Stator core assembly and rotary electric machine

Abstract

The present invention provides a stator for a rotary electric machine, the stator comprising: a stator core including a plurality of laminated electromagnetic steel plates; and a plurality of end duct spacers which are arranged at intervals in the circumferential direction of the rotary electric machine and which press the end face on one side of the stator core in the axial direction of the rotary electric machine, wherein a plurality of slots for installing stator coils are formed at circumferential intervals on the inner circumferential surface of the stator core, the plurality of end duct spacers include a first end duct spacer disposed at a position displaced from the range where the slots are formed in the circumferential direction, and when a contact surface inner end position is defined to be the innermost position in the radial direction of the rotary electric machine from among contact surfaces contacting the plurality of end duct spacers on the end face of the stator iron core, the inner end of the first end duct spacer in the radial direction is located farther inward than the contact surface inner end position in the radial direction.

Description

Stator core assembly and rotating electric machine

[0001] The present disclosure relates to a stator core assembly and a rotating electric machine.

[0002] Generally, the stator of a large rotating electric machine, such as a turbine generator installed in a thermal power plant or a nuclear power plant, has a stator core and a stator coil (stator winding), and the stator core is formed by laminating multiple electromagnetic steel sheets (e.g., silicon steel sheets) (see, for example, Patent Document 1). The multiple electromagnetic steel sheets of the stator core are laminated with insulation on both sides, and adjacent electromagnetic steel sheets are electrically insulated from each other. Both ends of the stator core in the axial direction of the rotating electric machine are clamped by ring-shaped clamps via multiple end duct spacers to hold the multiple electromagnetic steel sheets together.

[0003] A plurality of slots (grooves) are formed on the inner peripheral surface of the stator core, and stator coils are embedded in the slots and fixed in place by wedges. The stator coils embedded in the slots are electrically connected to the axial ends (coil end portions) of the stator coils on the axial outside of the stator core.

[0004] The end duct spacers and the magnetic steel sheets are either electrically integrated by spot welding or insulated. According to the inventors' findings, in the case of an insulated design, if the insulation between the end duct spacers and the magnetic steel sheets breaks down, electrical continuity occurs, and the broken insulation point overheats due to eddy currents generated by leakage flux at the core end.

[0005] Japanese Patent Application Laid-Open No. 2003-219583

[0006] A short circuit between the end duct spacer and the electromagnetic steel sheet can cause local overheating. Repairs require opening a gap between the end duct spacer and the electromagnetic steel sheet, inserting a new insulating plate, and applying insulating paint. However, because the stator coil is inserted into the stator core, opening the gap between the end duct spacer and the electromagnetic steel sheet after the generator is completed carries the risk of damaging the stator coil. Opening the gap between the end duct spacer and the electromagnetic steel sheet for repairs typically requires removing all stator coils and shifting the end duct spacer in the axial direction, but this requires a great deal of time and expense. In this regard, Patent Document 1 does not disclose any knowledge for preventing a short circuit between the end duct spacer and the electromagnetic steel sheet caused by a breakdown in the insulation between the end duct spacer and the electromagnetic steel sheet.

[0007] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a stator core assembly and a rotating electric machine that can suppress short circuits between end duct spacers and electromagnetic steel sheets caused by a breakdown in insulation between the end duct spacers and the electromagnetic steel sheets.

[0008] In order to achieve the above object, a stator core assembly according to at least one embodiment of the present disclosure is a stator core assembly for a rotating electric machine, comprising: a stator core including a plurality of stacked electromagnetic steel plates, with an insulating layer formed on both sides of each of the electromagnetic steel plates; and a plurality of end duct spacers that are arranged at intervals in the circumferential direction of the rotating electric machine and press one end face of the stator core in the axial direction of the rotating electric machine, wherein a plurality of slots for installing stator coils are formed at intervals in the circumferential direction on an inner peripheral surface of the stator core, and the plurality of end duct spacers include a first end duct spacer that is arranged at a position shifted from an area in which the slots are formed in the circumferential direction, and if the innermost position in the radial direction of the rotating electric machine of the contact surfaces that are in contact with the plurality of end duct spacers on the end faces of the stator core is defined as the contact surface inner end position, then the inner end of the first end duct spacer in the radial direction is located more inward than the contact surface inner end position in the radial direction.

[0009] To achieve the above object, a rotating electric machine according to at least one embodiment of the present disclosure includes the above stator core assembly and a rotor.

[0010] According to at least one embodiment of the present disclosure, there is provided a stator unit and a rotating electric machine that can suppress short circuits between the end duct spacer and the electromagnetic steel sheet due to breakdown of insulation between the end duct spacer and the electromagnetic steel sheet.

