JP5423738B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine, and more particularly to a rotating electrical machine including a permanent magnet.

  Conventionally, a rotating electrical machine including a permanent magnet is known (see, for example, Patent Document 1).

  Patent Document 1 discloses an embedded magnet motor (rotary electric machine) including a laminated core (rotor core) and a permanent magnet embedded in the laminated core so as to extend in the radial direction. In this embedded magnet type motor, the inner peripheral surface of the permanent magnet is formed so as to be in close contact with the laminated iron core.

JP 2010-213457 A

  However, in the embedded magnet type motor (rotary electric machine) disclosed in Patent Document 1, the inner peripheral surface of the permanent magnet is formed so as to be in close contact with a soft magnetic body called a laminated core (rotor core). There is a problem that magnetic flux easily leaks from the inner peripheral surface side.

  Moreover, in the conventional rotary electric machine in which the permanent magnet as disclosed in Patent Document 1 is provided so as to extend in the radial direction inside the rotor core, the permanent magnet is moved from the inner peripheral side to the outer peripheral side of the rotor core. When a plurality of radial magnets are provided radially, the inner peripheral surface side of the permanent magnet is caused by the proximity of the end portions of the inner peripheral surface side of two permanent magnets adjacent in the circumferential direction via a soft magnetic material called a rotor core. There is also a problem in that irreversible demagnetization at the end of the wire tends to occur.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to reduce the leakage magnetic flux leaking from the inner peripheral surface side of the permanent magnet and to increase the inner peripheral surface of the permanent magnet. An object of the present invention is to provide a rotating electrical machine capable of suppressing the occurrence of irreversible demagnetization at the end portion on the side.

In order to achieve the above object, a rotating electrical machine according to one aspect of the present invention is provided with a rotor core, a stator core disposed so as to face the outer peripheral portion of the rotor core, and the width in the circumferential direction. A permanent magnet formed so as to increase from the inner peripheral side to the outer peripheral side of the rotor core, and an air gap is provided on the inner peripheral surface side of the permanent magnet, and the permanent magnet is interposed via the rotor core. The two adjacent permanent magnets are arranged so that the length of the first side surface facing each other in the radial direction is opposite to the first side surface. It is comprised so that it may become larger than the corresponding length.

  In the rotating electrical machine according to this one aspect, as described above, when a plurality of permanent magnets are provided radially from the inner peripheral portion side to the outer peripheral portion side of the rotor core by providing a gap on the inner peripheral surface side of the permanent magnet. Since the interval between the inner peripheral surface side ends of two permanent magnets adjacent in the circumferential direction via a soft magnetic material called a rotor core can be increased, the irreversible reduction of the inner peripheral surface side end portions of the permanent magnet The generation of magnetism can be suppressed. Also, unlike the case where the inner peripheral surface of the permanent magnet is formed so as to be in close contact with a soft magnetic material such as a rotor core, the magnetic circuit formed on the inner peripheral surface side of the permanent magnet by the gap on the inner peripheral surface side of the permanent magnet Therefore, the leakage magnetic flux leaking from the inner peripheral surface side of the permanent magnet can be reduced.

It is the figure which looked at the rotor and stator of the electric motor by one Embodiment of this invention from the axial direction. It is sectional drawing along the 200-200 line | wire of FIG. It is sectional drawing along the direction orthogonal to the axial direction of the rotor of the electric motor by one Embodiment of this invention. It is an expanded sectional view for demonstrating the magnetization direction of the permanent magnet of the electric motor by one Embodiment of this invention. It is the perspective view which showed the arrangement | positioning relationship between the some core part and the some permanent magnet of the electric motor by one Embodiment of this invention. It is sectional drawing along the direction orthogonal to the axial direction of the rotor of the electric motor by the 1st modification of one Embodiment of this invention. It is sectional drawing along the direction orthogonal to the axial direction of the rotor of the electric motor by the 2nd modification of one Embodiment of this invention. It is an expanded sectional view along the direction orthogonal to the axial direction of the rotor of the electric motor by the 3rd modification of one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIGS. 1-5, the structure of the electric motor 100 by one Embodiment of this invention is demonstrated.

