Stator and method for manufacturing a stator

Abstract

The objective is to obtain an efficient stator. [Solution] The stator comprises a stator core 21, an insulator 22 covering both ends of the base 21t in the axial direction Da, and a coil 23 wound around the base 21t and the insulator 22 in a concentrated winding manner. The insulator 22 covers the entire base 21t in the radial direction Dr, and a groove 22g passing through the radial direction Dr is formed at the corner between the end face in the axial direction Da and the end face in the circumferential direction Dc. A load-bearing support 29 is provided in the groove 22g, which is made of an insulating material with a higher modulus of elasticity than the material constituting the insulator 22, so that the bending rigidity is higher than that of the insulator 22 if the groove 22g were not formed.

Description

Technical Field

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[0001] The present disclosure relates to a stator and a method for manufacturing the stator.

Background Art

[0002] In the manufacture of a rotating electric machine, when winding a coil around the teeth of a stator to form a stator winding, a winding tension acts on the teeth and the insulators installed at both axial ends thereof. Therefore, the core constituting the teeth and the insulators are designed to have sufficient strength to prevent cracking or breakage due to the winding tension. However, if the dimensions of the insulators are increased to ensure strength, the coil end portion becomes larger, resulting in an increase in the winding length and weight, which leads to a decrease in efficiency.

[0003] On the other hand, in concentrated winding in which a coil is wound around a tooth, a technique for preventing an increase in the winding length is disclosed, such as arranging a plurality of spiral coil portions along the radial direction (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, although the winding order and the coil connection method are shown, there is no mention of the load during winding, and an increase in the coil end portion has not been suppressed.

[0006] <000**********]] The present disclosure solves the above problems and aims to obtain an efficient stator.

Means for Solving the Problems

[0007] The stator of the present disclosure comprises a stator core formed of an annular core back portion and a plurality of teeth intermittently arranged along the circumferential direction, each having a base portion projecting radially inward from the core back portion and a tooth tip portion extending circumferentially from the tip of the base portion toward both sides; an insulator covering both axial ends of the base portion for each of the plurality of teeth; and a coil wound around the base portion and the insulator in a concentrated winding manner for each of the plurality of teeth, wherein the insulator covers the entire base portion radially, and a radial groove is formed at the corner between the axial end face and the circumferential end face, and a load-bearing is provided in the groove, which is made of an insulating material with a higher modulus of elasticity than the material constituting the insulator, such that the bending rigidity is higher than that of the insulator if the groove were not formed.

[0008] The present disclosure is a method for manufacturing a stator, comprising the steps of: installing an insulator that covers the entire base in the radial direction at both axial ends for each of the plurality of teeth of a stator core formed by an annular core back portion and a plurality of teeth intermittently arranged along the circumferential direction, each having a base portion that protrudes radially inward from the core back portion and a tooth tip portion that spreads outward on both sides in the circumferential direction from the tip of the base portion; and winding a coil around each of the plurality of teeth in a concentrated winding manner around the base portion and the insulator, wherein in the coil winding step, a load-bearing made of a material with a higher modulus of elasticity than the material constituting the insulator is provided in a radial groove formed at the corner between the axial end face and the circumferential end face of the insulator, such that the bending rigidity is higher than that of the insulator if the groove were not formed. [Effects of the Invention]

[0009] According to the stator or method for manufacturing the stator of this disclosure, winding can be performed without increasing the size of the coil end portion, thus enabling the creation of an efficient stator. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of the stator core and insulator for one tooth that constitute the stator according to Embodiment 1. [Figure 2] This is an end view including the shaft of a rotating electric machine composed of a stator and rotor according to Embodiment 1. [Figure 3] This is a cross-sectional view perpendicular to the radial direction of a stator core and insulator for one tooth that constitutes the stator according to Embodiment 1. [Figure 4] This is a perspective view of a stator core and insulator for one tooth, showing the state when winding wires in the stator manufacturing method according to Embodiment 1. [Figure 5] This is a flowchart showing the method for manufacturing a stator according to Embodiment 1. [Figure 6] This is a perspective view of the stator core and insulator for one tooth that constitutes the stator according to Embodiment 2. [Figure 7] This is a cross-sectional view perpendicular to the radial direction for one tooth of the stator according to Embodiment 2. [Figure 8] This is a flowchart showing the method for manufacturing a stator according to Embodiment 2. [Figure 9] This is a perspective view of the stator core and insulator for one tooth that constitutes the stator according to Embodiment 3. [Figure 10] This is a cross-sectional view perpendicular to the radial direction for one tooth of the stator according to Embodiment 3. [Figure 11] This is a flowchart showing the method for manufacturing a stator according to Embodiment 3. [Modes for carrying out the invention]

