Rotor of a permanent magnet type rotating electric machine

Abstract

In permanent magnet type rotating electric machines, the rotor rotation speed is increased compared to conventional models. [Solution] Multiple flux barriers are formed in the rotor core 20. The multiple flux barriers include an outer flux barrier 30 and an inner flux barrier 40. The outer flux barrier 30 and the inner flux barrier 40 are arch-shaped. The outer flux barrier 30 has a flatter arch shape compared to the inner flux barrier 40. The circumferential end of the outer flux barrier 30 has a tapered shape in which the groove width narrows as it moves circumferentially outward.

Description

[Technical Field]

[0001] This specification discloses a rotor for a permanent magnet type rotating electric machine. [Background technology]

[0002] In permanent magnet type rotating electric machines, permanent magnets are installed in the rotor. For example, in an embedded magnet type synchronous motor (IPMSM, Interior Permanent Magnet Synchronous Motor), permanent magnets are embedded inside the rotor core.

[0003] The rotor core has slits formed in it for embedding permanent magnets. These slits are called flux barriers because they obstruct the flow of magnetic flux.

[0004] In Patent Document 1, an outer flux barrier is provided on the rotor core. The outer flux barrier extends along the outer circumference near the outer circumference of the rotor core. Furthermore, a substantially V-shaped flux barrier is formed radially inward from the outer flux barrier on the rotor core.

[0005] In Patent Document 2, a first magnet loading section is formed near the outer edge of the rotor core. Furthermore, a second magnet loading section is formed radially inward from the first magnet loading section on the rotor core. The first and second magnet loading sections function as flux barriers. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-229395 [Patent Document 2] Japanese Patent Publication No. 2020-137139 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, the maximum rotational speed of a rotating electric machine is determined by the induced voltage and the maximum voltage of the inverter. When the rotor rotates, an induced voltage is generated according to the principle of electromagnetic induction. Current flows through the coils according to the difference between the voltage applied by the inverter to the stator coils and the induced voltage.

[0008] The magnitude of the induced voltage is proportional to the time change of the magnetic flux. In other words, as the rotor rotates at high speed, the induced voltage increases. When the rotor speed increases and the induced voltage reaches the inverter's maximum voltage, the potential difference becomes zero, and the current supply from the inverter to the stator coil stops. At this point, the rotor speed is at its maximum, and the torque becomes zero.

[0009] Therefore, this specification discloses a rotor for a permanent magnet type rotating electric machine that is capable of increasing the rotational speed of the rotor compared to conventional models. [Means for solving the problem]

[0010] This specification discloses a rotor for a permanent magnet rotating electric machine. The rotor comprises a rotor core and permanent magnets. A plurality of flux barriers are formed in the rotor core. The permanent magnets are embedded in the flux barriers. The plurality of flux barriers include an outer flux barrier and an inner flux barrier. The outer flux barrier is positioned relatively radially outward. The inner flux barrier is positioned relatively radially inward. The outer and inner flux barriers are arranged along the radial direction. Furthermore, the outer and inner flux barriers are arch-shaped. That is, the outer and inner flux barriers extend along the circumferential direction of the rotor core, with their circumferential central portions being closest to the center of rotation. The outer flux barrier has a flatter arch shape compared to the inner flux barrier. The circumferential end of the outer flux barrier has a tapered shape, with the groove width narrowing towards the circumferential side.

[0011] In the above configuration, the outer flux barrier has a flattened arch shape. Furthermore, the circumferential end of the outer flux barrier tapers towards the circumferential end of the inner flux barrier. By making the outer flux barrier a so-called elongated shape, the entrance width of the magnetic path (second magnetic path q2) formed between the outer flux barrier and the inner flux barrier is narrowed. As a result, the magnetic flux passing through the magnetic path can be reduced compared to the case where the entrance width is wide. The reduced magnetic flux can reduce the induced voltage.

[0012] Furthermore, in the above configuration, the inner flux barrier may include a flattened portion, an inclined portion, and a splayed portion. The flattened portion is formed in the circumferential central part. The inclined portion is connected to the circumferential end of the flattened portion. The inclined portion extends radially relative to the flattened portion. The splayed portion is connected to the circumferential end of the inclined portion. The splayed portion opens circumferentially relative to the inclined portion.

