JP2015073417A - Embedded magnet dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embedded magnet dynamo-electric machine, the torque characteristics of which can be enhanced by reducing the leakage flux of a permanent magnet.SOLUTION: A embedded magnet dynamo-electric machine includes a stator around which a coil is wound, and a rotor 30 where the outer peripheral surface of a cylindrical rotor core 40 is arranged to face the inner peripheral side of a stator through a gap, and a pair of permanent magnets per pole are embedded in V-shape so as to spread to the outer peripheral side in the peripheral direction of the rotor core 40. A flux barrier is formed between the inner peripheral edge of the pair of permanent magnets in V-shape, and projecting in the d-axis direction from the inner peripheral edge P1 of the gap side magnetic pole face of the permanent magnet. Following relation is satisfied 0.2≤Y/X≤0.3, where Y is the projection amount, and X is the distance between both ends P1, P2 of the gap side magnetic pole face in the d-axis direction.

Description

  The present invention relates to a magnet-embedded rotating electrical machine.

  In the rotor of the rotating electrical machine disclosed in Patent Document 1, the pair of permanent magnet insertion slots are arranged in a V shape that opens from the rotation center axis side toward the outer peripheral side, and the pair of slots is arranged in the radial direction. A permanent magnet is inserted and held in each slot so as to form a gap (flux barrier) at each end of the slot.

JP 2011-223836 A

  In Patent Document 1, there is a description that “the bridge between the magnetic poles is desirably as thin as possible in order to reduce the leakage flux”, but other specific techniques for reducing the leakage flux are disclosed. Absent. In particular, there is a concern that the leakage magnetic flux between the permanent magnets arranged in a V shape increases, which affects torque characteristics (output characteristics if the rotation speed is constant).

  An object of the present invention is to provide a magnet-embedded rotating electrical machine that can reduce the magnetic flux leakage of a permanent magnet and improve torque characteristics.

  According to the first aspect of the present invention, the stator around which the coil is wound and the outer peripheral surface of the cylindrical rotor core are arranged so as to face each other on the inner peripheral side of the stator via a gap, and the stator is arranged in the circumferential direction of the rotor core. And a rotor embedded in a V shape so that a pair of permanent magnets per pole spread outward, an inner peripheral end of the V-shaped pair of permanent magnets in the rotor core A flux barrier is formed between them, and the flux barrier protrudes in the d-axis direction from the inner peripheral end portion of the gap-side magnetic pole surface of the permanent magnet, and the amount of protrusion is Y, between both end portions of the gap-side magnetic pole surface. The gist is that when the distance in the d-axis direction is X, 0.2 ≦ Y / X ≦ 0.3 is satisfied.

  According to the first aspect of the present invention, the flux barrier is formed between the inner peripheral ends of the pair of V-shaped permanent magnets in the rotor core. The flux barrier protrudes in the d-axis direction from the inner peripheral end of the gap-side magnetic pole surface of the permanent magnet. When the pop-out amount is Y and the distance in the d-axis direction between both ends of the gap side magnetic pole surface is X, 0.2 ≦ Y / X ≦ 0.3 is satisfied. Therefore, the leakage flux of the permanent magnet can be lengthened to increase the magnetic resistance to reduce the leakage flux, thereby improving the torque performance.

  As described in claim 2, in the magnet-embedded rotary electric machine according to claim 1, the protruding portion of the flux barrier may have a surface whose angle with respect to the gap-side magnetic pole surface is 90 ± 15 °.

  As described in claim 3, in the magnet-embedded rotary electric machine according to claim 1 or 2, the rotor has a pair of V-shaped permanent magnets arranged in two layers in a radial direction per pole. The flux barrier is preferably formed at least on the pair of V-shaped permanent magnets on the outer peripheral side.

  As described in claim 4, in the magnet-embedded rotating electrical machine according to claim 3, the permanent magnets adjacent to each other in the path of the d-axis magnetic flux in the pair of V-shaped permanent magnets arranged in the two layers. About the length of the inner peripheral side permanent magnet is longer than the length of the outer peripheral side permanent magnet, and the length of the flux barrier formed at the inner peripheral end of the outer peripheral side short magnet is shorter at the outer peripheral end. It may be longer than the length of the flux barrier.