[0011] Embodiment 1. Figures 1 to 5 illustrate the configuration and operation of a stator and a rotating electric machine using the same according to Embodiment 1, or a method for manufacturing the stator. Figure 1 is a perspective view of the stator core and insulator for one tooth of the stator, viewed from the inside in the radial direction. Figure 2 is an end view including the shaft of the rotating electric machine composed of the stator and rotor. Figure 3 is a cross-sectional view of the stator core and insulator for one tooth, perpendicular to the radial direction and corresponding to line AA in Figure 1.

[0012] Figure 4 is a perspective view of the stator core and insulator for one tooth, showing the state during winding in the stator manufacturing method, and Figure 5 is a flowchart of the stator manufacturing method.

[0013] Before providing a detailed description of the stator and the method for manufacturing the stator according to Embodiment 1, the configuration of the rotating electric machine will be briefly explained. As shown in Figure 2, the rotating electric machine 1 consists of an annular stator 2 and a rotor 4 that is coaxially arranged to rotate freely with a gap between it and the inner circumferential surface of the stator 2. The stator 2 consists of a stator core 21, which is a magnetic material formed by laminating electromagnetic steel sheets along the axial direction Da, coils 23 wound around each tooth of the stator core 21 (described later), and an insulator 22 interposed between the coils 23 and the stator core 21. The layers of the stator core 21 are fixed together by crimping or adhesive.

[0014] The shape of one tooth obtained by dividing the stator core 21 along the circumferential direction Dc before winding the coil 23 is as shown in Figure 1. When viewed from a distance in the axial direction Da, it forms a T shape, and the core back portion 21b extending along the circumferential direction Dc on the outside of the radial direction Dr is connected to form an annular shape. Each tooth has a core back portion 21b, a base portion 21t extending inward from the center of the core back portion 21b in the circumferential direction Dc toward the inside in the radial direction Dr, and a tooth tip portion 21a extending along the circumferential direction Dc from the tip of the base portion 21t on the inside in the radial direction Dr.

[0015] Then, an insulator 22 made of an insulating material such as PBT (Poly Butylene Terephthalate) or LCP (Liquid Crystal Polymer) is provided at both ends of the base portion 21t in the axial direction Da for each tooth. The radial length Li (Fig. 2) of the insulator 22 is longer than that of the base portion 21t and is arranged at a position covering the base portion 21t.

[0016] Also, as shown in Fig. 3, on the outer side of the insulator 22 in the axial direction Da at both circumferential ends, that is, at the corner portions when winding the coil 23, grooves 22g extending in the radial direction (the three-dimensional shape is drawn in Fig. 6) are formed. Then, a load receiver 29 made of a material having a higher elastic modulus than that of the insulator 22 is provided in the groove 22g. The load receiver 29 is made of an insulating material such as ceramic or special stainless steel having insulation properties by surface film treatment, and the radial length is longer than that of the base portion 21t. Also, a through hole 29h penetrating in the radial direction Dr is provided.

[0017] Here, the elastic modulus E22 of the resin-based material constituting the insulator 22, for example, PBT, is 9.9 GPa, and the elastic modulus E29 of the steel material constituting the load receiver 29 is 206 GPa. Let the second moment of area in the axial thickness t22 of the insulator 22 be It22, and the second moment of area in the thickness t29 of the load receiver 29 be It29. However, the cross-sectional shape of the load receiver 29 perpendicular to the radial direction Dr is a sector, and the second moment of area considering the through hole 29h is It29. And since these bending rigidities satisfy the relationship of Equation (1), the sum of the bending rigidities of the two load receivers 29 is greater than the bending rigidity of the insulator with respect to the force in the axial direction Da of the insulator when the groove 22g is not formed. E29×It29>E22×It22 / 2 (1)

[0018] Based on the above-described configuration, the manufacturing method of the stator 2 according to Embodiment 1 will be explained with reference to the flowchart in Figure 5. Here, we will begin from the state in which the insulators 22 have been installed at both ends of the axial direction Da of each base portion 21t. First, a load receiver 29 is installed in the groove 22g extending radially Dr of the insulator 22 (step S100).

