Rotor for a permanent-magnet type rotary electric machine

Abstract

In permanent magnet rotary electric machines, the rotor speed can be increased compared to previous methods. Multiple magnetic flux barriers are formed on the rotor core. These magnetic flux barriers include outer and inner magnetic flux barriers. Both the outer and inner magnetic flux barriers are arched. Compared to the inner magnetic flux barrier, the outer magnetic flux barrier is a flattened arch. The circumferential ends of the outer magnetic flux barrier have a constricted shape where the slot width gradually narrows circumferentially outwards.

Description

Technical Field

[0001] This specification discloses a rotor for a permanent magnet rotary electric motor. Background Technology

[0002] In permanent magnet rotary motors, permanent magnets are mounted on the rotor. For example, in an interior permanent magnet synchronous motor (IPMSM), permanent magnets are embedded inside the rotor core.

[0003] A slit is formed on the rotor core for embedding permanent magnets. This slit obstructs the flow of magnetic flux and is therefore called a flux barrier.

[0004] In Patent Document 1, an outer peripheral magnetic flux barrier is provided on the rotor core. The outer peripheral magnetic flux barrier extends along the outer periphery and is located near the outer periphery of the rotor core. In addition, a generally V-shaped magnetic flux barrier is formed radially inward of the rotor core, closer to the outer peripheral magnetic flux barrier.

[0005] In Patent Document 2, a first magnet filling portion is formed near the outer periphery of the rotor core. Furthermore, a second magnet filling portion is formed on the rotor core, further radially inward than the first magnet filling portion. Both the first and second magnet filling portions function as magnetic flux barriers.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-229395 Patent Document 2: Japanese Patent Application Publication No. 2020-137139 Summary of the Invention The maximum speed of a rotating electric machine is determined by the induced voltage and the maximum voltage of the inverter. As the rotor rotates, an induced voltage is generated based on the principle of electromagnetic induction. Current flows through the coils based on the difference between the voltage applied to the stator coils by the inverter and the induced voltage.

[0007] The magnitude of the induced voltage is proportional to the time change of the magnetic flux. That is, as the rotor rotates at high speed, the induced voltage increases. If 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 coils stops. At this point, the rotor speed reaches its maximum, and the torque becomes zero.

[0008] Therefore, this specification discloses a rotor for a permanent magnet type rotary electric motor that can increase the rotor speed compared to the conventional type.

[0009] This specification discloses a rotor for a permanent magnet rotary electric machine. The rotor includes a rotor core and permanent magnets. Multiple magnetic flux barriers are formed on the rotor core. The permanent magnets are embedded in the magnetic flux barriers. The multiple magnetic flux barriers include outer magnetic flux barriers and inner magnetic flux barriers. The outer magnetic flux barriers are arranged radially outwards relative to each other. The inner magnetic flux barriers are arranged radially inwards relative to each other. The outer and inner magnetic flux barriers are arranged radially. Furthermore, both the outer and inner magnetic flux barriers are arched. That is, the outer and inner magnetic flux barriers extend circumferentially along the rotor core, with their circumferential center portions closest to the center of rotation. Compared to the inner magnetic flux barriers, the outer magnetic flux barriers are flattened arches. The circumferential ends of the outer magnetic flux barriers have a constricted shape where the slot width gradually narrows circumferentially outwards.

[0010] Based on the above configuration, the outer magnetic flux barrier is a flat, arched shape. Furthermore, the circumferential ends of the outer magnetic flux barrier gradually narrow to approach the circumferential ends of the inner magnetic flux barrier. Thus, by setting the outer magnetic flux barrier to a so-called horizontally elongated shape, the entrance width of the magnetic circuit (second magnetic circuit q2) formed between the outer and inner magnetic flux barriers becomes narrower. As a result, compared to the case where the entrance width is increased, the magnetic flux passing through this magnetic circuit can be reduced. With the reduction in magnetic flux, the induced voltage can be lowered.

[0011] Furthermore, in the above configuration, the inner magnetic flux barrier may include a flat portion, an inclined portion, and an open portion. The flat portion is formed at the circumferential center. The inclined portion is connected to the circumferential end of the flat portion. The inclined portion extends radially further than the flat portion. The open portion is connected to the circumferential end of the inclined portion. The open portion opens circumferentially further than the inclined portion.