[0011] 3 is a partially cutaway perspective view showing a schematic configuration of a rotating electric machine 100. It is a diagram schematically showing a cross section of a portion of a stator core 2 along the axial direction. It is a cross-sectional view showing the structure of an axial end portion of the rotating electric machine 100, a view of a portion of the cross section of the rotating electric machine 100 along the axial direction viewed from the lateral direction (a direction perpendicular to a vertical plane including the rotation axis of the rotating electric machine 100). It is a perspective cross-sectional view showing the structure of the axial end portion of the rotating electric machine 100. It is a diagram showing the positional relationship between an end face 34 of the stator core 2 and multiple end duct spacers 22 when plane V indicated by a dashed line in FIG. 3 is viewed from the direction of arrow A, i.e., the arrangement of multiple end duct spacers 22 and the end face 34 of the stator core 2 when viewed from the outside in the axial direction (the opposite side of the stator core 2 with the end duct spacers 22 sandwiched between them). It is an enlarged view of portion X of FIG. 3 (the inner peripheral end portion at the contact portion between the axial end portion 33 of the stator core 2 and the end duct spacer 22). 7 is a cross-sectional view showing the structure of the axial end portion of a rotating electric machine according to a comparative embodiment, showing a portion of a cross section of the rotating electric machine along the axial direction as viewed from the lateral direction (a direction perpendicular to a vertical plane including the rotation axis of the rotating electric machine). It is a diagram showing the positional relationship between the end face 34 of the stator core 2 and multiple end duct spacers 22, as viewed from the direction of arrow A of plane V indicated by the dashed line in FIG. 7. It is an enlarged view of portion X in FIG. 7 (the inner peripheral end portion at the contact portion between the axial end portion 33 of the stator core 2 and the end duct spacer 22). It is a diagram for explaining a configuration in which the end plate 36 and multiple end duct spacers 22 are integrally formed as a single component.

[0012] Several embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the invention. For example, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express relative displacements with a tolerance or angle or distance to the extent that the same function is achieved. For example, expressions expressing the equality of things, such as "same," "equal," and "homogeneous," not only express strict equality, but also express tolerance or differences to the extent that the same function is achieved. For example, expressions expressing shapes such as a square or cylindrical shape not only express shapes such as a square or cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is achieved. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0013] First, a configuration of a rotating electric machine 100 according to an embodiment of the present disclosure will be described. Fig. 1 is a partially cutaway perspective view showing a schematic configuration of the rotating electric machine 100. Note that Fig. 1 shows the rotating electric machine 100 with a portion thereof removed for convenience of explanation.

[0014] Generally, rotating electric machines are roughly classified into three types according to their output (capacity): water-cooled rotating electric machines in which the stator coil is water-cooled and the interior of the machine is cooled with hydrogen gas, hydrogen-cooled rotating electric machines in which the stator coil and the interior of the machine are cooled with hydrogen gas, and air-cooled rotating electric machines in which the stator coil and the interior of the machine are cooled with air. In water-cooled rotating electric machines and hydrogen-cooled rotating electric machines, the interior of the machine is filled with pressurized hydrogen gas.

[0015] The rotating electrical machine (turbine generator) 100 according to this embodiment is filled with hydrogen gas and cooled by the hydrogen gas.

[0016] The rotating electric machine 100 includes a rotor 1 and a stator 4 that is disposed to face the outer peripheral surface of the rotor 1 and that forms a predetermined gap between the rotor 1 and the stator 4. The stator 4 includes a stator core 2 and a stator coil 3.

[0017] In the following description, unless otherwise specified, "axial direction" means the axial direction of the rotating electric machine 100 (the axial direction of the rotor 1, i.e., the axial direction of the stator 4), "radial direction" means the radial direction of the rotating electric machine 100 (the radial direction of the rotor 1, i.e., the radial direction of the stator 4) unless otherwise specified, and "circumferential direction" means the circumferential direction of the rotating electric machine 100 (the circumferential direction of the rotor 1, i.e., the circumferential direction of the stator 4) unless otherwise specified.

[0018] the rotor 1, the stator 4, the crossover wires 13, the lead wires 14, etc., are housed inside the rotating electric machine outer casing 6, which is filled with hydrogen gas; a terminal box 7 connected to the rotating electric machine outer casing 6 and installed below the rotating electric machine outer casing 6; a hydrogen cooler 8 connected to the rotating electric machine outer casing 6 and used to cool the interior of the machine with hydrogen gas; an end bracket 9 that closes the axial end of the rotating electric machine outer casing 6 and houses bearings, etc.; a rocker device 10 that houses current collector tubes and carbon brushes that supply DC current to the coil of the rotor 1; legs 11 to which the rotating electric machine outer casing 6 is fixed; and a current transformer 12 that measures the current that is output from the high-voltage bushing 5 to the outside of the machine.

