Rotating electric machine

Abstract

This suppresses damage to rotating electrical machinery caused by frictional heat between the rotor core and stator core. [Solution] The rotating electric machine comprises a rotor core (50) made of steel plates (501) stacked in the axial direction of the rotor's rotation axis (C1), and a stator core (10) made of steel plates (101) stacked in the axial direction and provided on the outer circumference of the rotor core. The average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core, and in the steel plates of the stator core, the thickness of the portion (101a) on the outer diameter side of a predetermined radial position (P1) perpendicular to the axial direction centered on the rotation axis is thinner than the thickness of the portion (101b) on the inner diameter side of the predetermined position.

Description

[[Technical Field]]

[0001] The present invention relates to a rotating electric machine comprising a stator core and a rotor core each formed of laminated steel sheets. [[Background Art]]

[0002] Conventionally, there is an electric motor including a rotor core obtained by laminating laminated steel sheets in the axial direction of the rotating shaft of a rotor, and a stator core obtained by laminating laminated steel sheets in said axial direction, wherein the thickness of the laminated steel sheets of the rotor core is larger than the thickness of the laminated steel sheets of the stator core (see Patent Document 1). According to the electric motor described in Patent Document 1, the magnetic flux flowing axially in the stator core is reduced, the generation of eddy current is suppressed, and motor efficiency can be improved. [[Prior Art Literature]] [[Patent Literature]]

[0003] [[Patent Document 1]] Japanese Patent No. 7003267 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0004] By the way, in recent years, there has been a demand for small-sized and high-output motors (rotating electric machines), and along with the reduction of the gap between the rotor core and the stator core, the rotation speed of the rotor tends to increase. For this reason, the rotor core and the stator core may come into contact with each other due to press variations of steel sheets, lamination misalignment, or distortion of the rotor core caused by centrifugal force during rotation of the rotor. In this case, friction heat is generated between the rotor core and the stator core due to the rotation of the rotor, which may cause overheating and damage to the motor.

[0005] It should be noted that such a situation is common not only to motors but also to rotating electric machines such as generators and MG (motor generators) provided with similar rotor cores and stator cores.

[0006] This invention was made to solve the above problems, and its main purpose is to suppress damage to a rotating electric machine caused by frictional heat between the rotor core and the stator core. [Means for solving the problem]

[0007] A first means for solving the above problem is a rotating electric machine comprising a rotor core made of steel plates stacked in the axial direction of the rotor's rotation axis, a stator core provided on the outer circumference of the rotor core and made of steel plates stacked in the axial direction, and an outer cylinder which is an outer peripheral member fitted to the outer circumference of the stator core, wherein the average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core, and in the steel plates of the stator core, the thickness of the portion on the outer diameter side of a predetermined radial position centered on the rotation axis is thinner than the thickness of the portion on the inner diameter side of the predetermined position, a gap is formed between the outer diameter portions, and the outer cylinder is press-fitted onto the outer circumference of the stator core, causing the irregularities on the outer peripheral edge of the outer diameter portion to be deformed by the inner circumferential surface of the outer cylinder.

[0008] According to the above configuration, the rotor core is made of steel plates stacked in the axial direction. The stator core is provided on the outer circumference of the rotor core and is made of steel plates stacked in the axial direction. As described above, due to variations in the pressing and stacking of the steel plates, and distortion of the rotor core due to centrifugal force during rotor rotation, there is a risk that the rotor core and the stator core may come into contact. In this case, frictional heat is generated between the rotor core and the stator core due to the rotation of the rotor, which may cause the rotating electric machine to overheat and be damaged.

[0009] Here, if the thickness of the steel plate of the stator core and the thickness of the steel plate of the rotor core are the same, there is a risk that one steel plate of either the stator core or the rotor core, which protrudes radially, will be sandwiched by the other two steel plates from the axial direction. In that case, the contact area between the steel plates will increase, and the amount of frictional heat may increase. In contrast, since the average thickness of the steel plate of the stator core is thinner than the average thickness of the steel plate of the rotor core, it is possible to suppress the situation in which one steel plate that protrudes radially is sandwiched by the other two steel plates from the axial direction. Therefore, the contact area when the steel plates of the rotor core and the steel plates of the stator core come into contact can be reduced, and the amount of frictional heat can be suppressed.

[0010] Furthermore, in the steel plates of the stator core, the thickness of the portion on the outer diameter side of a predetermined radial position perpendicular to the axial direction is thinner than the thickness of the portion on the inner diameter side of that predetermined position. Therefore, in the portion of the steel plates of the stator core on the outer diameter side of a predetermined radial position, gaps can be formed between the steel plates, increasing the surface area. Consequently, the portion of the steel plates of the stator core on the outer diameter side of a predetermined radial position can act like a heat dissipation fin, allowing frictional heat to be efficiently dissipated. In particular, since the average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core, the surface area of ​​the steel plates of the stator core can be increased compared to the case where the relationship between the average thicknesses is reversed. As a result, damage to the rotating electric machine due to frictional heat between the rotor core and the stator core can be suppressed.

[0011] In the second method, the stator core comprises a yoke portion (11) extending in the circumferential direction about the rotation axis and a teeth portion (12) extending from the yoke portion toward the rotation axis, wherein the predetermined position is included in the yoke portion.

[0012] According to the above configuration, the stator core comprises a yoke portion extending in the circumferential direction and a teeth portion extending from the yoke portion toward the rotation axis. Generally, a stator coil is wound around the teeth portion, and the heat generated by the stator coil is conducted to the teeth portion.

