Stator for rotary electric machine

Abstract

A stator (12) of a rotary electric machine (10) is provided with: a stator core (23) in which a plurality of core pieces (40) are laminated in the axial direction (Y); and insulators (21) respectively installed at least at both ends of the stator core (23) in the axial direction (Y). Each core piece (40) is formed with a hole (62) penetrating in the axial direction Y at the same location. The stator core (23) has a through-hole (60) formed by communicating each hole (62) of each core piece (40) in the axial direction (Y) and is provided with an insulating rod (61) inserted into the through-hole (60).

Description

Stator of a rotating electrical machine

[0001] The present disclosure relates to a stator for a rotating electric machine.

[0002] In conventional rotating electric machine stators, a stator core is generally constructed by laminating electromagnetic steel sheets to suppress iron loss, which is one of the main causes of loss in rotating electric machines. Crimping, welding, and adhesive bonding are commonly used methods for securing the laminations of the electromagnetic steel sheets together. Another known method involves proceeding to the insulator insertion process and winding process without securing the laminations of the electromagnetic steel sheets together, and then securing the laminations together using the insulators and windings (see, for example, Patent Document 1).

[0003] International Publication No. WO2007 / 043224

[0004] Stators that have laminations fixed together using conventional lamination methods each have their own problems. Caulking and welding create electrical continuity between laminations of the electromagnetic steel sheets, resulting in increased iron loss. Bonding also creates the problem of adhesive entering the gaps between the laminations, reducing the density of the laminated core (i.e., the space factor), and thus reducing the performance of the rotating electrical machine. Furthermore, when proceeding to the insulator insertion process and winding process without fixing the laminations between the electromagnetic steel sheets, and then fixing the laminations together using the insulators and windings, there are problems with insufficient strength between the laminations or reduced dimensional accuracy.

[0005] The present disclosure discloses technology for solving the above-mentioned problems, and aims to provide a stator for a rotating electric machine that can suppress iron loss in the stator and ensure strength and dimensional accuracy between laminations of core pieces without degrading performance.

[0006] The stator of a rotating electric machine disclosed in the present disclosure is a stator of a rotating electric machine comprising a stator core in which a plurality of core pieces are stacked in the axial direction, and insulators installed at least on both axial ends of the stator core, wherein each of the core pieces has a hole or notch formed therethrough in the axial direction at the same location, the stator core has a through hole formed by connecting each of the holes or notches of each of the core pieces in the axial direction, and is equipped with an insulating rod inserted into the through hole.

[0007] According to the stator of the rotating electric machine disclosed in the present disclosure, it is possible to suppress iron loss of the stator, and ensure strength and dimensional accuracy between laminations of core laminations without deteriorating performance.

