WO2018101160A1

WO2018101160A1 - Magnet unit

Info

Publication number: WO2018101160A1
Application number: PCT/JP2017/042174
Authority: WO
Inventors: 池本正幸; 宮路剛; 津田哲平
Original assignee: アイシン・エィ・ダブリュ株式会社; アイシン精機株式会社
Priority date: 2016-11-30
Filing date: 2017-11-24
Publication date: 2018-06-07

Abstract

A magnet unit (30) is provided with a first permanent magnet (41), and a second permanent magnet having a lower residual magnetic flux density than that of the first permanent magnet (41). The first permanent magnet (41) and the second permanent magnet (42) are placed aligned in a target direction (D) that is orthogonal to both an axial direction (L) and a magnetization direction (M) so that the respective magnetization directions (M) thereof are oriented facing the same side. A facing surface (51) of the first permanent magnet (41) and the second permanent magnet (42) has a first inclined surface (61) that faces a target direction first side (D1) in accordance with facing an axial direction first side (L1).

Description

Magnet unit

The present invention relates to a magnet unit used for a rotor for a rotating electrical machine.

As an example of a magnet unit used in a rotor for a rotating electrical machine, one described in JP-A-2015-115985 (Patent Document 1) is known. Patent Document 1 discloses a permanent magnet (2) used for a rotor core (1) having a step skew structure. Specifically, the rotor core (1) of Patent Document 1 is divided into a plurality of blocks in the axial direction, and a stage skew structure is formed by disposing each block in the circumferential direction. . And the permanent magnet (2) is divided | segmented into the axial direction by the same number as the division | segmentation number of the axial direction of a rotor core (1). By adopting such a step skew structure, it is possible to reduce cogging torque and torque ripple.

However, in the configuration described in Patent Document 1, a plurality of permanent magnets arranged in the axial direction are arranged so as to be gradually shifted in the circumferential direction for each of a plurality of blocks. Therefore, the effect of suppressing a rapid change in the magnetic flux density distribution formed in the air gap between the rotor core and the stator core is limited, and it is difficult to greatly reduce cogging torque and torque ripple.

JP2015-115985A

Therefore, it is desired to realize a magnet unit that can further reduce cogging torque and torque ripple.

In view of the above, a first feature of a magnet unit that is used in a rotor for a rotating electrical machine having a rotor core in which magnet insertion holes extending in the axial direction are formed at a plurality of positions in the circumferential direction is inserted into one magnet insertion hole. The configuration includes a first permanent magnet and a second permanent magnet having a residual magnetic flux density lower than that of the first permanent magnet, and the first permanent magnet and the second permanent magnet have the same magnetization direction. So that one side of the axial direction is the first side in the axial direction and one side of the target direction is the first in the target direction As a side, the opposing surfaces of the first permanent magnet and the second permanent magnet have a first inclined surface that goes toward the first direction in the target direction toward the first side in the axial direction.

According to the first characteristic configuration, the opposed surfaces of the first permanent magnet and the second permanent magnet have the first inclined surface inclined with respect to the axial direction. Therefore, even when the magnet unit is formed so as to extend parallel to the axial direction as a whole, the position in the target direction where the density of the magnetic flux generated from the magnet unit is the highest is the axial direction of the first inclined surface. In the formation region, it can be configured to move toward the first direction in the target direction toward the first side in the axial direction, and a continuous skew structure can be realized with a single magnet unit. In addition, according to the first characteristic configuration, since the second permanent magnet is arranged in the space where the first permanent magnet in the magnet insertion hole is not arranged, compared to the case where the second permanent magnet is not arranged in the space. Thus, it is easy to suppress a sudden change in the magnetic flux density distribution formed in the air gap between the rotor core and the stator core. From the above, according to the first characteristic configuration, a magnet unit capable of further reducing cogging torque and torque ripple can be realized.

In view of the above, the second feature of the magnet unit that is used in a rotor for a rotating electrical machine having a rotor core in which magnet insertion holes extending in the axial direction are formed at a plurality of positions in the circumferential direction is inserted into one magnet insertion hole. The configuration includes a magnet body including at least a first permanent magnet, and a second permanent magnet having a residual magnetic flux density lower than that of the first permanent magnet, and the magnet body and the second permanent magnet have respective magnetization directions. Are arranged side by side in a target direction orthogonal to both the axial direction and the magnetization direction, and the magnet body and the second permanent magnet each have a width in the magnetization direction in the axial direction. The width in the target direction of one of the magnet body and the second permanent magnet increases toward the first axial direction. And the magnet body The other of the target width of the fine said second permanent magnet is that is decreasing toward the axially first side.

According to said 2nd characteristic structure, the width | variety of one object direction is the axial direction 1st in the magnet body in which the 1st permanent magnet whose residual magnetic flux density is higher than a 2nd permanent magnet is contained, and a 2nd permanent magnet. It arrange | positions so that it may increase as it goes to the side and the width | variety of the other object direction decreases as it goes to the axial direction 1st side. Therefore, even when the magnet unit is formed so as to extend in parallel in the axial direction as a whole, the position in the target direction where the density of magnetic flux generated from the magnet unit is the highest is directed toward the first side in the axial direction. It can be set as the structure which moves to the one side of an object direction, and a continuous skew structure is realizable with a magnet unit single-piece | unit. In addition, according to the second feature configuration, since the second permanent magnet is disposed in a space where the magnet body in the magnet insertion hole is not disposed, compared to the case where the second permanent magnet is not disposed in the space, It is easy to suppress a sudden change in the magnetic flux density distribution formed in the air gap between the rotor core and the stator core. From the above, according to the second characteristic configuration, a magnet unit capable of further reducing cogging torque and torque ripple can be realized.

The figure which shows the rotary electric machine which concerns on 1st embodiment. Axial view of a part of the rotor according to the first embodiment Sectional drawing orthogonal to the axial direction of a part of the rotor according to the first embodiment The perspective view of the magnet unit which concerns on 1st embodiment Partial axial view of the rotor according to the second embodiment Sectional drawing orthogonal to the axial direction of a part of the rotor according to the second embodiment The perspective view of the magnet unit which concerns on 2nd embodiment. Side view of magnet unit according to other embodiment Side view of magnet unit according to other embodiment

[First embodiment]
A first embodiment of a magnet unit will be described with reference to the drawings (FIGS. 1 to 4). In the following description, “axial direction L”, “radial direction R”, and “circumferential direction C” are axes A of a rotor for a rotating electrical machine (hereinafter referred to as “rotor 2”) (see FIG. 1). Is defined as a standard. The axis A is a virtual axis, and the rotor 2 rotates about the axis A. As shown in FIG. 4, one side in the axial direction L is referred to as “first axial direction L1”, and the other side in the axial direction L (side opposite to the first axial direction L1) is referred to as “second axial direction. Side L2 ". One side in the circumferential direction C is referred to as a “circumferential first side C1”, and the other side in the circumferential direction C (a side opposite to the circumferential first side C1) is referred to as a “circumferential second side C2”. Further, as described later, a direction orthogonal to both the axial direction L and the magnetization direction M is defined as a target direction D (see FIG. 4). One side of the target direction D is set as “target direction first side D1”, and the other side of the target direction D (the side opposite to the target direction first side D1) is set as “target direction second side D2.”