  As shown in FIGS. 1 and 2, the electric motor 100 includes a stator 1 that is a fixed portion and a rotor 2 that is a rotating portion. The electric motor 100 is an example of the “rotary electric machine” in the present invention.

  As shown in FIG. 1, the stator 1 includes a stator tooth 11, a winding 12, and a stator yoke 13. The stator teeth 11 are arranged with a predetermined space (gap 3) therebetween so as to face an outer peripheral portion of a rotor core 22 described later of the rotor 2. Further, a plurality (12 in this embodiment) of slots 14 are formed inside the stator teeth 11. The stator teeth 11 are an example of the “stator core” in the present invention.

  The plurality of slots 14 are arranged at substantially equal angular intervals (approximately 30 ° intervals in the present embodiment) along the rotation direction of the rotor 2 (hereinafter referred to as the circumferential direction). The winding 12 is housed in each of the plurality of slots 14. The stator yoke 13 is provided so as to surround the outer peripheral portion of the stator teeth 11.

  As shown in FIGS. 1 to 3, the rotor 2 includes a shaft 21, a rotor core 22, a plurality of permanent magnets 23 a and 23 b, and a plate 24. The shaft 21 is provided so as to penetrate the center of the rotor 2 and extend in the X direction (see FIG. 2) (hereinafter referred to as the axial direction). The rotor core 22 is provided so as to surround the shaft 21. The rotor core 22 is formed of a soft magnetic material called a plurality of electromagnetic steel plates (see FIG. 2) stacked in the axial direction. The shaft 21 is an example of the “rotating shaft portion” of the present invention, and is formed of a soft magnetic material such as carbon steel for machine structure.

  Here, in this embodiment, as shown in FIGS. 3 to 5, the rotor core 22 includes a plurality (five in the present embodiment) of core portions 22 a that function as N poles of the rotor 2, and S of the rotor 2. A plurality of (in this embodiment, five) core portions 22b functioning as poles. As shown in FIG. 3, the plurality of core portions 22a and 22b are alternately arranged one by one along the circumferential direction at substantially equal angular intervals (approximately 36 ° intervals in the present embodiment). Further, a bar insertion hole 22c into which a bar 50 described later is inserted is formed in the central portion in the circumferential direction in the vicinity of the outer peripheral portion of each of the plurality of core portions 22a and 22b.

  Moreover, the magnet coating | coated part 22d which protrudes in the circumferential direction is provided in the both ends of the circumferential direction of the outer peripheral part of the core part 22a (22b). The magnet covering portion 22d is formed so as to cover the vicinity of the end portion on the core portion 22a (22b) side of the outer peripheral surface of the permanent magnet 23a (23b) adjacent to the core portion 22a (22b). Moreover, the magnet coating | coated part 22d is formed so that it may extend in the circumferential direction along the outer periphery of the core part 22a (22b).

  As shown in FIGS. 1 to 5, a plurality of permanent magnets 23 a and 23 b are provided radially inside the rotor core 22 from the inner peripheral side toward the outer peripheral side. That is, each of the plurality of permanent magnets 23 a and 23 b is provided so as to extend in the radial direction from the inner peripheral side of the rotor core 22 toward the outer peripheral side. As shown in FIGS. 3 and 4, the permanent magnets 23a and 23b are arranged between the core portions 22a and 22b so as to be adjacent to each other in the circumferential direction without the core portions 22a and 22b. .

  Here, as shown in FIGS. 3 to 5, the inner peripheral surfaces of the permanent magnets 23 a and 23 b are spaced apart from the outer peripheral surface of the shaft 21 in the radial direction so as not to contact the outer peripheral surface of the shaft 21. Is arranged. Thereby, the space | gap 30 is provided in the inner peripheral surface side of the permanent magnet 23a (23b). The radial length l (see FIG. 4) of the air gap 30 is about 5 minutes of the radial length L (see FIG. 4) from the outer peripheral surface of the shaft 21 to the inner peripheral surface of the magnet covering portion 22d. It is preferable to set the length to 1 or less.