[0008] FIG. 1 is a longitudinal cross-sectional view showing the configuration of a three-phase (UVW phase) AC rotating electric machine according to a first embodiment. FIG. 3A is a perspective view showing the configuration of a split core of the rotating electric machine shown in FIG. 1. FIG. 3B is a perspective view showing the configuration of a rod shown in FIG. 2. FIG. 4A is a perspective view showing a configuration in which an insulator is attached to the split core shown in FIG. 2. FIG. 4B is a longitudinal cross-sectional view of the split core with the insulator of FIG. 4A attached. FIG. 5A is an enlarged view of a portion surrounded by dotted line T1 of the split core with the insulator attached as shown in FIG. 4B attached. FIG. 5B is an enlarged view of a portion surrounded by dotted line T2 of the split core with the insulator attached as shown in FIG. 4B attached. FIG. 6A is a perspective view showing another configuration of the split core of the rotating electric machine shown in FIG. 1. FIG. 6B is an enlarged view of a portion surrounded by dotted line T3 of the split core shown in FIG. 6A. FIG. 7A is a perspective view showing another configuration of the split core of the rotating electric machine shown in FIG. 1. FIG. 7B is a perspective view showing another configuration of the rod of the split core of the rotating electric machine shown in FIG. 1. FIG. 8A is a perspective view showing a configuration in which an insulator is installed on the split core shown in FIG. 7 . FIG. 8B is a longitudinal cross-sectional view of the split core on which the insulator shown in FIG. 8A is installed. FIG. 9A is an enlarged view of a portion surrounded by dotted line T4 of the split core on which the insulator shown in FIG. 8B is installed. FIG. 9B is an enlarged view of a portion surrounded by dotted line T5 of the split core on which the insulator shown in FIG. 8B is installed. FIG. 10A is a perspective view showing a configuration of a split core for a rotating electric machine according to embodiment 2. FIG. 10B is a perspective view showing a configuration of a rod-integrated insulator for a rotating electric machine according to embodiment 2. FIG. 11A is a perspective view showing a configuration in which an insulator is installed on the split core shown in FIG. 10 . FIG. 11B is a longitudinal cross-sectional view of the split core on which the insulator shown in FIG. 11A is installed. FIG. 12A is an enlarged view of a portion surrounded by dotted line T6 of the split core on which the insulator shown in FIG. 11B is installed. FIG. 12B is an enlarged view of a portion surrounded by dotted line T7 of the split core on which the insulator shown in FIG. 11B is installed. Fig. 13A is a perspective view showing the configuration of a split core and an insulator according to embodiment 3. Fig. 13B is a longitudinal cross-sectional view of the split core and the insulator of Fig. 13A. Fig. 14A is an enlarged view of a portion surrounded by dotted line T8 of the split core with the insulator shown in Fig. 12B installed.Fig. 14B is an enlarged view of a portion surrounded by dotted line T9 of the split core with the insulator shown in Fig. 12B installed. Fig. 15A is a perspective view showing the configuration of a split core according to a comparative example. Fig. 15B is a longitudinal cross-sectional view of the split core of Fig. 15A. Fig. 15B is a perspective view showing the configuration of a split core according to another comparative example. Fig. 18A is a perspective view showing another configuration in which an insulator is installed in the split core of the rotating electric machine according to embodiment 2. Fig. 18B is a longitudinal cross-sectional view of the split core with the insulator of Fig. 18A installed.

[0009] Hereinafter, embodiments of this disclosure will be described with reference to the drawings. Note that the dimensional relationships between components in the following drawings, including FIG. 1, may differ from those in reality. In addition, in each drawing, including FIG. 1, components denoted with the same reference numerals are identical or equivalent, and this applies throughout the entire specification. Furthermore, the embodiments of components shown in the entire specification are illustrative in all respects and are not limiting. The scope of this disclosure is defined by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

[0010] In the following description, the axial direction of the rotating shaft of the rotating electric machine is referred to as the axial direction Y. Therefore, the axial direction Y and the lamination direction of the core laminations are the same direction. Therefore, these directions are the same in the stator and other parts, and the following description will use this direction as a reference.

[0011] Before describing the embodiment, a comparative example will be described with reference to the drawings. First, as shown in Fig. 15, when the core laminations have an uneven shape and adjacent core laminations in the axial direction Y are fitted together to ensure joint strength between the core laminations during lamination, the uneven portions are electrically connected as shown in Fig. 15B. As a result, when magnetic flux generated by the coil is passed through during operation of the rotating electric machine, the current generated in each core lamination is conducted between the laminations, leading to an increase in iron loss and a decrease in the efficiency of the rotating electric machine.

[0012] Furthermore, as shown in Fig. 16, when the side surfaces of the core laminations stacked in the axial direction Y are welded in the axial direction Y to ensure the joint strength between the core laminations in the axial direction Y at the welded points, the welded points end up being electrically connected as shown in Fig. 16. As a result, when the magnetic flux generated by the coil is passed during operation of the rotating electric machine, the current generated in each core lamination is conducted between the laminations, which leads to an increase in iron loss and a decrease in the efficiency of the rotating electric machine.