[0013] Here, the predetermined position is included in the yoke portion. Therefore, the portion of the steel plate of the stator core in which the plate thickness is reduced can be limited to the yoke portion. Consequently, the surface area (heat dissipation area) of the stator core can be increased without hindering the conduction of heat generated in the stator coil to the teeth portion.

[0014] In the third method, insulating layers (102a, 102b) are provided on the surface of the steel plate of the stator core, and the thickness of the insulating layer (102a) in the portion of the steel plate of the stator core that is on the outer diameter side of the predetermined position is thinner than the thickness of the insulating layer (102b) in the portion of the steel plate that is on the inner diameter side of the predetermined position.

[0015] According to the above configuration, since an insulating layer is provided on the plate surface (main surface) of the steel plate of the stator core, it is possible to suppress the generation of eddy currents within the stator core when magnetic flux enters the stator core from the radial direction of the rotation axis. However, since insulating layers generally have a lower thermal conductivity than steel plates, there is a risk that heat dissipation from the plate surface (surface) may be hindered by the insulating layer in the portion of the steel plate of the stator core that is on the outer diameter side of a predetermined position (hereinafter referred to as the "fin portion").

[0016] In this regard, the thickness of the insulating layer on the outer diameter side of the steel plate of the stator core is thinner than the thickness of the insulating layer on the inner diameter side of the steel plate of the stator core. Therefore, in the fin portion, it is possible to suppress the obstruction of heat dissipation from the plate surface (surface) by the insulating layer, and thus suppress a decrease in heat dissipation performance.

[0017] In the fourth method, the thickness of the steel plate of the stator core is thinner towards the outer diameter side of the predetermined position. With this configuration, the gaps between the steel plates are made larger towards the outer diameter side in the fin portion, which promotes the penetration of the cooling refrigerant into the gaps and improves heat dissipation.

[0018] In the fifth method, the mechanical strength of the steel plate of the stator core is lower than that of the steel plate of the rotor core. With this configuration, when the steel plate of the rotor core and the steel plate of the stator core rub against each other, the steel plate of the stator core can be actively worn down. As a result, the friction between the steel plate of the rotor core and the steel plate of the stator core can be resolved in a shorter period of time, and the period during which frictional heat is generated can be shortened. Furthermore, if magnets are provided inside the rotor core, the wear occurs on the stator core rather than the rotor core, which can prevent damage to the bridge portion that holds the magnets inside the rotor core.

[0019] In the sixth method, the magnetic permeability of the steel plate of the rotor core is higher than that of the steel plate of the stator core. With this configuration, the amount of magnets in the rotor can be reduced, the amount of core deformation due to centrifugal force during rotor rotation can be suppressed, and the amount of contact between the stator core and the rotor core can be suppressed. Therefore, heat generation due to contact can be suppressed, and damage due to motor overheating can be suppressed.

[0020] In the seventh means, an insulating layer (502) is provided on the plate surface of the steel plate of the rotor core, and an insulating layer is provided on the plate surface of the steel plate of the stator core, wherein the total thickness of the insulating layer provided on the rotor core is thinner than the total thickness of the insulating layer provided on the stator core.

[0021] According to the above configuration, since an insulating layer is provided on the plate surface of the steel plate of the rotor core, it is possible to suppress the generation of eddy currents in the rotor core when magnetic flux enters the rotor core from the radial direction of the rotation shaft. However, since insulating layers generally have a lower thermal conductivity than steel plates, the insulating layer may hinder heat conduction in the axial direction of the rotation shaft in the rotor core, potentially reducing heat dissipation from the axial end face.

[0022] In this regard, the total thickness of the insulating layer provided on the rotor core is thinner than the total thickness of the insulating layer provided on the stator core. Therefore, compared to the stator core, the rotor core can suppress the obstruction of heat conduction in the axial direction of the rotation shaft by the insulating layer, and the reduction in heat dissipation from the axial end face can be suppressed.

[0023] The eighth means includes a housing for housing the rotor and the stator core, and a cooling fluid sealed within the housing together with the rotor and the stator core, wherein the rotor and the stator core are installed within the housing such that the cooling fluid can flow on the outer circumferential surface of the stator core. In addition, the stator core may be provided with a discharge section for dripping the cooling fluid from its outer circumferential surface. With this configuration, the cooling fluid enters the gaps between the steel plates in the fin portion and transfers heat, thereby significantly improving the heat dissipation performance of the stator core.

[0024] According to a ninth aspect, the invention comprises a cooling jacket (70) fitted to an outer circumference of the stator core, the cooling jacket including a flow passage through which a cooling fluid flows. In the stator core, the thickness of a steel plate at a fin portion is smaller than the thickness of a steel plate at an inner diameter side portion of the fin portion. Since the fin portion has a reduced plate thickness, the rigidity thereof is lower than that of other portions. Therefore, when the outer circumferential surface of the stator core is fitted to the inner circumferential surface of the cooling jacket, irregularities at the outer circumferential edge of the fin portion are deformed by the inner circumferential surface of the cooling jacket, and are corrected to reduce the irregularities. Accordingly, the contact area between the fin portion and the cooling jacket is increased to promote heat conduction, and the heat dissipation performance of the stator core can be significantly improved.

[0025] According to a tenth aspect, an insulating layer is provided on a plate surface of the steel plate of the rotor core, an insulating layer is provided on a plate surface of the steel plate of the stator core, and a thickness of each insulating layer provided on the steel plate of the rotor core is smaller than a thickness of each insulating layer provided on the steel plate of the stator core.