[0019] The rotating electric machine 100 is connected to, for example, a steam turbine or a gas turbine, and generates electricity by transmitting the rotational energy of the steam turbine or gas turbine to the rotor 1 and rotating the rotor 1 at high speed inside the stator 4. The stator 4 includes a stator core 2 and a stator coil 3.

[0020] Fig. 2 is a schematic diagram showing an axial cross section of a portion of the stator core 2. As shown in Fig. 2, the stator core 2 includes a plurality of silicon steel plates 30 (a plurality of electromagnetic steel plates) stacked in the axial direction. An insulating layer 32 is formed on both sides of each of the plurality of silicon steel plates 30, and adjacent silicon steel plates 30 are electrically insulated from each other by the insulating layer 32. The thickness of each of the plurality of silicon steel plates 30 may be, for example, 1 mm or less (e.g., approximately 0.35 to 0.50 mm).

[0021] Next, the structure of the axial end portion of the rotating electric machine 100 will be described from the side and from a perspective. Fig. 3 is a cross-sectional view showing the structure of the axial end portion of the rotating electric machine 100, and is a view of a portion of a cross section of the rotating electric machine 100 along the axial direction as viewed from the side (a direction perpendicular to a vertical plane including the rotation axis of the rotating electric machine 100). Fig. 4 is a perspective cross-sectional view showing the structure of the axial end portion of the rotating electric machine 100 from a perspective view.

[0022] As partially shown in Figures 3 and 4, end plates 36 of core clamps 20 are installed at both axial ends of the rotating electric machine 100 to clamp the multiple silicon steel plates 30 that make up the stator core 2 from both sides of the stator core 2 in the axial direction (the stacking direction of the silicon steel plates 30), and multiple end duct spacers 22 are installed between each end plate 36 and the stator core 2 to transmit an axial compressive force (compressive force of the core clamps 20) to the stator core 2. The multiple end duct spacers 22 provided along one end face 34 of the stator core 2 in the axial direction are spaced apart in the circumferential direction and are configured to press the one axial end face 34 of the stator core 2 in the axial direction by the compressive force of the core clamp 20, and the multiple end duct spacers 22 provided along the other axial end face (not shown) of the stator core 2 are spaced apart in the circumferential direction and are configured to press the other axial end face of the stator core 2 in the axial direction by the compressive force of the core clamp 20. In other words, the pair of end plates 36 of the core clamp 20 are configured to sandwich the stator core 2 via the multiple end duct spacers 22 on both sides of the stator core 2 in the axial direction.

[0023] Keybars 23 (support rods serving as support members) that support the stator core 2 from the outer periphery are provided on the outer periphery of the stator core 2, and both axial ends of the keybars 23 are fixed (bolted) to end plates 36 via keybar bolts 24 and keybar nuts 25. That is, the keybars 23 and the keybar bolts 24 and keybar nuts 25 provided at both ends of the keybar 23 axially compress both axial ends of the stator core 2 (more specifically, the outer periphery at both axial ends of the stator core 2) via a pair of end plates 36 provided at both ends of the keybar 23. That is, the keybars 23, the keybar bolts 24 and keybar nuts 25 provided at both ends of the keybar 23, and the pair of end plates 36 provided at both ends of the keybar 23 form a core clamp 20 that clamps the plurality of silicon steel plates 30 that make up the stator core 2 from both sides of the stator core 2 in the axial direction (the stacking direction of the silicon steel plates 30). The end duct spacers 22 serve to transmit the compressive force of the core clamp 20 to the stator core 2 .

[0024] The stator core 2, the plurality of end duct spacers 22 that press against one end face 34 of the stator core 2 in the axial direction, the plurality of end duct spacers 22 that press against the other end face (not shown) of the stator core 2 in the axial direction, and the core clamp 20 that clamps the stator core 2 via the plurality of end duct spacers 22 on both sides of the stator core 2 in the axial direction constitute a stator core assembly 90. Note that, because the configurations of both ends of the stator core assembly 90 in the axial direction are basically the same (symmetrical), a description in this disclosure of the configuration of one end of the stator core assembly 90 in the axial direction also serves as a description of the configuration of the other end of the stator core assembly 90 in the axial direction.

[0025] A stator main plate 31 and a rotating electric machine outer casing 6 filled with hydrogen gas are installed on the outer periphery of the key bar 23 (on the outer periphery of the stator core 2). The stator main plate 31 forms a predetermined space inside the rotating electric machine outer casing 6 and supports the rotating electric machine outer casing 6. A plurality of stator main plates 31 are installed inside the rotating electric machine outer casing 6 at predetermined intervals in the axial direction, and each of the plurality of stator main plates 31 is formed in a ring shape.

