of the non-welded portion 18 of the second thin plate 12b coincide with each other in the direction of the rotation axis 11. The center of the non-welded portion 17 of the first layer thin plate 12a and the center of the laser welded portion 16 of the second layer thin plate 12b coincide with each other in the direction of the rotation axis 11. This relationship is the same for the third and subsequent thin plates 12c, 12d,.

  The dent amount h1 of the non-welded portion 17 is such that the width k1 of the narrowest portion of the yoke 13 including the non-welded portion 17 is equal to or greater than the width k1 of the narrowest portion of the portion not including the non-welded portion 17. Is set. This is because the flow of magnetic flux between adjacent yokes 13 is not hindered. Similarly, the dent amount h2 of the non-welded portion 18 is also set.

  The dividing boundary 23a on the rotating shaft 11 side of the first thin plate 12a, the dividing boundary 23b on the rotating shaft 11 side of the second thin plate 12b,... It is set to make. Thereby, the precision improvement of the division surface of the stator core 10 and a perpendicular magnetic flux reduction are implement | achieved.

  FIG. 3 is an enlarged view of the laser welded portions 15 and 16 when the stator core 10 of the present invention is ideally laser welded (FIG. 3 shows the case of spot welding). 3A is a plan view and FIG. 3B is a front view. As shown in FIG. 3B, the laser is spot-irradiated at the center of the laser welded portion 15 of the thin plate 12a of the first layer. The center of the laser penetration part 19 coincides with the center of the laser welding part 15. The laser penetration part 19 does not reach the adjacent lower thin plate 12b. Therefore, the thin plate 12a of the first layer and the thin plate 12b of the second layer are electrically insulated.

  The laser is spot-irradiated at the center of the laser welded portion 16 of the second thin plate 12b. The center of the laser penetration 20 coincides with the center of the laser weld 16. The laser penetration part 20 does not reach the adjacent upper thin plate 12a and the lower thin plate 12c. Therefore, the thin plate 12a of the first layer, the thin plate 12b of the second layer, and the thin plate 12c of the third layer are electrically insulated. This relationship is the same for the third and subsequent thin plates 12c, 12d,.

  FIG. 4 is an enlarged view of the actual state of the laser welds 15 and 16 that are laser-welded in a spot manner. 4A is a plan view and FIG. 4B is a front view. The stator core 10 is formed by laminating about 200 to 300 thin plates 102 having a thickness of about 0.3 mm to 0.5 mm. Therefore, in the stator core 10 as a whole, a slight thickness error of each thin plate 12 is accumulated, and the accumulated error in the thickness direction may exceed the thickness of one thin plate 12. In addition, laser positioning errors must be considered.

  The thickness error of the thin plate 12 and the laser positioning error overlap, and in reality, as shown in FIG. 4B, the positions of the laser melted portions 19 and 20 may vary in the rotation axis direction. However, as shown in FIG. 4B, in the stator core 10 of the present invention, even if the positions of the laser penetration portions 19 and 20 vary in the rotation axis direction, the laser penetration portions 19 and 20 are thin plates adjacent in the rotation axis direction. Less than 12.

  For example, the laser penetration part 19 of the thin plate 12a of the first layer is shifted downward. This is because the laser irradiation position is shifted downward. At this time, the laser irradiates the first layer 12a and the second layer 12b simultaneously. Since the laser is focused on the laser welding portion 15 of the first thin plate 12a, the laser penetration portion 19 is formed by melting. However, the laser irradiation portion of the second thin plate 12b is a non-welded portion 18 having a concave shape that is recessed from the outer periphery of the stator core 10, so that the laser is not focused. For this reason, the non-welded portion 18 does not melt even when irradiated with a laser. Therefore, although the laser irradiation position is shifted downward, the laser penetration portion 19 is formed only on the first thin plate 12a. As a result, the electrical insulation between the first layer 12a and the second layer 12b is maintained.