[0026] According to the above configuration, the thickness of each insulating layer provided on the steel plate of the rotor core is smaller than the thickness of each insulating layer provided on the steel plate of the stator core. Therefore, in the rotor core compared with the stator core, inhibition of heat conduction in the axial direction of the rotating shaft by the insulating layers can be suppressed, and a decrease in heat dissipation from the axial end face can be suppressed.

[0027] According to an eleventh aspect, an insulating layer is provided on a plate surface of the steel plate of the rotor core, an insulating layer is provided on a plate surface of the steel plate of the stator core, and a thickness of each insulating layer provided on the steel plate of the stator core is smaller than a thickness of each insulating layer provided on the steel plate of the rotor core.

[0028] According to the above configuration, the thickness of each insulating layer provided on the steel plate of the stator core is thinner than the thickness of each insulating layer provided on the steel plate of the rotor core. Therefore, compared to the rotor core, the stator core can suppress the obstruction of heat conduction in the axial direction of the rotating shaft by the insulating layer, and heat conduction from the high-temperature part to the low-temperature part of the stator core can be promoted. [Brief explanation of the drawing]

[0029] [Figure 1] A cross-sectional view showing the motor. [Figure 2] A cross-sectional view showing the stator core. [Figure 3] A longitudinal cross-sectional view showing the motor. [Figure 4] A schematic diagram showing the shape of each steel plate. [Figure 5] A schematic diagram showing each steel plate and its insulating layer. [Figure 6] A schematic diagram showing the heat dissipation surfaces of the rotor and stator. [Figure 7] A schematic diagram showing the insulating layer on the outer diameter side of the steel plate of the stator core. [Figure 8] A schematic diagram showing the rotor, stator, and cooling fluid. [Figure 9] A schematic diagram illustrating the wear pattern of the stator core. [Figure 10] A schematic diagram showing how a cooling jacket is press-fitted onto the stator core. [Figure 11] A schematic diagram showing an example of a change in the steel plate of the stator core. [Modes for carrying out the invention]

[0030] The following describes one embodiment of this technology implemented in a motor mounted on a vehicle (for example, a hybrid vehicle or an electric vehicle), with reference to the drawings. <Motor Configuration> As shown in Figure 1, the motor 100 (motor generator, rotating electric machine) is a permanent magnet embedded type motor in which permanent magnets 53 are embedded in the rotor 5.

[0031] The motor 100 is of an inner rotor type and has a stator 1 and a rotor 5 rotatably mounted inside the stator 1. An air gap of, for example, 0.3 to 1.0 mm is formed between the stator 1 and the rotor 5.

[0032] Hereafter, the direction of the central axis C1, which is the rotation axis of the rotor 5, will be simply referred to as the "axial direction." Also, the circumferential direction (indicated by arrow R1 in Figure 1) centered on the central axis C1 (hereinafter also referred to as the "rotation axis C1") will be simply referred to as the "circumferential direction." Furthermore, the radial direction centered on the central axis C1 will be simply referred to as the "radial direction." Figure 1 is a cross-sectional view taken in a plane perpendicular to the central axis C1. <Rotor Configuration> The rotor 5 includes a cylindrical rotor core 50, permanent magnets 53 embedded in the rotor core 50, and a shaft 58 fixed to the center of the rotor core 50.

[0033] The rotor core 50 is formed by laminating steel plates 501 (see Figure 4) in the axial direction and integrating them using crimping or the like. The steel plates 501 are, for example, electrical steel sheets. The thickness of the steel plates 501 and the lamination gap will be described later.

[0034] Multiple magnet insertion holes 51 into which permanent magnets 53 are inserted are formed along the outer circumferential surface of the rotor core 50. The magnet insertion holes 51 are through holes that penetrate the rotor core 50 in the axial direction. In this case, there are 2 magnet insertion holes 51 per magnetic pole, for a total of 16. However, the number of magnet insertion holes 51 per magnetic pole is not limited to 2 and can be any number. The space between the magnet insertion holes 51 of adjacent magnetic poles is called the pole space.

[0035] Within one magnetic pole, a pair of magnet insertion holes 51 are formed in a V-shape such that their circumferential center protrudes most towards the central axis C1. Each magnet insertion hole 51 has a permanent magnet 53 positioned on either side of its circumferential center. The two permanent magnets 53 in each magnet insertion hole 51 within one magnetic pole are magnetized such that the same polarity faces radially outward, while adjacent magnetic poles are magnetized with different polarities.

[0036] The permanent magnet 53 is a flat plate-shaped member with length in the axial direction, having width in the longitudinal direction and thickness in the short direction in Figure 1. The permanent magnet 53 is magnetized in the thickness direction.

[0037] Here, one permanent magnet 53 is placed in each magnet insertion hole 51, but multiple permanent magnets 53 may be placed in each magnet insertion hole 51. <Stator Configuration> The stator 1 comprises a stator core 10 and a coil 4 wound around the stator core 10. The stator core 10 has an annular yoke portion 11 centered on a central axis C1 and a plurality of teeth portions 12 extending radially inward from the yoke portion 11 (i.e., toward the central axis C1). The radially inward ends of the teeth portions 12 are formed with tooth tips 13 facing the outer circumferential surface of the rotor 5.

[0038] Here, 48 teeth 12 are arranged at regular intervals in the circumferential direction, and slots 14, which are spaces for housing the coil 4, are formed between adjacent teeth 12 in the circumferential direction.