[0026] On the other hand, on the axial outside of the stator core 2, the stator coil 3 has a curved shape, and the stator coil 3 is bound by glass fiber roving to a permanent ring 17 and a support ring 18 that are integrally installed on an axial support 16 that is fixed to an end plate 36, and is fixed in place with epoxy varnish.

[0027] The stator coil 3 is electrically connected to the stator core 2 at the axial end of the stator coil 3 on the axial outside.

[0028] In this way, the coil end support 41 (coil end portion) composed of the axial support 16, permanent ring 17 and support ring 18 is fixed to the end plate 36 installed on the axial end 33 of the stator core 2 (one end of the stator core 2 in the axial direction).

[0029] Then, on the axial outside of the stator core 2, the axial ends of the stator coil 3 are fixed by, for example, glass laminate, non-magnetic metal, glass fiber and / or epoxy varnish, to form coil end supports 41.

[0030] Furthermore, a copper shield 21 is installed between the axial support 16 and the end plate 36 , and the axial support 16 is fixed to the end plate 36 via the copper shield 21 .

[0031] Additionally, a slide bearing 15 is installed on the outside of the copper shield 21 to transmit axial compressive force to the stator core 2. The slide bearing 15 is installed on an axial support 16, and absorbs the difference in thermal expansion between the stator coil 3 and the stator core 2 that occurs as the temperature of the stator coil 3 rises.

[0032] Furthermore, a plurality of intermediate ducts 28 are provided at predetermined intervals in the axial direction in the stator core 2. The intermediate ducts 28 are gaps through which hydrogen gas flows, and may be formed between adjacent silicon steel plates 30 for every predetermined number of silicon steel plates 30 that make up the stator core 2, and are formed from, for example, H-beams.

[0033] Fig. 5 is a diagram showing the positional relationship between the end face 34 of the stator core 2 and the multiple end duct spacers 22 when plane V shown by the dashed line in Fig. 3 is viewed from the direction of arrow A, that is, the arrangement of the multiple end duct spacers 22 and the end face 34 of the stator core 2 when viewed from the outside in the axial direction (the opposite side of the stator core 2 with the end duct spacer 22 in between). Fig. 6 is an enlarged view of part X in Fig. 3 (the inner peripheral end at the contact portion between the axial end 33 of the stator core 2 and the end duct spacer 22).

[0034] As shown in Fig. 5, the silicon steel plate 30 of the stator core 2 may be formed by connecting a plurality of generally sector-shaped segments 38 in the circumferential direction. As shown in Fig. 5, a plurality of slots 19 for installing the stator coil 3 are formed at intervals in the circumferential direction on the inner peripheral surface 40 of the stator core 2. The stator core 2 includes a core back 44 and teeth portions 29 formed by a plurality of ridges 46 that protrude radially inward from the inner peripheral surface of the core back 44. Each of the ridges 46 extends axially, and a slot 19 is formed between adjacent ridges 46. The stator coil 3 (see Fig. 1) is embedded in the slot 19 and fixed in the slot 19 by wedges (not shown). In the exemplary embodiment shown in Figure 5, a groove 49 into which the key bar 23 (see Figure 1) fits is formed on the outer surface of the stator core 2, and the cross-sectional shapes of the groove 49 and the key bar 23 in a cross section perpendicular to the axial direction are each non-circular (trapezoidal in the example shown), so that the position of the stator core 2 does not shift circumferentially when the key bar 23 fits into the groove 49.

[0035] The plurality of end duct spacers 22 also include a plurality of first end duct spacers 22A arranged in positions circumferentially shifted from the range S1 where the slots 19 are formed (positions that do not overlap with the range S1 where the slots 19 are formed in the circumferential direction), and a plurality of second end duct spacers 22B arranged in positions circumferentially overlapping with the range S1 where the slots 19 are formed. The first end duct spacers 22A and the second end duct spacers 22B are arranged alternately in the circumferential direction, and the first end duct spacers 22A have a longer radial length than the second end duct spacers 22B.

[0036] In the illustrated exemplary embodiment, each of the plurality of first end duct spacers 22A extends radially from near the outer peripheral edge 35 of the end face 34 of the stator core 2, and is arranged at a position that overlaps with the core back 44 and the teeth 29 in the axial view, but does not overlap with the slots 19. Each of the plurality of second end duct spacers 22B extends radially from near the outer peripheral edge 35 of the end face 34 of the stator core 2, and is arranged at a position that overlaps with the core back 44 in the axial view, but does not overlap with the teeth 29 and the slots 19.

