Rotating electrical machine

Abstract

The rotor (30) is composed of a rotor core (31) fixed to the shaft (5), a pair of magnet grooves (35) configured in a V-shape in a manner of moving apart from each other toward the radial outside, permanent magnets (32) inserted in the magnet grooves (35), and hole portions (33) provided on the radial outside of the magnet grooves (35). The distance between the permanent magnets (32) and the hole portions (33) is configured to become larger as it goes toward the radial outside, and the distance between the outer periphery of the rotor core (31) and the hole portions (33) is configured to be larger than the distance between the magnet grooves (35) and the outer periphery of the rotor core (31).

Description

TECHNICAL FIELD

[0001] The present application relates to a rotary electric machine. BACKGROUND

[0002] As a rotor structure of a permanent magnet synchronous rotary electric machine, a structure in which magnets are deeply embedded in a rotor core to obtain high torque is well known. In such a configuration, in order to maintain the core located at the outer peripheral side of the magnets and the core located at the inner peripheral side of the magnets with respect to the centrifugal force applied to the core, it is necessary to provide a bridge-like structure at the core portion at the outer peripheral side of the magnets and at the core portion at the inner peripheral side of the magnets. The bridge-like structure is usually configured by a core that is formed integrally with the core at the outer peripheral side and the core at the inner peripheral side of the magnets, but becomes a leakage magnetic path that shorts the magnetic flux of the magnets in the rotor. With the increase in the centrifugal force applied to the bridge portion with the increase in the speed of rotation, the stress caused by the centrifugal force applied to the bridge portion increases, and thus it is necessary to thicken the bridge portion. Consequently, the leakage magnetic path also increases, and thus the magnetic flux cannot be effectively used for generating torque, and it is difficult to simultaneously achieve high torque and high speed rotation.

[0003] In response to this, there is a structure in which the bridge portion is not provided, and the rotor is held in the axial direction by a bolt, thereby simultaneously achieving high torque and high speed rotation (see Patent Literature 1).

[0004] In addition, in a permanent magnet synchronous rotary electric machine in which the magnets are arranged in a In a permanent magnet synchronous rotary electric machine in which the magnets are arranged in a In a permanent magnet synchronous rotary electric machine in which the magnets are arranged in a

[0005] PRIOR ART

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2001-178045

[0008] Patent Literature 2: Japanese Patent Application Publication No. 2015-173545 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] In the structure in which the bridge portion is not provided as in Patent Literature 1 described above, the assembly of the rotor becomes difficult, and there is a problem in that it is difficult to secure the concentricity and the outer diameter roundness of the rotor. In addition, in the permanent magnet synchronous rotary electric machine in which the magnets are arranged in a In the permanent magnet synchronous rotary electric machine in which the magnets are arranged in a In the permanent magnet synchronous rotary electric machine in which the magnets are arranged in a

[0011] The present application discloses a rotating electric machine that can prevent damage due to centrifugal force and reduce magnetic flux leakage.

[0012] Solution to the problem

[0013] The rotating electric machine disclosed in the present application has a rotor disposed on the inner circumferential side of a stator, wherein the rotor is composed of a rotor core fixed to a shaft, a pair of magnet grooves disposed in a V shape in such a manner as to move apart from each other toward the radial outside of the rotor core, permanent magnets inserted in each of the magnet grooves, and hole portions provided on the radial outside of each of the magnet grooves, the distance between the permanent magnets and the hole portions is configured to become larger as it goes toward the radial outside, and the distance between the outer circumference of the rotor core and the hole portions is configured to be larger than the distance between each of the magnet grooves and the outer circumference of the rotor core.

[0014] Effects of the invention

[0015] According to the rotating electric machine disclosed in the present application, it is possible to prevent damage due to centrifugal force and reduce magnetic flux leakage. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a cross-sectional side view along the rotational axis of a motor as a rotating electric machine.

[0017] Figure 2 is a partial cross-sectional plan view showing the rotor in Embodiment 1.

[0018] Figure 3 is a partial cross-sectional plan view showing the rotor in Embodiment 2.

[0019] Figure 4 is a diagram for explaining the principle of a general reluctance motor.

[0020] Figure 5 is a schematic diagram showing the state of magnetic flux passing through the rotor core.

[0021] Figure 6 is a partial cross-sectional plan view showing the rotor in Embodiment 2.

[0022] Figure 7 is a partial cross-sectional plan view showing the rotor in Embodiment 3.

[0023] Figure 8 is a partial cross-sectional plan view showing the rotor in Embodiment 4.

[0024] Figure 9 is a partial cross-sectional plan view showing the rotor in Embodiment 5.

[0025] Figure 10 is a partial cross-sectional plan view showing the rotor in Embodiment 6.

[0026] Figure 11 is a partial cross-sectional plan view showing the rotor in Embodiment 7.

[0027] Figure 12 is a partial cross-sectional plan view showing the rotor in Embodiment 8. DETAILED DESCRIPTION

[0028] Embodiment 1.

[0029] This embodiment relates to a rotor structure of a buried magnet type permanent magnet synchronous rotating electric machine.

[0030] Hereinafter, the inner periphery side and the outer periphery side are referred to as the inner periphery side and the outer periphery side of the rotor. Figure 1 is a cross-sectional side view along the rotating axis of a motor as a rotating electric machine. Figure 2 is a partial cross-sectional plan view showing the rotor in Embodiment 1, and is a cross-sectional view in a direction perpendicular to the rotating axis. In addition, the rotor is configured in a state in which a plurality of magnet grooves 35 are arranged in the circumferential direction. Figure 2 is configured in a state in which a structure similar to a part of the rotor shown in

[0031] As shown in Figure 1 , the motor 1 is configured of a stator 20 and a rotor 30 housed in a frame 10. In addition, in the rotor 30, the axial both ends of a shaft 5 are rotatably held by a load side bearing 6 and a load opposite side bearing 7. The stator 20 is configured of a stator core 21 having a tooth portion protruding in the radial direction from a yoke portion toward the rotor 30, and a coil 22 wound around the tooth portion.

[0032] As shown in Figure 2 , the rotor 30 has a rotor core 31 fixed to the shaft 5 by press-fitting or the like, and a pair of magnet grooves 35 arranged in a V shape and in a band shape in the rotor core 31. That is, the pair of magnet grooves 35 are arranged so as to be apart from each other toward the radial direction outside, and are arranged with a gap (Dbi to be described later) on the radial direction inside.

[0033] Further, the rotor 30 is configured of a permanent magnet 32 inserted in the magnet groove 35, and a hole portion 33 provided on the radial direction outside of the pair of magnet grooves 35. By providing the hole portion 33, the mass of the entire rotor 30 is reduced, stress in each bridge portion to be described later due to centrifugal force can be alleviated, and high speed rotation of the rotating electric machine can be promoted.