[0039] Coil 4 is made by winding magnet wire through an insulator 2 (see Figure 3). The conductor cross-section of coil 4 is rectangular, and eight wires are inserted into each slot 14 and connected in a three-phase Y connection. The wire diameter and number of turns of coil 4 are determined according to the required rotational speed, torque, applied voltage, or area of ​​slot 14.

[0040] Figure 2 is a cross-sectional view showing the stator core 10. The stator core 10 is formed by laminating steel plates 101 (see Figure 4) in the axial direction and integrating them by crimping or the like. The steel plates 101 are, for example, electrical steel sheets.

[0041] The stator core 10 has an annular yoke portion 11 and a plurality of teeth portions 12 extending radially inward from the yoke portion 11. The teeth portions 12 have a tooth tip portion 13 at their radially inward end that is wider than the rest of the teeth portion 12.

[0042] The inner circumferential surface 111 of the yoke portion 11, the side surface 121 of the tooth portion 12, and the outer circumferential surface 131 of the tooth tip portion 13 all face the slot 14.

[0043] Figure 3 is a longitudinal cross-sectional view showing the motor 100. As described above, the stator core 10 is made by stacking steel plates 101 in the axial direction, and the rotor core 50 is made by stacking steel plates 501 in the axial direction.

[0044] The thickness T0 of the steel plate 501 is constant throughout the entire axial direction of the rotor core 50. Thickness T0 refers to the thickness of a single sheet of steel plate 501. The thickness of the steel plate 101 varies radially, as will be described later, and the thickness of the thickest part is the maximum thickness T1.

[0045] The thickness T0 of the steel plate 501 of the rotor core 50 is greater than the maximum thickness T1 of the steel plate 101 of the stator core 10. In other words, the thickness T0 of the steel plate 501 of the rotor core 50 and the maximum thickness T1 of the steel plate 101 of the stator core 10 satisfy the relationship T0 > T1. Also, the average thickness of the steel plate 101 of the stator core 10 is thinner than the average thickness T0 of the steel plate 501 of the rotor core 50.

[0046] The thickness T0 of the steel plate 501 of the rotor core 50 is, for example, 0.35 mm, and the maximum thickness T1 of the steel plate 101 of the stator core 10 is, for example, 0.25 mm. Note that the thickness T0 of the steel plate 501 of the rotor core 50 and the maximum thickness T1 of the steel plate 101 of the stator core 10 include manufacturing variations within tolerance.

[0047] Figure 4 is a schematic diagram showing the shapes of each steel plate 501 and 101. Due to pressing variations and lamination misalignment, the steel plates 501 of the rotor core 50 and 101 of the stator core 10 have variations in the outer diameter end positions of the steel plates 501 of the rotor core 50 and variations in the inner diameter end positions of the steel plates 101 of the stator core 10.

[0048] In the steel plate 101 of the stator core 10, the thickness of the portion 101a on the outer diameter side of a predetermined radial position P1 perpendicular to the axial direction is thinner than the thickness of the portion 101b on the inner diameter side of the predetermined position P1. As a result, a gap is formed between the portions 101a on the outer diameter side of the steel plate 101 on the outer diameter side of the predetermined position P1. Therefore, the outer diameter portion 101a acts like a heat dissipation fin. The predetermined position P1 is included in the yoke portion 11. That is, the thickness of the steel plate 101 of the stator core 10 is constant in the teeth portion 12, and changes from the middle of the radial direction in the yoke portion 11. Furthermore, the thickness of the portion 101a on the outer diameter side of the steel plate 101 of the stator core 10 becomes thinner towards the outer diameter side.

[0049] Figure 5 is a schematic diagram showing steel plate 501, portion 101b of steel plate 101, and their insulating layers 502 and 102b. For illustrative purposes, in Figure 5, the thickness of insulating layers 502 and 102b is shown as thicker than it actually is. The plate surface of steel plate 501 of the rotor core 50 is provided with an insulating layer 502 that suppresses the generation of eddy currents within the rotor core 50 when magnetic flux enters the rotor core 50 from the radial direction. The plate surface of portion 101b of steel plate 101 of the stator core 10 is provided with an insulating layer 102b that suppresses the generation of eddy currents within the stator core 10 when magnetic flux enters the stator core 10 from the radial direction.

[0050] Figure 6 is a schematic diagram showing the heat dissipation surface S1 of the rotor 5 and the heat dissipation surface S2 of the stator 1.

[0051] The thickness T0 of the steel plate 501 of the rotor core 50 is greater than the maximum thickness T1 of the steel plate 101 of the stator core 10. Furthermore, the total thickness of the insulating layer 502 provided on the rotor core 50 is less than the total thickness of the insulating layer 102b provided on the stator core 10.

[0052] Figure 7 is a schematic diagram showing the insulating layer 102a on the outer diameter side of the steel plate 101 of the stator core 10. The insulating layer 102a is provided on the surface of portion 101a of the steel plate 101 of the stator core 10. The thickness of the insulating layer 102a on portion 101a on the outer diameter side of the steel plate 101 of the stator core 10 is thinner than the thickness of the insulating layer 102b on portion 101b on the inner diameter side of the predetermined position P1. Furthermore, the thickness of the insulating layer 102a on portion 101a becomes thinner as it moves towards the outer diameter side of the predetermined position P1.

[0053] The mechanical strength of the steel plate 101 of the stator core 10 is lower than that of the steel plate 501 of the rotor core 50. This can be achieved by using different materials for steel plate 101 and steel plate 501. In other words, the mechanical strength of the material of steel plate 101 is lower than that of the material of steel plate 501.