[0012] Based on the above configuration, the circumferential end of the inner magnetic flux barrier opens circumferentially. As a result, the entrance width of the magnetic circuit (the third magnetic circuit q3), which is further radially inward than the inner magnetic flux barrier, becomes narrower.

[0013] Furthermore, in the above configuration, a first magnetic circuit is formed radially outward from the outer magnetic flux barrier. A second magnetic circuit is formed between the outer and inner magnetic flux barriers. The entrance width of the first magnetic circuit is wider than the entrance width of the second magnetic circuit.

[0014] As described later, field weakening control is performed to increase the rotor speed. With the execution of field weakening control, the magnetic flux through the first magnetic circuit q1 is reduced. That is, by setting the entrance width of the first magnetic circuit q1, which reduces the magnetic flux in the high-speed region of the rotor, to be wider than that of the second magnetic circuit q2, the magnetic flux through the rotor core at high speeds can be reduced.

[0015] Furthermore, in the above configuration, a third magnetic circuit is formed radially inward than the inner magnetic flux barrier. The entrance width of the third magnetic circuit is narrower than the entrance width of the second magnetic circuit.

[0016] As will be described later, the magnetic flux through the second magnetic circuit q2 is of greater importance in obtaining reluctance torque compared to the first magnetic circuit q1 and the third magnetic circuit q3. Reluctance torque is ensured by setting the entrance width of the second magnetic circuit q2 to be wider than that of the third magnetic circuit q3.

[0017] Invention Effects The rotor of the permanent magnet rotary motor disclosed in this specification can increase the rotor speed compared to the past. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the rotor of the permanent magnet type rotary electric motor according to this embodiment.

[0019] Figure 2 This is a diagram of one pole of the rotor.

[0020] Figure 3 It is a diagram illustrating the magnetic circuit through the rotor core.

[0021] Figure 4 This is a diagram illustrating the entrance width of each magnetic circuit.

[0022] Figure 5 This is a diagram illustrating the distribution of magnetic flux lines in a rotating electric machine.

[0023] Figure 6 This is a diagram showing a first other example of the rotor of the permanent magnet type rotary electric machine according to this embodiment.

[0024] Figure 7 This is a diagram showing a second other example of the rotor of the permanent magnet type rotary electric motor according to this embodiment.

[0025] Figure 8 This is a diagram showing a third other example of the rotor of the permanent magnet type rotary electric machine according to this embodiment. Detailed Implementation

[0026] The rotor of the permanent magnet rotary electric motor according to this embodiment will now be described using the accompanying drawings. The shapes, materials, quantities, and values ​​described below are illustrative examples. These shapes, etc., can be appropriately changed depending on the rotor specifications. Furthermore, equivalent elements will be indicated with the same symbols in all the accompanying drawings below.

[0027] 1. Overall Composition exist Figure 1 The rotor 10 of the rotary electric machine according to this embodiment is illustrated in the diagram. Additionally, in... Figures 1-8 The diagram shows a rotating electric motor viewed from the direction of the rotation axis.

[0028] The rotary motor is a permanent magnet motor. More specifically, the rotary motor is an interior permanent magnet synchronous motor (IPMSM).

[0029] refer to Figure 1 The rotor 10 is, for example, an 8-pole structure. Figures 2-8 The diagram illustrates a structure with only one pole. Based on the symmetry of the magnetic pole structure, the other magnetic poles also possess similar characteristics. Figures 2-8 Same structure.

[0030] refer to Figure 2 The rotor 10 includes a rotor core 20, permanent magnets 51, 52, and 53, and a shaft 15. This is achieved through the stator 60 (reference). Figure 5 The rotating magnetic field generated in the rotor drives the rotor 10 to rotate. Moreover, the rotational driving force of the rotor 10 is transmitted to the external load via the shaft 15.

[0031] The rotor core 20 is, for example, composed of a laminate of electromagnetic steel plates. Slits are formed inside the rotor core 20. These slits are called magnetic flux barriers. Multiple magnetic flux barriers are formed on the rotor core 20. These multiple magnetic flux barriers include an outer magnetic flux barrier 30 and an inner magnetic flux barrier 40.

[0032] The magnetic flux barrier is also known as an air gap. A magnetic flux barrier can be understood as magnetic resistance. Therefore, the magnetic flux barrier acts as an obstacle to the passage of magnetic flux through the rotor core 20. That is, as... Figure 3 As illustrated, three magnetic circuits (first magnetic circuit q1, second magnetic circuit q2, and third magnetic circuit q3) are formed on the rotor core 20 through the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40. The detailed structure of the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40 will be described later.