  The magnetic pole surface of the long permanent magnet in the flux barrier formed in the inner peripheral end of the permanent magnet with a short length in the magnet-embedded rotating electrical machine according to claim 4, as in claim 5. It is preferable that the surface opposite to be parallel to the magnetic pole surface of the long permanent magnet.

  According to the present invention, the leakage flux of the permanent magnet can be reduced and the torque characteristics can be improved.

The schematic diagram of the rotary electric machine in embodiment. The partial expansion schematic diagram of a rotary electric machine. The partial expansion schematic diagram of a rotary electric machine. The figure which shows the measurement result of a torque. The figure which shows a torque measurement result. The schematic diagram of the rotary electric machine of another example. The schematic diagram of the rotary electric machine of another example. The schematic diagram of the rotary electric machine for a comparison.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the magnet-embedded rotating electrical machine 10 includes a stator (stator) 20 around which a coil 21 is wound and a permanent magnet embedded magnet rotor (rotor) 30. A stator 20 is disposed on the outer peripheral side of a cylindrical permanent magnet embedded magnet rotor core 40 having a cylindrical shape. The inner peripheral surface of the stator 20 faces the outer peripheral surface of the permanent magnet embedded magnet rotor core 40 with a gap G therebetween. Each figure is a schematic diagram, and the shape is emphasized. The magnet-embedded rotating electrical machine 10 has “8” poles.

  In the stator 20, the stator core 22 has a cylindrical shape, and a plurality of slots 23 are formed in the stator core 22 in the circumferential direction. Each slot 23 opens to the inner peripheral surface. Teeth 24 is formed between the slots 23. The stator 20 has “6” slots per pole (the number of teeth per pole is “6”), and the angle from the center per pole is 45 °. A coil (winding) 21 is wound around the teeth 24 provided at equal intervals.

  The permanent magnet embedded magnet rotor 30 is arranged inside the stator 20, and the permanent magnet embedded magnet rotor core 40 is configured by laminating a plurality of (for example, several tens) electromagnetic disk-shaped steel plates. ing. A shaft 50 is inserted through the center of the rotor core 40. The permanent magnet embedded magnet rotor 30 is rotatably supported by a bearing of a housing (not shown) via a shaft 50 in a state where the outer peripheral surface of the rotor core 40 is spaced from the teeth 24 by a predetermined distance.

Thus, the rotor 30 is disposed such that the outer peripheral surface of the cylindrical rotor core 40 faces the inner peripheral side of the stator 20 via the gap G.
As shown in FIG. 2, permanent magnet embedded holes 40a, 40b, 40c, and 40d are formed in the permanent magnet embedded magnet rotor core 40, and the permanent magnet embedded holes 40a, 40b, 40c, and 40d extend in the axial direction. ing. Permanent magnets 60, 61, 70, 71 are inserted into the permanent magnet embedded holes 40a, 40b, 40c, 40d. Specifically, in the embedded permanent magnet rotor core 40, two pairs of permanent magnets (60 and 61, 70 and 71) per pole are embedded in a V shape in the circumferential direction. Each permanent magnet 60, 61, 70, 71 is formed in a flat plate shape having a rectangular cross section, and is magnetized in the thickness direction. Two pairs of permanent magnets (60 and 61, 70 and 71) are V-shaped spreading toward the outer peripheral side of the rotor core 40 and are arranged so that the same side (for example, the outer peripheral side of the rotor) has the same polarity. .

  The permanent magnets arranged in adjacent regions (one pole) are arranged so that the outer peripheral side of the rotor 30 has a different polarity. For example, when the permanent magnets 60, 61, 70, 71 shown in FIG. 2 are arranged so that the teeth 24 side is an N pole, the permanent magnets arranged in the adjacent region (one pole) are S on the teeth 24 side. Arranged to be poles.