[0034] The rotor core 31 is constructed by laminating thin steel sheets in the axial direction. Further, the gap portion 35A of the magnet slot 35 is provided so as to be less affected by the high-order harmonic magnetic flux flowing out from the outer circumferential surface of the rotor core 31. Furthermore, the magnetic barrier portion 35B in the magnet slot 35 is provided so as to prevent occurrence of leakage magnetic flux. The pair of magnet slots 35, which are arranged in a V shape and in a band shape, are divided into two in the rotor core 31, and the portion A of the rotor core 31, which divides the pair of magnet slots 35, is referred to as a central bridge portion. In contrast, the portion B between the magnet slot 35 and the outermost circumferential portion of the rotor 30 is referred to as an outer circumferential bridge portion. Further, the width of the smallest portion of the central bridge portion A of the rotor core 31, which divides the magnet slot 35, is Dbi.

[0035] The permanent magnet 32 is inserted in the pair of magnet slots 35, which are divided into two. In a case where the distance between the magnet slot 35 and the hole portion 33 is taken into account, the edge of the permanent magnet 32, which faces the radial outer side, takes a minimum value x at an X point from the corner 35D of the permanent magnet 32, which is closest to the central bridge portion A. Further, x = Dbi / 2. That is, the stress caused by centrifugal force, which acts on the width Dbi of the smallest portion of the central bridge portion A, must be supported between the magnet slot 35 and the hole portion 33, and the X point exists at two portions, and thus the minimum value x needs to be Dbi / 2.

[0036] Further, if the residual magnetic flux density (magnetic flux density of the magnetic force obtained by the permanent magnet) of the permanent magnet 32 is set to Br, the magnetic flux saturation density of the rotor core 31 (iron) is set to 2T (TESLA), and the axial length of the rotor 30 is set to L, the maximum magnetic flux that can pass through the central bridge portion A is obtained by the following formula (1).

[0037] 2(T) x Dbi x L (1)

[0038] On the other hand, at the X point, the magnetic flux (leakage magnetic flux) that disappears from the permanent magnet 32 through the central bridge portion A is obtained by the following formula (2).

[0039] x x Br x L x 2 (X point exists at two portions) (2)

[0040] Since the formula (1) = formula (2) holds, the relationship x = Dbi / Br holds.

[0041] With respect to the distance between the permanent magnet 32 and the hole portion 33, the distance x at the X point is the minimum, and gradually increases toward the radial outer circumferential side, and the distance d between the hole portion 33 and the permanent magnet 32 at a point, which is apart from the X point by a distance m along the edge of the permanent magnet 32, which faces the radial outer side, is d = Br x m / 2.

[0042] That is, the magnetic flux flowing out to the outer periphery side of the rotor core 31 from the range in the permanent magnet 32 from the point X to the point at a distance m is found by the following equation (3).

[0043] Br x m x L...(3)

[0044] On the other hand, if the magnetic flux saturation density of iron is set to 2T, the maximum amount of magnetic flux that can pass at the point at a distance m from the point X is found by the following equation (4).

[0045] d x L x 2(T)...(4)

[0046] Therefore, the relationship of equation (4) ≥ equation (3) needs to be satisfied,

[0047] d ≥ Br x m / 2.

[0048] In addition, if the magnetic flux saturation density of the metal constituting the rotor core 31 is set to BS, the relationship of d ≥ Br x m / BS needs to be satisfied.

[0049] In addition, the distance of the outer periphery of the rotor core 31 from the hole portion 33 is equal to the distance of the magnet slot 35 divided into two from the outer periphery of the rotor core 31 (the distance at the outer periphery bridge portion B). That is, since the distance of the magnet slot 35 from the outer periphery of the rotor core 31 is ensured at the outer periphery bridge portion B in order to prevent the rotor core 31 from being damaged, the distance is made sufficient by designing the distance of the outer periphery of the rotor core 31 from the hole portion 33 to be equal to the distance of the magnet slot 35 from the outer periphery of the rotor core 31.

[0050] As described above, along the edge of the permanent magnet 32 facing the radially outer side from the corner portion 35D closest to the central bridge portion A, at the point X, the distance of the permanent magnet 32 from the hole portion 33 is the smallest, and gradually becomes larger as it goes from the point X to the radially outer periphery side, and at the point at a distance m from the point X along the edge of the permanent magnet 32 facing the radially outer side, the distance d of the hole portion 33 from the permanent magnet 32 is d = Br x m / 2. Therefore, the hole portion 33 can be provided without hindering the magnetic flux flowing out from the permanent magnet 32. By thus providing the hole portion 33, the weight of the outer periphery side of the permanent magnet 32 in the rotor core 31 can be reduced, so the centrifugal force can be reduced. Furthermore, since the strength is sufficiently ensured, the widths of the central bridge portion A and the outer periphery bridge portion B can be reduced, so the magnetic flux leakage can be reduced.

[0051] At the X point on the side of the permanent magnet 32 facing the radially outer side from the corner 35D of the permanent magnet 32 closest to the central bridge portion A, the distance between the permanent magnet 32 and the hole portion 33 is the smallest, and this distance is Dbi / 2. Therefore, the stress in the rotor core 31 between the permanent magnet 32 and the hole portion 33 due to centrifugal force is equal to the stress in the central bridge portion A due to centrifugal force, and it is possible to prevent the rotor core 31 from being damaged by stress.

[0052] In addition, the distance between the outer periphery of the rotor core 31 and the hole portion 33 is equal to the distance between the divided two magnet grooves 35 and the outer periphery of the rotor core 31. Therefore, the stress in the rotor core 31 on the outer periphery side of the hole portion 33 due to centrifugal force is equal to the stress in the outer bridge portion B of the rotor core 31 due to centrifugal force, and the distance between the magnet groove 35 and the outermost periphery of the rotor core 31 is ensured in the outer bridge portion B in order to prevent the rotor core 31 from being damaged, and thus it is possible to prevent the rotor core 31 from being damaged by centrifugal force.

[0053] In addition, in order to further increase the strength, the distance between the outer periphery of the rotor core 31 and the hole portion 33 can also be made to be greater than or equal to the distance between the divided two magnet grooves 35 and the outer periphery of the rotor core 31.

[0054] In addition, in the present embodiment, if the residual magnetic flux density of the permanent magnet 32 is Br, for the distance between the magnet groove 35 and the hole portion 33, the distance is the smallest at the X point on the side of the permanent magnet 32 facing the radially outer side from the corner 35D of the permanent magnet 32 closest to the central bridge portion A, and this distance is Dbi / 2. Also, for the distance between the permanent magnet 32 and the hole portion 33, the distance is the smallest at the X point, and gradually increases toward the radially outer periphery side, and at the point on the side of the permanent magnet 32 facing the radially outer side which is a distance m from the X point, the distance d between the hole portion 33 and the permanent magnet 32 is d = Br x m / 2 (d = Br x m / BS). However, if the distance between the permanent magnet 32 and the hole portion 33 at the X point is greater than or equal to Dbi / 2, the same effect is obtained. Thus, d ≥ Dbi / 2. Further, for the distance d between the hole portion 33 and the permanent magnet 32 at the point on the side of the permanent magnet 32 facing the radially outer side which is a distance m from the X point, the same effect is obtained if the distance d is greater than or equal to Br x m / BS.