[0033] A permanent magnet is embedded within the magnetic flux barrier. The permeability of the permanent magnet is equal to that in vacuum, and therefore can be understood as magnetic reluctance in the same way as the magnetic flux barrier. (Reference) Figure 2 Permanent magnets 51 and 52 are disposed on the outer magnetic flux barrier 30. Permanent magnets 52, 52, 53, and 53 are disposed on the inner magnetic flux barrier 40.

[0034] To pass through the rotation center P1 (reference) Figure 1 Furthermore, the axis passing through the circumferential center of the magnetic poles is the axis of symmetry, and the permanent magnets 51, 52, and 53 are arranged symmetrically. This axis of symmetry then becomes the d-axis. The d-axis represents the axis of the main magnetic flux direction. In a permanent magnet type rotary electric motor, the central axis of the permanent magnets 51, 52, and 53 becomes the d-axis. Moreover, the q-axis is determined as an axis that is electrically and magnetically orthogonal to the d-axis.

[0035] 2. Inner magnetic flux barrier refer to Figure 2 The outer magnetic flux barrier 30 and the inner magnetic flux barrier 40 are arranged radially. The inner magnetic flux barrier 40 is arranged radially inward relative to each other.

[0036] In addition, Figures 2-5 In the middle, the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40 are divided into two parts by intermediate walls 37 and 47. The intermediate walls 37 and 47 are positioned on the d-axis. However, for example, as... Figures 6-8 As illustrated, the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40 can be a continuous, undivided slot.

[0037] Viewed from the axis of rotation, the inner magnetic flux barrier 40 is arched. That is, the inner magnetic flux barrier 40 extends circumferentially along the rotor core 20. Furthermore, the circumferential center portion of the inner magnetic flux barrier 40 is closest to the rotation center P1 (see reference). Figure 1 ).

[0038] Furthermore, the inner magnetic flux barrier 40 includes a flat portion 41, an inclined portion 42, and an open portion 43. For example, a permanent magnet 53 is disposed on the flat portion 41. And a permanent magnet 52 is disposed on the inclined portion 42.

[0039] The flat portion 41 is disposed at the circumferential center of the inner magnetic flux barrier 40. The inclined portion 42 is connected to the circumferential end of the flat portion 41. The inclined portion 42 extends further radially than the flat portion 41. That is, the inclined portion 42 has a higher gradient than the flat portion 41.

[0040] The opening portion 43 is connected to the circumferential end of the inclined portion 42. The opening portion 43 opens further outward in the circumferential direction than the inclined portion 42. In other words, the angle between the opening portion 43 and the d-axis is larger than the angle between the inclined portion 42 and the d-axis. With this configuration, reference... Figure 4 The opening portion 43 separates from the outer magnetic flux barrier 30.

[0041] For example, the inner magnetic flux barrier 40, through the flat portion 41, the inclined portion 42, and the opening portion 43, has a slot width that is determined to be constant. That is, reference... Figure 4 The separation distance between the sides 46A and 46B of the inner magnetic flux barrier 40 is kept constant by the flat part 41, the inclined part 42 and the opening part 43.

[0042] The terminal edge 44 is connected to the circumferential ends of the side edges 46A and 46B. The terminal edge 44 is closest to the outer peripheral surface 25 of the rotor core 20 among the edges of the inner flux barrier 40. For example, the terminal edge 44 extends along the outer peripheral surface 25. A bridge 45 is formed between the terminal edge 44 and the outer peripheral surface 25.

[0043] 3. External magnetic flux barrier refer to Figure 2When comparing the outer magnetic flux barrier 30 with the inner magnetic flux barrier 40, the outer magnetic flux barrier 30 is positioned radially outward.

[0044] Viewed from the axis of rotation, the outer flux barrier 30 is arched. That is, the outer flux barrier 30 extends circumferentially along the rotor core 20. Furthermore, the circumferential center portion of the outer flux barrier 30 is closest to the rotation center P1 (see reference). Figure 1 ).

[0045] Furthermore, the outer magnetic flux barrier 30 is a flatter arch shape compared to the inner magnetic flux barrier 40. For example, the outer magnetic flux barrier 30 is flatter than the flat portion 41 of the inner magnetic flux barrier 40. In addition, if the ratio of the circumferential dimension to the radial dimension is defined as the flatness, the flatness of the outer magnetic flux barrier 30 is greater than the flatness of the flat portion 41 of the inner magnetic flux barrier 40.