[0019] Next, the load support 29 installed on the insulator 22 is clamped and fixed from both sides in the radial direction Dr by the fixing plate 9, as shown in Figure 4 (step S110). In the figure, the load support 29 is shown to be fixed by the fixing plate 9 using bolts 91 passed through through holes 29h provided in the load support 29, but this is not the only method. The fixing plate 9 is made of a material with an elastic modulus equal to or greater than that of the load support 29.

[0020] In this state, winding is performed to form the coil 23 (step S120). Once the coil 23 is formed, the fixing plate 9 is removed (step S130). If the teeth were arranged in a straight line during winding so that the spacing between adjacent tooth tips 21a was wide, they are rearranged into a ring shape. This forms the stator 2, and the process can end at this point, or the process can proceed to assembling the rotating electric machine 1.

[0021] In this way, by fixing the load support 29 to the insulator 22 during winding, the winding load acting on the stator core 21 and the insulator 22 can be supported by the load support 29 and the fixing plate 9. Therefore, the number of crimps between the laminates of the stator core 21 can be reduced, or the adhesive strength can be reduced. In addition, the load on the insulator 22 can be reduced, and the insulator 22 can be made thinner.

[0022] Embodiment 2. In Embodiment 1, an example was described in which the stator was completed with the load bearings installed. In Embodiment 2, an example is described in which the load bearings are removed after winding, and the stator is completed without the load bearings.

[0023] Figures 6 to 8 illustrate the stator configuration and manufacturing method of the stator according to Embodiment 2. Figure 6 is a perspective view of the stator core and insulator for one tooth of the stator, viewed from the inside in the radial direction. Figure 7 is a cross-sectional view of one tooth of the stator, perpendicular to the radial direction and corresponding to line BB in Figure 6. Figure 4 is a flowchart illustrating the manufacturing method of the stator. Except for the addition of the step of removing the load support, it is the same as Embodiment 1, and the explanation of the similar parts will be omitted, with reference to Figures 2 to 4 used in Embodiment 1.

[0024] As shown in Figures 6 to 8, in the manufacturing method of the stator 2 according to Embodiment 2, after the coil 23 is formed by the winding process (step S120), an additional step is added in which the load support 29 is pulled out and removed along the radial direction Dr (step S140).

[0025] During the winding process (step S120), the load-bearing support 29 is sandwiched between the coil 23 and the insulator 22 while bearing the load. However, since the load-bearing support 29 has a higher modulus of elasticity than the insulator 22, the individual wires constituting the coil 23 do not get pinched. Moreover, since the groove 22g extends straight along the radial direction Dr, the load-bearing support 29 can be easily removed without damaging the coil 23 and the insulator 22 simply by pulling it out along the radial direction Dr.

[0026] With this configuration, the weight can be reduced by the product of the volume of the space created by the grooves 22g in the insulator 22 and the density of the insulator 22. In addition, the grooves 22g can be used as a coolant passage to cool the heat generated in the coil 23.

[0027] In this second embodiment, the load-bearing support 29 only needs to perform a function corresponding to its material properties, which have a higher modulus of elasticity than the insulator 22 during the winding process, and is ultimately removed, so there is no need to worry about its insulating properties. In other words, the material constituting the load-bearing support 29 can be selected by focusing only on its modulus of elasticity, and it is possible to use steel, for example.

[0028] Embodiment 3. Embodiment 1 described an example in which the load support is left in place after winding, and Embodiment 2 described an example in which the load support is removed after winding. Embodiment 3 describes an example in which the load support is replaced with a different material after winding.

[0029] Figures 9 to 11 illustrate the stator configuration and manufacturing method of the stator according to Embodiment 3. Figure 9 is a perspective view of the stator core and insulator for one tooth of the stator, viewed from the radially inward. Figure 10 is a cross-sectional view of one tooth of the stator, perpendicular to the radial direction and corresponding to the CC line in Figure 9. Figure 11 is a flowchart illustrating the manufacturing method of the stator. Except for the step of replacing the load bearing with a different material, this is the same as Embodiments 1 and 2, and the explanation of the similar parts will be omitted, with reference to Figures 2 and 4 used in Embodiment 1.