[0013] According to the above configuration, the circumferential end of the inner flux barrier opens in the circumferential direction. This narrows the entrance width of the magnetic path (third magnetic path q3) that is radially inward of the inner flux barrier.

[0014] In the above configuration, a first magnetic path is formed radially outward from the outer flux barrier. A second magnetic path is formed between the outer flux barrier and the inner flux barrier. The entrance width of the first magnetic path is wider than the entrance width of the second magnetic path.

[0015] As will be described later, field weakening control is performed to increase the rotor speed. With the execution of field weakening control, the magnetic flux passing through the first magnetic path q1 decreases. In other words, by making the inlet width of the first magnetic path q1, where the magnetic flux decreases in the rotor's high-speed range, wider than that of the second magnetic path q2, it is possible to reduce the magnetic flux passing through the rotor core at high speeds.

[0016] Furthermore, in the above configuration, a third magnetic path is formed radially inward from the inner flux barrier. The entrance width of the third magnetic path is narrower than the entrance width of the second magnetic path.

[0017] As will be described later, compared with the first magnetic path q1 and the third magnetic path q3, the magnetic flux passing through the second magnetic path q2 is highly important for obtaining reluctance torque. By making the inlet width of the second magnetic path q2 wider than that of the third magnetic path q3, the reluctance torque is ensured.

Advantages of the Invention

[0018] According to the rotor of the permanent magnet type rotating electric machine disclosed in this specification, it is possible to improve the rotational speed of the rotor more than before.

Brief Description of the Drawings

[0019] [Figure 1] It is a diagram illustrating a rotor of a permanent magnet type rotating electric machine according to this embodiment. [Figure 2] It is a diagram of one pole of the rotor. [Figure 3] It is a diagram for explaining the magnetic path passing through the rotor core. [Figure 4] It is a diagram for explaining the inlet width of each magnetic path. [Figure 5] It is a diagram illustrating the distribution of flux lines in the rotating electric machine. [Figure 6] It is a diagram showing a first alternative example of the rotor of a permanent magnet type rotating electric machine according to this embodiment. [Figure 7] It is a diagram showing a second alternative example of the rotor of a permanent magnet type rotating electric machine according to this embodiment. [Figure 8] It is a diagram showing a third alternative example of the rotor of a permanent magnet type rotating electric machine according to this embodiment.

Mode for Carrying Out the Invention

[0020] Hereinafter, the rotor of the permanent magnet type rotating electric machine according to this embodiment will be described with reference to the drawings. The shapes, materials, numbers, and numerical values described below are examples for explanation. These shapes and the like can be appropriately changed according to the specifications of the rotor. Also, in all the drawings below, the same reference numerals are given to equivalent elements.

[0021] 1. Overall Structure Figure 1 illustrates the rotor 10 of a rotating electric machine according to this embodiment. Figures 1-8 illustrate the rotating electric machine as viewed from the direction of the rotation axis.

[0022] A rotating electric machine is a permanent magnet motor. More specifically, a rotating electric machine is an embedded magnet synchronous motor (IPMSM, Interior Permanent Magnet Synchronous Motor).

[0023] Referring to Figure 1, the rotor 10 has, for example, an 8-pole structure. Figures 2-8 illustrate a structure with only one pole. Based on the symmetry of the magnetic pole structure, the other magnetic poles also have a structure similar to that in Figures 2-8.

[0024] Referring to Figure 2, the rotor 10 comprises a rotor core 20, permanent magnets 51, 52, 53, and a shaft 15. The rotor 10 is driven to rotate by the rotating magnetic field generated in the stator 60 (see Figure 5). The rotational driving force of the rotor 10 is then transmitted to an external load via the shaft 15.

[0025] The rotor core 20 is made of, for example, a laminate of electrical steel sheets. Slits are formed inside the rotor core 20. These slits are called flux barriers. Multiple flux barriers are formed in the rotor core 20. These multiple flux barriers include an outer flux barrier 30 and an inner flux barrier 40.

[0026] The flux barrier is also called an air gap. The flux barrier can be considered as magnetic resistance. Therefore, the flux barrier acts as a barrier to the magnetic flux passing through the rotor core 20. In other words, as illustrated in Figure 3, the outer flux barrier 30 and the inner flux barrier 40 form three magnetic paths (first magnetic path q1, second magnetic path q2, and third magnetic path q3) in the rotor core 20. The detailed structures of the outer flux barrier 30 and the inner flux barrier 40 will be described later.