[0046] Furthermore, the circumferential end of the outer magnetic flux barrier 30 has a constricted shape where the groove width gradually narrows outward along the circumferential direction. The outer magnetic flux barrier 30, for example, has a constant width portion 31 and a constricted portion 32. The constant width portion 31 is disposed in the circumferential central portion of the outer magnetic flux barrier 30.

[0047] In the equal-width section 31, the separation distance between the opposing sides 36A and 36B is determined in such a way that it is equal along the circumferential direction. Furthermore, a permanent magnet 51 is disposed on the equal-width section 31.

[0048] The narrowing portion 32 connects to the circumferential end of the equal-width portion 31. In the narrowing portion 32, the slot width gradually narrows as it extends outward circumferentially. That is, the separation distance between the sides 36A and 36B shortens outward circumferentially. In other words, the narrowing portion 32 becomes narrower the further it is from the circumferential center of the outer magnetic flux barrier 30.

[0049] For example, side 36A extends linearly through the equal-width portion 31 and the narrowing portion 32. On the other hand, side 36B curves at the boundary between the equal-width portion 31 and the narrowing portion 32. That is, side 36B tilts towards the circumferential center in the narrowing portion 32 (becoming an upward tilt).

[0050] The terminal edge 34 is connected to the circumferential ends of the side edges 36A and 36B. The terminal edge 34 is closest to the outer peripheral surface 25 of the rotor core 20 among the edges of the outer flux barrier 30. For example, the terminal edge 34 extends along the outer peripheral surface 25. A bridge 35 is formed between the terminal edge 34 and the outer peripheral surface 25. For example, the bridge 35 and bridge 45 are defined such that their circumferential lengths are equal.

[0051] 4. Magnetic circuit in the rotor core Multiple magnetic circuits (magnetic flux paths) are formed on the rotor core 20 through the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40. That is, referring to... Figure 3A first magnetic circuit q1, a second magnetic circuit q2, and a third magnetic circuit q3 are formed on the rotor core 20.

[0052] The first magnetic circuit q1 is formed radially outward from the outer magnetic flux barrier 30. The second magnetic circuit q2 is formed between the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40. The third magnetic circuit q3 is formed radially inward from the inner magnetic flux barrier 40.

[0053] refer to Figure 4 The entrance widths W1, W2, and W3 of the first magnetic path q1, the second magnetic path q2, and the third magnetic path q3 are determined by the outer magnetic flux barrier 30 and the inner magnetic flux barrier 40. The entrance width refers to the width through which magnetic flux can enter each magnetic path from the outside of the rotor core 20. Regarding the first magnetic path q1, the structural boundary is not clearly defined, but according to the flow of magnetic flux, the area between the d-axis and the bridge 35 is considered the entrance width.

[0054] The entrance width W1 of the first magnetic circuit q1 widens as it passes through the outer magnetic flux barrier 30. The entrance width W1 of the first magnetic circuit q1 is wider than the entrance width W2 of the second magnetic circuit q2 and the entrance width W3 of the third magnetic circuit q3. That is, the entrance width W1 is wider because the outer magnetic flux barrier 30 has a flatter shape compared to the inner magnetic flux barrier 40. For example, based on the electrical angle of the magnetic poles, the entrance width W1 is determined to be 70° (electrical angle) or more and 100° (electrical angle) or less.

[0055] The entrance width of the second magnetic circuit q2 narrows as it passes through the outer magnetic flux barrier 30. That is, the outer magnetic flux barrier 30 has a flatter shape compared to the inner magnetic flux barrier 40. Furthermore, the circumferential ends of the outer magnetic flux barrier 30 gradually narrow and terminate. Thus, the outer magnetic flux barrier 30 becomes a so-called horizontally elongated shape, thereby narrowing the entrance width W2 of the second magnetic circuit q2. For example, based on the electrical angle of the magnetic poles, the entrance width W2 is determined to be 17° (electrical angle) or more and 30° (electrical angle) or less. By narrowing the entrance width W2, the magnetic reluctance of the second magnetic circuit q2 increases. As a result, the magnetic flux through the second magnetic circuit q2 decreases.