[0054] Figure 8 is a schematic diagram showing the stator 1, rotor 5, and cooling fluid L. The motor 100 is mounted so that the cooling fluid L can flow over the outer circumferential surface of the stator core 10. The cooling fluid L may be sealed within a housing that contains the motor body (stator 1, rotor 5), or it may be provided with a discharge section 60 for dripping the cooling fluid L. The cooling fluid L is a liquid such as lubricating oil. The discharge section 60 is formed, for example, in a pipe shape (cylindrical shape), with holes formed at predetermined intervals opposite the stator core 10 and coil 4. By pressurizing the cooling fluid L inside the discharge section 60, the cooling fluid L is dripped out of the holes. As a result, the cooling fluid L is dripped onto the outer circumferential surface of the stator core 10 and the coil 4. The cooling fluid L may also flow over the outer circumferential surface of the stator core 10 due to stirring caused by the rotation of the rotor 5 or vibrations of the vehicle on which the motor 100 is mounted. Furthermore, a gas such as air can be used as the cooling fluid L.

[0055] Figure 9 is a schematic diagram showing the wear pattern of the stator core 10. As shown in Figure 9(a), before the rotor core 50 and the stator core 10 come into contact, the outer diameter end positions of the steel plates 501 of the rotor core 50 and the inner diameter end positions of the steel plates 101 of the stator core 10 are inconsistent. When the rotor core 50 is distorted by the centrifugal force during the rotation of the rotor 5, the rotor core 50 and the stator core 10 come into contact. As a result, as shown in Figure 9(b), the steel plate 101 of the stator core 10 wears down more than the steel plate 501 of the rotor core 50, as the steel plate 101 of the stator core 10 has lower mechanical strength.

[0056] The embodiment described in detail above has the following advantages.

[0057] Since the average thickness of the steel plates 101 of the stator core 10 is thinner than the average thickness of the steel plates 501 of the rotor core 50, it is possible to prevent a situation where one steel plate of either the stator core 10 or the rotor core 50, which protrudes radially, is sandwiched in the axial direction by the other two steel plates. Therefore, the contact area when the steel plates 501 of the rotor core 50 and the steel plates 101 of the stator core 10 come into contact can be reduced, and an increase in frictional heat can be suppressed.

[0058] In the steel plate 101 of the stator core 10, the thickness of the portion 101a on the outer diameter side of a predetermined radial position P1 perpendicular to the axial direction is thinner than the thickness of the portion 101b on the inner diameter side of the predetermined position P1. Therefore, in the steel plate 101 of the stator core 10, a gap can be formed between the steel plates 101a on the outer diameter side of the predetermined radial position P1, increasing the surface area. Consequently, the portion 101a on the outer diameter side of the predetermined radial position P1 in the steel plate 101 of the stator core 10 can act like a heat dissipation fin, allowing frictional heat to be efficiently dissipated. In particular, since the average thickness of the steel plate 101 of the stator core 10 is thinner than the average thickness of the steel plate 501 of the rotor core 50, the surface area of ​​the steel plate 101 of the stator core 10 can be increased compared to the case where the relationship between the average thicknesses is reversed. As a result, damage to the motor 100 due to frictional heat between the rotor core 50 and the stator core 10 can be suppressed.

[0059] The stator core 10 comprises a yoke portion 11 extending in the circumferential direction and a teeth portion 12 extending from the yoke portion 11 toward the rotation axis C1. A coil 4 is wound around the teeth portion 12, and the heat generated in the coil 4 is conducted to the teeth portion 12. Here, the predetermined position P1 is included in the yoke portion 11. Therefore, in the steel plate 101 of the stator core 10, the portion 101a in which the plate thickness is reduced can be limited to the yoke portion 11. Thus, the surface area (heat dissipation area) of the stator core 10 can be increased without hindering the conduction of heat generated in the coil 4 to the teeth portion 12.

[0060] Since insulating layers 102a and 102b are provided on the plate surface (main surface) of the steel plate 101 of the stator core 10, it is possible to suppress the generation of eddy currents within the stator core 10 when magnetic flux enters the stator core 10 from the radial direction. However, since the insulating layers 102a and 102b have lower thermal conductivity than the steel plate 101, there is a risk that heat dissipation from the plate surface (surface) may be hindered by the insulating layers 102a and 102b in the portion 101a (hereinafter also referred to as the "fin portion 101a") on the outer diameter side of the predetermined position P1 of the steel plate 101 of the stator core 10. In this regard, the thickness of the insulating layer 102a in the portion 101a on the outer diameter side of the predetermined position P1 of the steel plate 101 of the stator core 10 is thinner than the thickness of the insulating layer 102b in the portion 101b on the inner diameter side of the predetermined position P1. Therefore, in the fin portion 101a, it is possible to suppress the obstruction of heat dissipation from the plate surface (surface) by the insulating layer 102a, and thus suppress a decrease in heat dissipation performance.

[0061] The thickness of the steel plate 101 of the stator core 10 in the portion 101a on the outer diameter side of the predetermined position P1 is thinner towards the outer diameter. With this configuration, the gap between the steel plates 101 can be made larger towards the outer diameter side in the fin portion 101a, thereby improving heat dissipation.

[0062] The mechanical strength of the steel plate 101 of the stator core 10 is lower than that of the steel plate 501 of the rotor core 50. With this configuration, when the steel plate 501 of the rotor core 50 and the steel plate 101 of the stator core 10 rub against each other, the steel plate 101 of the stator core 10 can be actively worn down. As a result, the friction between the steel plate 501 of the rotor core 50 and the steel plate 101 of the stator core 10 can be resolved in a shorter period of time, and the period during which frictional heat is generated can be shortened. Furthermore, since the permanent magnet 53 is provided inside the rotor core 50, wear occurs on the stator core 10 rather than the rotor core 50, which can prevent damage to the bridge portion that holds the permanent magnet 53 inside the rotor core 50.