  Based on the same principle, even if the laser irradiation position is shifted in the rotation axis direction, the laser penetration portion 20 of the second thin plate 12b does not reach the first thin plate 12a or the third thin plate 12c. Therefore, the electrical penetration between the second thin plate 12b and the first thin plate 12a and the third thin plate 12c is not broken by the laser penetration portion 20 of the second thin plate 12b.

  The same applies to all the thin plates 12a, 12b, 12c, 12d,... That form the stator core 10. Therefore, even if the laser irradiation position is shifted in the rotation axis direction, the insulation in the rotation axis direction among all the thin plates 12a, 12b, 12c, 12d,.

  If the laser penetration portion 19 reaches the non-welded portion 17 in one thin plate, the non-welded portion 17 may be melted and insulation between the thin plates 12 adjacent in the rotation axis direction may be lost. Therefore, the laser welded portion 15 and the non-welded portion 17 are separated by a distance that the laser penetration portion 19 does not reach the non-welded portion 17. Similarly, the laser welded portion 16 and the non-welded portion 18 are separated by a distance that the laser penetration portion 20 does not reach the non-welded portion 18.

  Even if the laser irradiation position is shifted in the rotation axis direction, the laser may be irradiated continuously in the rotation axis direction instead of spot irradiation if the principle of maintaining insulation between the thin plates 12 adjacent in the rotation axis direction is maintained. Continuous irradiation is easier to control than spot irradiation.

  FIG. 5 is a schematic view of the laser welds 15 and 16 continuously laser-welded in the direction of the rotation axis. FIG. 5A is a plan view and FIG. 5B is a front view. Unlike the spot welding in FIG. 4, when the laser is moved in the direction of the rotation axis, the intensity of the laser may be constant.

  If the laser welding portion 15 of the first thin plate 12a is irradiated while the laser moves downward (in the direction of the rotation axis), the laser welding portion 15 is in focus, so the laser welding portion 15 melts and the laser penetration portion 21 is formed. When the laser moves to the second-layer thin plate 12b, the laser irradiation portion is a concave non-welded portion 18 that has receded from the outer periphery of the stator core 10, so that the laser is not focused. For this reason, the non-welded portion 18 does not melt even when irradiated with a laser. Therefore, even if the laser irradiates the second layer thin plate 12b while moving downward, the laser melting portion is not formed in the second layer thin plate 12b.

  Next, when the laser welding part 15 of the third layer thin plate 12c is irradiated while the laser moves downward (in the direction of the rotation axis), the laser welding part 15 is melted because the laser welding part 15 is focused. The melted part 21 is formed. When the laser moves to the thin plate 12d of the fourth layer, the laser irradiation portion is a concave non-welded portion 18, and therefore the laser is not focused. For this reason, even if the laser irradiates the fourth layer thin plate 12c while moving downward, the laser melting portion is not formed in the fourth layer thin plate 12d.

  In this way, the laser penetration portion 21 of the laser welded portion 15 of the odd-numbered thin plate 12 such as the laser welded portion 15 of the first-layer thin plate 12a and the laser welded portion 15 of the third-layer thin plate 12c is formed. The even-numbered thin plate 12 is not formed with a laser penetration portion.

  Next, the laser irradiation line is moved to the laser welding part 16 of the thin plate 12b of the second layer, and the laser is moved downward (in the direction of the rotation axis). In the same manner as above, the laser welded portion 22 is formed in the laser welded portion 16 of the second thin plate 12b, but the laser welded portion is not formed in the first thin plate 12a and the third thin plate 12c. . By repeating this, the laser welded portion 22 of the laser welded portion 16 of the even-numbered thin plate 12 such as the laser welded portion 16 of the second-layer thin plate 12b and the laser welded portion 16 of the fourth-layer thin plate 12d is formed. The odd-numbered thin plates 12 are not formed with a laser penetration portion.