[0055] Embodiment 2

[0056] Figure 3 is a partial cross-sectional plan view showing a rotor in Embodiment 2. In the present embodiment, in the case where a rotating electric machine is used as a reluctance motor, the magnetic flux for generating a reluctance torque into the rotor core 31 is not hindered by the hole portion 33, and a high torque can be obtained. Figure 4is a diagram for explaining the principle of a general reluctance motor, and the stator and the rotor are drawn in a straight line for simplicity of explanation, but are actually formed in a circular shape. In Figure 4 , magnetic flux from the rotating magnetic field of the stator 100 flows to the rotor 101, and thus a magnetic force is generated in the convex portion 102 formed in the rotor 101, and the rotor 101 rotates. It is known that, at this time, even if the plate-shaped object 103 is present in the upper portion between the convex portions 102, the motor operates as a reluctance motor. Also, in Figure 3 , the portion shown by reference numeral 60 corresponds to the convex portion 102, and the hole portion 33 corresponds to the concave portion 104.

[0057] Also, in the present embodiment, the sum (E+F) of the shortest distance E from the outermost circumference of the rotor core 31 to the hole portion 33 and the shortest distance F of the line connecting the corner portion 35D of the permanent magnet 32 near the central bridge portion A to the hole portion 33 is half the distance G between the corner portions 35H of the permanent magnet 32 located at the outermost circumference. That is, in Figure 3 , the relational expression 2 x (E+F) = G is satisfied.

[0058] By so configuring, the magnetic flux for generating reluctance torque that enters the rotor core 31 located at the outer circumferential side of the pair of permanent magnets 32 arranged in a V shape and in a band shape is not hindered by the hole portion 33, and thus a large reluctance torque can be obtained. That is, as shown in Figure 5 , since (E+F) = G / 2 is designed, the magnetic flux from the stator falling within the range of G / 2 all passes through the rotor core 31 side, and thus a large reluctance torque can be obtained. Further, as shown in Figure 3 , the circular arc shape 33A protruding in a convex shape toward the inner circumferential side is provided at the outer circumferential side of the hole portion 33, and the magnetic flux from the stator can be made to pass more.

[0059] In addition, in the present embodiment, the sum (E+F) of the shortest distance E from the outer circumference of the rotor core 31 to the hole portion 33 and the shortest distance F of the line connecting the corner portion 35D of the permanent magnet 32 near the central bridge portion A to the hole portion 33 is half the distance G between the corner portions 35H of the permanent magnet 32 located at the outermost circumference, but the more the (E+F) is, the more the magnetic flux is likely to flow, and thus the same effect can be exerted if designed to be more than half the distance G.

[0060] Figure 6 is a diagram for explaining the principle of a general reluctance motor, and the stator and the rotor are drawn in a straight line for simplicity of explanation, but are actually formed in a circular shape. In Figure 3The same figure is a partial cross-sectional plan view showing the rotor in Embodiment 2. As in Embodiment 1, the permanent magnets 32 are inserted in the magnet grooves 35 divided into two. If the residual flux density of the permanent magnets 32 is set to Br, then for the distance from the permanent magnets 32 to the hole portions 33, the distance from the corner 35D of the permanent magnets 32 closest to the central bridge portion A along the edge of the permanent magnets 32 facing the radial outside is smallest at a point on the radial outside by a distance ml from the point Xl at which the distance is Dbi / Br, and the distance of the magnet groove 35 from the hole portion 33 at this point is configured to be greater than Dbi / 2, greater than Br x ml / 2, as in Embodiment 1. The distance between the permanent magnets 32 and the hole portions 33 is smallest at the point by the distance ml, gradually increases as it goes toward the radial outside, and gradually increases as it goes toward the radial inside. The distance d1 of the hole portion 33 from the permanent magnets 32 at the point by the distance ml from the point Xl along the edge of the permanent magnets 32 facing the radial outside is greater than the greater one of Br x ml / 2 and Dbi / 2. The other configurations are the same as in Embodiment 1. In this configuration, too, the leakage flux can be reduced as in Embodiment 1, and the rotor core 31 can be prevented from being damaged by centrifugal force.

[0061] Embodiment 3.

[0062] Figure 7 is a partial cross-sectional plan view showing the rotor in Embodiment 3. In this embodiment, as in Embodiment 2, in the case where the rotary electric machine is used as a reluctance motor, the magnetic flux for generating a reluctance torque that enters the rotor core 31 is not hindered by the hole portions 33, and a high torque can be obtained.

[0063] As shown in Figure 7 , the distance J from the outer periphery of the rotor core 31 to the hole portions 33 is configured to be half the distance I between the corners 35H of the permanent magnets 32 located at the outermost periphery. The other configurations are the same as in Embodiment 2.

[0064] Since the distance J from the outer periphery of the rotor core 31 to the hole portions 33 is half the distance I between the corners 35H of the permanent magnets 32 located at the outermost periphery, as in Embodiment 2, the magnetic flux for generating a reluctance torque that enters the rotor core 31 on the outer periphery side of the permanent magnets 32 arranged in a V shape and in a band shape is not hindered by the hole portions 33, and a high torque can be obtained.

[0065] In addition, in Embodiment 3, the distance J from the outer periphery of the rotor core 31 to the hole portions 33 is set to be half the distance I between the corners 35H of the permanent magnets 32 located at the outermost periphery, but the greater the distance J, the more magnetic flux can flow, so as long as it is half or more, the same effect is obtained.

[0066] Embodiment 4.

[0067] Figure 8 is a partial cross-sectional plan view showing a rotor in Embodiment 4.

[0068] As shown in Figure 8 , a slit portion 50 that penetrates toward the radial outside is provided between the circumferential center of the hole portion 33 and the outer periphery of the rotor core 31. In order to prevent the magnetic flux that generates the reluctance torque from becoming less, the width of the slit portion 50 is made smaller than the distance between the hole portion 33 and the outer periphery of the rotor core 31. The other configurations are the same as in Embodiment 3.

[0069] In this configuration, as in Embodiment 3, the magnetic flux that generates the reluctance torque that enters the rotor core 31 is not hindered by the hole portion 33, and a high torque can be obtained.

[0070] In addition, since the slit portion 50 blocks the hoop stress (tensile stress acting in the tangential direction of the circumference) that is generated in the vicinity of the outer periphery of the rotor core 31 due to the centrifugal force, the centrifugal force that is generated in the outer periphery bridge portion B can be reduced, the width at the outer periphery bridge portion B can be reduced, and thus the magnetic flux leakage can be reduced. In addition, since the slit portion 50 is in the central portion of the pair of permanent magnets 32, the deflection of the stress due to the centrifugal force does not occur, and the magnetic flux leakage can be reduced uniformly.