Hereinafter, the magnet unit 30 will be described using each of the above directions, assuming that the magnet unit 30 is mounted on the rotor core 15 (the state shown in FIGS. 2 and 3). Further, in this specification, terms related to dimensions, arrangement direction, arrangement position, and the like are used as a concept including a state having a difference due to an error (an error that is acceptable in manufacturing).

The magnet unit 30 is used for the rotor 2. As will be described in detail later, as shown in FIGS. 2 and 3, the rotor 2 includes a rotor core 15 in which magnet insertion holes 20 extending in the axial direction L are formed at a plurality of positions in the circumferential direction C. 30 is inserted into one magnet insertion hole 20 (each of the magnet insertion holes 20). As shown in FIG. 1, the rotor 2 is a rotor for a rotating electrical machine, and is used for the rotating electrical machine 1 together with the stator 3. In the example shown in FIG. 1, the rotating electrical machine 1 is housed in a case 4, a stator core 10 that is a core of the stator 3 is fixed to the case 4 (here, the inner surface of the case 4), and the rotor 2 is attached to the case 4. On the other hand, it is rotatably supported. Specifically, the rotating electrical machine 1 includes a rotor shaft 6 that is rotatably supported with respect to the case 4 via a bearing 5, and a rotor core 15 that is a core of the rotor 2 rotates integrally with the rotor shaft 6. To be connected.

The rotor core 15 is disposed to face the stator core 10 in the radial direction R. In this embodiment, the rotating electrical machine 1 is an inner rotor type rotating electrical machine. In other words, in the present embodiment, the rotor 2 in which the magnet unit 30 is used is an inner rotor type rotor for a rotating electrical machine, and the rotor 2 is on the inner side in the radial direction R with respect to the diameter of the stator 3 (stator core 10). It is arranged at a position overlapping with the stator 3 (stator core 10) when viewed in the direction R. The rotating electrical machine 1 is a rotating field type rotating electrical machine, and a coil 13 is wound around the stator core 10. Then, the magnetic field generated from the stator 3 rotates the rotor 2 as a field. In this specification, “rotary electric machine” is used as a concept including a motor (electric motor), a generator (generator), and a motor / generator that performs both functions of the motor and the generator as necessary. Yes.

The rotor 2 has a rotor core 15 to which the magnet unit 30 is attached. As shown in FIGS. 2 and 3, magnet insertion holes 20 extending in the axial direction L are formed at a plurality of positions in the circumferential direction C in the rotor core 15 to which the magnet unit 30 is attached. The magnet unit 30 is inserted into one magnet insertion hole 20 (each of the magnet insertion holes 20). That is, one rotor core 15 is equipped with the same number of magnet units 30 as the magnet insertion holes 20 formed in the rotor core 15. The rotor 2 is a rotor used in a rotary electric machine (for example, a synchronous motor) having an embedded magnet structure, and the magnet insertion hole 20 has a shape that does not open in a direction orthogonal to the axial direction L (that is, viewed in the axial direction L). The shape is closed over the entire circumference). The rotor core 15 is formed, for example, by laminating a plurality of annular plate-like magnetic plates (for example, electromagnetic steel plates) in the axial direction L, or press-molding magnetic powder that is magnetic material powder. The green compact is formed as the main component.

The magnet insertion hole 20 is formed so as to penetrate the rotor core 15 in the axial direction L. As shown in FIG. 1, in this embodiment, the magnet insertion hole 20 is formed so as to extend parallel to the axial direction L. In the present embodiment, the magnet insertion hole 20 has a cross-sectional shape orthogonal to the axial direction L that is formed uniformly (uniformly) along the axial direction L. According to the shape of the magnet insertion hole 20, in this embodiment, the magnet unit 30 is disposed inside the magnet insertion hole 20 so as to extend in parallel with the axial direction L as a whole. And the cross-sectional shape orthogonal to the axial direction L of the whole magnet unit 30 is formed uniformly along the axial direction L.

Since the magnet insertion hole 20 is formed as described above, the center position S in the circumferential direction C is arranged along the axial direction L in the magnet insertion hole 20 in the present embodiment. Since the magnet insertion hole 20 is arranged at the same position in the radial direction R at each position in the axial direction L, the center position S in the circumferential direction C of the magnet insertion hole 20 is arranged along the axial direction L. Center positions of the magnet insertion hole 20 in both the circumferential direction C and the radial direction R are arranged along the axial direction L. In this specification, “arranged along the axial direction L” is not limited to being arranged parallel to the axial direction L, and is less than a predetermined angle with respect to the axial direction L (for example, less than 20 degrees). ) Is used as a concept including the case of being inclined. In the present embodiment, the magnet insertion hole 20 is arranged such that the center position S in the circumferential direction C is parallel to the axial direction L.

2 and 3, in the present embodiment, each of the magnetic poles P formed in the circumferential direction C is formed by one magnet unit 30. That is, in the present embodiment, the magnet unit 30 is inserted into the magnet insertion hole 20 disposed in the central portion of the magnetic pole P in the circumferential direction C. The center in the circumferential direction C of the magnetic pole P is a region in the circumferential direction C including the magnetic pole center Q, where the center in the circumferential direction C of the magnetic pole P is the magnetic pole center Q. The magnet unit 30 is inserted into each of the magnet insertion holes 20 formed in a plurality (the same number as the magnetic poles P) in the circumferential direction C so that two magnetic poles P adjacent in the circumferential direction C have opposite polarities. In the example shown in FIGS. 2 and 3, the magnet insertion hole 20 functions as a magnetic resistance (flux barrier) against the magnetic flux flowing inside the rotor core 15 in addition to the magnet arrangement region in which the magnet unit 30 is arranged. The region to be operated is provided on both sides in the circumferential direction C with respect to the magnet arrangement region.

As shown in FIGS. 2 and 3, in the present embodiment, the magnet insertion hole 20 (magnet arrangement region) is seen in the axial direction L, on both sides of the circumferential direction C from the magnetic pole center Q, and in the radial direction at the magnetic pole center Q. It is formed so as to extend linearly in a direction orthogonal to R (hereinafter referred to as “extending direction”). That is, the extending direction of the magnet insertion hole 20 coincides with the tangential direction at the magnetic pole center Q of the circle with the axis A as a reference when viewed in the axial direction L. In this embodiment, the magnet insertion hole 20 (magnet arrangement region) has a width in a direction orthogonal to both the axial direction L and the extending direction (a width in a direction parallel to the radial direction R at the magnetic pole center Q). Is uniformly formed along the extending direction. And this width | variety of the magnet insertion hole 20 (magnet arrangement | positioning area | region) is shorter than the width | variety of the said extension direction of the magnet insertion hole 20 (magnet arrangement | positioning area | region). That is, in this embodiment, the magnet insertion hole 20 (magnet arrangement region) is formed in a rectangular shape with a long side extending along the extending direction, with the cross-sectional shape orthogonal to the axial direction L.