[0013] Furthermore, as shown in Figure 17, when the core pieces are laminated in the axial direction Y by adhesive bonding to ensure the bond strength between the core pieces in the axial direction Y, the bond strength between the core pieces can be ensured without causing electrical continuity between the laminations as occurs with crimping or welding. Common methods for sandwiching the adhesive between the core pieces include using electromagnetic steel sheets with adhesive pre-applied or applying the adhesive during processing. When using these methods, a certain thickness is required for the adhesive layer to secure the laminations. As a result, the density of the core in the lamination direction decreases, and the size of the rotating electric machine increases to achieve the same output as a rotating electric machine using laminated electromagnetic steel sheets without adhesive.

[0014] As in prior art document 1, which solves these problems, when the core pieces are transported to the winding process without fixing the spaces between the laminations and then fixed by winding, and when the spaces between the laminations of the core pieces are fixed only by the winding, it may be difficult to ensure sufficient strength against the force exerted by the permanent magnets attached to the rotor while the rotating electric machine is running, and misalignment between the laminations due to the laminations not being fixed may lead to a decrease in assembly accuracy and a decrease in dimensional accuracy such as the roundness of the stator, which determines the performance of the rotating electric machine.

[0015] Embodiment 1. Fig. 1 is a longitudinal cross-sectional view showing the configuration of a three-phase (UVW phase) AC rotating electric machine according to embodiment 1. Fig. 2 is a perspective view showing the configuration of a split core of the rotating electric machine shown in Fig. 1. Fig. 3A is a perspective view showing the configuration of the split core shown in Fig. 2. Fig. 3B is a perspective view showing the configuration of the rod shown in Fig. 2. Fig. 4A is a perspective view showing a configuration in which an insulator is attached to the split core shown in Fig. 2. Fig. 4B is a longitudinal cross-sectional view of the split core with the insulator of Fig. 4A attached. Fig. 5A is an enlarged view of a portion surrounded by dotted line T1 of the split core with the insulator attached shown in Fig. 4B. Fig. 5B is an enlarged view of a portion surrounded by dotted line T2 of the split core with the insulator attached shown in Fig. 4B.

[0016] FIG. 6A is a perspective view showing another configuration of the split core of the rotating electric machine shown in FIG. 1 . FIG. 6B is an enlarged view of the portion surrounded by dotted line T3 of the split core shown in FIG. 6A . FIG. 7A is a perspective view showing the configuration of the split core of the rotating electric machine shown in FIG. 1 . FIG. 7B is a perspective view showing the configuration of the rod of the split core of the rotating electric machine shown in FIG. 1 . FIG. 8A is a perspective view showing a configuration in which an insulator is installed in the split core shown in FIG. 7 . FIG. 8B is a longitudinal cross-sectional view of the split core with the insulator of FIG. 8A installed. FIG. 9A is an enlarged view of the portion surrounded by dotted line T4 of the split core with the insulator installed shown in FIG. 8B . FIG. 9B is an enlarged view of the portion surrounded by dotted line T5 of the split core with the insulator installed shown in FIG. 8B .

[0017] 1 , for example, a three-phase (UVW phase) AC rotating electric machine 10 includes an annular stator 12 fixed by a housing 11, a rotor 13 provided inside the stator 12, and a rotating shaft 14 attached to the center of the rotor 13. The stator 12 is composed of a stator core 23 in which a plurality of split cores 20 are arranged in an annular shape, an insulator 21 made of insulating resin, and a coil 22 wound around the stator core 23 with the insulator 21 interposed therebetween.

[0018] Generally, when manufacturing the stator 12, assembling a plurality of split cores 20 into an annular shape is expected to improve the winding density and the space factor of the coils 22. It is also expected to improve the yield of electromagnetic steel sheets when manufacturing the stator core 23. In the embodiment of the present disclosure, an example is described in which the stator core 23 is configured by arranging a plurality of split cores 20 in an annular shape, but the stator core can also be formed in the same way using a single, undivided annular core.