[0071] Embodiment 5.

[0072] Figure 9 is a partial cross-sectional plan view showing a rotor in Embodiment 5.

[0073] As shown in Figure 9 , in the rotor 30, a rotor core 31 that is fixed to the shaft 5 by press-fitting or the like, three magnet grooves 35 that are arranged in a bathtub shape and in a strip shape in the rotor core 31, permanent magnets 32 that are inserted in the magnet grooves 35, and hole portions 33 that are provided on the radial outside of the magnet grooves 35 are configured. The magnet grooves 35 are divided into three portions in the rotor core 31, and the portions of the rotor core 31 that divide the magnet grooves 35 are referred to as central bridge portions Al. The width of the smallest portion of the two central bridge portions Al of the rotor core 31 that divide the magnet grooves 35 is Dbi. In this embodiment, unlike in Embodiment 1, the smallest portion of the width Dbi exists in two.

[0074] Permanent magnets 32 are respectively inserted in the three divided magnet grooves 35. Also, as with Embodiment 1, if the residual magnetic flux density of the permanent magnets 32 is set to Br, the distance from the hole portion 33 to the permanent magnets 32 on both sides is smallest at the point X on the side of the permanent magnets 32 facing the radially outer side from the corner 35D of the permanent magnets 32 on both sides closest to the central bridge portion Al, and gradually increases toward the radially outer side, and the distance d of the hole portion 33 from the permanent magnets 32 at the point m distance from the point X on the side of the permanent magnets 32 facing the radially outer side is d = Br x m / 2. In the present embodiment, unlike Embodiment 1, since there are two central bridge portions Al of width Dbi, the distance is not Dbi / 2, but Dbi. Also, as with Embodiment 1, the distance from the hole portion 33 to the permanent magnets 32 on both sides is smallest at the point X, and gradually increases toward the radially outer side, and the distance d of the hole portion 33 from the permanent magnets 32 at the point m distance from the point X on the side of the permanent magnets 32 facing the radially outer side is d = Br x m / 2. The principle of the above-described structure is the same as that explained in Embodiment 1.

[0075] Also, as with Embodiment 3, the distance from the outer periphery of the rotor core 31 to the hole portion 33 is half the distance between the outermost corners 35H of the permanent magnets 32 on both sides. Also, a central magnet groove 35N is provided between the magnet grooves 35 on both sides arranged in a V-shape and on the inner periphery side of the hole portion 33, and a central permanent magnet 32A is inserted in the central magnet groove 35N. Also, the distance from the central magnet groove 35N in which the central permanent magnet 32A is inserted to the hole portion 33 is smallest at the central portion of the central permanent magnet 32A, and this distance is Dbi.

[0076] The shortest distance K from the outer periphery of the rotor core 31 to the hole portion 33 is equal to the distance between the outermost corners of the permanent magnets 32 on both sides and the outer periphery of the rotor core 31, and the position of the shortest distance is a position apart in the circumferential direction from the center of the hole portion 33, and the distance from the outer periphery of the rotor core 31 to the hole portion 33 gradually increases toward the center. Thus, it is possible to increase the reluctance torque.

[0077] As described above, the distance from the permanent magnets 32 on both sides to the hole portion 33 is smallest at the point X on the side of the permanent magnets 32 facing the radially outer side from the corner 35D of the permanent magnets 32 on both sides closest to the central bridge portion Al, and gradually increases toward the radially outer side, and the distance d of the hole portion 33 from the permanent magnets 32 at the point m distance from the point X on the side of the permanent magnets 32 facing the radially outer side is d = Br x m / 2. Thus, as with Embodiment 1, it is possible to provide the hole portion 33 without hindering the flow of magnetic flux from the permanent magnets 32. Also, by reducing the core weight on the outer periphery side of the permanent magnets 32 in the rotor core 31, it is possible to reduce the centrifugal force. Also, since it is possible to reduce the width of the central bridge portion Al and the outer periphery bridge portion, it is possible to reduce the magnetic flux leakage.

[0078] The distance between the permanent magnet 32 ​​and the hole 33 is minimized at point X, which is Dbi, located at the corner 35D closest to the central bridging portion A1 of the permanent magnet 32, along the radially outward side of the permanent magnet 32. Therefore, the stress caused by centrifugal force on the rotor core 31 between the permanent magnet 32 ​​and the hole 33 is equal to the stress caused by centrifugal force on the central bridging portion A1, preventing damage to the rotor core 31 due to centrifugal force.

[0079] Furthermore, the shortest distance K from the outer periphery of the rotor core 31 to the hole 33 is equal to the distance between the outermost peripheral corner 35H of the permanent magnets 32 on both sides and the outer periphery of the rotor core 31. The position of the shortest distance is located circumferentially away from the center of the hole 33, and the distance from the outer periphery of the rotor core 31 to the hole 33 gradually increases towards the center.

[0080] Therefore, the stress caused by centrifugal force generated on the outer periphery of the hole 33 in the rotor core 31 is equal to the stress generated at the outer periphery bridging portion of the rotor core 31, preventing damage to the rotor core 31 due to centrifugal force. Furthermore, since the outermost peripheral position 33D of the hole 33 is located on the inner periphery compared to the outermost peripheral corner 35H of the permanent magnet 32, a large opening width on the outer periphery of the magnetic circuit between the permanent magnet 32 ​​and the hole 33 can be obtained, allowing for the introduction of a large amount of magnetic flux to generate reluctance torque, thus increasing the torque. Moreover, the shortest distance K from the outer periphery of the rotor core 31 to the hole 33 exists at a position circumferentially away from the center of the hole 33, and the distance from the outer periphery of the rotor core 31 to the hole 33 gradually increases towards the center. Therefore, in the rotor core 31 located between the outer periphery of the rotor core 31 and the hole 33, a large amount of magnetic flux to generate reluctance torque can be introduced, increasing the reluctance torque and obtaining high torque.

[0081] Furthermore, in this embodiment, similar to Embodiment 1, if the distance between the permanent magnet 32 ​​at point X and the hole 33 is Dbi or more, the same effect is achieved. Additionally, if the distance d between the hole 33 and the permanent magnet 32 ​​at a point m away from point X along the radially outward edge of the permanent magnet 32 ​​is Br×m / 2 (Br×m / BS) or more, the same effect is achieved. Furthermore, it is also possible to... Figure 9 The configuration shown includes the slit portion 50 as shown in Embodiment 4.

[0082] Implementation method 6.

[0083] Figure 10 This is a partial cross-sectional top view showing the rotor in Embodiment 6.