Next, the configuration of the magnet unit 30 that is a main part of the present disclosure will be described. As shown in FIG. 4, the magnet unit 30 includes a first permanent magnet 41 and a second permanent magnet 42 having a residual magnetic flux density lower than that of the first permanent magnet 41. In the present embodiment, the magnet unit 30 further includes a third permanent magnet 43 having a residual magnetic flux density lower than that of the first permanent magnet 41. In the present embodiment, the third permanent magnet 43 has the same residual magnetic flux density as the second permanent magnet 42. As described above, the magnet unit 30 includes the magnet body 40 including at least the first permanent magnet 41 and the second permanent magnet 42 having a residual magnetic flux density lower than that of the first permanent magnet 41. In this embodiment, the magnet body 40 includes a third permanent magnet 43 in addition to the first permanent magnet 41. Thus, the magnet unit 30 is formed by a combination of a plurality of permanent magnets. As shown in FIG. 4, in the present embodiment, the entire shape of the magnet unit 30 is formed in a rectangular parallelepiped shape in accordance with the shape of the magnet insertion hole 20 (magnet arrangement region). The plurality of permanent magnets forming one magnet unit 30 are inserted into the magnet insertion hole 20 while being fixed to each other by an adhesive or the like, or are inserted into the magnet insertion hole 20 without being fixed to each other. The In the latter case, the relative positions of the plurality of permanent magnets inside the magnet insertion hole 20 are fixed directly or indirectly by an adhesive, a filler, or the like.

The plurality of permanent magnets included in the magnet unit 30 may be permanent magnets whose main components are the same as each other or permanent magnets whose main components are different from each other. When the plurality of permanent magnets included in the magnet unit 30 are the same as each other, for example, by adjusting the amount of additive element (for example, dysprosium) added to the main component, The residual magnetic flux densities can be made different from each other. In this case, for example, the first permanent magnet 41, the second permanent magnet 42, and the third permanent magnet 43 can all be rare earth magnets such as neodymium magnets. When the plurality of permanent magnets included in the magnet unit 30 are permanent magnets having different main components, for example, a rare earth magnet such as a neodymium magnet is used as the first permanent magnet 41, and the second permanent magnet 42 and the third permanent magnet 42 are used. A ferrite magnet can be used as the permanent magnet 43. In addition, as a permanent magnet which comprises the magnet unit 30, not a sintered magnet but a bond magnet, a rubber magnet, etc. can also be used. It is preferable to combine (use) an inexpensive magnet that is strong against a demagnetizing field.

As shown in FIG. 4, the first permanent magnet 41 and the second permanent magnet 42 are arranged in the target direction D orthogonal to both the axial direction L and the magnetization direction M so that the respective magnetization directions M face the same side. Be placed. Therefore, as shown in FIGS. 2 and 3, the first permanent magnet 41 and the second permanent magnet 42 included in one magnet unit 30 generate magnetic fluxes B in the same direction. In addition, the third permanent magnet 43 is the first permanent magnet 41 in the target direction D such that the magnetization direction M of the third permanent magnet 43 faces the same side as the magnetization direction M of the first permanent magnet 41. The two permanent magnets 42 are arranged side by side on the opposite side. That is, the second permanent magnet 42 is disposed on the first direction D1 in the target direction with respect to the first permanent magnet 41, and the third permanent magnet 43 is disposed on the second direction D2 in the target direction with respect to the first permanent magnet 41. . Therefore, as shown in FIG. 3, the first permanent magnet 41, the second permanent magnet 42, and the third permanent magnet 43 provided in one magnet unit 30 generate magnetic fluxes B in the same direction. Thus, the plurality of permanent magnets constituting the magnet body 40 (a plurality of permanent magnets including the first permanent magnet 41, and in the present embodiment, the first permanent magnet 41 and the third permanent magnet 43) Arranged in the target direction D so that the magnetization direction M faces the same side. That is, the magnetization direction M of the magnet body 40 is the common magnetization direction M between the plurality of permanent magnets constituting the magnet body 40. The magnet body 40 and the second permanent magnet 42 are arranged side by side in the target direction D so that the respective magnetization directions M face the same side. 2 is a view of a part of the rotor 2 as viewed from the second axial side L2, and FIG. 3 shows a sectional shape of a part of the rotor 2 at the central part in the axial direction L of the magnet unit 30. ing. As described above, the magnetization direction M is a common direction among the plurality of permanent magnets provided in one magnet unit 30. Hereinafter, the common magnetization direction M may be referred to as the magnetization direction M of the magnet unit 30. As shown in FIGS. 2 and 3, the magnet unit 30 is arranged so that the magnetization direction M of the magnet unit 30 faces the outside or the inside of the radial direction R.

Here, as shown in FIGS. 2 to 4, the opposing surface (the opposing surface in the target direction D) of the first permanent magnet 41 and the second permanent magnet 42 is a first opposing surface 51, A surface facing the third permanent magnet 43 (a surface facing the target direction D) is defined as a second facing surface 52. As shown in FIG. 4, the first facing surface 51 has a first inclined surface 61 that goes toward the target direction first side D <b> 1 as it goes toward the axial direction first side L <b> 1. In this embodiment, the 1st inclined surface 61 is made into the plane which goes to the object direction 1st side D1 by a fixed ratio as it goes to the axial direction 1st side L1. Therefore, the first inclined surface 61 is formed in a straight line shape toward the first direction D1 in the target direction as viewed from the magnetization direction M of the magnet unit 30 toward the first side L1 in the axial direction. In the present embodiment, the entire first facing surface 51 is the first inclined surface 61. In addition, the second facing surface 52 is an inclined surface (third inclined surface 63) that faces the first direction D1 in the target direction toward the first axial direction L1 in the region in the axial direction L where the first inclined surface 61 is formed. )have. In this embodiment, the 3rd inclined surface 63 is made into the plane which goes to the object direction 1st side D1 by a fixed ratio as it goes to the axial direction 1st side L1. Therefore, the third inclined surface 63 is formed in a straight line shape toward the first direction D1 in the target direction as it goes toward the first side L1 in the axial direction when viewed in the magnetization direction M of the magnet unit 30. The third inclined surface 63 is formed in parallel with the first inclined surface 61. In the present embodiment, the entire second facing surface 52 is a third inclined surface 63.

As described above, the entire shape of the magnet unit 30 is formed in a rectangular parallelepiped shape. Therefore, the end surfaces on both sides in the target direction D of the magnet unit 30 are formed in a planar shape along a plane orthogonal to the target direction D, unlike the first inclined surface 61 and the third inclined surface 63. In this embodiment, the end surface of the target direction first side D1 of the magnet unit 30 is formed by the end surface of the second permanent magnet 42 on the first direction D1 in the target direction. In the present embodiment, the end surface on the second direction D2 in the target direction of the magnet unit 30 is formed by the end surface on the second direction D2 in the target direction of the third permanent magnet 43.

As shown in FIG. 4, in the present embodiment, the first permanent magnet 41 is formed so that the width in the target direction D is uniform along the axial direction L. Here, the end surface on the first direction D1 in the target direction of the first permanent magnet 41 is formed in a planar shape that forms the first inclined surface 61, and the end surface on the second direction D2 in the target direction of the first permanent magnet 41 is The three inclined surfaces 63 are formed in a planar shape. That is, the first permanent magnet 41 is formed in a parallelogram shape when viewed in the magnetization direction M. In the present embodiment, the first permanent magnet 41 is formed such that the width of the magnetization direction M is uniform along the target direction D and the axial direction L.