  If the laser penetration part 21 reaches the non-welded part 17, the non-welded part 17 melts, and there is a possibility that insulation between the thin plates 12 adjacent to each other in the rotation axis direction is lost. Therefore, the laser welded portion 15 and the non-welded portion 17 are separated by a distance that the laser penetration portion 21 does not reach the non-welded portion 17. Similarly, the laser welded portion 16 and the non-welded portion 18 are separated by a distance that the laser penetration portion 22 does not reach the non-welded portion 18.

  FIG. 6 is an enlarged view of a laser welded portion of a stator core 30 according to another example of the present invention. 6A is a plan view of the first layer 31a, FIG. 6B is a plan view of the second layer 31b, and FIG. 6C is a front view of the stator core 30. FIG. The third layer thin plate 31c has the same shape as the first layer thin plate 31a, and the fourth layer thin plate 31d has the same shape as the second layer thin plate 31b. Even after the fifth layer, the odd layer has the same shape as the thin plate 31a of the first layer, and the even layer has the same shape as the thin plate 31b of the second layer.

  The first layer thin plate 31 a includes a laser welded portion 32 and a non-welded portion 33. The second layer thin plate 31 b includes a laser welded portion 34 and a non-welded portion 35. Also in the third and subsequent layers, the odd layer includes the laser welded portion 32 and the non-welded portion 33, and the even layer includes the laser welded portion 34 and the non-welded portion 35. The non-welded portions 33 and 35 have a convex shape protruding from the outer periphery of the stator core 30. The protrusion amount h3 of the non-welded portion 33 and the protrusion amount h4 of the non-welded portion 35 are set so as not to melt even when the laser is out of focus and the protrusion portion is irradiated with the laser. The protrusion amount h3 of the non-welded portion 33 and the protrusion h4 of the non-welded portion 35 are desirably set to the same value. Thus, the odd-numbered thin plates 31a, 31c,... And the even-numbered thin plates 31b, 31d,. Therefore, when the thin plate 31 having the same shape is laminated on the front, back, front, back,..., The stator core 30 is formed. In this way, only one type of punching die is required. The laser welds 32 and 34 have an arc shape along the outer periphery of the stator core 30 or a linear shape that is a tangent to the outer periphery of the stator core 30.

  As shown in FIG. 6, by providing the laser welded portion 32 and the non-welded portion 35 in the direction of the rotation axis and providing the laser welded portion 34 and the non-welded portion 33 in the direction of the rotation axis, the stator core 30 is spot-like like the stator core 10. In both cases of laser welding and continuous laser welding, insulation between the thin plates 31 adjacent in the axial direction is maintained. According to this, since the width of the yoke is not limited by the non-welded portion 33, magnetic saturation can be avoided.

  FIG. 7 is a plan view of the first layer thin plate 41a of the stator core 40 of another example of the present invention. The thin plate 41 a has a welding heat blocking gap 44 between the laser welding portion 42 and the slot 43. In the case of FIG. 7, the welding heat insulation gap 44 is a through hole provided between adjacent thin plates 41a. The hole shape of the welding heat blocking gap 44 is not particularly limited. Around the slot 43, there is an insulating material 45 that is weak against heat. The welding heat blocking gap 44 prevents the insulating material 45 from being deteriorated by the heat of laser welding.