[0084] like Figure 10As shown, the rotor 30 has a rotor core 31 fixed to the shaft 5 by pressing or the like. Furthermore, the rotor core 31 has an outer peripheral magnet slot and an inner peripheral magnet slot arranged in a V-shape and a strip-like configuration, forming two layers on the outer and inner peripheral sides. Specifically, the rotor core 31 has an inner peripheral magnet slot 35a (first inner peripheral magnet slot), an inner peripheral permanent magnet 32a (first inner peripheral permanent magnet) inserted into the inner peripheral magnet slot 35a, an outer peripheral magnet slot 35b, and an outer peripheral permanent magnet 32b inserted into the outer peripheral magnet slot 35b. Furthermore, the rotor core 31 has a hole 33 located radially outside the outer peripheral magnet slot 35b arranged in a V-shape and a strip-like configuration.

[0085] By multiplying the magnet in this way, reluctance torque is easily generated, thus enabling high torque. If the magnet is changed from one layer to two layers, a new magnetic circuit is created between the first and second layers. This magnetic circuit corresponds to the q-axis magnetic circuit in the dq coordinate system. Due to the flow of magnetic flux along the q-axis, the q-axis inductance increases. The reluctance torque is generated based on the salient polarity of the d-axis and q-axis inductances; therefore, if the q-axis inductance increases, the reluctance torque increases. Thus, high torque can be easily achieved through multilayering.

[0086] On the other hand, when magnets are multi-layered, the amount of iron core within the rotor through which the magnetic flux passes is reduced, making magnetic saturation more likely. In particular, because... Figure 10 The iron core shown exists between the outer peripheral permanent magnet 32b and the outer periphery of the rotor 30. Figure 10 The portion surrounded by the dashed line Z is reduced, so magnetic saturation is more likely to occur compared to the previous two-layer construction. However, as shown in this embodiment, by forming the hole 33, magnetic saturation will not occur in the above-mentioned portion, thus achieving weight reduction. Therefore, the width of the bridging portion can be reduced, leakage flux can be reduced, and thus high torque can be achieved.

[0087] The rotor core 31 is constructed by axially laminating thin steel plates. The inner circumferential magnet slots 35a and 35b, arranged in a V-shape and strip shape, are divided into two parts within the rotor core 31. The rotor core 31 that separates the inner circumferential magnet slots 35a and 35b is referred to as the inner circumferential central bridging portion A3 and the outer circumferential central bridging portion A4, respectively. Furthermore, the minimum width of the outer circumferential central bridging portion A4 of the rotor core 31 that separates the outer circumferential magnet slots 35b is Dbi. The inner circumferential permanent magnets 32a and 32b are inserted into the two separate inner circumferential magnet slots 35a and 35b, respectively.

[0088] If the residual magnetic flux density of the outer peripheral side permanent magnet 32b is set to Br, as with the field of Embodiment 1, the distance between the outer peripheral side magnet groove 35b and the hole portion 33 is smallest at the X point along the edge of the outer peripheral side permanent magnet 32b toward the radial direction outside from the corner of the outer peripheral side permanent magnet 32b closest to the outer peripheral side central bridge portion A4, and is Dbι / 2. The distance between the outer peripheral side permanent magnet 32b and the hole portion 33 is smallest at the X point, and gradually increases as it goes toward the radial direction outside, and the distance d between the hole portion 33 and the outer peripheral side permanent magnet 32b at the point which is a distance m from the X point along the edge of the outer peripheral side permanent magnet 32b toward the radial direction outside is d = Br x m / 2.

[0089] Further, as with Embodiment 3, the distance between the outer periphery of the rotor core 31 and the hole portion 33 is half the distance between the outermost corners of the outer peripheral side permanent magnet 32b.

[0090] As described above, it is configured in such a manner that the distance between the outer peripheral side permanent magnet 32b and the hole portion 33 is smallest at the X point along the edge of the outer peripheral side permanent magnet 32b toward the radial direction outside from the corner of the outer peripheral side permanent magnet 32b closest to the outer peripheral side central bridge portion A4, and gradually increases as it goes toward the radial direction outside, and the distance d between the hole portion 33 and the outer peripheral side permanent magnet 32b at the point which is a distance m from the X point along the edge of the outer peripheral side permanent magnet 32b toward the radial direction outside is d = Br x m / 2. Therefore, as with the field of Embodiment 1, the hole portion 33 can be provided without hindering the magnetic flux flowing out from the outer peripheral side permanent magnet 32b. Further, the core weight of the outer peripheral side of the outer peripheral side permanent magnet 32b in the rotor core 31 can be reduced, and the centrifugal force can be reduced. Further, the width of the central bridge portion and the outer peripheral bridge portion can be reduced, and the magnetic flux leakage can be reduced.

[0091] Further, as with Embodiment 1, the distance between the outer peripheral side permanent magnet 32b and the hole portion 33 is smallest at the X point along the edge of the outer peripheral side permanent magnet 32b toward the radial direction outside from the corner of the outer peripheral side permanent magnet 32b closest to the outer peripheral side central bridge portion A4, and is Dbι / 2. Therefore, the stress in the rotor core 31 between the outer peripheral side permanent magnet 32b and the hole portion 33 due to the centrifugal force is equal to the stress in the outer peripheral side central bridge portion A4, and the rotor core 31 can be prevented from being damaged due to the centrifugal force.

[0092] Further, as with Embodiment 3, the distance between the outer periphery of the rotor core 31 and the hole portion 33 is larger than half the distance between the outermost corners of the outer peripheral side permanent magnet 32b, and therefore, the magnetic flux related to the magnetic resistance torque generated in the position of the outer peripheral side of the rotor core 31 where the outer peripheral side magnet groove 35b which is configured in a V shape and a band shape is not hindered, and therefore, the torque can be increased.

[0093] Further, in Embodiment 6, if the residual flux density of the outer peripheral side permanent magnet 32b is set to Br, with respect to the distance from the outer peripheral side magnet slot 35b to the hole portion 33, from the corner of the outer peripheral side permanent magnet 32b closest to the outer peripheral side central bridge portion A4 along the edge of the outer peripheral side permanent magnet 32b facing the radial direction outward, the distance is smallest at the X point at a distance of Dbi / Br from the edge, and the distance is Dbi / 2. Further, with respect to the distance from the outer peripheral side permanent magnet 32b to the hole portion 33, the distance at the X point is set to be the smallest, and gradually increases as it goes to the radial direction outward, and at the point at a distance m from the X point along the edge of the outer peripheral side permanent magnet 32b facing the radial direction outward, the distance d of the hole portion 33 from the outer peripheral side permanent magnet 32b is d = Br x m / 2. However, if the distance d of the outer peripheral side permanent magnet 32b from the hole portion 33 at the X point is Dbi / 2 or more, it is possible to prevent the rotor core 31 from being damaged due to centrifugal force.

[0094] Further, if the distance d of the hole portion 33 from the outer peripheral side permanent magnet 32b at the point at a distance m from the X point along the edge of the outer peripheral side permanent magnet 32b facing the radial direction outward is Br x m / 2 or more, it is possible to provide the hole portion 33 without hindering the magnetic flux flowing out from the permanent magnet 32.

[0095] Further, although the outer peripheral side permanent magnet 32b is inserted in the outer peripheral side magnet slot 35b, it is also possible to provide only the outer peripheral side magnet slot 35b without inserting the outer peripheral side permanent magnet 32b.