[0037] In the above configuration, the multiple end duct spacers 22 are sandwiched between the end plates 36 and the stator core 2, so multiple passages 51 extending radially are formed in the space between the end plates 36 and the stator core 2, and are partitioned by the multiple end duct spacers. Hydrogen gas passes through these multiple passages 51, thereby cooling the end surface 34 of the stator core 2.

[0038] 6 , if the radially innermost position of the contact surface 50 on the end face 34 of the stator core 2 that is in contact with the multiple end duct spacers 22 is defined as the contact surface inner end position Pi, the radially inner end 52 of the first end duct spacer 22A is located radially inward of the contact surface inner end position Pi. In the illustrated exemplary embodiment, the cross-sectional shape of the first end duct spacer 22A along the axial direction is rectangular, and the first end duct spacer 22A includes a side surface 54 facing the stator core 2 and a side surface 56 facing the end plate 36 (see FIG. 3 ). Each of the side surfaces 54 and 56 is flat, and if the radially innermost position of the side surface 54 (the position where the radially inner end face 53 of the first end duct spacer 22A and the side surface 54 connect) is defined as the side surface inner end position Pk, the side surface inner end position Pk is located radially inward of the contact surface inner end position Pi. In other words, the radially inner end face 53 of first end duct spacer 22A and the side face 54 of the first end duct spacer form a corner 55, and corner 55 is located radially inward of contact surface inner end position Pi. Note that contact surface 50 is the flat surface of insulating layer 32 of silicon steel plate 30 at one axial end of the multiple silicon steel plates 30 that make up stator core 2.

[0039] 6 , at the axial end 33 of the stator core 2, the end face 34 of the stator core 2 and the inner circumferential surface 40 are connected by a stepped portion 60 including a plurality of steps. As shown in Fig. 6 , in a cross section along the axial direction, the stepped portion 60 includes: a first-stage axially extending surface 61a extending in the axial direction from a contact surface inner end position Pi at the end face 34 of the stator core 2; a first-stage radially extending surface 61r extending radially inward from an end of the first-stage axially extending surface 61a opposite the end face 34 of the stator core 2; a second-stage axially extending surface 62a extending in the axial direction from an inner end of the first-stage radially extending surface 61r; and a second-stage radially extending surface 62r extending radially inward from an end of the second-stage axially extending surface 62a opposite the first-stage radially extending surface 61r. In the exemplary embodiment shown in FIG. 6 , the stepped portion 60 further includes a third-step axially extending surface 63 a extending along the axial direction from an inner end of the second-step radially extending surface 62 r in the radial direction, a third-step radially extending surface 63 r extending inward in the radial direction from an end of the third-step axially extending surface 63 a opposite to the second-step radially extending surface 62 r, and a fourth-step axially extending surface 64 a extending along the axial direction from the inner end of the third-step radially extending surface 63 r in the radial direction. a fourth-stage radial extending surface 64r extending radially inward from an end of the fourth-stage axial extending surface 64a opposite to the fourth-stage radial extending surface 64r, a fifth-stage axial extending surface 65a extending axially from an inner end of the fourth-stage radial extending surface 64r in the radial direction, and a fifth-stage radial extending surface 65r extending radially inward from an end of the fifth-stage axial extending surface 65a opposite to the fourth-stage radial extending surface 64r.

[0040] 6, the radially inner end 52 of the first end duct spacer 22A may be located radially inward of the second-stage axially extending surface 62a. In the illustrated exemplary embodiment, the radially inner end 52 of the first end duct spacer 22A is located radially inward of the fifth-stage axially extending surface 65a.

[0041] In some embodiments, as shown in FIG. 5, the radially inner end 70 of the second end duct spacer 22B may be configured not to protrude radially inward beyond the bottom surface 42 of the slot 19.

[0042] In some embodiments, for example as shown in FIG. 3, the radial inner end 52 of the first end duct spacer 22A may be configured not to protrude radially inward beyond the innermost end 2i of the stator core 2.

[0043] The effects of the stator core assembly 90 will now be described in comparison with a comparative embodiment. Fig. 7 is a cross-sectional view showing the structure of the axial end portion of a rotating electric machine according to the comparative embodiment, a view of a portion of the axial cross section of the rotating electric machine viewed from the lateral direction (a direction perpendicular to a vertical plane including the rotation axis of the rotating electric machine). Fig. 8 is a view showing the positional relationship between the end face 34 of the stator core 2 and multiple end duct spacers 22, as viewed from the direction of arrow A on plane V indicated by the dashed line in Fig. 7. Fig. 9 is an enlarged view of portion X in Fig. 7 (the inner peripheral end portion at the contact portion between the axial end portion 33 of the stator core 2 and the end duct spacers 22).