[0030] As shown in Figures 9 to 11, in the manufacturing method of the stator 2 according to Embodiment 3, a step is added in which, after the coil 23 is formed and the load support 29 is removed (step S140), a material with a higher thermal conductivity than the load support 29 (filler 3) is filled into the space (groove 22g portion) (step S150).

[0031] As described in Embodiment 2, in step S140, the load support 29 can be easily removed without damaging the coil 23 and the insulator 22. By filling the space with a filler material 3 that has a higher thermal conductivity than the load support 29, the heat generated in the coil 23 can be transferred to the stator core 21 via the insulator 22, thereby improving the cooling capacity of the coil 23.

[0032] In this example, the load support 29 is replaced with the filler material 3, but this is not the only option. For example, the load support 29 may be left in place, and the filler material 3 may be filled into the through-hole 29h provided in the load support 29. In that case, it is preferable that the filler material 3 has a higher thermal conductivity than the load support 29, but this is not the only option. For example, even if a material with a lower thermal conductivity than the load support 29 is used, as long as it is not a gas, its thermal conductivity will be higher than that of air, so the thermal conductivity will be higher than when the through-hole 29h is filled with air, thereby improving the cooling capacity.

[0033] In this third embodiment, if the load support 29 is removed, there is no need to worry about insulation, as in the second embodiment, and the material can be selected based solely on its modulus of elasticity. For example, steel can be used. In this case, the filler material 3 only needs to have thermal conductivity and insulation properties, and there is no need to worry about its modulus of elasticity. On the other hand, if the load support 29 is left in place, insulation is necessary, but the filler material 3 to be filled into the through hole 29h can be selected without worrying about mechanical strength and insulation properties.

[0034] While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable individually or in various combinations to the embodiments. Therefore, countless variations not illustrated are conceivable within the scope of the art disclosed in this specification. These include, for example, modifying, adding, or omitting at least one component, or even extracting at least one component and combining it with components from other embodiments.

[0035] For example, while the example shown illustrates fixing the layers of the stator core 21 by crimping or adhesive, this is not the only option. Similarly, while the example shown illustrates the use of PBT and LCP as materials for the insulator 22, this is not the only option.

[0036] As described above, the stator 2 of this disclosure comprises a stator core 21 formed of an annular core back portion 21b and a plurality of teeth intermittently arranged along the circumferential direction Dc, each having a base portion 21t protruding inward in the radial direction Dr from the core back portion 21b and a tooth tip portion 21a extending circumferentially from the tip of the base portion 21t toward both sides; an insulator 22 covering both ends of the base portion 21t in the axial direction Da for each of the plurality of teeth; and a coil 23 wound around the base portion 21t and the insulator 22 in a concentrated winding manner for each of the plurality of teeth. The insulator 22 covers the entire base portion 21t in the radial direction Dr, and a groove 22g passing through the radial direction Dr is formed at the corner between the end face in the axial direction Da and the end face in the circumferential direction Dc. A load receiver 29 is provided in the groove 22g, which is made of an insulating material with a higher modulus of elasticity than the material constituting the insulator 22, so as to have higher bending rigidity than the insulator 22 if the groove 22g were not formed. This improves resistance to winding even when the insulator 22 is thinned without excessively increasing its axial height, allowing for a shorter winding length and a more efficient stator 2. Furthermore, it allows for a reduction in the number of crimps between the layers of the stator core 21, or a reduction in adhesive strength.

[0037] In this case, if the load-bearing support 29 is made of ceramic or special stainless steel with a surface coating, the bending rigidity can be reliably improved.