[0027] Permanent magnets are embedded in the flux barrier. Since the permeability of the permanent magnets is equal to that of a vacuum, they can be considered as having magnetic resistance, similar to the flux barrier. Referring to Figure 2, permanent magnets 51, 51 are placed in the outer flux barrier 30. Permanent magnets 52, 52, 53, 53 are placed in the inner flux barrier 40.

[0028] The permanent magnets 51, 52, and 53 are arranged symmetrically with respect to an axis that passes through the rotation center P1 (see Figure 1) and the circumferential center of the magnetic pole. This axis of symmetry is the d-axis. The d-axis represents the axis of the principal magnetic flux direction. In a permanent magnet type rotating electric machine, the central axis of the permanent magnets 51, 52, and 53 is the d-axis. Furthermore, the q-axis is defined as an axis electrically and magnetically orthogonal to the d-axis.

[0029] 2. Internal flux barrier Referring to Figure 2, the outer flux barrier 30 and the inner flux barrier 40 are arranged along the radial direction. The inner flux barrier 40 is positioned radially inward relative to the outer flux barrier.

[0030] In Figures 2-5, the outer flux barrier 30 and the inner flux barrier 40 are divided into two by intermediate walls 37 and 47. The intermediate walls 37 and 47 are positioned on the d-axis. However, as illustrated in Figures 6-8, for example, the outer flux barrier 30 and the inner flux barrier 40 may be a single continuous groove that is not divided.

[0031] The inner flux barrier 40 has an arch shape when viewed from the rotation axis. That is, the inner flux barrier 40 extends along the circumferential direction of the rotor core 20. In addition, the circumferential central portion of the inner flux barrier 40 is closest to the rotation center P1 (see Figure 1).

[0032] Furthermore, the inner flux barrier 40 includes a flattened portion 41, an inclined portion 42, and a leg-spreading portion 43. For example, a permanent magnet 53 is placed on the flattened portion 41. Another permanent magnet 52 is placed on the inclined portion 42.

[0033] The flattened portion 41 is positioned in the circumferential center of the inner flux barrier 40. The inclined portion 42 is connected to the circumferential end of the flattened portion 41. The inclined portion 42 extends radially more than the flattened portion 41. In other words, the inclined portion 42 has a higher uphill gradient compared to the flattened portion 41.

[0034] The splayed portion 43 is connected to the circumferential end of the inclined portion 42. The splayed portion 43 opens circumferentially outward relative to the inclined portion 42. In other words, the angle that the splayed portion 43 makes with the d-axis is larger than that of the inclined portion 42. With this arrangement, as shown in Figure 4, the splayed portion 43 is separated from the outer flux barrier 30.

[0035] For example, the inner flux barrier 40 has a constant groove width through the flattened portion 41, the inclined portion 42, and the splayed portion 43. In other words, referring to Figure 4, the separation distance between the sides 46A and 46B of the inner flux barrier 40 is constant through the flattened portion 41, the inclined portion 42, and the splayed portion 43.

[0036] The terminal edges 44 are connected to the circumferential ends of the side edges 46A and 46B. The terminal edges 44 are the closest of the sides of the inner flux barrier 40 to the outer circumferential surface 25 of the rotor core 20. For example, the terminal edges 44 extend along the outer circumferential surface 25. A bridge 45 is formed between the terminal edges 44 and the outer circumferential surface 25.

[0037] 3. External flux barrier Referring to Figure 2, comparing the outer flux barrier 30 and the inner flux barrier 40, the outer flux barrier 30 is positioned relatively radially outward.

[0038] The outer flux barrier 30 has an arch shape when viewed from the rotation axis. That is, the outer flux barrier 30 extends along the circumferential direction of the rotor core 20. In addition, the circumferential central portion of the outer flux barrier 30 is closest to the rotation center P1 (see Figure 1).

[0039] Furthermore, the outer flux barrier 30 has a flatter arch shape than the inner flux barrier 40. For example, the outer flux barrier 30 is even flatter than the flattened portion 41 of the inner flux barrier 40. If the ratio of the circumferential dimension to the radial dimension is defined as the degree of flatness, then the outer flux barrier 30 has a higher degree of flatness than the flattened portion 41 of the inner flux barrier 40.