[0044] As shown in Figures 7 to 9, in the rotating electric machine of the comparative embodiment, the multiple end duct spacers 22 include multiple first end duct spacers 22C arranged at positions shifted circumferentially from the range in which the slots 19 are formed (positions that do not overlap with the range in which the slots 19 are formed circumferentially), and multiple second end duct spacers 22B arranged at positions that overlap with the range in which the slots 19 are formed circumferentially, and the configuration of the first end duct spacers 22C differs from that of the first end duct spacer 22A of the above embodiment.

[0045] In the comparative example shown in Figures 7 to 9, the radial position of the inner end 52 of the first end duct spacer 22C coincides with the contact surface inner end position Pi, and the corner 55 between the radial inner end face 53 of the first end duct spacer 22C and the side face 54 of the first end duct spacer 22C abuts against the end face 34 of the stator core 2.

[0046] As a result, the radial inner end 52 (more specifically, the corner 55) of the first end duct spacer 22C may dig into the end face 34 of the stator core 2, potentially damaging the insulating layer 32 on the surface of the stator core 2.

[0047] In contrast, in the rotating electric machine 100 according to the above-described embodiment, the radially inner end 52 of the first end duct spacer 22A is located radially inward of the contact surface inner end position Pi, so that the inner end 52 (more specifically, the corner 55) of the first end duct spacer 22A does not dig into the contact surface 50 of the stator core 2, and this makes it possible to prevent the insulating layer 32 on the surface of the stator core 2 (the insulating layer 32 on the surface of the silicon steel plate 30) from being broken. Therefore, it is possible to prevent a short circuit between the first end duct spacer 22A and the silicon steel plate 30 due to a breakdown in the insulation between the first end duct spacer 22A and the silicon steel plate 30.

[0048] Furthermore, in the rotating electric machine 100 according to the above-described embodiment, the inner end 52 of the first end duct spacer 22A in the radial direction does not protrude further inward than the innermost end 2i of the stator core 2 in the radial direction, and therefore it is possible to suppress an increase in the risk of contact between the inner end 52 of the first end duct spacer 22A and the rotor 1, while also suppressing a short circuit between the first end duct spacer 22A and the silicon steel plate 30 due to a breakdown in the insulation between the first end duct spacer 22A and the silicon steel plate 30.

[0049] Furthermore, in the rotating electric machine 100 according to the above-described embodiment, the radially inner end 52 of the second end duct spacer 22B does not protrude radially inward beyond the bottom surface 42 of the slot 19. This makes it possible to prevent interference between the stator coil 3 installed in the slot 19 and the second end duct spacer 22B, while suppressing a short circuit between the first end duct spacer 22A and the silicon steel plate 30 that would be caused by a breakdown in the insulation between the first end duct spacer 22A and the silicon steel plate 30.

[0050] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these embodiments. Furthermore, the above-described embodiments have been specifically described for ease of understanding, and are not limited to those having all of the described configurations. Furthermore, some of the configurations of the above-described embodiments may be deleted, and other configurations may be added, or they may be replaced with other configurations.

[0051] 10 , the end plate 36 provided at the axial end 33 of the stator core 2 and the multiple end duct spacers 22 may be integrally configured as a single, inseparable part, for example, molded integrally from a single material. In this case, as in the above-described embodiment, the radially inner end 52 of the first end duct spacer 22A is positioned radially inward of the contact surface inner end position Pi. This prevents the inner end 52 (more specifically, the corner 55) of the first end duct spacer 22A from digging into the contact surface 50 of the stator core 2, thereby preventing damage to the insulating layer 32 on the surface of the stator core 2 (the insulating layer 32 on the surface of the silicon steel plate 30). This prevents a short circuit between the first end duct spacer 22A and the silicon steel plate 30 due to a breakdown in insulation between the first end duct spacer 22A and the silicon steel plate 30.

[0052] Furthermore, for example, in the above-described embodiment, silicon steel sheets are given as an example of electromagnetic steel sheets that constitute the stator core 2, but the electromagnetic steel sheets are not limited to silicon steel sheets and may be other electromagnetic steel sheets (magnetic steel sheets) that do not contain silicon.

[0053] The contents described in each of the above embodiments can be understood, for example, as follows.