The second permanent magnet 42 is formed to have the same length in the axial direction L as the first permanent magnet 41. The width in the target direction D of the second permanent magnet 42 is equal to the width in the target direction D of the first permanent magnet 41 at the end portion on the second axial side L2, and zero at the end portion on the first axial side L1. It is formed to become. Here, the end surface of the target direction first side D1 of the second permanent magnet 42 is formed in a planar shape along a surface orthogonal to the target direction D, and the end surface of the second permanent magnet 42 on the target direction second side D2 is The first inclined surface 61 is formed in a planar shape. That is, the second permanent magnet 42 is formed in a right triangle shape with the first facing surface 51 (first inclined surface 61) as the hypotenuse as viewed in the magnetization direction M. In the present embodiment, the second permanent magnet 42 is formed such that the width in the magnetization direction M is equal to the width in the magnetization direction M of the first permanent magnet 41 (the width in the magnetization direction M of the magnet body 40). And uniformly formed along the target direction D and the axial direction L. Thus, the second permanent magnet 42 is formed so that the width of the magnetization direction M is uniform along the axial direction L.

The third permanent magnet 43 is formed to have the same length in the axial direction L as the first permanent magnet 41. The width of the third permanent magnet 43 in the target direction D becomes zero at the end portion on the second axial side L2, and the width of the first permanent magnet 41 in the target direction D at the end portion on the first axial side L1. It is formed to be equal. Here, the end surface of the target direction first side D1 of the third permanent magnet 43 is formed in a planar shape that forms the third inclined surface 63, and the end surface of the third permanent magnet 43 on the target direction second side D2 is the target. It is formed in a planar shape along a plane orthogonal to the direction D. That is, when viewed in the magnetization direction M, the third permanent magnet 43 is formed in a right triangle shape in which the second facing surface 52 (third inclined surface 63) is a hypotenuse. In the present embodiment, the third permanent magnet 43 is formed so that the width in the magnetization direction M is equal to the width in the magnetization direction M of the first permanent magnet 41, and along the target direction D and the axial direction L. It is formed uniformly. That is, the magnet body 40 formed by the first permanent magnet 41 and the third permanent magnet 43 is formed so that the width of the magnetization direction M is uniform along the axial direction L. Further, the magnet body 40 is formed so that the width of the magnetization direction M is uniform along the target direction D. The third permanent magnet 43 has a shape obtained by inverting the second permanent magnet 42 in the axial direction L (a shape in which the direction of the axial direction L is changed).

As shown in FIG. 4, in the present embodiment, the first permanent magnet 41, the second permanent magnet 42, and the third permanent magnet 43 configured as described above are combined to form a rectangular parallelepiped (flat plate) magnet as a whole. A unit 30 is formed. That is, the first permanent magnet 41, the second permanent magnet 42, and the third permanent magnet 43 that constitute one magnet unit 30 are the sum of the widths in the target direction D in each cross section (cross section orthogonal to the axial direction L). Is formed to be uniform along the axial direction L. In other words, the sum of the widths in the target direction D of the magnet body 40 and the second permanent magnet 42 constituting one magnet unit 30 is the same in the entire region in the axial direction L. And as shown in FIG. 4, the width | variety of the object direction D of the 2nd permanent magnet 42 is decreasing (it decreases at a fixed ratio here) toward the axial direction 1st side L1. Therefore, the width in the target direction D of the magnet body 40 increases at the same rate as the decreasing rate of the width in the target direction D of the second permanent magnet 42 toward the first axial side L1. In the present embodiment, the width of the first permanent magnet 41 in the target direction D is the same in the entire area in the axial direction L, and the width of the third permanent magnet 43 in the target direction D is on the first axial direction L1. The width in the target direction D of the magnet body 40, which is the sum of the width of the target direction D of the first permanent magnet 41 and the width of the target direction D of the third permanent magnet 43, increases as it goes toward the first direction in the axial direction. Increasing toward L1. Thus, in the present embodiment, the width in the target direction D of one of the magnet body 40 and the second permanent magnet 42 (magnet body 40 in the present embodiment) is the first side in the axial direction in the entire region in the axial direction L. The width in the target direction D of the other of the magnet body 40 and the second permanent magnet 42 (in the present embodiment, the second permanent magnet 42) decreases toward the first axial side L1. Yes.

2 and 3, in the state where the magnet unit 30 is arranged in the magnet insertion hole 20, the center in the arrangement region of the first permanent magnet 41 in the target direction D coincides with the magnetic pole center Q. In the present embodiment, the position in the target direction D of the end portion on the second side L2 in the axial direction of the first opposing surface 51 (first inclined surface 61) is the axial direction of the second opposing surface 52 (third inclined surface 63). It is equal to the position in the target direction D at the end of the first side L1. That is, in this embodiment, the center in the arrangement region of the first permanent magnet 41 in the target direction D is the target direction D of the end portion on the second axial side L2 of the first facing surface 51 (first inclined surface 61). 2, the position of the first facing surface 51 in the target direction D (see FIG. 4) coincides with the magnetic pole center Q at the end on the second axial side L2.

As a result of the magnet unit 30 being arranged in the magnet insertion hole 20 as described above, the first permanent magnet 41 has a plurality of magnetic poles of the rotor 2 more than the second permanent magnet 42 in at least a partial region in the axial direction L. It arrange | positions at the center side (namely, magnetic pole center Q side) of the circumferential direction C in each of P. In the present embodiment, the first permanent magnet 41 is disposed closer to the magnetic pole center Q than the second permanent magnet 42 in the entire region in the axial direction L excluding the end portion on the second axial side L2. Further, in at least a part of the region in the axial direction L, the first permanent magnet 41 is more central than the third permanent magnet 43 in the circumferential direction C in each of the plurality of magnetic poles P of the rotor 2 (that is, the magnetic pole center Q Is arranged on the side). In the present embodiment, the first permanent magnet 41 is disposed closer to the magnetic pole center Q than the third permanent magnet 43 in the entire region in the axial direction L excluding the end portion on the first axial side L1.

In the magnet unit 30 configured as described above, the density of the magnetic flux B generated from the magnet unit 30 in each cross section (cross section orthogonal to the axial direction L) is the first permanent magnet 41 as shown in FIGS. Becomes the highest at the position in the target direction D (position in the circumferential direction C). And since the center position (center position of the circumferential direction C) of the object direction D of the 1st permanent magnet 41 goes to the object direction 1st side D1 (circumferential direction 2nd side C2) as it goes to the axial direction 1st side L1. The position where the magnetic flux density is highest in each cross section of the magnet unit 30 moves to the target direction first side D1 (circumferential second side C2) as it goes to the first axial direction L1 (here, continuously moving). To do). And in this embodiment, since the center in the arrangement | positioning area | region of the target direction D of the 1st permanent magnet 41 corresponds with the magnetic pole center Q as mentioned above, the position where the magnetic flux density in each cross section of the magnet unit 30 becomes the highest is The magnetic pole center from the position in the target direction second side D2 (circumferential first side C1) with respect to the magnetic pole center Q through the magnetic pole center Q (see FIG. 3) as it goes toward the first axial direction L1. It moves to the position of the object direction first side D1 (circumferential direction second side C2) rather than Q (here, it moves continuously). That is, it is possible to realize a skew structure in which the position where the magnetic flux density is highest extends in a direction inclined with respect to the axial direction L. As a result, it is possible to reduce cogging torque, torque ripple, iron loss, and the like. It is possible.