[0019] The rotor 13 is composed of a rotor core 30 and permanent magnets 31 provided on the outer peripheral surface of the rotor core 30, and is rotated by the magnetic flux generated between the rotor core 30 and the stator core 23. The rotating shaft 14 is fixed to the rotor core 30, and transmits power by rotating together with the rotor 13 while being supported by bearings 32.

[0020] 2 and 3 , the split core 20 is formed by stacking a plurality of core pieces 40 in the axial direction Y. When the split core pieces 20 are assembled into a ring shape, the split core 20 has a back yoke portion 201 that forms a ring in the circumferential direction, and teeth portions 202 that protrude in the radial direction X from the back yoke portion 201. The core pieces 40 are each formed with a first hole 621 formed in the back yoke portion 201 and a second hole 622 formed in the teeth portions 202 as holes 62 that penetrate in the axial direction Y.

[0021] Thus, split core 20 has first through holes 601 formed in back yoke portion 201 by first holes 621 and second through holes 602 formed in tooth portions 202 by second holes 622, as through holes 60 formed by connecting the holes 62 of each core piece 40 in the axial direction Y. An insulating rod 61 is inserted into each through hole 60, with a first rod 611 inserted in first through hole 601 and a second rod 612 inserted in second through hole 602. Note that, in the first embodiment, an example has been shown in which back yoke portion 201 is provided with both first through holes 601 and tooth portions 202 are provided with second through holes 602, but this is not limiting, and it is also possible to form only one of first through holes 601 in back yoke portion 201 or second through holes 602 in tooth portions 202.

[0022] In the following explanation and in figures other than Figures 2 and 3, unless a distinction is required, the first through hole 601 and the second through hole 602 will be referred to as through holes 60, the first hole 621 and the second hole 622 as holes 62, and the first rod 611 and the second rod 612 as rods 61.

[0023] Here, an example is shown in which the number of holes 62 formed in the core piece 40 is two, but this is not limited thereto, and any number of holes 62 may be formed as long as there is one or more holes 62. Furthermore, although an example is shown in which the through holes 60 and rods 61 have a circular cross section perpendicular to the axial direction Y, through holes 60 and rods 61 of other shapes, such as triangular or rectangular, may also be used. Possible materials for the rods 61 include resin, ceramic, and insulatingly coated metal. In the following embodiments, if the number, shape, and material of the through holes 60 and rods 61 are similar, their explanations will be omitted as appropriate.

[0024] As shown in Fig. 3, the length H2 of the rod 61 in the axial direction Y is longer than the length H1 of the split core 20 in the axial direction Y. Therefore, as shown in Fig. 2, when the rod 61 is inserted into the through hole 60, the rod 61 has portions at both ends in the axial direction Y that protrude beyond the split core 20 in the axial direction Y.

[0025] As shown in Fig. 4, insulators 21 are provided at least on both ends of the split core 20 in the axial direction Y. Insulators 21 are also formed at other predetermined locations as appropriate to insulate the coil 22 from the split core 20. As shown in Fig. 5, the insulator 21 is formed with a recess 210 into which the end of the rod 61 in the axial direction Y can be inserted. Therefore, the portion of the rod 61 protruding beyond the split core 20 is fitted into the recess 210 of the insulator 21. In addition, both ends of the first rod 611 in the axial direction Y are fixed to outer flanges 212 formed on the outer side X1 of the insulator 21 in the radial direction X.

[0026] Next, a method for manufacturing the stator of the rotating electric machine of the first embodiment configured as described above will be described. Core laminations 40 with holes 62 drilled therein are manufactured, and multiple core laminations are stacked in the axial direction Y. In the same process as this stacking process, or in a process subsequent to the stacking process, rods 61 are passed through the through holes 60 formed by the holes 62 to secure the core laminations 40. Press-fitting is a suitable method for passing the rods 61 through the through holes 60 to secure the core laminations 40. When press-fitting, the rods 61 only need to have uniform dimensions in a direction perpendicular to the axial direction Y, and the rods 61 will not separate from the split core laminations 20 after press-fitting. Therefore, the rods 61 suppress misalignment between the laminated layers of the core laminations 40 in the axial direction Y. Next, the axial end of the rod 61 exposed from the axial direction Y of the split core laminations 20 is inserted into the recesses 210 of the insulator 21 to install the insulator 21 on the split core laminations 20.