  FIG. 8 is a plan view of a stator core 50 according to another example of the present invention. The stator core 50 is formed by laminating a first layer thin plate 51a, a second layer thin plate 51b, a third layer thin plate 51c,. The first layer thin plate 51 a includes a laser welded portion 52 and a non-welded portion 53. The second layer thin plate 51 b includes a laser welded portion 54 and a non-welded portion 55. In the third and subsequent thin plates 51c, 51d,..., The odd-numbered layer includes the laser welded portion 52 and the non-welded portion 53, and the even-numbered layer includes the laser welded portion 54 and the non-welded portion 55. The non-welded portions 53 and 55 have a concave shape that is recessed from the inner periphery of the yoke 56. The dent amount h5 of the non-welded portion 53 and the dent amount h6 of the non-welded portion 55 are set so as not to melt even if the laser is out of focus due to the dent and the inside of the dent is irradiated with the laser. The dent amount h5 of the non-welded portion 53 and the dent amount h6 of the non-welded portion 55 are desirably set to the same value. As a result, the odd-numbered thin plates 51a, 51c,... And the even-numbered thin plates 51b, 51d,. Therefore, when the thin plates 51 having the same shape are stacked on the front, back, front, back,..., The stator core 50 is formed. In this way, only one type of punching die is required.

  In the stator core 50, after winding the slot 57, laser welding can be performed by irradiating the slot opening 58 with laser. Thereby, aligned winding becomes possible. Further, even a flat wire can be wound with a high space factor.

  FIG. 9 is a plan view of a stator core 60 of another example of the present invention. The stator core 60 is formed by laminating a first layer 61a, a second layer 61b, a third layer 61c, and so on. In the stator core 60, the thin plates 61a, 61b, 61c,... The first-layer thin plate 61 a includes a laser welded portion 63 and a non-welded portion 64. The second layer thin plate 61 b includes a laser welded portion 65 and a non-welded portion 66. In the third and subsequent thin plates 61c, 61d,..., The odd-numbered layer includes a laser welded portion 63 and a non-welded portion 64, and the even-numbered layer includes a laser welded portion 65 and a non-welded portion 66. The non-welded portions 64 and 66 have a concave shape that is recessed from the inner periphery of the tooth 62. The dent amount h7 of the non-welded portion 64 and the dent amount h8 of the non-welded portion 66 are set so as not to melt even when the laser is defocused by the dent and the inside of the dent is irradiated with the laser. The dent amount h7 of the non-welded portion 64 and the dent amount h8 of the non-welded portion 66 are desirably set to the same value. As a result, the odd-numbered thin plates 61a, 61c,... And the even-numbered thin plates 61b, 61d,. Therefore, when the thin plates 61 having the same shape are laminated on the front, back, front, back,..., The stator core 60 is formed. In this way, only one type of punching die is required. At this time, it is not desirable to make the non-welded portion convex as shown in FIG. This is because the non-welded portion protrudes into the air gap and contacts the rotor.

  The stator cores 10, 30, 40, and 50 (excluding the stator core 60 divided in the teeth) of the present invention are preferably used for concentrated winding. In the case of using concentrated winding, productivity is high because the stator core can be connected to the teeth of the stator core in a divided state, and then the necessary laser welding can be performed.

  The stator core of the present invention is also used for distributed winding. When used in distributed winding, the stator core is coupled, and necessary winding is performed after laser welding.

  Although the above description is a stator core suitable for an inner rotor, the stator core of the present invention is also used for an outer rotor. When the stator core of the present invention is used for the outer rotor, “the outer periphery of the stator core” in the above description may be read as “the inner periphery of the stator core”.

  The stator core of the present invention is suitably used for PM motors, synchronous reluctance motors, and switched reluctance motors.

DESCRIPTION OF SYMBOLS 10 Stator core 11 Rotating shaft 12, 12a, 12b, 12c, 12d Thin plate 13 Yoke 14 Teeth 15, 16 Laser welding part 17, 18 Non-welding part 19, 20, 21, 22 Laser penetration part 23a, 23b Split boundary 30 Stator core 31, 31a, 31b, 31c, 31d Thin plate 32, 34 Laser welded portion 33, 35 Non-welded portion 40 Stator core 41a Thin plate 42 Laser welded portion 43 Slot 44 Welding heat blocking gap 45 Insulating material 50 Stator core 51a, 51b, 51c, 51d Thin plate 52, 54 Laser welded portions 53, 55 Non-welded portion 56 Yoke 57 Slot 58 Slot open 60 Stator core 61a, 61b, 61c, 61d Thin plate 62 Teeth 63, 65 Laser welded portion 64, 66 Non-welded portion 100 Stator core 101 Rotating shaft 102 Thin plate 10 3 Laser welded part 104 Yoke 105 Teeth 106 Laser penetration part