  In this manner, the rotor 30 is embedded in a V shape so that a pair of permanent magnets 60 and 61 and a pair of permanent magnets 70 and 71 per one pole spread in the circumferential direction of the rotor core 40. More specifically, the rotor 30 has a pair of V-shaped permanent magnets 60 and 61 and a pair of permanent magnets 70 and 71 arranged in two layers in the radial direction per pole. Further, the rotor 30 is symmetrical with respect to the d-axis per pole.

  Regarding the pair of permanent magnets 60, 61 and the pair of permanent magnets 70, 71, the permanent magnet 60 and the permanent magnet 70 have surfaces 60g, 70g perpendicular to the magnetic pole surface of the permanent magnet in a straight line. That is, the gap side ends of the pair of permanent magnets 60 and 70 are aligned. Similarly, the permanent magnet 61 and the permanent magnet 71 have surfaces 61g and 71g perpendicular to the magnetic pole surface of the permanent magnet in a straight line. That is, the gap side end portions of the pair of permanent magnets 61 and 71 are aligned.

  As shown in FIGS. 2 and 3, flux barriers 62 and 63 are disposed between the inner peripheral ends of a pair of V-shaped permanent magnets 60 and 61 in the rotor core 40 on the d-axis side (inner periphery) of the permanent magnet embedded holes 40a and 40b. Side) is formed in a continuous state. The flux barriers 62 and 63 extend in the axial direction. The flux barriers 62 and 63 are pentagonal. The flux barriers 62 and 63 protrude in the d-axis direction from the inner peripheral end portion P1 of the gap-side magnetic pole surfaces 60a and 61a of the permanent magnets 60 and 61, the amount of protrusion is Y, and both end portions of the gap-side magnetic pole surfaces 60a and 61a. When the distance in the d-axis direction between P1 and P2 is X, 0.2 ≦ Y / X ≦ 0.3 is satisfied. Since the flux barriers 62 and 63 are formed independently, a bridge is formed between the flux barriers 62 and 63 so that the strength of the rotor core 40 is maintained.

The protruding portions of the flux barriers 62 and 63 have surfaces 62a and 63a having an angle θ1 of 90 ± 15 ° with respect to the gap-side magnetic pole surfaces 60a and 61a.
Flux barriers 64, 65 are formed at the outer peripheral ends of a pair of V-shaped permanent magnets 60, 61 in the rotor core 40 in a state of being continuous with the q-axis side (outer peripheral side) ends of the permanent magnet embedded holes 40 a, 40 b. ing. The flux barriers 64 and 65 extend in the axial direction. The flux barriers 64 and 65 are rectangular.

  Between the inner peripheral ends of the pair of V-shaped permanent magnets 70 and 71 in the rotor core 40, the flux barriers 72 and 73 are continuous with the end on the d-axis side (inner peripheral side) of the permanent magnet embedded holes 40c and 40d. A flux barrier 74 is formed between the flux barriers 72 and 73. The flux barriers 72, 73, 74 extend in the axial direction. The flux barriers 72 and 73 are formed in polygons, and the flux barrier 74 has a rectangular shape. In addition, flux barriers 75 and 76 are continuous with the q-axis side (outer peripheral side) ends of the permanent magnet embedded holes 40c and 40d at the outer peripheral ends of the pair of V-shaped permanent magnets 70 and 71 in the rotor core 40. Is formed. The flux barriers 75 and 76 extend in the axial direction. The flux barriers 75 and 76 are rectangular.

  In the rotor 30, a pair of V-shaped permanent magnets are arranged in two layers in the radial direction per pole, but at least a pair of V-shaped permanent magnets 60, 61 on the outer peripheral side have flux barriers 62, 63. Is formed.

  As shown in FIG. 2, the permanent magnets 60 and 70 and the permanent magnets 61 and 71 adjacent to each other in the path of the d-axis magnetic flux φ12 in the pair of V-shaped permanent magnets arranged in two layers are as shown in FIG. Further, the length L2 of the inner peripheral side permanent magnets 70, 71 is longer than the length L1 of the outer peripheral side permanent magnets 60, 61.

  Further, the length L3 of the flux barriers 62, 63 formed at the inner peripheral ends of the outer peripheral permanent magnets 60, 61 having a short length is longer than the length L4 of the flux barriers 64, 65 formed at the outer peripheral ends. Yes.