[0054] [1] A stator core assembly (e.g., the above-mentioned stator core assembly 90) according to at least one embodiment of the present disclosure is a stator core assembly for a rotating electric machine (e.g., the above-mentioned rotating electric machine 100), and comprises: a stator core (e.g., the above-mentioned stator core 2) including a plurality of laminated electromagnetic steel plates (e.g., the above-mentioned silicon steel plates 30), with an insulating layer (e.g., the above-mentioned insulating layer 32) formed on both sides of each of the electromagnetic steel plates; and a plurality of end duct spacers (e.g., the above-mentioned plurality of end duct spacers 22) that are arranged at intervals in the circumferential direction of the rotating electric machine and that press an end face (e.g., the above-mentioned end face 34) on one side of the stator core in the axial direction of the rotating electric machine, wherein a plurality of slots (e.g., the above-mentioned plurality of slots 19) for installing a stator coil (e.g., the above-mentioned stator coil 3) are formed at intervals in an inner peripheral surface of the stator core, The multiple end duct spacers include a first end duct spacer (e.g., the above-mentioned first end duct spacer 22A) that is positioned at a position shifted in the circumferential direction from the range in which the slots are formed (e.g., the above-mentioned range S1), and if the innermost position in the radial direction of the rotating electric machine among the contact surfaces (e.g., the above-mentioned contact surface 50) that are in contact with the multiple end duct spacers on the end face of the stator core is defined as the contact surface inner end position (e.g., the above-mentioned contact surface inner end position Pi), then the inner end of the first end duct spacer in the radial direction (e.g., the above-mentioned inner end 52) is located more inward in the radial direction than the contact surface inner end position.

[0055] According to the stator core assembly described in [1] above, the radially inner end of the first end duct spacer is located radially inward of the inner end position of the contact surface, which prevents the inner end of the first end duct spacer from digging into the contact surface of the stator core and breaking down the insulating layer on the surface of the electromagnetic steel sheet, thereby preventing a short circuit between the first end duct spacer and the electromagnetic steel sheet due to a breakdown in insulation between the first end duct spacer and the electromagnetic steel sheet.

[0056] [2] In some embodiments, in the stator core assembly described in [1] above, at the one end of the stator core in the axial direction (for example, the axial end 33 described above), the end face of the stator core and the inner circumferential surface are connected by a stepped portion including a plurality of steps (for example, the stepped portion 60 described above), In a cross section along the axial direction, the stepped portion includes: a first-stage axially extending surface (e.g., the above-described first-stage axially extending surface 61 a) extending along the axial direction from an inner end position of the contact surface on the end face of the stator core; a first-stage radially extending surface (e.g., the above-described first-stage radially extending surface 61 r) extending inward in the radial direction from an end of the first-stage axially extending surface opposite to the end face of the stator core (e.g., the above-described end face 34); a second-stage axially extending surface (e.g., the above-described second-stage axially extending surface 62 a) extending along the axial direction from an inner end of the first-stage radially extending surface; and a second-stage radially extending surface (e.g., the above-described second-stage radially extending surface 62 r) extending inward in the radial direction from an end of the second-stage axially extending surface opposite to the first-stage radially extending surface, The inner end (for example, the inner end 52 described above) of the first end duct spacer in the radial direction is located more inward than the second stage axially extending surface in the radial direction.

[0057] According to the stator core assembly described in [2] above, the radially inner end of the first end duct spacer is located inside the second-stage axially extending surface, which prevents the inner end of the first end duct spacer from digging into the contact surface of the stator core and breaking down the insulating layer on the surface of the electromagnetic steel sheet, thereby preventing a short circuit between the first end duct spacer and the electromagnetic steel sheet due to a breakdown in insulation between the first end duct spacer and the electromagnetic steel sheet.

[0058] [3] In some embodiments, in the stator core assembly described in [1] or [2] above, the inner end of the first end duct spacer in the radial direction (e.g., the inner end 52 described above) does not protrude further inward than the innermost end of the stator core in the radial direction (e.g., the end 2i described above).

[0059] According to the stator core assembly described in [3] above, it is possible to suppress an increase in the risk of contact between the inner end of the first end duct spacer and the rotor, while suppressing a short circuit between the first end duct spacer and the electromagnetic steel sheet caused by a breakdown in the insulation between the first end duct spacer and the electromagnetic steel sheet.

[0060] [4] In some embodiments, in the stator core assembly described in any of [1] to [3] above, the plurality of end duct spacers include a second end duct spacer (e.g., the above-mentioned second end duct spacer 22B) arranged at a position overlapping the range in the circumferential direction where the slot is formed (e.g., the above-mentioned range S1), and the inner end of the second end duct spacer in the radial direction (e.g., the above-mentioned inner end 70) does not protrude radially inward beyond the bottom surface of the slot (e.g., the above-mentioned bottom surface 42).