[0063] Since an insulating layer 502 is provided on the surface of the steel plate 501 of the rotor core 50, it is possible to suppress the generation of eddy currents within the rotor core 50 when magnetic flux enters the rotor core 50 from the radial direction. However, since the insulating layer 502 has a lower thermal conductivity than the steel plate 501, the insulating layer 502 may hinder heat conduction in the axial direction of the rotating shaft in the rotor core 50, potentially reducing heat dissipation from the axial end face (surface S1). In this regard, the total thickness of the insulating layer 502 provided on the rotor core 50 is thinner than the total thickness of the insulating layer 102b provided on the stator core 10. Therefore, compared to the stator core 10, the inhibition of heat conduction in the axial direction by the insulating layer 502 can be suppressed in the rotor core 50, and the reduction in heat dissipation from the axial end face can be suppressed.

[0064] The motor 100 is installed in a housing so that a cooling fluid L can flow over the outer surface of the stator core 10. It also has a discharge section 60 for dripping the cooling fluid L onto the stator core 10 and coil ends. As a result, the cooling fluid L can enter the gaps between the steel plates 101 in the fin section 101a, significantly improving the heat dissipation performance of the stator core 10.

[0065] The total thickness of each insulating layer 502 provided on the steel plate 501 of the rotor core 50 is thinner than the total thickness of each insulating layer 102b provided on the steel plate 101 of the stator core 10. Therefore, compared to the stator core 10, the axial heat conduction in the rotor core 50 can be suppressed by the insulating layer 502, and the reduction in heat dissipation from the axial end face can be suppressed.

[0066] Furthermore, the above embodiment can also be implemented with the following modifications. Parts identical to those in the above embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0067] The thickness of the insulating layer 102a in the steel plate 101 of the stator core 10 may be constant.

[0068] The thickness of the steel plate 101 of the stator core 10 may be constant in the portion 101a on the outer diameter side of the predetermined position P1.

[0069] In the steel plate 101 of the stator core 10, the region in which the thickness of the portion 101a on the outer diameter side of the predetermined position P1 is thinner than the thickness of the portion 101b on the inner diameter side of the predetermined position P1 does not have to be the entire region in the circumferential direction, but may be partial.

[0070] By using different materials for the steel plates 501 of the rotor core 50 and the steel plates 101 of the stator core 10, the permeability of the steel plates 501 of the rotor core 50 can be made higher than that of the steel plates 101 of the stator core 10. With this configuration, the amount of magnets in the rotor 5 can be reduced, the amount of core deformation due to centrifugal force when the rotor 5 rotates can be suppressed, and the amount of contact between the stator core 10 and the rotor core 50 can be suppressed. Therefore, heat generation due to contact can be suppressed, and damage to the motor 100 due to overheating can be suppressed.

[0071] The mechanical strength of the steel plate 101 of the stator core 10 can be made to be greater than or equal to the mechanical strength of the steel plate 501 of the rotor core 50.

[0072] As shown in Figure 10(b), the motor 100 may be press-fitted (fitted) onto the outer circumference of the stator core 10 and may include a cooling jacket 70 with a flow section through which a cooling fluid L flows. The flow section has a flow path for the cooling fluid L formed inside. Here, in the steel plate 101 of the stator core 10, the thickness of the fin portion 101a is thinner than the thickness of the portion 101b on the inner diameter side of the fin portion 101a. The fin portion 101a has reduced rigidity compared to other parts due to its thinner thickness. Therefore, when fitting the inner surface of the cooling jacket 70 onto the outer circumference of the stator core 10 from the state shown in Figure 10(a) to the state shown in Figure 10(b), the irregularities on the outer edge of the fin portion 101a are deformed by the inner surface of the cooling jacket 70 and corrected so that the irregularities are reduced. Thus, the contact surface between the fin portion 101a and the cooling jacket 70 increases, which can promote heat conduction and significantly improve the heat dissipation performance of the stator core 10.

[0073] - A configuration can also be adopted in which the thickness of each insulating layer 102a, 102b provided on the steel plate 101 of the stator core 10 is thinner than the thickness of each insulating layer 502 provided on the steel plate 501 of the rotor core 50. With such a configuration, compared to the rotor core 50, the axial heat conduction in the stator core 10 can be suppressed by the insulating layers 102a, 102b, and heat conduction from the high-temperature part to the low-temperature part of the stator core 10 can be promoted.

[0074] As shown in Figure 11, the steel plates 101 of the stator core 10 can be made thinner towards the outer diameter. This configuration also allows for the formation of gaps between the steel plates 101. Therefore, the steel plates 101 of the stator core 10 can act like heat dissipation fins, allowing for efficient heat dissipation through friction. In particular, since the average thickness of the steel plates 101 of the stator core 10 is thinner than the average thickness of the steel plates 501 of the rotor core 50, the surface area of ​​the steel plates 101 of the stator core 10 can be increased compared to the case where the relationship between the average thicknesses is reversed. As a result, damage to the rotating electric machine due to friction heat between the rotor core 50 and the stator core 10 can be suppressed. Note that in the configuration of Figure 11, even if a predetermined position P1 is set at any radial position on the steel plate 101, the thickness of the portion on the outer diameter side of the predetermined position P1 will be thinner than the thickness of the portion on the inner diameter side of the predetermined position P1.