  As shown in FIGS. 1 and 2, the flux barriers 62 and 63 formed at the inner peripheral ends of the short permanent magnets 60 and 61 are opposed to the magnetic pole surfaces 70a and 71a of the long permanent magnets 70 and 71, respectively. The surfaces 62b and 63b are parallel to the magnetic pole surfaces 70a and 71a of the long permanent magnets 70 and 71, respectively.

Next, the operation of the rotating electrical machine 10 configured as described above will be described.
When the rotating electrical machine is driven, a three-phase current is supplied to the coil 21 of the stator 20, a rotating magnetic field is generated in the stator 20, and the rotating magnetic field acts on the permanent magnet embedded magnet rotor 30. Then, the permanent magnet embedded magnet rotor 30 rotates in synchronization with the rotating magnetic field by the magnetic attractive force and repulsive force between the rotating magnetic field and the permanent magnets 60, 61, 70, 71. As shown in FIG. 2, a path of q-axis magnetic flux φ10 is formed on the outer peripheral side of the permanent magnets 60 and 61. Further, a path of q-axis magnetic flux φ11 is formed between the permanent magnet 60 and the permanent magnet 70 and between the permanent magnet 61 and the permanent magnet 71.

  Here, the flux barriers 62, 63 formed between the inner peripheral ends of the pair of V-shaped permanent magnets 60, 61 in the rotor core 40 are the inner peripheral ends of the gap-side magnetic pole surfaces 60 a, 61 a of the permanent magnets 60, 61. It protrudes from the part P1 in the d-axis direction. When the protrusion amount is Y and the distance in the d-axis direction between both ends P1 and P2 of the gap-side magnetic pole surfaces 60a and 61a is X, 0.2 ≦ Y / X ≦ 0.3 is satisfied. Thereby, torque characteristics can be improved.

  Next, torque will be described with reference to FIG. At this time, the present embodiment shown in FIG. 1 is compared with the comparative example shown in FIG. That is, in FIG. 1, the flux barriers 62 and 63 formed between the inner peripheral ends of the pair of V-shaped permanent magnets 60 and 61 in the rotor core 40 are formed on the gap-side magnetic pole surfaces 60a and 61a of the permanent magnets 60 and 61. It protrudes from the inner peripheral end P1 in the d-axis direction. On the other hand, in FIG. 8, the flux barriers 200 and 201 formed between the inner peripheral ends of the pair of V-shaped permanent magnets 60 and 61 in the rotor core 40 are the inner peripheral ends of the gap-side magnetic pole surfaces of the permanent magnets 60 and 61. It does not protrude in the d-axis direction from the part. Therefore, the path of leakage flux φ100 is shorter than those in FIGS.

  In FIG. 4, the flux barriers 62 and 63 do not protrude in the case where the flux barriers 62 and 63 protrude in the d-axis direction from the inner peripheral ends P <b> 1 of the gap-side magnetic pole surfaces 60 a and 61 a of the permanent magnets 60 and 61. The measurement result of the torque about a case (comparative example) is shown. That is, FIG. 8 is a comparative example, and flux barriers 200 and 201 are formed between the inner peripheral ends of a pair of V-shaped permanent magnets 60 and 61 in the rotor core. The flux barriers 200 and 201 are permanent magnets. 3, the Y value in FIG. 3 is “0”.

  In FIG. 4, the case where the permanent magnets 60, 61 protrude in the d-axis direction from the inner peripheral ends P <b> 1 of the gap-side magnetic pole surfaces 60 a, 61 a (this embodiment) is the case where they do not protrude (comparative example). It can be seen that a larger torque is generated.

  Next, with reference to FIG. 5, the ratio Y / X between the protrusion amount Y of the flux barriers 62 and 63 and the distance X in the d-axis direction between both ends P1 and P2 of the gap-side magnetic pole surfaces 60a and 61a, and the torque The relationship will be described.

  In FIG. 5, the horizontal axis represents the ratio Y / X, and the vertical axis represents torque. When the ratio Y / X = 0, that is, when the flux barriers 62 and 63 do not protrude, the torque is shown as 1.0 (= 100%).