[0040] Furthermore, the circumferential end of the outer flux barrier 30 has a tapered shape, with the groove width narrowing towards the circumferential outer edge. The outer flux barrier 30 includes, for example, a uniform width section 31 and a narrowed width section 32. The uniform width section 31 is located in the circumferential central portion of the outer flux barrier 30.

[0041] In the uniform width section 31, the distance between opposing sides 36A and 36B is determined to be equal along the circumferential direction. A permanent magnet 51 is also placed in the uniform width section 31.

[0042] A narrowed width section 32 is connected to the circumferential end of the uniform width section 31. The groove width of the narrowed width section 32 narrows as it moves circumferentially outward. In other words, the separation distance between the side edges 36A and 36B becomes shorter as it moves circumferentially outward. To put it another way, the groove width of the narrowed width section 32 becomes narrower the further it is from the circumferential center of the outer flux barrier 30.

[0043] For example, side 36A extends linearly through the uniform width section 31 and the narrowed width section 32. On the other hand, side 36B bends at the boundary between the uniform width section 31 and the narrowed width section 32. In other words, side 36B slopes towards the circumferential center in the narrowed width section 32 (it becomes an upward slope).

[0044] The terminal edges 34 are connected to the circumferential ends of the side edges 36A and 36B. The terminal edges 34 are the closest of the edges of the outer flux barrier 30 to the outer circumferential surface 25 of the rotor core 20. For example, the terminal edges 34 extend along the outer circumferential surface 25. A bridge 35 is formed between the terminal edges 34 and the outer circumferential surface 25. For example, the circumferential lengths of bridge 35 and bridge 45 are determined to be equal.

[0045] 4. Magnetic path in the rotor core The outer flux barrier 30 and the inner flux barrier 40 form multiple magnetic paths (magnetic flux paths) in the rotor core 20. Specifically, referring to Figure 3, a first magnetic path q1, a second magnetic path q2, and a third magnetic path q3 are formed in the rotor core 20.

[0046] The first magnetic path q1 is formed radially outward from the outer flux barrier 30. The second magnetic path q2 is formed between the outer flux barrier 30 and the inner flux barrier 40. The third magnetic path q3 is formed radially inward from the inner flux barrier 40.

[0047] Referring to Figure 4, the outer flux barrier 30 and the inner flux barrier 40 define the inlet widths W1, W2, and W3 of the first magnetic path q1, the second magnetic path q2, and the third magnetic path q3. The inlet width refers to the width through which magnetic flux can enter each magnetic path from outside the rotor core 20. Although the structural boundary of the first magnetic path q1 is ambiguous, based on the flow of magnetic flux, the region between the d-axis and the bridge 35 becomes the inlet width.

[0048] The entrance width W1 of the first magnetic path q1 is widened by the outer flux barrier 30. The entrance width W1 of the first magnetic path q1 is wider than the entrance width W2 of the second magnetic path q2 and the entrance width W3 of the third magnetic path q3. In other words, the entrance width W1 is wider because the outer flux barrier 30 has a flatter shape than the inner flux barrier 40. For example, based on the electric angle of the magnetic pole, the entrance width W1 is set to be between 70° (electric angle) and 100° (electric angle).

[0049] The entrance width of the second magnetic path q2 is narrowed by the outer flux barrier 30. That is, the outer flux barrier 30 has a flatter shape compared to the inner flux barrier 40. In addition, the circumferential end of the outer flux barrier 30 tapers to a terminating point. In this way, the outer flux barrier 30 has a somewhat elongated shape, which narrows the entrance width W2 of the second magnetic path q2. For example, based on the electric angle of the magnetic pole, the entrance width W2 is set to be between 17° (electrical angle) and 30° (electrical angle). Narrowing the entrance width W2 increases the magnetic resistance of the second magnetic path q2. As a result, the magnetic flux passing through the second magnetic path q2 is reduced.

[0050] The entrance width of the third magnetic circuit q3 is narrowed by the inner flux barrier 40. That is, the entrance width W3 is narrowed as the legs 43 of the inner flux barrier 40 open outward in the circumferential direction. For example, based on the electric angle of the magnetic pole, the entrance width W3 of the third magnetic circuit q3 is set to be between 5° (electric angle) and 15° (electric angle).