[0075] The rotor 5 is not limited to a permanent magnet embedded type; it may also be a field winding type.

[0076] The steel plates 101 of the stator core 10 are not limited to individual plates, but may be plates connected in a spiral; in other words, the stator core 10 may be a helical core. Similarly, the steel plates 501 of the rotor core 50 are not limited to individual plates, but may be plates connected in a spiral; in other words, the rotor core 50 may be a helical core.

[0077] Furthermore, it is possible to combine and implement the above examples of changes.

[0078] The following describes the characteristic configurations extracted from the embodiments and modifications described above. [Configuration 1] A rotating electric machine (100) comprising a rotor core (50) made of steel plates (501) stacked in the axial direction of the rotation axis (C1) of the rotor (5), and a stator core (10) provided on the outer circumference of the rotor core and made of steel plates (101) stacked in the axial direction, The average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core. A rotating electric machine in which, in the steel plate of the stator core, the thickness of the portion (101a) on the outer diameter side of a predetermined radial position (P1) centered on the rotation axis is thinner than the thickness of the portion (101b) on the inner diameter side of the predetermined position. [Configuration 2] The stator core comprises a yoke portion (11) extending in the circumferential direction around the rotation axis and a teeth portion (12) extending from the yoke portion toward the rotation axis. The predetermined position is the rotating electric machine described in configuration 1, which is included in the yoke portion. [Configuration 3] An insulating layer (102a, 102b) is provided on the plate surface of the steel plate of the stator core. The rotating electric machine according to configuration 1 or 2, wherein the thickness of the insulating layer (102a) in the portion of the steel plate of the stator core that is on the outer diameter side of the predetermined position is thinner than the thickness of the insulating layer (102b) in the portion that is on the inner diameter side of the predetermined position. [Structure 4] The rotating electric machine according to any one of configurations 1 to 3, wherein the thickness of the steel plate of the stator core in the portion on the outer diameter side of the predetermined position is thinner towards the outer diameter side. [Composition 5] A rotating electric machine according to any one of configurations 1 to 4, wherein the mechanical strength of the steel plate of the stator core is lower than the mechanical strength of the steel plate of the rotor core. [Composition 6] The rotating electric machine according to any one of configurations 1 to 5, wherein the permeability of the steel plate of the rotor core is higher than the permeability of the steel plate of the stator core. [Composition 7] An insulating layer (502) is provided on the plate surface of the steel plate of the rotor core. An insulating layer is provided on the plate surface of the steel plate of the stator core. The rotating electric machine according to any one of configurations 1 to 6, wherein the total thickness of the insulating layer provided on the rotor core is thinner than the total thickness of the insulating layer provided on the stator core. [Structure 8] A rotating electric machine according to any one of configurations 1 to 7, comprising a housing for housing the rotor and the stator core, and a cooling fluid sealed within the housing together with the rotor and the stator core, wherein the rotor and the stator core are installed within the housing such that the cooling fluid can flow on the outer circumferential surface of the stator core. [Composition 9] A rotating electric machine according to any one of configurations 1 to 7, comprising a cooling jacket (70) fitted to the outer circumference of the stator core and including a flow section through which a cooling fluid flows. [Configuration 10] An insulating layer is provided on the plate surface of the steel plate of the rotor core. An insulating layer is provided on the plate surface of the steel plate of the stator core. The rotating electric machine according to any one of configurations 1 to 9, wherein the thickness of each insulating layer provided on the steel plate of the rotor core is thinner than the thickness of each insulating layer provided on the steel plate of the stator core. [Composition 11] An insulating layer is provided on the plate surface of the steel plate of the rotor core. An insulating layer is provided on the plate surface of the steel plate of the stator core. The rotating electric machine according to any one of configurations 1 to 9, wherein the thickness of each insulating layer provided on the steel plate of the stator core is thinner than the thickness of each insulating layer provided on the steel plate of the rotor core. [Composition 21] A rotating electric machine (100) comprising a rotor core (50) made of steel plates (501) stacked in the axial direction of the rotation axis (C1) of the rotor (5), and a stator core (10) provided on the outer circumference of the rotor core and made of steel plates (101) stacked in the axial direction, The average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core. In the steel plate of the stator core, the thickness of the portion (101a) on the outer diameter side of a predetermined radial position (P1) centered on the rotation axis is thinner than the thickness of the portion (101b) on the inner diameter side of the predetermined position. A rotating electric machine wherein the material of the steel plate of the rotor core is different from the material of the steel plate of the stator core, and the permeability of the steel plate of the rotor core is higher than that of the steel plate of the stator core. [Composition 22] A rotating electric machine (100) comprising a rotor core (50) made of steel plates (501) stacked in the axial direction of the rotation axis (C1) of the rotor (5), and a stator core (10) provided on the outer circumference of the rotor core and made of steel plates (101) stacked in the axial direction, The average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core. In the steel plate of the stator core, the thickness of the portion (101a) on the outer diameter side of a predetermined radial position (P1) centered on the rotation axis is thinner than the thickness of the portion (101b) on the inner diameter side of the predetermined position. The stator core is press-fitted onto its outer circumference and includes a cooling jacket (70) with a flow section through which a cooling fluid flows. A rotating electric machine in which the outer peripheral edge of the outer diameter portion (101a) of all the steel plates constituting the stator core is in contact with the cooling jacket. [Composition 23] A rotating electric machine (100) comprising a rotor core (50) made of steel plates (501) stacked in the axial direction of the rotation axis (C1) of the rotor (5), and a stator core (10) provided on the outer circumference of the rotor core and made of steel plates (101) stacked in the axial direction, The average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core. In the steel plate of the stator core, the thickness of the portion (101a) on the outer diameter side of a predetermined radial position (P1) centered on the rotation axis is thinner than the thickness of the portion (101b) on the inner diameter side of the predetermined position. The system comprises a housing for housing the rotor and the stator core, and a cooling fluid sealed within the housing together with the rotor and the stator core, wherein the rotor and the stator core are installed within the housing such that the cooling fluid can flow on the outer circumferential surface of the stator core. A rotating electric machine having a discharge section for dripping cooling fluid onto the stator core from its outer circumference. [Composition 24] The stator core comprises a yoke portion (11) extending in the circumferential direction around the rotation axis and a teeth portion (12) extending from the yoke portion toward the rotation axis. The predetermined position is a rotating electric machine according to any of the configurations 21 to 23, which is included in the yoke portion. [Composition 25] An insulating layer (102a, 102b) is provided on the plate surface of the steel plate of the stator core. A rotating electric machine according to any one of configurations 21 to 24, wherein the thickness of the insulating layer (102a) in the portion of the steel plate of the stator core that is on the outer diameter side of the predetermined position is thinner than the thickness of the insulating layer (102b) in the portion that is on the inner diameter side of the predetermined position. [Composition 26] The rotating electric machine according to any of configurations 21 to 25, wherein the thickness of the steel plate of the stator core in the portion on the outer diameter side of the predetermined position is thinner towards the outer diameter side. [Composition 27] A rotating electric machine according to any one of configurations 21 to 26, wherein the mechanical strength of the steel plate of the stator core is lower than the mechanical strength of the steel plate of the rotor core. [Composition 28] An insulating layer (502) is provided on the plate surface of the steel plate of the rotor core. An insulating layer is provided on the plate surface of the steel plate of the stator core. A rotating electric machine according to any one of configurations 21 to 27, wherein the total thickness of the insulating layer provided on the rotor core is thinner than the total thickness of the insulating layer provided on the stator core. [Composition 29] An insulating layer is provided on the plate surface of the steel plate of the rotor core. An insulating layer is provided on the plate surface of the steel plate of the stator core. A rotating electric machine according to any one of configurations 21 to 27, wherein the thickness of each insulating layer provided on the steel plate of the rotor core is thinner than the thickness of each insulating layer provided on the steel plate of the stator core. [Composition 30] An insulating layer is provided on the plate surface of the steel plate of the rotor core. An insulating layer is provided on the plate surface of the steel plate of the stator core. The rotating electric machine according to any one of configurations 21 to 27, wherein the thickness of each insulating layer provided on the steel plate of the stator core is thinner than the thickness of each insulating layer provided on the steel plate of the rotor core. [Explanation of Symbols]