[0096] In this case, it is possible to consider that Br of the outer peripheral side permanent magnet 32b is 0, and at the X point, the distance of the outer peripheral side magnet slot 35b from the hole portion 33 becomes infinitely large, and the distance of the outer peripheral side permanent magnet 32b from the hole portion 33 satisfies the condition of Dbi / 2 or more and Br x m / 2 at all points, so as a result, it is sufficient that the distance of the outer peripheral side magnet slot 35b from the hole portion 33 is Dbi / 2 or more.

[0097] Further, with respect to the inner peripheral side magnet slot 35a and the inner peripheral side permanent magnet 32a inserted in the inner peripheral side magnet slot 35a, it is possible to be any structure.

[0098] Embodiment 7.

[0099] Figure 11 is a partial cross-sectional plan view showing the rotor in Embodiment 7.

[0100] As Figure 11As shown, the rotor 30 is composed of a rotor core 31 fixed to the shaft 5 by press-fitting or the like, and a magnet slot 35c and a magnet slot 35d configured in a V-shape and in a belt shape in the rotor core 31 so as to be asymmetric in the circumferential direction. Further, the rotor 30 is composed of a permanent magnet 32c, a permanent magnet 32d, and a hole portion 33 provided on the radially outer side of the magnet slot 35c and the magnet slot 35d, which are respectively inserted in the magnet slot 35c and the magnet slot 35d.

[0101] The rotor core 31 is composed by laminating thin steel sheets in the axial direction. The portion of the rotor core 31 that divides the magnet slot 35c and the magnet slot 35d is referred to as a central bridge portion A5. The width of the smallest portion in the central bridge portion A5 is Dbi. The lengthwise dimensions of the permanent magnet 32c and the permanent magnet 32d are different. Thus, the torque when rotating in one direction (counterclockwise direction in Figure 11 Figure 11 In the embodiment 2, since the area of the portion 31M in the rotor core 31 is smaller, the magnetic flux easily concentrates in this portion, which is advantageous for counterclockwise rotation. If the residual magnetic flux density of the permanent magnet 32c and the permanent magnet 32d is Br, the distance between the magnet slot 35c and the hole portion 33 and the distance between the magnet slot 35d and the hole portion 33 are configured the same as in the embodiment 1. That is, for the distance of the magnet slot 35c and the hole portion 33, from the corner of the permanent magnet 32c closest to the central bridge portion A5 along the edge of the permanent magnet 32c facing the radially outer side, the distance is smallest at the point Xa at a distance of Dbi / Br from the central bridge portion A5, and the distance is Dbi / 2. Further, for the distance of the magnet slot 35d and the hole portion 33, from the corner of the permanent magnet 32d closest to the central bridge portion A5 along the edge of the permanent magnet 32d facing the radially outer side, the distance is smallest at the point Xb at a distance of Dbi / Br from the central bridge portion A5, and the distance is Dbi / 2.

[0102] For the distance of the permanent magnet 32c and the hole portion 33, the distance at the point Xa is set to be the smallest, and gradually increases as it goes to the radially outer side, and the distance da of the hole portion 33 and the permanent magnet 32c at the point at a distance ma from the point Xa along the edge of the permanent magnet 32c facing the radially outer side is da = Br x m / 2. Further, for the distance of the permanent magnet 32d and the hole portion 33, the distance at the point Xb is set to be the smallest, and gradually increases as it goes to the radially outer side, and the distance db of the hole portion 33 and the permanent magnet 32d at the point at a distance mb from the point Xb along the edge of the permanent magnet 32d facing the radially outer side is db = Br x m / 2.

[0103] ​Also, as in Embodiment 3, the distance from the outer periphery of the rotor core 31 to the hole portion 33 is half the distance between the outermost corners of the permanent magnets 32c and 32d. Thus, the relevant magnetic flux of the reluctance torque is not hindered, and the torque can be increased.

[0104] Further, a slit portion 50 that penetrates toward the radial outside is provided between the circumferential center of the hole portion 33 and the outer periphery of the rotor core 31. Also, the width of the slit portion 50 is smaller than the distance between the hole portion 33 and the outer periphery of the rotor core 31.

[0105] In Figure 11 In this embodiment, the permanent magnets 32c and 32d differ in the lengthwise dimension, and the other configurations are the same. However, the widthwise dimension or the residual magnetic flux density Br can also differ, in addition to the lengthwise dimension. Also, the lengthwise dimension, the widthwise dimension, and the residual magnetic flux density Br can be the same, and the inclination of the magnet grooves 35c and 35d can be configured to be asymmetric with respect to the radial center line Q. Alternatively, the inclination of the magnet grooves 35c and 35d can be configured to be symmetric with respect to the radial center line Q, and any one or all of the lengthwise dimension, the widthwise dimension, and the residual magnetic flux density Br of the permanent magnets 32c and 32d can differ. Also, the inclination of the magnet grooves 35c and 35d can be symmetric with respect to the radial center line Q, the lengthwise dimension, the widthwise dimension, and the residual magnetic flux density Br of the permanent magnets 32c and 32d can be the same, and the slit portion 50 can be configured to be angularly inclined with respect to the radial center line Q. In this configuration, the torque when rotating in one direction can be increased. Also, because the slit portion 50 is angularly inclined with respect to the radial center line Q, and is inclined in the counterclockwise direction, the magnetic flux is easily concentrated on the advancing side of the rotational direction when rotating in the counterclockwise direction, and the torque with respect to this direction can be increased. Further, the hole portion 33 can be configured to be asymmetric with respect to the radial center line Q.

[0106] Embodiment 8.

[0107] Figure 12 is a partial cross-sectional plan view of the rotor in Embodiment 8.

[0108] As Figure 12As shown, the rotor 30 has a rotor core 31 fixed to the shaft 5 by press-fitting or the like. Also, the rotor core 31 has: three inner periphery-side magnet grooves 35f, 35g, 35h (second inner periphery-side magnet grooves) arranged in a bathtub shape and in a band shape on the inner periphery side; inner periphery-side permanent magnets 32f, 32g, 32h (second inner periphery-side permanent magnets) inserted in the inner periphery-side magnet grooves 35f, 35g, 35h; outer periphery-side magnet grooves 35i, 35j arranged in a V shape and in a band shape on the outer periphery side; and outer periphery-side permanent magnets 32i, 32j inserted in the outer periphery-side magnet grooves 35i, 35j. Here, as shown, the bathtub shape means that the inner periphery-side magnet groove 35g is arranged in the center of the V shape of the inner periphery-side magnet grooves 35f, 35h arranged in a V shape, and the three inner periphery-side magnet grooves are arranged in a U shape. Also, in the embodiment, the three inner periphery-side magnet grooves 35f, 35g, 35h are arranged in a U shape on the inner periphery side, but the bathtub shape is not limited to three magnet grooves arranged in a U shape, and more than three magnet grooves arranged in a U shape are also possible. Furthermore, in the rotor core 31, a hole portion 33 is provided on the radial outer side of the outer periphery-side magnet grooves 35i, 35j arranged in a V shape and in a band shape. Figure 12 Figure 12

[0109] Thus, by arranging the three inner periphery-side magnet grooves 35f, 35g, 35h in a U shape on the inner periphery side, the same effects as in Embodiment 6 are exerted, and by dividing the permanent magnets in a bathtub shape (U shape) rather than a V shape into three, the excess iron core through which the q-axis magnetic flux passes between the first layer and the second layer can be reduced, and thus the width of the bridge portion can be reduced. If the width of the bridge portion can be reduced, the leakage magnetic flux can also be reduced, and thus high torque can be achieved.