  In FIG. 5, the torque is a gentle quadratic curve convex upward with respect to the ratio Y / X, and its maximum value is around 0.24. Therefore, it can be seen that 0.2 ≦ Y / X ≦ 0.3 can make the torque near the maximum.

explain in detail.
As shown in FIG. 2, the magnetic flux (d-axis magnetic flux) φ12 of the permanent magnet itself deviates (leaks) from the normal path, and a leakage magnetic flux (self-short circuit component) φ1 is generated. The leakage flux φ1 passes through the bridge between the flux barriers 62 and 63, which is necessary for the strength of the rotor core 40.

  In the region Z1 of FIG. 5, it is possible to reduce the leakage flux, that is, the self-short circuit component, by increasing the pop-out amount Y and increasing the path length of the leakage flux φ1 to increase the magnetic resistance. On the other hand, if the pop-out amount Y is excessively increased in the region Z2 in FIG. 5, the flow of the q-axis magnetic flux φ10 on the outer peripheral side in FIG. Therefore, considering the balance with the q-axis magnetic flux φ10 on the outer peripheral side, the pop-out amount Y of the flux barriers 62 and 63 and the distance X in the d-axis direction between both ends P1 and P2 of the gap-side magnetic pole surfaces 60a and 61a The ratio Y / X is preferably 0.2 ≦ Y / X ≦ 0.3.

  Thus, high torque and high output can be achieved by reducing leakage magnetic flux. That is, the leakage magnetic flux of the outer peripheral side permanent magnets 60 and 61 can be reduced and the torque / output characteristics can be improved. At this time, there is no increase in cost without using an expensive material permanent magnet. Further, it is possible to reduce the size of the rotating electrical machine only by changing the shape of the flux barrier.

According to the above embodiment, the following effects can be obtained.
(1) Flux barriers 62 and 63 are formed between the inner peripheral ends of a pair of V-shaped permanent magnets 60 and 61 in the rotor core 40. The flux barriers 62 and 63 protrude in the d-axis direction from the inner peripheral ends P1 of the gap-side magnetic pole surfaces 60a and 61a of the permanent magnets 60 and 61. When the protrusion amount is Y and the distance in the d-axis direction between both ends P1 and P2 of the gap-side magnetic pole surfaces 60a and 61a is X, 0.2 ≦ Y / X ≦ 0.3 is satisfied. Therefore, the leakage flux can be reduced by increasing the path length of the leakage flux φ1 of the permanent magnets 60 and 61 to increase the magnetic resistance, thereby improving the torque performance.

  (2) Since the protruding portions of the flux barriers 62 and 63 have the surfaces 62a and 63a having an angle θ1 of 90 ± 15 ° with respect to the gap-side magnetic pole surfaces 60a and 61a, the flow of the q-axis magnetic flux φ10 on the outer periphery is hardly obstructed. Further, the path length of the leakage flux φ1 can be increased and the path width of the magnetic flux from the permanent magnets 60 and 61 can be ensured.

  (3) The rotor 30 has a pair of V-shaped permanent magnets (60, 61, 70, 71) arranged in two layers in the radial direction per pole, and at least a pair of V-shaped magnets on the outer peripheral side. Since the flux barriers 62 and 63 are formed on the permanent magnets 60 and 61, the torque characteristics can be improved.

  (4) The inner peripheral side of the adjacent permanent magnets (60, 70, 61, 71) in the path of the d-axis magnetic flux in the pair of V-shaped permanent magnets (60, 61, 70, 71) arranged in two layers The length L2 of the permanent magnets 70 and 71 is longer than the length L1 of the permanent magnets 60 and 61 on the outer peripheral side. The length L3 of the flux barriers 62, 63 formed at the inner peripheral ends of the outer peripheral permanent magnets 60, 61 having a short length is longer than the length L4 of the flux barriers 64, 65 formed at the outer peripheral ends. As a result, the path length of the leakage magnetic flux φ1 can be increased, and the q-axis magnetic flux φ11 using the flux barriers 62 and 63 for the path of the q-axis magnetic flux φ11 in the permanent magnets (60, 70, 61, 71) having different lengths. It is possible to equalize the path widths.