[0056] The entrance width of the third magnetic circuit q3 narrows as it passes through the inner magnetic flux barrier 40. That is, the opening portion 43 of the inner magnetic flux barrier 40 opens outward in a circumferential direction, thereby narrowing the entrance width W3. For example, based on the electrical angle of the magnetic poles, the entrance width W3 of the third magnetic circuit q3 is determined to be 5° (electrical angle) or more and 15° (electrical angle) or less.

[0057] Thus, in the rotor core 20 of this embodiment, the entrance width W1 of the first magnetic circuit q1 is wider than the entrance width W2 of the second magnetic circuit q2 and the entrance width W3 of the third magnetic circuit q3.

[0058] Here, the following equation (1) is the formula for the current flowing in a rotating electric machine.

[0059]

[0060] In equation (1), V inv V represents the voltage vector applied from the inverter. mo Let R represent the induced voltage vector, R represent the resistance, and I represent the current vector. Furthermore, in known vector control, the current vector I is decomposed into d-axis current and q-axis current.

[0061] As the rotational speed of rotor 10 increases, the induced voltage V mo Increase. According to equation (1), if the induced voltage V mo When the inverter reaches its maximum voltage, the stator voltage is 60 (reference). Figure 5 No current flows in coil 68. That is, when V inv =V mo At that time, the rotor 10 reaches its maximum speed and the torque becomes zero.

[0062] By reducing the induced voltage V mo This can increase the rotational speed of rotor 10. Here, in order to reduce the induced voltage V... mo This involves performing field weakening control. In field weakening control, a magnetic flux in the opposite direction to the d-axis flux is generated through the d-axis current. That is, the magnetic flux of the permanent magnet is weakened. Consequently, the induced voltage V... mo reduce.

[0063] exist Figure 5 The diagram illustrates the distribution of magnetic flux lines (magnetic lines of force) during field weakening control. In this diagram, the magnetic flux lines passing through the stator core 62 are represented by thin lines. Figure 5 In the stator core 62, the teeth 66A-66G and the coils 68A-68F are opposite to one pole of the rotor core 20.

[0064] The first magnetic circuit q1 spans only three teeth 66C-66E out of teeth 66A-66G. Therefore, the magnetic flux generated by coils 68C and 68D, which are positioned between these teeth 66C-66E, mainly flows into the first magnetic circuit q1. Furthermore, in Figure 5 In the middle, the outer magnetic flux barrier 30 is directly opposite the coils 68C and 68D. However, if the relative position of the outer magnetic flux barrier 30 and the coils 68C and 68D deviates, the magnetic flux flowing into the first magnetic circuit q1 becomes less.

[0065] In field weakening control, the magnetic flux of the permanent magnet cancels out the magnetic flux generated by the d-axis current. Therefore, compared to this periphery, there are fewer magnetic flux lines around the coils 68C and 68D near the d-axis. That is, when the rotor 10 rotates at high speed, the magnetic flux through the first magnetic circuit q1 is reduced compared to the low-speed rotation without field weakening control.

[0066] Thus, when the rotor 10 rotates at high speed, the magnetic flux flowing into the first magnetic circuit q1 is reduced. This is achieved by increasing the inlet width W1 of the first magnetic circuit q1 (reference...). Figure 4 The induced voltage is reduced when the inlet width W2 of the second magnetic circuit q2 is wider than that of the inlet width W3 of the third magnetic circuit q3. This allows the rotor 10 to rotate at a higher speed.

[0067] Furthermore, the entrance width W2 of the second magnetic circuit q2 is made wider than the entrance width W3 of the third magnetic circuit q3. For example, by forming an opening 43 at the circumferential end of the inner magnetic flux barrier 40, the entrance width W2 of the second magnetic circuit q2 is wider than the entrance width W3 of the third magnetic circuit q3.

[0068] The so-called motor torque is the resultant force of the magnet torque and the reluctance torque. When performing field weakening control, the current advance angle is set to a larger angle than when maximum torque is achieved. At this time, the magnet torque decreases, but the reluctance torque increases. That is, in field weakening control, the motor torque is dominated by the reluctance torque.

[0069] Theoretically, reluctance torque reaches its maximum at an advance angle of 45° (electrical angle). Therefore, in the magnetic circuit near a position of 45° (electrical angle) from the d-axis, reluctance torque is ensured by facilitating the passage of magnetic flux.