[0110] The rotor core 31 is configured by laminating thin steel sheets in the axial direction. The inner periphery-side magnet grooves 35f, 35g, 35h arranged in a bathtub shape and in a band shape are divided into three in the rotor core 31, and the outer periphery-side magnet grooves 35i, 35j arranged in a V shape and in a band shape are divided into two in the rotor core 31. Also, the portions of the rotor core 31 dividing the inner periphery-side magnet grooves 35f, 35g, 35h and the outer periphery-side magnet grooves 35i, 35j are referred to as an inner periphery-side central bridge portion A6 and an outer periphery-side central bridge portion A7, respectively. Also, the width of the smallest portion of the outer periphery-side central bridge portion A7 of the rotor core 31 dividing the outer periphery-side magnet grooves 35i, 35j is Db i. The inner periphery-side permanent magnets 32f, 32g, 32h are inserted in the inner periphery-side magnet grooves 35f, 35g, 35h divided into three, and the outer periphery-side permanent magnets 32i, 32j are inserted in the outer periphery-side magnet grooves 35i, 35j divided into two.

[0111] ​​If the residual magnetic flux density of the outer peripheral side permanent magnet 32i is set to Br, as with the field of Embodiment 1, the distance between the outer peripheral side magnet groove 35i and the hole portion 33 is smallest at the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside from the corner of the outer peripheral side permanent magnet 32i closest to the outer peripheral side central bridge portion A7, and is Dbi / 2. As with the field of Embodiment 1, the distance between the outer peripheral side permanent magnet 32i and the hole portion 33 is smallest at the X point, and gradually increases as it goes toward the radial direction outside, and the distance d between the hole portion 33 and the outer peripheral side permanent magnet 32i at the point m distance from the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside is d = Br x m / 2.

[0112] In addition, as with Embodiment 3, the distance between the outer periphery of the rotor core 31 and the hole portion 33 is half the distance between the outermost corner portions of the outer peripheral side permanent magnets 32i, 32j from each other.

[0113] As described above, it is configured in such a manner that the distance between the outer peripheral side permanent magnet 32i and the hole portion 33 is smallest at the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside from the corner of the outer peripheral side permanent magnet 32i closest to the outer peripheral side central bridge portion A7, and gradually increases as it goes toward the radial direction outside, and the distance d between the hole portion 33 and the outer peripheral side permanent magnet 32i at the point m distance from the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside is d = Br x m / 2. Therefore, as with the field of Embodiment 1, the hole portion 33 can be provided without obstructing the magnetic flux flowing out from the outer peripheral side permanent magnet 32i. Furthermore, the core weight of the outer peripheral side of the outer peripheral side permanent magnet 32i in the rotor core 31 can be reduced, and the centrifugal force can be reduced. Furthermore, the width of the central bridge portion and the outer peripheral bridge portion can be reduced, and the magnetic flux leakage can be reduced.

[0114] Furthermore, as with Embodiment 1, the distance between the outer peripheral side permanent magnet 32i and the hole portion 33 is smallest at the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside from the corner of the outer peripheral side permanent magnet 32i closest to the outer peripheral side central bridge portion A7, and is Dbi / 2. Therefore, the stress in the rotor core 31 between the outer peripheral side permanent magnet 32i and the hole portion 33 due to the centrifugal force is equal to the stress generated at the outer peripheral side central bridge portion A7, and the rotor core 31 can be prevented from being damaged due to the centrifugal force.

[0115] In addition, as with Embodiment 3, the distance between the outer periphery of the rotor core 31 and the hole portion 33 is greater than half the distance between the outermost corner portions of the outer peripheral side permanent magnet 32i from each other, and therefore, the magnetic flux related to the magnetic resistance torque generated at a position radially outward of the outer peripheral side magnet groove 35i arranged in a V shape and in a band shape in the rotor core 31 is not obstructed, and thus the torque can be increased.

[0116] Further, in Embodiment 8, if the residual flux density of the outer peripheral side permanent magnet 32i is set as Br, with respect to the distance from the outer peripheral side magnet groove 35i to the hole portion 33, from the corner of the outer peripheral side permanent magnet 32i closest to the outer peripheral side central bridge portion A7 along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside, the distance is smallest at the X point at a distance of Dbi / Br from the edge, and the distance is Dbi / 2. Further, with respect to the distance from the outer peripheral side permanent magnet 32i to the hole portion 33, the distance at the X point is set as the smallest, and gradually increases as it goes toward the radial direction outside, at the point at a distance m from the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside, the distance d of the hole portion 33 from the outer peripheral side permanent magnet 32i is d = Br x m / 2. However, if the distance of the outer peripheral side permanent magnet 32i from the hole portion 33 at the X point is Dbi / 2 or more, it is possible to prevent the rotor core 31 from being damaged due to centrifugal force. Further, this means that if d ≥ Dbi / 2, it is possible to prevent the rotor core 31 from being damaged due to centrifugal force.

[0117] Further, if the distance d of the hole portion 33 from the outer peripheral side permanent magnet 32i at the point at a distance m from the X point along the edge of the outer peripheral side permanent magnet 32i toward the radial direction outside is Br x m / 2 or more, it is possible to provide the hole portion 33 without hindering the magnetic flux flowing out from the permanent magnet 32.

[0118] Further, the outer peripheral side permanent magnet 32i is inserted into the outer peripheral side magnet groove 35i, but it is also possible to not insert the outer peripheral side permanent magnet 32i and only provide the outer peripheral side magnet groove 35i. In this case, it can be considered that Br of the outer peripheral side permanent magnet 32i is 0, and at the X point, the distance of the outer peripheral side magnet groove 35i from the hole portion 33 becomes infinitely large, and since the distance of the outer peripheral side permanent magnet 32i from the hole portion 33 satisfies the condition of Dbi / 2 or more and Br x m / 2 at all points, as a result, the distance of the outer peripheral side magnet groove 35i from the hole portion 33 only needs to be Dbi / 2 or more.

[0119] Further, with respect to the inner peripheral side magnet grooves 35f, 35g, 35h and the inner peripheral side permanent magnets 32f, 32g, 32h inserted into the inner peripheral side magnet grooves 35f, 35g, 35h, it is possible to be any structure.