[0027] An example of another embodiment 1 will be described with reference to FIG. 6 . As described above, a case will be described in which the rod 61 is inserted into the split core 20 rather than press-fitted. As shown in FIG. 6B , the diameter W2 of the hole 62 is larger than the diameter W1 of the rod 61. As a result, a gap 63 is formed when the rod 61 is inserted into the through-hole 60. Note that if the gap 63 is too large, the core pieces 40 may not be sufficiently fixed. Therefore, the gap 63 referred to here is determined by setting the difference between the diameter W1 of the hole 62 and the diameter W2 of the rod 61 so that the gap 63 is small enough to be what is generally referred to as a clearance fit. With this level of gap 63, the core pieces 40 can be sufficiently fixed together. Furthermore, because the rod 61 can be inserted into the through-hole 60 by clearance fit, no external force is required when inserting the core pieces 40, improving the ease of assembly of the stator 12.

[0028] Another example of the first embodiment will be described with reference to FIGS. 7 to 9 . As shown in FIG. 7B , a flange portion 64 is formed at one end of the rod 61 in the axial direction Y. Naturally, the flange portion 64 is not inserted into the through-hole 60. Furthermore, the length H4 of the rod 61 in the axial direction Y is longer than the length H3 of the split core 20 in the axial direction Y. This configuration prevents the core pieces 40 from falling off the rod 61 due to their own weight during transportation, even if a gap 63 exists between the through-hole 60 and the rod 61. The flange portion 64 may be attached to the rod 61 before the rod 61 is inserted into the through-hole 60, or may be attached to the rod 61 after the rod 61 has penetrated the through-hole 60.

[0029] The flange portion 64 may be formed by machining the rod 61 before inserting the rod 61 into the split core 20, or may be formed by machining the rod 61 after inserting the rod 61 into the split core 20. Here, an example in which the flange portion 64 is round is shown, but it may be other shapes such as triangular or rectangular, or may be an angled shape such as a conical shape. Then, as in the above case, the end of the rod 61 in the axial direction Y and the flange portion 64 exposed from the axial direction Y of the split core 20 are inserted into the recesses 210 and 211 of the insulator 21 to install the insulator 21 on the split core 20, as shown in Figures 8 and 9 .

[0030] According to the stator of the rotating electric machine of embodiment 1 configured as described above, in a stator of a rotating electric machine including a stator core in which a plurality of core pieces are stacked in the axial direction, and insulators installed at least on both axial ends of the stator core, each of the core pieces has a hole formed therethrough in the axial direction at the same location, the stator core has a through hole formed by connecting each of the holes of each of the core pieces in the axial direction, and is equipped with an insulating rod inserted into the through hole, thereby suppressing iron loss of the stator and ensuring strength and dimensional accuracy between the stacked core pieces without degrading performance.

[0031] Specifically, this first embodiment can prevent a situation where, as in the comparative example, when laminations are fixed by crimping or welding, current generated in each core lamination when magnetic flux generated by the coil is passed through the laminations during operation of the rotating electric machine, resulting in increased iron loss and reduced efficiency of the rotating electric machine. Furthermore, this first embodiment can prevent a situation where, as in the comparative example, when laminations are fixed by bonding, the density of the core in the lamination direction decreases, resulting in an increased size of the rotating electric machine when outputting the same output as a rotating electric machine using laminated electromagnetic steel sheets without adhesive. Furthermore, compared to the comparative example, in which the laminations are not fixed between the laminations but are transported to the winding process, wound, and then fixed, this first embodiment can ensure sufficient strength against the force exerted by the permanent magnets attached to the rotor during operation of the rotating electric machine, thereby improving assembly accuracy.