[0051] Thus, in the rotor core 20 according to this embodiment, the inlet width W1 of the first magnetic path q1 is wider than the inlet width W2 of the second magnetic path q2 and the inlet width W3 of the third magnetic path q3.

[0052] Here, equation (1) below is the equation for the current flowing through a rotating electric machine. JPEG2026112491000002.jpg976

[0053] In equation (1), V inv V is the voltage vector applied from the inverter. mo R represents the induced voltage vector, R represents the resistance, and I represents the current vector. Note that the current vector I is decomposed into d-axis current and q-axis current in known vector control systems.

[0054] As the rotational speed of rotor 10 increases, the induced voltage V mo It increases. Based on equation (1), the induced voltage V mo When the inverter reaches its maximum voltage, no current flows through the coil 68 of the stator 60 (see Figure 5).inv = V mo When this occurs, the rotational speed of the rotor 10 becomes maximum and the torque becomes zero.

[0055] Induced voltage V mo By reducing, the rotational speed of the rotor 10 can be increased. Here, in order to reduce the induced voltage V mo field weakening control is executed. In field weakening control, a magnetic flux opposite to the magnetic flux in the d-axis is generated by the d-axis current. That is, the magnetic flux of the permanent magnet is weakened. As a result, the induced voltage V mo is reduced.

[0056] Fig. 5 illustrates the distribution of flux lines (magnetic field lines) during the execution of field weakening control. In this figure, the magnetic flux passing through the stator core 62 is shown by thin lines. In Fig. 5, one pole of the stator core 62, the teeth 66A - 66G and the coils 68A - 68F face the rotor core 20.

[0057] The first magnetic path q1 only spans three teeth 66C - 66E out of the teeth 66A - 66G. Therefore, the magnetic flux generated from the coils 68C, 68D arranged between these teeth 66C - 66E flows exclusively into the first magnetic path q1. Also, in Fig. 5, although the outer flux barrier 30 and the coils 68C, 68D are facing each other, if the relative position of the outer flux barrier 30 and the coils 68C, 68D is displaced, the magnetic flux flowing into the first magnetic path q1 will be less.

[0058] During field weakening control, since the magnetic flux of the permanent magnet and the magnetic flux due to the d-axis current cancel each other out, the flux lines around the coils 68C, 68D close to the d-axis are fewer compared to their surroundings. That is, when the rotor 10 is rotating at high speed, the magnetic flux passing through the first magnetic path q1 is reduced compared to when rotating at low speed without field weakening being executed.

[0059] Thus, when the rotor 10 rotates at high speed, the magnetic flux flowing into the first magnetic path q1 is reduced. By making the inlet width W1 of the first magnetic path q1 (see Figure 4) wider than the inlet width W2 of the second magnetic path q2 and the inlet width W3 of the third magnetic path q3, the induced voltage is reduced. In other words, it becomes possible to further increase the rotational speed of the rotor 10.

[0060] Furthermore, the entrance width W2 of the second magnetic path q2 is formed to be wider than the entrance width W3 of the third magnetic path q3. For example, by forming an open leg portion 43 at the circumferential end of the inner flux barrier 40, the entrance width W2 of the second magnetic path q2 becomes wider than the entrance width W3 of the third magnetic path q3.

[0061] Motor torque is the resultant force of magnet torque and reluctance torque. When field weakening control is performed, the current advance angle is set to a larger advance angle than when maximum torque is obtained. In this case, magnet torque decreases, but reluctance torque increases. In other words, in field weakening control, reluctance torque becomes dominant in motor torque.

[0062] Theoretically, reluctance torque is maximized when the advance angle is 45° (electrical angle). Therefore, reluctance torque can be ensured by making it easier for magnetic flux to pass through the magnetic path in a position close to 45° (electrical angle) from the d-axis.

[0063] Referring to Figure 3, of the first magnetic path q1, the second magnetic path q2, and the third magnetic path q3, the magnetic path closest to a position of 45° (electrical angle) from the d-axis is the second magnetic path q2. Therefore, the inlet width W2 of the second magnetic path q2 is formed to be wider than the inlet width W3 of the third magnetic path q3. For example, the inlet widths W2 of the second magnetic path q2 and W3 of the third magnetic path q3 are determined such that W3 / W2 < 0.5.