[0038] As described above, according to the manufacturing method of the stator 2 of the present disclosure, the stator core 21 is formed by an annular core back portion 21b and a plurality of teeth intermittently arranged along the circumferential direction Dc, each of which has a base portion 21t protruding inward from the core back portion 21b in the radial direction Dr and a tooth tip portion 21a extending from the tip of the base portion 21t toward both sides in the circumferential direction Dc, and the steps of installing an insulator 22 that covers the entire base portion 21t in the radial direction Dr at both ends in the axial direction Da for each of the plurality of teeth, and a plurality The process includes winding a coil 23 around each of the teeth in a concentrated winding manner (step S120), and in the process of winding the coil 23, a load-bearing support 29 made of a material with a higher modulus of elasticity than the material constituting the insulator 22 is provided in a groove 22g that runs through the radial direction Dr and is formed at the corner between the axial end face Da and the circumferential end face Dc of the insulator 22, so that the bending rigidity is higher than that of the insulator 22 if the groove 22g were not formed. As a result, even if the wall thickness of the insulator 22 is reduced without excessively increasing the axial height, the resistance to winding is improved, so the winding length can be shortened and an efficient stator 2 can be obtained. Furthermore, the number of crimps between the laminates of the stator core 21 can be reduced or the adhesive strength can be reduced.

[0039] In this process, when winding the coil 23, a fixing plate 9 is installed to sandwich the insulator 22 and load support 29 from both radial sides, and after winding the coil 23, the fixing plate 9 is removed (step S130). This ensures that the radial Dr range of the coil 23 is reliably defined, allowing for efficient winding.

[0040] If the process includes a step (step S140) to remove the load support 29 after winding the coil 23, the load support 29 does not need to be insulating, which broadens the range of materials that can be used, increases the bending rigidity during winding, and allows for a thinner insulator 22 thickness t22. Furthermore, the groove 22g portion can be used as a passage for refrigerant or replaced with other materials.

[0041] If the process includes a step (step S150) in which the groove 22g after the load support 29 has been removed is filled with an insulating material that has a higher thermal conductivity than the load support 29 or the insulator 22, the cooling efficiency will be increased and the performance will be improved. [Explanation of symbols]

[0042] 1: Rotating electric machine, 2: Stator, 21: Stator core, 21a: Tooth tip, 21b: Core back, 21t: Base, 22: Insulator, 22g: Groove, 23: Coil, 29: Load bearing, 3: Filler, 4: Rotor, 9: Fixing plate, Da: Axial direction, Dc: Circumferential direction, Dr: Radial direction, E22, E29: Modulus of elasticity, t22, t29: Thickness.

Claims

1. A stator core formed by an annular core back portion and a plurality of teeth intermittently arranged along the circumferential direction, each having a base portion that protrudes radially inward from the core back portion and tooth tip portions that spread outward on both sides in the circumferential direction from the tip of the base portion. For each of the plurality of teeth, an insulator is provided to cover both axial ends of the base, and Each of the aforementioned plurality of teeth is provided with a coil wound in a concentrated manner around the base and the insulator, The insulator covers the entire base in the radial direction, and a groove running radially is formed at the corner between the axial end face and the circumferential end face. The groove is provided with a load-bearing made of an insulating material with a higher modulus of elasticity than the material constituting the insulator, such that the bending rigidity is higher than that of the insulator if the groove were not formed. A stator characterized by the following features.

2. The stator according to claim 1, characterized in that the load bearing is made of ceramic or special stainless steel having a surface coating.

3. A stator core is formed by an annular core back portion and a plurality of teeth intermittently arranged along the circumferential direction, each having a base portion that protrudes radially inward from the core back portion and a tooth tip portion that expands circumferentially from the tip of the base portion toward both sides; the step of installing an insulator that covers the entire base portion radially at both ends in the axial direction for each of the plurality of teeth, and The process includes winding a coil around each of the plurality of teeth in a concentrated winding manner, between the base and the insulator. A method for manufacturing a stator, characterized in that, in the process of winding the coil, a load-bearing support made of a material with a higher modulus of elasticity than the material constituting the insulator is provided in a radial groove formed at the corner between the axial end face and the circumferential end face of the insulator, such that the bending rigidity is higher than that of the insulator if the groove were not formed.

4. The method for manufacturing a stator according to claim 3, characterized in that, in the process of winding the coil, a fixing plate is installed to sandwich the insulator and the load support from both radial sides, and the fixing plate is removed after the winding of the coil is completed.

5. A method for manufacturing a stator according to claim 3 or 4, characterized in that it includes a step of removing the load support after winding the coil.

6. The method for manufacturing a stator according to claim 5, characterized in that it includes a step of filling the groove after removing the load-bearing with an insulating material that has a higher thermal conductivity than the load-bearing or the insulator.

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