[0032] Furthermore, according to the stator of the rotating electric machine of embodiment 1 configured as described above, the axial length of the rod is formed longer than the axial length of the stator core, and the insulator has a recess that fits into the axial end of the rod, so that the multiple core pieces stacked in the axial direction can be securely held by the rod.

[0033] Furthermore, according to the stator of the rotating electric machine of embodiment 1 configured as described above, the diameter of the hole is formed larger than the diameter of the rod, which makes it easier to insert the rod into the through hole and improves the assembly ease of the stator.

[0034] Furthermore, according to the stator of the rotating electric machine of embodiment 1 configured as described above, one axial end of the rod is provided with a flange portion larger than the hole, so that the flange portion can prevent the core pieces from falling off the rod due to the weight of the core pieces when moved, improving the ease of assembly of the stator.

[0035] Furthermore, according to the stator of the rotating electric machine of embodiment 1 configured as described above, the stator core has a back yoke portion that is annular in the circumferential direction and teeth portions that protrude radially from the back yoke portion, and the through holes include first through holes formed in the back yoke portion, thereby further improving the strength and dimensional accuracy between laminations in the back yoke portion.

[0036] Furthermore, according to the stator of the rotating electric machine of embodiment 1 configured as described above, the stator core has a back yoke portion that is annular in the circumferential direction and teeth portions that protrude radially from the back yoke portion, and the through holes include second through holes formed in the teeth portions, thereby further improving the strength and dimensional accuracy between laminations in the teeth portions.

[0037] Embodiment 2. Fig. 10A is a perspective view showing the configuration of a split core of a rotating electric machine according to embodiment 2. Fig. 10B is a perspective view showing the configuration of an insulator integrated with a rod of a rotating electric machine according to embodiment 2. Fig. 11A is a perspective view showing a configuration in which an insulator is installed on the split core shown in Fig. 10. Fig. 11B is a longitudinal cross-sectional view of the split core on which the insulator of Fig. 11A is installed. Fig. 12A is an enlarged view of a portion surrounded by dotted line T6 of the split core on which the insulator of Fig. 11B is installed. Fig. 12B is an enlarged view of a portion surrounded by dotted line T7 of the split core on which the insulator of Fig. 11B is installed. Fig. 18A is a perspective view showing another configuration in which an insulator is installed on the split core of a rotating electric machine according to embodiment 2. Fig. 18B is a longitudinal cross-sectional view of the split core on which the insulator of Fig. 18A is installed.

[0038] In each figure, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. In the second embodiment, the description will focus on the parts that are different from the first embodiment. As shown in FIG. 10B , one of the insulators 21 in the axial direction Y and the rod 61 are injection molded in advance as an integrated structure. Here, the rod 61 is made of a resin so that it is injection molded as an integrated structure with the insulator 21. The length H6 of the rod 61 in the axial direction Y is longer than the length H5 of the split core 20 in the axial direction Y.

[0039] As shown in Figures 11 and 12, the end of the rod 61 is exposed in the axial direction Y of the split core 20. The upper end of the rod 61 in the axial direction Y is inserted into the recess 210 of the insulator 21 to install the insulator 21 on the split core 20. Furthermore, the lower end of the rod 61 in the axial direction Y is formed integrally with the insulator 21, so no recess exists at this location on the insulator 21. By forming the rod 61 in this manner, even if a gap 63 exists between the through-hole 60 and the rod 61, the insulator 21 and the rod 61 are integrally formed, so that the weight of the core pieces 40 prevents the core pieces 40 from falling off the rod 61 during transportation. Furthermore, the number of steps for inserting the rod 61 into the insulator 21 can be reduced, and the connection between the rod 61 and the insulator 21 can be strengthened.