[0064] 5. Another example of a flux barrier Figure 6 shows a first alternative example of the rotor core 20. In this example, the outer flux barrier 30 and the inner flux barrier 40 extend continuously along their entire circumferential length. In other words, the outer flux barrier 30 and the inner flux barrier 40 are not divided by barriers such as intermediate walls 47 (see Figure 2).

[0065] In Figure 6, a permanent magnet 54 is positioned at the circumferential center of the outer flux barrier 30. A permanent magnet 55 is also positioned at the circumferential center of the inner flux barrier 40.

[0066] Figure 7 shows a second alternative example of the rotor core 20. In this example as well, the outer flux barrier 30 and the inner flux barrier 40 extend continuously along their entire circumferential length. In addition, permanent magnets 56 and 57 are arranged without gaps in the outer flux barrier 30 and the inner flux barrier 40. The permanent magnets 56 and 57 are made of, for example, bonded magnets.

[0067] Figure 8 shows a third alternative example of the rotor core 20. In this example as well, the outer flux barrier 30 and the inner flux barrier 40 extend continuously along the entire length in the circumferential direction. Both the outer flux barrier 30 and the inner flux barrier 40 are V-shaped.

[0068] Permanent magnets 58A and 58B are arranged in the outer flux barrier 30 with the d-axis as the axis of symmetry. Permanent magnets 59A and 59B are also arranged in the inner flux barrier 40 with the d-axis as the axis of symmetry.

[0069] In all of Figures 6-8, the outer flux barrier 30 and the inner flux barrier 40 are arranged radially. Furthermore, the outer flux barrier 30 and the inner flux barrier 40 extend along the circumferential direction of the rotor core 20 and have an arch shape, with the circumferential center portion being closest to the center of rotation. The outer flux barrier 30 has a flatter arch shape compared to the inner flux barrier 40. Furthermore, the circumferential end of the outer flux barrier 30 has a tapered shape, with the groove width narrowing as it moves circumferentially outward.

[0070] By incorporating the above structure, the entrance width W2 of the second magnetic path q2 can be narrowed. As a result, the magnetic flux passing through the second magnetic path q2 can be reduced compared to the case where the entrance width W2 is wide. [Explanation of Symbols]

[0071] 10 Rotor, 20 Rotor core, 30 Outer flux barrier, 31 Uniform width section, 32 Reduced width section, 40 Inner flux barrier, 41 Flattened section, 42 Inclined section, 43 Spreading leg section, 51, 52, 53, 54, 55, 56, 57, 58, 59 Permanent magnets, 60 Stator, q1 First magnetic circuit, q2 Second magnetic circuit, q3 Third magnetic circuit.

Claims

1. A rotor core with multiple flux barriers formed therein, A permanent magnet embedded in the flux barrier, Equipped with, The plurality of flux barriers include an outer flux barrier positioned relatively radially outward and an inner flux barrier positioned relatively radially inward. The outer flux barrier and the inner flux barrier are arranged radially. Furthermore, the outer flux barrier and the inner flux barrier extend along the circumferential direction of the rotor core and have an arch shape such that their circumferential central portion is closest to the center of rotation. The outer flux barrier has a flatter arch shape compared to the inner flux barrier. The circumferential end of the outer flux barrier has a tapered shape, where the groove width narrows as it moves circumferentially outward. Rotor of a permanent magnet type rotating electric machine.

2. A rotor of a permanent magnet type rotating electric machine according to claim 1, The inner flux barrier comprises a flattened portion formed in the circumferential central portion, an inclined portion connected to the circumferential end of the flattened portion and extending radially relative to the flattened portion, and an open leg portion connected to the circumferential end of the inclined portion and opening circumferentially relative to the inclined portion, A rotor for a permanent magnet type rotating electric machine.

3. A rotor of a permanent magnet type rotating electric machine according to claim 2, The entrance width of the first magnetic path, which is formed radially outward from the outer flux barrier, is wider than the entrance width of the second magnetic path, which is formed between the outer flux barrier and the inner flux barrier. Rotor of a permanent magnet type rotating electric machine.

4. A rotor of a permanent magnet type rotating electric machine according to claim 3, The entrance width of the third magnetic path, which is formed radially inward from the inner flux barrier, is narrower than the entrance width of the second magnetic path. Rotor of a permanent magnet type rotating electric machine.

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