[0061] According to the stator core assembly described in [4] above, it is possible to prevent interference between the stator coil installed in the slot and the second end duct spacer, while suppressing a short circuit between the end duct spacer and the electromagnetic steel sheet caused by a breakdown in the insulation between the first end duct spacer and the electromagnetic steel sheet.

[0062] [5] A rotating electric machine according to at least one embodiment of the present disclosure (e.g., the rotating electric machine 100 described above) includes a stator core assembly according to any one of [1] to [4] above, and a rotor (e.g., the rotor 1 described above).

[0063] According to the rotating electric machine described in [5] above, by suppressing a short circuit between the end duct spacer and the electromagnetic steel sheet caused by a breakdown in the insulation between the first end duct spacer and the electromagnetic steel sheet, it is possible to suppress the occurrence of localized heating of the stator core and to operate the rotating electric machine stably.

[0064] DESCRIPTION OF SYMBOLS 1 Rotor 2 Stator core 2i End 3 Stator coil 4 Stator 5 High voltage bushing 6 Rotating electric machine outer casing 7 Terminal box 8 Hydrogen cooler 9 End bracket 10 Rocker device 11 Leg 12 Current transformer 13 Crossover wire 14 Lead wire 15 Slide bearing 16 Axial support 17 Permanent ring 18 Support ring 19 Slot 20 Core clamp 21 Copper shield 22 End duct spacer 22A, 22C First end duct spacer 22B Second end duct spacer 23 Keybar 24 Keybar bolt 25 Keybar nut 26 Wedge 27 Damaged part of stator core 2 28 Intermediate duct 29 Teeth part 30 Silicon steel plate 31 Stator main plate 32 Insulating layer 33 Axial end 34, 53 End face 35 Outer periphery 36 End plate 38 Divided piece 40 Inner periphery 41 Coil end support 42 Bottom face 44 Core back 46 Projection 49 Groove 50 Contact surface 51 Passage 52, 70 Inner end 54, 56 Side face 55 Corner 60 Step part 61a First stage axial extension surface 61r 1st stage radially extending surface 62a 2nd stage axially extending surface 62r 2nd stage radially extending surface 63a 3rd stage axially extending surface 63r 3rd stage radially extending surface 64a 4th stage axially extending surface 64r 4th stage radially extending surface 65a 5th stage axially extending surface 65r 5th stage radially extending surface 90 Stator core assembly 100 Rotating electric machine

Claims

1. A stator core assembly for a rotating electrical machine, comprising a stator core including a plurality of laminated electromagnetic steel sheets with insulating layers formed on both surfaces of each of the electromagnetic steel sheets, and a plurality of end duct spacers arranged at intervals in the circumferential direction of the rotating electrical machine and pressing one end face of the stator core in the axial direction of the rotating electrical machine. A plurality of slots for installing a stator coil are formed at intervals in the circumferential direction on the inner circumferential surface of the stator core. The plurality of end duct spacers include a first end duct spacer arranged at a position shifted from a range in which the slots are formed in the circumferential direction. Among contact surfaces in contact with the plurality of end duct spacers on the end face of the stator core, when a position on the innermost side in the radial direction of the rotating electrical machine is defined as an inner end position of the contact surface, an inner end of the first end duct spacer in the radial direction is located inward of the inner end position of the contact surface in the radial direction. Stator core assembly.

2. At one end of the stator core in the axial direction, the end face and the inner circumferential surface of the stator core are connected by a stepped portion including a plurality of steps. In a cross-section along the axial direction, the stepped portion includes a first stepped axial extending surface extending along the axial direction from the inner end position of the contact surface on the end face of the stator core, a first stepped radial extending surface extending inward in the radial direction from an end on the opposite side of the end face of the stator core on the first stepped axial extending surface, a second stepped axial extending surface extending along the axial direction from the inner end of the first stepped radial extending surface in the radial direction, and a second stepped radial extending surface extending inward in the radial direction from an end on the opposite side of the first stepped radial extending surface on the second stepped axial extending surface. The inner end of the first end duct spacer in the radial direction is located inward of the second stepped axial extending surface in the radial direction. The stator core assembly according to claim 1.

3. The inner end of the first end duct spacer in the radial direction does not protrude inward of the innermost end of the stator core in the radial direction. The stator core assembly according to claim 1.

4. The plurality of end duct spacers includes a second end duct spacer disposed at a position overlapping the range in which the slots are formed in the circumferential direction, and an inner end of the second end duct spacer in the radial direction does not protrude inward in the radial direction from a bottom surface of the slot. The stator core assembly according to claim 1.

5. A rotating electrical machine comprising the stator core assembly according to any one of claims 1 to 4 and a rotor.

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