[0040] Next, another stator of a rotating electric machine according to the second embodiment will be described with reference to FIG. 18 . In the example of the second embodiment described above, the through hole 60 is formed by a hole 62. However, as shown in FIG. 18 , a notch 623 is formed on the outer surface X1 in the radial direction X of the back yoke portion 201 of the core lamination 40. The through hole 60 is formed so that the notch 623 communicates with the axial direction Y. Note that the rod 61 inserted into the through hole 60 in FIG. 18 is formed integrally with the insulator 21, similar to FIG. 10 . Note that in FIG. 18 , the through hole 60 is formed in the back yoke portion 201, and therefore corresponds to the first through hole.

[0041] Furthermore, while Figure 18 shows an example in which through holes 60 are provided only in back yoke portion 201 by cutouts 623, this is not limited to this, and it is also possible to form cutouts on the inner surface X2 of tooth portion 202 in the radial direction X to form through holes, or to form cutouts in both back yoke portion 201 and tooth portion 202 to form through holes in each.

[0042] The stator for a rotating electric machine according to the second embodiment configured as described above has the same effects as those of the first embodiment, and because one axial end of the rod is integrally molded with the insulator, the assembly of the stator is improved. In addition, the number of steps for inserting the rod into the insulator can be reduced, and the connection between the rod and the insulator can be strengthened.

[0043] Furthermore, according to the stator of the rotating electric machine of embodiment 2 configured as described above, in a stator of a rotating electric machine including a stator core in which a plurality of core pieces are stacked in the axial direction, and insulators installed at least on both axial ends of the stator core, each of the core pieces has a notch formed therethrough in the axial direction at the same location, the stator core has through holes formed by connecting each of the notches of each of the core pieces in the axial direction, and is equipped with an insulating rod inserted into the through hole, it is possible to suppress iron loss of the stator and ensure strength and dimensional accuracy between the stacked core pieces without degrading performance.

[0044] Embodiment 3. Fig. 13A is a perspective view showing the configuration of a split core and an insulator according to embodiment 3. Fig. 13B is a longitudinal cross-sectional view of the split core and the insulator of Fig. 13A. Fig. 14A is an enlarged view of a portion surrounded by a dotted line T8 of the split core with the insulator installed as shown in Fig. 12B. Fig. 14B is an enlarged view of a portion surrounded by a dotted line T9 of the split core with the insulator installed as shown in Fig. 12B.

[0045] In each drawing, parts similar to those in the above-described embodiments are denoted by the same reference numerals, and descriptions thereof will be omitted where appropriate. Furthermore, in this third embodiment, the description will focus on parts that are different from those in the above-described embodiments. As shown in FIG. 13 , the insulator 21 and the rod 61 are insert-molded. Here, the rod 61 is made of a resin suitable for injection molding, since it is insert-molded with the insulator 21. Because the rod 61 and the insulator 21 are insert-molded simultaneously in this manner, the steps of inserting the rod 61 into the through-hole 60 of the split core 20 and inserting the rod 61 into the insulator 21 can be reduced, and the connection between the rod 61 and the insulator 21 can be made stronger.

[0046] The rotating electric machine stator of the third embodiment configured as described above has the same effects as the above embodiments, and also has the following features: In a rotating electric machine stator including a stator core in which a plurality of core laminations are stacked in the axial direction and insulators installed at at least both axial ends of the stator core, each of the core laminations has a hole formed therethrough in the axial direction at the same location, the stator core has a through hole formed by connecting the holes in the core laminations in the axial direction, and an insulating rod inserted into the through hole and the insulator are insert-molded, thereby suppressing iron loss of the stator, ensuring strength and dimensional accuracy between the laminations of the core laminations without degrading performance, and improving the ease of assembly of the stator. Also, the number of steps for inserting the rod into the insulator can be reduced, and the connection between the rod and the insulator can be strengthened.

[0047] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0048] Various aspects of the present disclosure are summarized below as appendices.

