Stator

Abstract

To provide a stator having a case portion made of a cast component that can reduce compressive stress applied to a stator core.SOLUTION: A stator includes a hollow cylindrical stator core formed by stacking multiple laminated plates in the axial direction, with multiple segment coils inserted into slots formed on the inner surface and a protrusion on the outer peripheral surface, and a case portion which is a cast portion for fixing the multiple laminated plates which make up the stator core, the case portion is joined to each of the upper and lower surfaces of the stator core and extends along the axial direction of the stator core at a position facing the outer peripheral surface of the stator core, and the case portion is further joined to the protrusion on the outer peripheral surface of the stator core and positioned away from the outer peripheral surface other than the protrusion so as to form a gap with the outer peripheral surface other than the protrusion.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a stator, which is a component part of a rotating electric machine. [Background technology]

[0002] The stator includes a hollow cylindrical stator core formed by stacking multiple laminated plates in the axial direction, and multiple segment coils inserted into slots formed on the inner peripheral surface of the stator core. Patent Document 1 discloses a technique for fixing multiple laminated plates that make up the stator core using a case part that is an aluminum cast part. The case part is joined to the outer peripheral surface of the stator core so as to contact the entire outer peripheral surface of the stator core without any gaps. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-93891 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology of Patent Document 1 has a problem in that compressive stress is applied to the stator core when the aluminum case is cast, which deteriorates the iron loss of the stator core. This specification provides a stator having a case part made of a cast part that can suppress compressive stress applied to the stator core. [Means for solving the problem]

[0005] The stator disclosed in this specification may include a stator core having a hollow cylindrical shape formed by stacking a plurality of laminated plates in the axial direction, a plurality of segment coils being inserted into slots formed on the inner peripheral surface and having a protrusion on the outer peripheral surface, and a case part made of a cast part for fixing the plurality of laminated plates constituting the stator core. The case part may extend along the axial direction of the stator core at a position facing the outer peripheral surface of the stator core and be joined to each of the upper and lower surfaces of the stator core. The case part may further be joined to the protrusion on the outer peripheral surface of the stator core and be disposed apart from the outer peripheral surface other than the protrusion so as to form a gap between the case part and the outer peripheral surface other than the protrusion.

[0006] The case portion of the stator is disposed so as to be spaced apart from the outer peripheral surface of the stator core to form a gap therebetween, thereby suppressing compressive stress applied to the stator core when the case portion is cast in place. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic perspective view of the stator with a case portion removed; [Diagram 2] FIG. 2 is a cross-sectional view parallel to the axial direction of the stator core, and is a schematic cross-sectional view of a stator including a protrusion of the stator core. [Diagram 3] FIG. 2 is a cross-sectional view parallel to the axial direction of the stator core, and is a schematic cross-sectional view of a stator not including a protrusion of the stator core. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a stator, which is a component of a rotating electric machine, will be described with reference to the drawings. For the purpose of clarity of illustration, the shapes of common components may be changed between different drawings, but components with the same reference numerals indicate the same components.

[0009] As shown in Figures 1 to 3, the stator 1 includes a stator core 10 and a plurality of segment coils 20. Note that Figure 1 illustrates a state in which a case portion 30 shown in Figures 2 and 3 has been removed.

[0010] As shown in FIG. 1, the stator core 10 is formed by stacking a plurality of laminated steel plates 11, for example made of a magnetic material, in the axial direction. The stator core 10 has a hollow cylindrical yoke portion 12, a plurality of teeth 14 extending radially inward from the inner peripheral surface of the yoke portion 12, and a plurality of protrusions 16 protruding radially outward from the outer peripheral surface of the yoke portion 12. A rotor (not shown) is inserted into the central hole of the yoke portion 12. Each of the plurality of teeth 14 extends from the upper surface 10U to the lower surface 10B of the yoke portion 12 along the axial direction of the stator core 10, and is disposed at intervals from each other along the circumferential direction of the stator core 10. The space between adjacent teeth 14 is called a slot 18. Each of the plurality of protrusions 16 extends from the upper surface 10U to the lower surface 10B of the yoke portion 12 along the axial direction of the stator core 10, and is disposed at intervals from each other along the circumferential direction of the stator core 10.