[0070] refer to Figure 3 Among the first magnetic circuit q1, the second magnetic circuit q2, and the third magnetic circuit q3, the magnetic circuit closest to the first one at a position of 45° (electrical angle) from the d-axis is the second magnetic circuit q2. Therefore, the entrance width W2 of the second magnetic circuit q2 is set to be wider than the entrance width W3 of the third magnetic circuit q3. For example, the entrance width W2 of the second magnetic circuit q2 and the entrance width W3 of the third magnetic circuit q3 are determined in such a way that W3 / W2 < 0.5.

[0071] 5. Other examples of magnetic flux barriers exist Figure 6 The diagram 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, there is no intermediate wall 47 (see reference 40) in the outer flux barrier 30 and the inner flux barrier 40. Figure 2 Segmentation caused by obstacles such as ( ).

[0072] Furthermore, in Figure 6 In the middle, a permanent magnet 54 is arranged at the circumferential center of the outer magnetic flux barrier 30. And, a permanent magnet 55 is arranged at the circumferential center of the inner magnetic flux barrier 40.

[0073] exist Figure 7The diagram shows a second 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. Furthermore, permanent magnets 56 and 57 are arranged without gaps on the outer flux barrier 30 and the inner flux barrier 40. The permanent magnets 56 and 57 are, for example, made of bonded magnets.

[0074] exist Figure 8 The diagram shows a third 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. Both the outer flux barrier 30 and the inner flux barrier 40 are V-shaped.

[0075] Permanent magnets 58A and 58B are arranged on the outer magnetic flux barrier 30 with the d-axis as the axis of symmetry. Furthermore, permanent magnets 59A and 59B are arranged on the inner magnetic flux barrier 40 with the d-axis as the axis of symmetry.

[0076] exist Figures 6-8 In this configuration, both the outer flux barrier 30 and the inner flux barrier 40 are arranged radially. Furthermore, both the outer flux barrier 30 and the inner flux barrier 40 are arched shapes extending circumferentially along the rotor core 20, with their circumferential center portions closest to the center of rotation. Compared to the inner flux barrier 40, the outer flux barrier 30 is a flattened arch. Additionally, the circumferential end of the outer flux barrier 30 has a constricted shape where the slot width narrows outwards circumferentially.

[0077] By employing the above structure, the entrance width W2 of the second magnetic circuit q2 can be narrowed. As a result, compared to the case where the entrance width W2 is increased, the magnetic flux passing through the second magnetic circuit q2 can be reduced.

[0078] Symbol Explanation 10-Rotor, 20-Rotor core, 30-Outer magnetic flux barrier, 31-Equal width section, 32-Narrowing section, 40-Inner magnetic flux barrier, 41-Flat section, 42-Inclined section, 43-Opening 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 for a permanent magnet rotary electric motor, characterized in that, have: The rotor core has multiple magnetic flux barriers formed on it; and A permanent magnet, embedded in the magnetic flux barrier. The plurality of magnetic flux barriers include outer magnetic flux barriers disposed opposite each other radially outward and inner magnetic flux barriers disposed opposite each other radially inward. The outer magnetic flux barrier and the inner magnetic flux barrier are arranged radially. Furthermore, the outer magnetic flux barrier and the inner magnetic flux barrier extend circumferentially along the rotor core and are arched in shape with the circumferential center closest to the center of rotation. Compared to the inner magnetic flux barrier, the outer magnetic flux barrier is a flat arch shape, and the circumferential end of the outer magnetic flux barrier is a constricted shape in which the groove width gradually narrows along the circumferential outward.

2. The rotor of the permanent magnet rotary motor according to claim 1, characterized in that, The inner magnetic flux barrier comprises: a flat portion formed at the circumferential center; an inclined portion connected to the circumferential end of the flat portion and extending radially further than the flat portion; and an open portion connected to the circumferential end of the inclined portion and opening circumferentially further than the inclined portion.

3. The rotor of the permanent magnet rotary motor according to claim 2, characterized in that, The entrance width of the first magnetic circuit, which is formed radially outward from the outer magnetic flux barrier, is wider than the entrance width of the second magnetic circuit, which is formed between the outer magnetic flux barrier and the inner magnetic flux barrier.

4. The rotor of the permanent magnet rotary electric motor according to claim 3, characterized in that, The entrance width of the third magnetic circuit, which is formed radially inward than the inner magnetic flux barrier, is narrower than the entrance width of the second magnetic circuit.

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