Claims (18)

A stator core formed by dividing a hollow disk into a plurality in the circumferential direction, a T-shaped thin plate having a yoke and teeth, laminated in the rotation axis direction and coupled in the circumferential direction,
A laser welded portion provided on the outer periphery or inner periphery of the thin plate;
The non-divided portion of the outer periphery or inner periphery of the thin plate is provided with a non-welded portion that retreats or protrudes from the outer periphery or the inner periphery,
The laser welded portion and the non-welded portion are stator cores arranged alternately in the rotation axis direction.   The stator core according to claim 1, wherein a penetration portion of the laser welding portion does not reach the non-welded portion in each thin plate.   The stator core according to claim 1, wherein the laser welded portion is formed by spot welding to each laminated thin plate.   The stator core according to claim 1 or 2, wherein the laser welding portion is formed by continuous welding in the rotation axis direction.   5. The laser welded portion according to claim 1, wherein the laser welded portion is linear or arcuate about the rotation axis, and the non-welded portion is a concave shape having a smaller radius of curvature than the laser welded portion. Stator core.   The stator core according to claim 5, wherein a width of the narrowest portion of the yoke including the non-welded portion is equal to or greater than a width of the narrowest portion of the yoke not including the non-welded portion.   The said laser welding part is linear shape or the circular arc shape centering on the said rotating shaft, The said non-welding part is a convex shape with a smaller curvature radius than the said laser welding part. Stator core.   8. The stator core according to claim 1, wherein, except for the vicinity of the laser welded portion, the divided boundary surfaces of the laminated thin plates are flush with each other in the rotation axis direction.   The stator core according to any one of claims 1 to 8, wherein the yoke has a division boundary in the circumferential direction of the thin plate.   The stator core according to any one of claims 1 to 9, wherein the yoke has the laser welded portion and the non-welded portion on an outer peripheral portion of the yoke.   The stator core according to claim 1, wherein a welding heat blocking gap is provided between the laser weld and the slot.   The stator core according to any one of claims 1 to 9, or 11, wherein the laser welding portion and the non-welding portion are provided on an inner peripheral portion of the yoke.   The stator core according to claim 12, wherein the laser weld is welded from a slot open after winding.   The stator core according to any one of claims 1 to 8, wherein the teeth have a dividing boundary in the circumferential direction of the thin plate.   The stator core according to any one of claims 1 to 8, or 14, wherein the laser welded portion is provided on an inner peripheral portion of the teeth.   A motor comprising the stator core according to claim 1. A plurality of hollow discs in the circumferential direction having laser welded portions on the outer peripheral or inner peripheral portion, non-split portions on the outer peripheral or inner periphery, and non-welded portions that are retracted or protruded from the outer peripheral or inner periphery. Preparing a T-shaped thin plate having divided yokes and teeth;
Laminating the thin plates such that the laser welded portions and non-welded portions are alternately arranged in the rotation axis direction;
Coupling the laminated thin plates in the circumferential direction;
A method for manufacturing a stator core, comprising spot welding the laser weld. A plurality of hollow discs in the circumferential direction having laser welded portions on the outer peripheral or inner peripheral portion, non-split portions on the outer peripheral or inner periphery, and non-welded portions that are retracted or protruded from the outer peripheral or inner periphery. Preparing a T-shaped thin plate having divided yokes and teeth;
Laminating the thin plates such that the laser welded portions and non-welded portions are alternately arranged in the rotation axis direction;
Coupling the laminated thin plates in the circumferential direction;
A method for manufacturing a stator core, comprising continuously welding the laser weld.

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