Furthermore, in the present embodiment, the second permanent magnet 42 having a lower residual magnetic flux density than the first permanent magnet 41 is disposed on the first direction D1 (circumferential second side C2) in the target direction with respect to the first permanent magnet 41. In addition, the third permanent magnet 43 having a lower residual magnetic flux density than the first permanent magnet 41 is disposed on the second direction D2 in the target direction (circumferential first side C1) with respect to the first permanent magnet 41. That is, permanent magnets (42, 43) having a residual magnetic flux density lower than that of the first permanent magnet 41 are arranged on both sides in the target direction D (both sides in the circumferential direction C) with respect to the first permanent magnet 41. Therefore, compared with the case where the second permanent magnet 42 and the third permanent magnet 43 are not arranged, the magnetic flux density distribution formed in the air gap between the rotor core 15 and the stator core 10 is rapidly increased along the circumferential direction C. Can be suppressed (that is, harmonic components included in the magnetic flux density distribution can be reduced). As a result, it is possible to further reduce cogging torque, torque ripple, iron loss, and the like. Moreover, compared with the case where the 2nd permanent magnet 42 and the 3rd permanent magnet 43 are not arrange | positioned, the utilization factor of the space in the magnet insertion hole 20 can be raised, and the improvement of an output torque can also be aimed at.

Moreover, in this magnet unit 30, it is possible to use the thing of the shape continuous in the axial direction L as a permanent magnet (the 1st permanent magnet 41, the 2nd permanent magnet 42, etc.) which comprises the magnet unit 30, The rotor core 15 does not need to be divided into a plurality of stages in the axial direction L and arranged so as to be shifted in the circumferential direction C for each stage. Therefore, it is possible to realize the magnet unit 30 with few restrictions on the configuration of the rotor core 15 to be mounted while minimizing the increase in the number of parts required for realizing the skew structure.

[Second Embodiment]
A second embodiment of the magnet unit will be described with reference to FIGS. Below, the magnet unit of this embodiment is demonstrated centering on difference with 1st embodiment. The points not particularly specified are the same as those in the first embodiment, and the same reference numerals are assigned and detailed description is omitted.

As shown in FIGS. 5 and 6, in the present embodiment, each of the magnetic poles P formed in the circumferential direction C is formed by two magnet units 30 (a first magnet unit 31 and a second magnet unit 32 described later). It is formed. That is, in the present embodiment, the magnet unit 30 is inserted into each of the pair of magnet insertion holes 20 arranged on both sides of the center (magnetic pole center Q) of the magnetic pole P in the circumferential direction C. 5 is a view of a part of the rotor 2 as viewed from the second axial side L2, and FIG. 6 shows a sectional shape of a part of the rotor 2 at the central part in the axial direction L of the magnet unit 30. ing. Here, out of the pair of magnet insertion holes 20, the magnet insertion hole 20 disposed on the circumferential first side C <b> 1 is referred to as a first magnet insertion hole 21, and the magnet insertion hole 20 disposed on the circumferential second side C <b> 2. Is the second magnet insertion hole 22. The magnet unit 30 inserted into the first magnet insertion hole 21 is referred to as a first magnet unit 31, and the magnet unit 30 inserted into the second magnet insertion hole 22 is referred to as a second magnet unit 32.

As shown in FIGS. 5 and 6, the first magnet insertion hole 21 and the second magnet insertion hole 22 arranged on both sides in the circumferential direction C across the magnetic pole center Q are magnetic poles in a cross section orthogonal to the axial direction L. The line segments extending parallel to the radial direction R through the center Q are symmetrical to each other with the axis of symmetry as the axis of symmetry. Specifically, in the present embodiment, the first magnet insertion hole 21 and the second magnet insertion hole 22 are V-shaped so that the distance between the first magnet insertion hole 21 and the second magnet insertion hole 22 increases toward the outside in the radial direction R in the cross section orthogonal to the axial direction L. Arranged in a shape. And the 1st magnet unit 31 and the 2nd magnet unit 32 which form one magnetic pole P are arrange | positioned so that the magnetic pole surface of the mutually same polarity (N pole or S pole) may face the outer side of radial direction R. By adopting such an arrangement configuration of the magnet unit 30, in the rotating electrical machine 1 according to the present embodiment, in addition to the magnet torque generated by the interlinkage magnetic flux (coil interlinkage magnetic flux) by the magnet unit 30 (permanent magnet), The reluctance torque generated by the saliency (Ld <Lq) between the q-axis inductance (Lq) and the d-axis inductance (Ld) can also be used.

In the present embodiment, the magnet unit 30 (31, 32) includes the first permanent magnet 41 and the second permanent magnet 42, but does not include the third permanent magnet 43. That is, in this embodiment, the magnet unit 30 (31, 32) is formed by combining the first permanent magnet 41 and the second permanent magnet 42. In other words, in the present embodiment, the magnet body 40 includes only the first permanent magnet 41. As shown in FIG. 7, the first magnet unit 31 and the second magnet unit 32 are formed in a rectangular parallelepiped shape as a whole, like the magnet unit 30 according to the first embodiment.

Specifically, as shown in FIG. 7, the first permanent magnet 41 and the second permanent magnet 42 constituting one magnet unit 30 (31, 32) are each in a cross section (a cross section perpendicular to the axial direction L). The sum of the widths in the target direction D is uniform along the axial direction L. Specifically, each of the first permanent magnet 41 and the second permanent magnet 42 constituting one magnet unit 30 (31, 32) is seen in the magnetization direction M, and the first facing surface 51 (first inclined surface). 61) is formed in the shape of a right triangle that is the hypotenuse. That is, the second permanent magnet 42 has a shape obtained by inverting the first permanent magnet 41 in the axial direction L.

In the present embodiment, the end surface on one side of the target direction D of the first permanent magnet 41 is formed in a flat shape that forms the first inclined surface 61, and the end surface on the other side of the target direction D of the first permanent magnet 41 is , Formed in a planar shape along a plane orthogonal to the target direction D. Moreover, the end surface of the one side of the object direction D of the 2nd permanent magnet 42 is formed in the planar shape which forms the 1st inclined surface 61, and the end surface of the other side of the object direction D of the 2nd permanent magnet 42 is an object direction. It is formed in a planar shape along a plane orthogonal to D. In the first magnet unit 31, the width in the target direction D of the second permanent magnet 42, which is one of the magnet body 40 (first permanent magnet 41) and the second permanent magnet 42, is the axis in the entire region in the axial direction L. The width in the target direction D of the magnet body 40, which is the other of the magnet body 40 and the second permanent magnet 42, decreases toward the first axial side L1. On the other hand, in the second magnet unit 32, the width in the target direction D of the magnet body 40, which is one of the magnet body 40 (first permanent magnet 41) and the second permanent magnet 42, in the entire axial direction L is The width in the target direction D of the second permanent magnet 42, which is the other of the magnet body 40 and the second permanent magnet 42, decreases toward the first side L1 and decreases toward the first side L1 in the axial direction.