[0079] 1...stator, 5...rotor, 10...stator core, 50...rotor core, 100...rotating electric machine, 101...steel plate, 101a...part, 101b...part, 501...steel plate, 510...stator core, C1...rotating shaft.

Claims

1. A rotor core (50) is made up of steel plates (501) stacked in the axial direction of the rotation axis (C1) of the rotor (5), A stator core (10) is provided on the outer circumference of the rotor core and is composed of steel plates (101) stacked in the axial direction, A rotating electric machine (100) comprising an outer cylinder (70) which is an outer peripheral member fitted to the outer circumference of the stator core, The average thickness of the steel plates of the stator core is thinner than the average thickness of the steel plates of the rotor core. In the steel plate of the stator core, the thickness of the portion (101a) on the outer diameter side of a predetermined radial position (P1) centered on the rotation axis is thinner than the thickness of the portion (101b) on the inner diameter side of the predetermined position. A gap is formed between the aforementioned outer diameter portions. A rotating electric machine in which the outer cylinder is press-fitted onto the outer circumference of the stator core, causing the irregularities on the outer peripheral edge of the outer diameter portion to be deformed by the inner peripheral surface of the outer cylinder.

2. The rotating electric machine according to claim 1, wherein the outer cylinder is configured as a separate member of the stator core and is press-fitted onto the outer circumference of the stator core.

3. The rotating electric machine according to claim 1, wherein the outer cylinder includes a flow section through which a cooling fluid flows.

4. The rotating electric machine according to claim 1, further comprising a cooling fluid that can flow into and flow in the gap between the aforementioned outer diameter portions.

5. The stator core comprises a yoke portion (11) extending in the circumferential direction around the rotation axis and a teeth portion (12) extending from the yoke portion toward the rotation axis. The rotating electric machine according to any one of claims 1 to 4, wherein the predetermined position is included in the yoke portion.

6. The thickness of the steel plate of the stator core is constant in the teeth portion. The rotating electric machine according to claim 5, wherein the yoke portion changes from the middle in the radial direction.

7. The rotating electric machine according to any one of claims 1 to 4, wherein the thickness of the steel plate of the stator core in the portion on the outer diameter side of the predetermined position is thinner towards the outer diameter side.

8. The rotating electric machine according to any one of claims 1 to 4, wherein an insulating layer (102a, 102b) is provided on the plate surface of the steel plate of the stator core.

9. The rotating electric machine according to any one of claims 1 to 4, wherein the thickness of the insulating layer provided in the portion on the outer diameter side of the predetermined position is thinner than the thickness of the insulating layer provided in the portion on the inner diameter side of the predetermined position.

10. The rotating electric machine according to any one of claims 1 to 4, wherein the mechanical strength of the steel plate of the stator core is lower than the mechanical strength of the steel plate of the rotor core.

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