[0011] Each of the multiple segment coils 20 is inserted into a corresponding one of the multiple slots 18 of the stator core 10. Each of the multiple segment coils 20 is a rectangular wire formed by coating an insulator on the surface of a conductor (e.g., copper). Each of the multiple segment coils 20 has a first protruding portion 22 and a second protruding portion 24 protruding from the slot 18 of the stator core 10. The first protruding portion 22 is a portion of the segment coil 20 protruding from the slot 18 of the stator core 10 on one side in the axial direction of the stator core 10 (the upper surface side in this example). The second protruding portion 24 is a portion of the segment coil 20 protruding from the slot 18 of the stator core 10 on the other side in the axial direction of the stator core 10 (the lower surface side in this example). Each of the multiple segment coils 20 is formed into a substantially U-shape, and then inserted into the slots 18 of the stator core 10 along the axial direction of the stator core 10, and then formed by bending the first protrusions 22 of the segment coils 20. The tip of the first protrusion 22 of the bent segment coil 20 is welded to the tip of the first protrusion 22 of another bent segment coil 20. In this way, multiple coils are formed that are distributed around the inner circumferential surface of the stator core 10.

[0012] 2 and 3 show cross-sectional views of the stator 1 cut parallel to the axial direction of the stator core 10. Fig. 2 is a cross-section cut so as not to include the protrusions 16 of the stator core 10, and Fig. 3 is a cross-section cut so as to include the protrusions 16 of the stator core 10.

[0013] As shown in Figs. 2 and 3, the stator 1 further includes a case portion 30 which is an aluminum cast part. The case portion 30 has an annular shape surrounding the stator core 10 so as to cover the outer peripheral surface of the stator core 10. The case portion 30 has a U-shaped cross section, extends along the axial direction of the stator core 10 at a position facing the outer peripheral surface of the stator core 10, and is joined to each of the upper surface 10U and the lower surface 10B of the stator core 10. The case portion 30 is further joined to the protrusion 16 of the outer peripheral surface of the stator core 10 (see Fig. 3), and is disposed apart from the outer peripheral surface other than the protrusion 16 so as to form a gap 32 (see Fig. 2). In this way, the case portion 30 is joined to each of the upper surface 10U and the lower surface 10B of the stator core 10 and joined to the protrusion 16 of the outer peripheral surface, whereby the multiple laminated steel plates 11 are stably fixed. Meanwhile, since the case portion 30 is disposed so as to form a gap 32 with respect to the outer peripheral surface of the stator core 10 other than the protrusions 16, the surface pressure generated on the outer peripheral surface of the stator core 10 when the case portion 30 is cast is suppressed, and the compressive stress applied to the stator core 10 is suppressed. As a result, the deterioration of the iron loss of the stator core 10 is suppressed.

[0014] The gap 32 between the stator core 10 and the case portion 30 may be formed by casting with a core corresponding to the gap 32 placed in place. Alternatively, the gap 32 between the stator core 10 and the case portion 30 may be formed by controlling the temperature in the aluminum material when the molten aluminum material is hardened during casting. For example, the aluminum material may be contracted toward the outside in the radial direction of the stator core 10 by cooling from a mold arranged on the outside in the radial direction of the stator core 10, thereby forming the gap 32 between the stator core 10 and the case portion 30.

[0015] The protrusions 16 formed on the outer circumferential surface of the stator core 10 may have through holes and / or recesses extending in any direction. For example, a through hole extending from the upper surface to the lower surface of the protrusions 16 along the axial direction of the stator core 10 may be formed, or a plurality of recesses may be formed on the side surface of the protrusions 16. When such through holes and / or recesses are provided, the molten aluminum material flows into the through holes and / or recesses during casting, and the aluminum material hardens in the through holes and / or recesses, thereby more firmly joining the case part 30 and the stator core 10. [Explanation of symbols]

[0016] 1: stator, 10: stator core, 11: laminated steel plate, 12: yoke portion, 14: teeth, 16: protrusion portion, 18: slot, 20: segment coil, 30: case portion, 32: gap

Claims

[Claim 1] A stator core having a hollow cylindrical shape formed by stacking a plurality of laminated plates in an axial direction, the stator core having a plurality of segment coils inserted into slots formed on an inner peripheral surface thereof and a protrusion on an outer peripheral surface thereof; and a case portion of a casting part that fixes the plurality of laminated plates that constitute the stator core, the case portion extends along the axial direction of the stator core at a position facing the outer circumferential surface of the stator core and is joined to each of an upper surface and a lower surface of the stator core, The case portion is further joined to the protrusion portion of the outer peripheral surface of the stator core and is positioned away from the outer peripheral surface other than the protrusion portion to form a gap.

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