As shown in FIG. 7, for each of the first magnet unit 31 and the second magnet unit 32, the first permanent magnet 41 is a magnetic pole in the circumferential direction C rather than the second permanent magnet 42 in the entire area in the axial direction L. It is arranged on the center side of P (that is, on the side of the magnetic pole center Q). That is, the first magnet unit 31 is inserted into the first magnet insertion hole 21 in a direction in which the first permanent magnet 41 is closer to the magnetic pole center Q than the second permanent magnet 42, and the second magnet unit 32 is The permanent magnet 41 is inserted into the second magnet insertion hole 22 in a direction that is closer to the magnetic pole center Q than the second permanent magnet 42. And the 1st magnet unit 31 and the 2nd magnet unit 32 are the same side of the circumferential direction C as each 1st inclined surface 61 goes to the axial direction 1st side L1 (in the example shown in FIG. Arranged in the direction towards the second side C2).

By arranging the first magnet unit 31 and the second magnet unit 32 as described above, the magnetic flux density (first magnet unit) in each cross section (cross section orthogonal to the axial direction L) as shown in FIGS. The position where the magnetic flux density formed by both 31 and the second magnet unit 32 is the highest is from the position on the first circumferential side C1 with respect to the magnetic pole center Q toward the first axial side L1 (FIG. 5). Reference) Moves through the magnetic pole center Q (see FIG. 6) to the position on the second circumferential side C2 from the magnetic pole center Q (here, it moves continuously). Thereby, similarly to the first embodiment described above, it is possible to realize a skew structure in which the position where the magnetic flux density is highest extends in a direction inclined with respect to the axial direction L. As a result, the cogging torque can be reduced, It is possible to reduce torque ripple and iron loss.

Furthermore, in this embodiment, both the first magnet unit 31 and the second magnet unit 32 have a residual magnetic flux density higher than that of the first permanent magnet 41 on the side opposite to the magnetic pole center Q with respect to the first permanent magnet 41. A low second permanent magnet 42 is arranged. Therefore, compared with the case where the second permanent magnet 42 is not arranged, a rapid change along the circumferential direction C of the magnetic flux density distribution formed in the air gap between the rotor core 15 and the stator core 10 is suppressed. (In other words, it is possible to reduce the harmonic component included in the magnetic flux density distribution). As a result, it is possible to further reduce cogging torque, torque ripple, iron loss, and the like. Moreover, compared with the case where the 2nd permanent magnet 42 is not arrange | positioned, the utilization factor of the space in the magnet insertion hole 20 can be raised, and the improvement of output torque can also be aimed at.

[Other Embodiments]
Next, other embodiments of the magnet unit will be described.

(1) In the first and second embodiments, the configuration in which the entire first facing surface 51 is the first inclined surface 61 has been described as an example. However, the configuration is not limited to such a configuration, and the first facing surface 51 may have another surface in addition to the first inclined surface 61. For example, the second inclined surface 62 (see FIG. 8) is directed to the first direction D1 in the target direction as the first facing surface 51 moves to the second direction L2 in the axial direction at a position different from the first inclined surface 61 in the axial direction L. ). In such a configuration, the skew structure formed by the magnet unit 30 can be a V-shaped skew structure.

In the configuration of the first embodiment shown in FIG. 8, the first facing surface 51 is located at a different position in the axial direction L from the first inclined surface 61, and the first direction in the target direction toward the second axial direction L 2. The example comprised so that it might have the 2nd inclined surface 62 which goes to D1 is shown. In this example, the second facing surface 52 is directed to the second axial side L2 at a position different from the third inclined surface 63 in the axial direction L (a region in the axial direction L where the second inclined surface 62 is formed). Accordingly, the fourth inclined surface 64 toward the target direction first side D1 is provided. The fourth inclined surface 64 is formed in parallel with the second inclined surface 62. In this example, the first inclined surface 61 and the second inclined surface 62 are formed such that the moving amount (that is, the degree of inclination) in the target direction D with respect to the moving amount in the axial direction L is equal to each other. In the central portion in the direction L, the first inclined surface 61 and the second inclined surface 62 are connected. Similarly, in this example, the third inclined surface 63 and the fourth inclined surface 64 are connected in the central portion of the magnet unit 30 in the axial direction L. In this example, the second permanent magnet 42 is divided in the axial direction L into two second magnet portions 42a (magnet pieces).

In the first and second embodiments, in the entire area in the axial direction L, the width of one target direction D of the magnet body 40 and the second permanent magnet 42 increases toward the axial first side L1, and the magnet The width of the other target direction D of the body 40 and the second permanent magnet 42 has been described as an example in which the width decreases toward the first axial direction L1, but as in the example illustrated in FIG. Depending on the region, the tendency of the change in the width of the target direction D with respect to the movement toward the first axial direction L1 (the tendency to increase or decrease) may be different. That is, the width of one target direction D of the magnet body 40 and the second permanent magnet 42 is a first region that is a partial region of the axial direction L, and increases toward the first axial direction L1 and the shaft In the second region which is another partial region in the direction L, the width decreases in the other target direction D of the magnet body 40 and the second permanent magnet 42 in the first direction L1 in the axial direction. In the region, the distance decreases toward the first axial direction L1 and increases in the second region toward the first axial direction L1.

(2) In the first and second embodiments, the configuration in which the plurality of permanent magnets (41, 42, 43) constituting the magnet unit 30 are integrally formed has been described as an example. However, without being limited to such a configuration, at least one of the first permanent magnet 41, the second permanent magnet 42, and the third permanent magnet 43 may be formed by a set of a plurality of magnet pieces. For example, in the example of FIG. 8 described above, the second permanent magnet 42 is formed by an assembly of a plurality of magnet pieces (second magnet portions 42a). Further, for example, as in the example illustrated in FIG. 9, all of the first permanent magnet 41, the second permanent magnet 42, and the third permanent magnet 43 may be formed by a set of a plurality of magnet pieces. In the example of FIG. 8, the first permanent magnet 41 is formed by a set of four magnet pieces (first magnet portion 41a), and the second permanent magnet 42 is formed by a set of two magnet pieces (second magnet portion 42a). The third permanent magnet 43 is formed by a set of two magnet pieces (third magnet portion 43a).

(3) In said 1st embodiment, the 2nd opposing surface 52 goes to the object direction 1st side D1 toward the axial direction 1st side L1 in the area | region of the axial direction L in which the 1st inclined surface 61 is formed. The configuration having the inclined surface (the third inclined surface 63) is described as an example. However, without being limited to such a configuration, the second facing surface 52 is in the region in the axial direction L where the first inclined surface 61 is formed, and the target direction second side toward the first axial direction L1. A configuration having an inclined surface toward D2 is also possible.