  (5) In the flux barriers 62 and 63 formed at the inner peripheral ends of the short permanent magnets 60 and 61, the surfaces 62b and 63b facing the magnetic pole surfaces 70a and 71a of the long permanent magnets 70 and 71 are long. Since it is parallel to the magnetic pole surfaces 70a and 71a of the long permanent magnets 70 and 71, the flow of the q-axis magnetic flux φ11 is not hindered. That is, the path length of the leakage flux φ1 can be increased and the flow of the q-axis flux φ11 can be prevented from being hindered.

The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIG. 6, the effect can be obtained by causing the flux barrier to jump out in the outer peripheral direction regardless of the shape of the flux barriers 100 and 101.

  As shown in FIG. 7, it has V-shaped permanent magnets 110 and 111 and flux barriers 112, 113, 114, 115, and 116. As described above, a three-layer structure or more may be used, and the flux barriers 62 and 63 may be provided between the pair of V-shaped permanent magnets 60 and 61 on the outermost periphery, and a part of them may be protruded.

  Although FIG. 1 shows a two-layer structure and FIG. 7 shows a three-layer structure, a one-layer structure may be used, and flux barriers 62 and 63 are provided between a pair of V-shaped permanent magnets 60 and 61, and a part thereof Should just pop out.

  DESCRIPTION OF SYMBOLS 10 ... Magnet-embedded rotary electric machine, 20 ... Stator, 21 ... Coil, 30 ... Rotor, 40 ... Rotor core, 60 ... Permanent magnet, 60a ... Gap side magnetic pole surface, 61 ... Permanent magnet, 61a ... Gap side magnetic pole surface, 62 ... flux barrier, 62a ... face, 63 ... flux barrier, 63a ... face, 64 ... flux barrier, 65 ... flux barrier, 70 ... permanent magnet, 71 ... permanent magnet, G ... gap, P1 ... inner peripheral end, [theta] 1 ... angle.

Claims (5)

A stator wound with a coil;
The outer circumferential surface of the cylindrical rotor core is arranged so as to face the inner circumferential side of the stator via a gap, and a pair of permanent magnets per pole in the circumferential direction of the rotor core is V-shaped so as to spread on the outer circumferential side. An embedded rotor,
In a magnet-embedded rotary electric machine with
A flux barrier is formed between the inner peripheral ends of the pair of V-shaped permanent magnets in the rotor core, and the flux barrier protrudes in the d-axis direction from the inner peripheral end of the gap-side magnetic pole surface of the permanent magnet, The magnetic embedding is characterized in that 0.2 ≦ Y / X ≦ 0.3 is satisfied, where Y is the amount of protrusion and X is the distance in the d-axis direction between both ends of the gap-side magnetic pole surface. Built-in rotary electric machine.   2. The magnet-embedded rotating electrical machine according to claim 1, wherein the protruding portion of the flux barrier has a surface with an angle of 90 ± 15 ° with respect to the gap-side magnetic pole surface.   The rotor has a pair of V-shaped permanent magnets arranged in two layers in a radial direction per pole, and the flux barrier is formed at least on the pair of V-shaped permanent magnets on the outer peripheral side. The magnet-embedded rotary electric machine according to claim 1, wherein the magnet-embedded rotary electric machine is provided.   For the permanent magnets adjacent to each other in the path of the d-axis magnetic flux in the pair of V-shaped permanent magnets arranged in the two layers, the length of the inner permanent magnet is longer than the length of the outer permanent magnet, 4. The magnet-embedded rotation according to claim 3, wherein the length of the flux barrier formed at the inner peripheral end of the outer peripheral permanent magnet having a short length is longer than the length of the flux barrier formed at the outer peripheral end. Electric.   A surface of the flux barrier formed at the inner peripheral end of the short permanent magnet that faces the magnetic pole surface of the long permanent magnet is parallel to the magnetic pole surface of the long permanent magnet. The magnet-embedded rotary electric machine according to claim 4.