[0120] In the above-described Embodiments 1 to 8, the permanent magnet 32 is described as a form having a square cross section, but it is also possible to round the corners to an R angle, that is, a round angle (circular arc shape), or to chamfer the corners to a C angle, that is, a bevel chamfer (cut in a right-angled isosceles triangle). In this case, the above-described corners can be imaginary corners in the case where it is assumed to have a square cross section.

[0121] In the above-described Embodiments 1 to 8, the case where one hole portion 33 is provided is explained, but the hole portion can also be divided into a plurality. In this case, all of the hole portions are arranged in the position included in the hole portion 33 of the above-described Embodiments 1 to 8 where the hole portion is one.

[0122] In the above-described Embodiments 1 to 8, the case where the distance between the permanent magnet and the hole portion monotonously increases as it goes to the radial outside is explained, but it can also be locally parallel, or non-monotonously increase with the concave-convex provided in the hole portion 33.

[0123] In the above-described Embodiments 4, 7, the case where the slit portion 50 is through to the hole portion 33 is shown, but the rotor core 31 can also be divided in the middle.

[0124] Further, in the above-described Embodiments 1 to 8, the winding method of the stator coil can be either distributed winding or concentrated winding.

[0125] Although various exemplary embodiments and examples are described in the present application, the various features, forms, and functions described in one or more embodiments are not limited to the application of the specific embodiments, and can be applied individually or in various combinations to the embodiments. Therefore, an infinite number of modifications not exemplified are assumed within the technical scope disclosed in the present application. For example, cases where at least one constituent element is modified, added, or omitted, and cases where at least one constituent element is extracted and combined with the constituent elements of other embodiments are included.

[0126] Explanation of Reference Signs

[0127] 5 shaft, 20 stator, 30 rotor, 31 rotor core, 32 permanent magnet, 35 magnet slot, 33 hole portion, 50 slit portion.

Claims

1. A rotary electric machine having a rotor arranged on an inner peripheral side of a stator, wherein the rotor is composed of a rotor core fixed to a shaft, a pair of magnet grooves arranged in a V-shape in a manner of moving apart from each other toward a radial direction outer side of the rotor core, permanent magnets inserted in each of the magnet grooves, and hole portions provided on a radial direction outer side of each of the magnet grooves, a distance between the permanent magnets and the hole portions is configured to become larger as going toward the radial direction outer side, and a distance between an outer periphery of the rotor core and the hole portions is configured to be larger than a distance between each of the magnet grooves and the outer periphery of the rotor core.

2. The rotary electric machine according to claim 1, wherein a pair of first inner peripheral side magnet grooves arranged in a V-shape in a manner of moving apart from each other toward the radial direction outer side is provided on an inner peripheral side of the pair of magnet grooves arranged in the V-shape, and first inner peripheral side permanent magnets are inserted in the first inner peripheral side magnet grooves.

3. The rotary electric machine according to claim 1, wherein three or more second inner peripheral side magnet grooves arranged in a U-shape are provided on the inner peripheral side of the pair of magnet grooves arranged in the V-shape, and second inner peripheral side permanent magnets are inserted in the second inner peripheral side magnet grooves.

4. The rotary electric machine according to claim 1, wherein a sum of a shortest distance between the outer periphery of the rotor core and the hole portions and a shortest distance between lines connecting corners of the permanent magnets close to the central bridge portion to each other and the hole portions is larger than one half of a distance between the corners of the permanent magnets located on the outermost periphery to each other.

5. The rotary electric machine according to any one of claims 1 to 4, wherein the distance between the outer periphery of the rotor core and the hole portions is larger than one half of the distance between the corners of the permanent magnets located on the outermost periphery to each other.

6. The rotary electric machine according to any one of claims 1 to 4, wherein a slit portion penetrating toward the radial direction outer side is provided between the hole portions and the outer periphery of the rotor core, and a width of the slit portion is smaller than the distance between the hole portions and the outer periphery of the rotor core.

7. The rotary electric machine according to any one of claims 1 to 4, wherein a gradient of the pair of magnet grooves is configured to be asymmetric with respect to a center line in a radial direction.

8. The rotary electric machine according to any one of claims 1 to 4, wherein the hole portions are configured to be asymmetric with respect to the center line in the radial direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The rotary electric machine according to claim 6, wherein the slit portion is disposed so as to be inclined with respect to the center line in the radial direction.

10. A rotary electric machine having a rotor disposed on an inner peripheral side of a stator, wherein the rotor is composed of a rotor core fixed to a shaft, a pair of magnet grooves disposed in a V-shape so as to be apart from each other toward the radial direction outside in the rotor core, permanent magnets inserted in the respective magnet grooves, and hole portions provided on the radial direction outside of the respective magnet grooves, a distance between the permanent magnets and the hole portions is made larger as going toward the radial direction outside, and a distance between the outer periphery of the rotor core and the hole portions is made larger than a distance between the respective magnet grooves and the outer periphery of the rotor core, a central magnet groove is provided between the pair of magnet grooves disposed in the V-shape and on the inner peripheral side of the hole portions, and a central permanent magnet is inserted in the central magnet groove, a width of a smallest portion of a central bridge portion in the rotor which divides the pair of magnet grooves and the central magnet groove is set as Dbi, a residual magnetic flux density of the permanent magnet is set as Br, a magnetic flux saturation density of a metal constituting the rotor core is set as BS, a point where a distance between the hole portion and the permanent magnet along a side of the permanent magnet facing the radial direction outside becomes a minimum is set as an X point from a corner of the permanent magnet closest to the central bridge portion, a distance between the hole portion and the permanent magnet at a point where a distance m from the X point along the side of the permanent magnet facing the radial direction outside is set as d, in this case, a relational expression of d ≥ Br x m / BS and d ≥ Dbi is satisfied.

11. The rotary electric machine according to claim 10, wherein a sum of a shortest distance between the outer periphery of the rotor core and the hole portion and a shortest distance between a line connecting the corners of the permanent magnet closest to the central bridge portion to each other and the hole portion is more than one half of a distance between the corners of the permanent magnet located at the outermost periphery.

12. The rotary electric machine according to claim 10 or 11, wherein a distance between the outer periphery of the rotor core and the hole portion is more than one half of a distance between the corners of the permanent magnet located at the outermost periphery.

13. The rotary electric machine according to claim 10 or 11, wherein a slit portion which penetrates toward the radial direction outside is provided between the hole portion and the outer periphery of the rotor core, and a width of the slit portion is smaller than a distance between the hole portion and the outer periphery of the rotor core.

14. The rotary electric machine according to claim 10 or 11, wherein inclinations of the pair of magnet grooves are made asymmetric with respect to the center line in the radial direction.

15. The rotary electric machine according to claim 10 or 11, wherein the hole portion is made asymmetric with respect to the center line in the radial direction.

16. The rotary electric machine according to claim 13, wherein the slit portion is disposed so as to be inclined with respect to the center line in the radial direction.

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