(4) In the first embodiment, a case where one magnetic pole P is formed by one magnet unit 30 will be described as an example. In the second embodiment, one magnetic pole P has two magnet units 30. The case of forming by the above has been described as an example. However, without being limited to such a configuration, one magnetic pole P may be formed by three or more magnet units 30.

(5) In the first and second embodiments, the case where the magnet unit 30 is used in an inner rotor type rotor for a rotating electrical machine has been described as an example. However, the magnet unit 30 may be used for a rotor for an outer rotor type rotating electrical machine without being limited to such a configuration.

(6) It should be noted that the configuration disclosed in each of the above-described embodiments is applied in combination with the configuration disclosed in the other embodiment unless there is a contradiction (between the embodiments described as other embodiments. (Including combinations) is also possible. Regarding other configurations, the embodiments disclosed herein are merely examples in all respects. Accordingly, various modifications can be made as appropriate without departing from the spirit of the present disclosure.

[Overview of the above embodiment]
The outline of the magnet unit described above will be described below.

A magnet insertion hole (20) extending in the axial direction (L) is used in a rotating electrical machine rotor (2) having a rotor core (15) formed at a plurality of positions in the circumferential direction (C). 20) a magnet unit (30) inserted into the first permanent magnet (41) and a second permanent magnet (42) having a residual magnetic flux density lower than that of the first permanent magnet (41). The first permanent magnet (41) and the second permanent magnet (42) have both the axial direction (L) and the magnetization direction (M) so that the magnetization directions (M) face the same side. Are arranged side by side in a target direction (D) orthogonal to the first direction (L1) in one side of the axial direction (L) and the first side in the target direction (L1) of the target direction (D). D1), the first permanent magnet (41) and the second permanent magnet (42) Facing surfaces (51) has the first inclined surface toward the object direction the first side to the (D1) to (61) toward to the axial direction first side (L1).

According to this configuration, the opposing surface (51) between the first permanent magnet (41) and the second permanent magnet (42) has the first inclined surface (61) inclined with respect to the axial direction (L). Therefore, even when the magnet unit (30) is formed so as to extend parallel to the axial direction (L) as a whole, the target direction (D) in which the density of magnetic flux generated from the magnet unit (30) is the highest. In the axial direction (L) formation region of the first inclined surface (61), the position of the first direction (D1) moves toward the first direction (L1) in the axial direction. A continuous skew structure can be realized by a single magnet unit (30). In addition, according to the above configuration, since the second permanent magnet (42) is disposed in a space where the first permanent magnet (41) in the magnet insertion hole (20) is not disposed, the second permanent magnet is disposed in the space. Compared with the case where (42) is not arranged, it is easy to suppress a rapid change in the magnetic flux density distribution formed in the air gap between the rotor core (15) and the stator core (10). From the above, according to the above configuration, it is possible to realize the magnet unit (30) capable of further reducing the cogging torque and the torque ripple.

Here, in at least a part of the region in the axial direction (L), the first permanent magnet (41) has a plurality of magnetic poles of the rotating electrical machine rotor (2) rather than the second permanent magnet (42). It is preferable to adopt a configuration that is arranged on the center (Q) side in the circumferential direction (C) in each of (P).

According to this configuration, in consideration of the magnitude relationship of the residual magnetic flux density between the first permanent magnet (41) and the second permanent magnet (42), the rotor core (15) and the stator core (10) can be The magnetic flux density distribution formed in the air gap of the magnetic pole (P) has a peak at the central portion in the circumferential direction (C) of the magnetic pole (P) and gradually changes therefrom (for example, a distribution close to a sine wave). It becomes possible. As a result, the harmonic component contained in the magnetic flux density distribution can be reduced.

Further, the magnet unit (30) is inserted into the magnet insertion hole (20) disposed at the central portion in the circumferential direction (C) of the magnetic pole (P), and remains more than the first permanent magnet (41). The third permanent magnet (43) further includes a third permanent magnet (43) having a low magnetic flux density, and the magnetization direction (M) of the third permanent magnet (43) is the magnetization of the first permanent magnet (41). The first permanent magnet (41) is arranged side by side opposite to the second permanent magnet (42) in the target direction (D) so as to face the same side as the direction (M). The opposing surface (52) of the permanent magnet (41) and the third permanent magnet (43) is in the axial direction (L) where the first inclined surface (61) is formed. It has the inclined surface (63) which goes to the said target direction 1st side (D1) as it goes to the side (L1) It is preferable to have.

According to this configuration, the permanent magnets (42, 43) having a residual magnetic flux density lower than that of the first permanent magnet (41) are disposed on both sides of the target direction (D) with respect to the first permanent magnet (41). Therefore, an abrupt change in the magnetic flux density distribution formed in the air gap between the rotor core (15) and the stator core (10) is suppressed on both sides of the target direction (D) with respect to the first permanent magnet (41). be able to. Therefore, when the magnet unit (30) is inserted into the magnet insertion hole (20) disposed in the central portion of the magnetic pole (P) in the circumferential direction (C), the gap between the rotor core (15) and the stator core (10) is obtained. The magnetic flux density distribution formed in the air gap can be brought close to a sinusoidal distribution having a peak in the circumferential direction (C) where the first permanent magnet (41) is arranged. As a result, the magnetic flux density The harmonic component contained in the distribution can be further reduced.

A magnet unit (30) is inserted into each of the pair of magnet insertion holes (21, 22) arranged on both sides of the center (Q) of the magnetic pole (P) in the circumferential direction (C). In the whole axial direction (L), the first permanent magnet (41) is closer to the center (Q) side of the magnetic pole (P) in the circumferential direction (C) than the second permanent magnet (42). It is preferable that the configuration is arranged.

According to this configuration, in consideration of the magnitude relationship of the residual magnetic flux density between the first permanent magnet (41) and the second permanent magnet (42), the rotor core (15) and the stator core (10) can be A sudden change in the magnetic flux density distribution formed in the air gap can be suppressed on both sides in the circumferential direction (C) with respect to the center (Q) in the circumferential direction (C) of the magnetic pole (P). Therefore, when the magnet unit (30) is inserted into each of the pair of magnet insertion holes (21, 22) arranged on both sides across the center (Q) in the circumferential direction (C) of the magnetic pole (P). The magnetic flux density distribution formed in the air gap between the rotor core (15) and the stator core (10) can be approximated to a sinusoidal distribution, and as a result, the harmonic components contained in the magnetic flux density distribution can be reduced. More can be achieved.

The opposed surface (51) of the first permanent magnet (41) and the second permanent magnet (42) is different from the first inclined surface (61) in the axial direction (L). It is preferable to have a second inclined surface (62) heading toward the first direction (D1) in the target direction toward the second side (L2) in the axial direction opposite to the first side (L1) in the axial direction. It is.

According to this configuration, a V-shaped skew structure can be formed by the first inclined surface (61) and the second inclined surface (62). Thus, for example, by adjusting the V-shaped angle, a specific harmonic component included in the magnetic flux density distribution formed in the air gap between the rotor core (15) and the stator core (10) can be reduced. It becomes possible. In addition, for example, the axial direction (L) thrust that can be generated in the magnet unit (30) by providing the skew structure, the axial direction (L) formation region of the first inclined surface (61) and the second inclined surface ( 62) in the axial direction (L) formation region, the bearings (5) supporting the rotor core (15) can be prevented from being worn by the thrust load. .