[0049] (Supplementary Note 1) A stator for a rotating electric machine including a stator core in which a plurality of core laminations are stacked in the axial direction, and insulators installed on at least both axial ends of the stator core, wherein each of the core laminations has a hole or notch formed therethrough in the axial direction at the same location, the stator core has a through hole formed by connecting the holes or notches of each of the core laminations in the axial direction, and the stator core has an insulating rod inserted into the through hole. (Supplementary Note 2) The stator for a rotating electric machine according to Supplementary Note 1, wherein the axial length of the rod is longer than the axial length of the stator core, and the insulator has a recess that fits onto an axial end of the rod. (Supplementary Note 3) The stator for a rotating electric machine according to Supplementary Note 1 or Supplementary Note 2, wherein the diameter of the hole is larger than the diameter of the rod. (Supplementary Note 4) The stator for a rotating electric machine according to any one of Supplementary Notes 1 to 3, wherein one axial end of the rod is provided with a flange portion that is larger than the hole. (Supplementary Note 5) The stator for a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein one axial end side of the rod is integrally molded with the insulator. (Supplementary Note 6) A stator for a rotating electric machine including a stator core in which a plurality of core pieces are stacked in the axial direction, and insulators respectively installed on at least both axial ends of the stator core, wherein each of the core pieces has a hole formed therethrough in the axial direction at the same location, the stator core has a through hole formed so that the holes of each of the core pieces are in axial communication with each other, and an insulating rod inserted into the through hole and the insulator are insert-molded.

[0050] REFERENCE SIGNS LIST 10 Rotating electric machine, 11 Housing, 12 Stator, 13 Rotor, 14 Rotating shaft, 20 Split core, 201 Back yoke portion, 202 Teeth portion, 21 Insulator, 210 Recess, 211 Recess, 212 Outer flange portion, 22 Coil, 23 Stator core, 30 Rotor core, 31 Permanent magnet, 32 Bearing, 40 Core piece, 60 Through hole, 601 First through hole, 602 Second through hole, 61 Rod, 611 First rod, 612 Second rod, 62 Hole, 621 First hole, 622 Second hole, 623 Notch, 63 Gap, 64 Flange portion, H1 Length, H2 Length, H3 Length, H4 Length, H5 Length, H6 Length, X Radial direction, X1 Outer side, Y Axial direction, W1 Diameter, W2 Diameter.

Claims

1. A stator for a rotating electric machine comprising a stator core in which a number of core pieces are stacked in the axial direction, and insulators installed on at least both axial ends of the stator core, wherein each of the core pieces has a hole or notch formed therethrough in the axial direction at the same location, the stator core has a through hole formed by connecting each of the holes or notches of each of the core pieces in the axial direction, and the stator core comprises an insulating rod inserted into the through hole.

2. A stator for a rotating electric machine as described in claim 1, wherein the stator core has a back yoke portion that is annular in the circumferential direction and teeth portions that protrude radially from the back yoke portion, and the through holes include first through holes formed in the back yoke portion.

3. A stator for a rotating electric machine as described in claim 1 or claim 2, wherein the stator core has a back yoke portion that is annular in the circumferential direction and teeth portions that protrude radially from the back yoke portion, and the through holes include second through holes formed in the teeth portions.

4. A stator for a rotating electric machine as claimed in any one of claims 1 to 3, wherein the axial length of the rod is longer than the axial length of the stator core, and the insulator has a recess that fits into the axial end of the rod.

5. A stator for a rotating electric machine according to any one of claims 1 to 4, wherein the diameter of the hole is formed larger than the diameter of the rod.

6. A stator for a rotating electric machine according to any one of claims 1 to 5, wherein one axial end of the rod is provided with a flange portion larger than the hole.

7. A stator for a rotating electric machine according to any one of claims 1 to 5, wherein one axial end of the rod is integrally formed with the insulator.

8. A stator for a rotating electric machine comprising a stator core in which a number of core pieces are stacked in the axial direction, and insulators installed on at least both axial ends of the stator core, wherein each of the core pieces has a hole formed therethrough in the axial direction at the same location, the stator core has a through hole formed by connecting each of the holes in each of the core pieces in the axial direction, and a rod having insulating properties to be inserted into the through hole and the insulator are insert-molded.

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