A magnet insertion hole (20) extending in the axial direction (L) is used in a rotating electrical machine rotor (2) having a rotor core (15) formed at a plurality of positions in the circumferential direction (C). 20) a magnet unit (30) inserted into a magnet body (40) including at least a first permanent magnet (41), and a second permanent magnetic flux density lower than that of the first permanent magnet (41). A magnet (42), and the magnet body (40) and the second permanent magnet (42) have the axial direction (L) and the magnetization direction such that the respective magnetization directions (M) face the same side. The magnet body (40) and the second permanent magnet (42) are arranged side by side in a target direction (D) orthogonal to both directions (M), and the width of the magnetization direction (M) is the axial direction. One of the axial directions (L) formed uniformly along (L) Is the first axial direction (L1), the width of the target direction (D) of one of the magnet body (40) and the second permanent magnet (42) is toward the first axial direction (L1). And the width of the other target direction (D) of the magnet body (40) and the second permanent magnet (42) decreases toward the first axial direction (L1).

According to said structure, the magnet body (40) containing the 1st permanent magnet (41) whose residual magnetic flux density is higher than a 2nd permanent magnet (42), and a 2nd permanent magnet (42) are one side. It arrange | positions so that the width | variety of object direction (D) may increase as it goes to the axial direction 1st side (L1), and the width | variety of the other object direction (D) will decrease as it goes to the axial direction 1st side (L1). . Therefore, even when the magnet unit (30) is formed so as to extend parallel to the axial direction (L) as a whole, the target direction (D) in which the density of magnetic flux generated from the magnet unit (30) is the highest. Can move to one side of the target direction (D) as it goes to the first axial direction (L1), and a continuous skew structure can be realized with the magnet unit (30) alone. it can. In addition, according to the above configuration, since the second permanent magnet (42) is disposed in the space where the magnet body (40) in the magnet insertion hole (20) is not disposed, the second permanent magnet (42) is disposed in the space. ) Is not arranged, it is easy to suppress a rapid change in the magnetic flux density distribution formed in the air gap between the rotor core (15) and the stator core (10). From the above, according to the above configuration, it is possible to realize the magnet unit (30) capable of further reducing the cogging torque and the torque ripple.

Here, it is preferable that the center position (S) in the circumferential direction (C) of the magnet insertion hole (20) is arranged along the axial direction (L).

According to this configuration, the configuration of the rotor core (15) can be made relatively simple, and the cost of the rotor (2) for the rotating electrical machine can be reduced. Note that, as described above, in the magnet unit (30) according to the present disclosure, a continuous skew structure can be realized by the magnet unit (30) alone, and thus, as described above, the magnet insertion hole (20) Even in the configuration in which the center position (S) in the circumferential direction (C) is arranged along the axial direction (L), the cogging torque and the torque ripple can be reduced.

The magnet unit according to the present disclosure only needs to exhibit at least one of the effects described above.

2: Rotor (rotor for rotating electrical machines)
15: Rotor core 20: Magnet insertion hole 21: First magnet insertion hole (magnet insertion hole)
22: Second magnet insertion hole (magnet insertion hole)
30: Magnet unit 31: First magnet unit (magnet unit)
32: Second magnet unit (magnet unit)
40: Magnet body 41: First permanent magnet 42: Second permanent magnet 43: Third permanent magnet 51: First facing surface (facing surface between the first permanent magnet and the second permanent magnet)
52: Second facing surface (facing surface between the first permanent magnet and the third permanent magnet)
61: First inclined surface 62: Second inclined surface 63: Third inclined surface (inclined surface)
C: circumferential direction D: target direction D1: target direction first side L: axial direction L1: axial direction first side L2: axial direction second side M: magnetization direction P: magnetic pole Q: magnetic pole center (in the circumferential direction of the magnetic pole) center)
S: Center position

Claims

A magnet unit that is used in a rotor for a rotating electrical machine having a rotor core formed with a plurality of axially extending magnet insertion holes in a circumferential direction, and is inserted into one of the magnet insertion holes,
A first permanent magnet, and a second permanent magnet having a lower residual magnetic flux density than the first permanent magnet,
The first permanent magnet and the second permanent magnet are arranged side by side in a target direction orthogonal to both the axial direction and the magnetization direction so that the respective magnetization directions face the same side,
One side of the axial direction is set as the first side in the axial direction, and one side of the target direction is set as the first side in the target direction, and the opposing surfaces of the first permanent magnet and the second permanent magnet are The magnet unit which has the 1st inclined surface which goes to the said target direction 1st side as it goes to one side.
2. The first permanent magnet is arranged at a center side in the circumferential direction in each of a plurality of magnetic poles of the rotor for a rotating electrical machine with respect to the second permanent magnet in at least a partial region in the axial direction. 2. The magnet unit according to 1.
Inserted in the magnet insertion hole disposed in the central portion of the magnetic pole in the circumferential direction;
A third permanent magnet having a lower residual magnetic flux density than the first permanent magnet,
The third permanent magnet includes the second permanent magnet in the target direction with respect to the first permanent magnet such that the magnetization direction of the third permanent magnet faces the same side as the magnetization direction of the first permanent magnet. Are placed side by side on the opposite side,
The facing surfaces of the first permanent magnet and the third permanent magnet are directed to the first direction in the target direction toward the first axial direction in the axial direction region where the first inclined surface is formed. The magnet unit according to claim 2, wherein the magnet unit has an inclined surface.
Inserted into each of the pair of magnet insertion holes arranged on both sides across the circumferential center of the magnetic pole,
3. The magnet unit according to claim 2, wherein the first permanent magnet is disposed closer to the center side of the magnetic pole in the circumferential direction than the second permanent magnet in the entire area in the axial direction.
The opposing surface of the first permanent magnet and the second permanent magnet is at a position different from the first inclined surface in the axial direction and toward the second axial side opposite to the first axial side. The magnet unit according to any one of claims 1 to 4, wherein the magnet unit has a second inclined surface toward the first side in the target direction as it goes.
A magnet unit that is used in a rotor for a rotating electrical machine having a rotor core formed with a plurality of axially extending magnet insertion holes in a circumferential direction, and is inserted into one of the magnet insertion holes,
A magnet body including at least a first permanent magnet, and a second permanent magnet having a residual magnetic flux density lower than that of the first permanent magnet,
The magnet body and the second permanent magnet are arranged side by side in a target direction orthogonal to both the axial direction and the magnetization direction so that the respective magnetization directions face the same side,
Each of the magnet body and the second permanent magnet is formed with a uniform width in the magnetization direction along the axial direction.
With one side in the axial direction as the first side in the axial direction, the width of the target direction of one of the magnet body and the second permanent magnet increases toward the first side in the axial direction, and the magnet body and the The magnet unit in which the width of the other target direction of the second permanent magnet decreases toward the first side in the axial direction.
The magnet unit according to any one of claims 1 to 6, wherein a center position of the circumferential direction of the magnet insertion hole is arranged along the axial direction.