  In the present embodiment, as shown in FIGS. 2 to 4, the gap 30 is filled with an adhesive layer 40 made of an adhesive that is a nonmagnetic material. Although not shown in FIGS. 2 to 4, the gap between the permanent magnet 23 a (22 b) and the core portion 22 a (22 b) adjacent in the circumferential direction, the permanent magnet 23 a and the permanent magnet adjacent in the circumferential direction. The adhesive layer is also filled in the gap between the outer peripheral surface of the permanent magnet 23a (23b) and the inner peripheral surface of the magnet covering portion 22d of the core portion 22a (22b). .

  As shown in FIGS. 3 and 4, the inner peripheral surfaces of the permanent magnets 23a and 23b and the outer peripheral surface of the shaft 21 are separated from each other over the entire circumferential length of the inner peripheral surfaces of the permanent magnets 23a and 23b. . Further, the circumferential end portions of the inner peripheral surfaces of the permanent magnets 23a and 23b are farther away from the outer peripheral surface of the shaft 21 than the central portion in the circumferential direction of the inner peripheral surfaces of the permanent magnets 23a and 23b. Specifically, the end portions (see points P1 and P2 in FIG. 4) of the side surfaces adjacent to the core portions 22a and 22b of the permanent magnets 23a and 23b are adjacent to each other of the permanent magnets 23a and 23b. It is farther away from the outer peripheral surface of the shaft 21 than the end of the side surface on the inner peripheral surface side (see point Q in FIG. 4). That is, the air gap 30 is configured to increase from the circumferential central portion of the inner peripheral surfaces of the permanent magnets 23a and 23b toward the circumferential end. Further, the inner peripheral surfaces of the permanent magnets 23a and 23b facing the outer peripheral surface of the columnar shaft 21 are not curved surfaces (curved shapes) but flat surfaces that extend continuously in a straight line.

  Moreover, as shown in FIGS. 3-5, the mutually opposing side surfaces of the two permanent magnets 23a (23b) adjacent in the circumferential direction via the core portion 22a (22b) are the outer circumferences of the permanent magnets 23a (23b). It is formed so as to extend in a straight line in the radial direction so as to gradually approach each other from the surface side toward the inner peripheral surface side and to be separated in a state of being close to each other at the end portion on the inner peripheral surface side. In the present embodiment, as shown in FIG. 4, the mutually opposing side surfaces of two permanent magnets 23a adjacent to each other in the circumferential direction via the core portion 22a are end portions on the inner peripheral surface side (see points P1 and P3). Are separated from each other by a predetermined distance D1. Similarly, although not shown in FIG. 4, the side surfaces of the two permanent magnets 23b that are adjacent to each other in the circumferential direction via the core portion 22b also have a predetermined distance D1 between the end portions on the inner peripheral surface side. Only separated. The predetermined distance D1 is preferably set to about 0.5 mm or more.

  As shown in FIGS. 2 and 5, the inner peripheral surfaces of the permanent magnets 23 a and 23 b and the outer peripheral surface of the shaft 21 are separated from each other over the entire axial length of the rotor core 22. That is, the gap 30 is provided over the entire length of the rotor core 22 in the axial direction. FIG. 5 is a perspective view showing a plurality of core portions 22a (22b) constituting the rotor core 22 and a plurality of permanent magnets 23a (23b) provided inside the rotor core 22. For convenience of explanation, FIG. The shaft 21 and the adhesive layer 40 are not shown.

  As shown in FIGS. 3 and 4, the permanent magnets 23a and 23b have a rectangular shape in which the circumferential width gradually increases from the inner periphery to the outer periphery of the rotor core 22 (core portions 22a and 22b). It is formed to have a cross section. Moreover, as shown in FIG. 4, the permanent magnet 23a (23b) includes a corner portion adjacent to the core portion 22a (22b) of the end portion on the outer peripheral portion side of the rotor core 22 of the permanent magnet 23a (23b), and the permanent magnet 23a (23b). Of the end of the magnet 23a (23b) on the inner peripheral side of the rotor core 22, the corner adjacent to the permanent magnet 23b (23a) is formed at a right angle.

  Further, as shown in FIG. 4, the permanent magnets 23a and 23b are perpendicular to the q axis of the electric motor 100 (the axis in the direction electrically perpendicular to the axis (d axis) in the direction along the main magnetic flux) (arrow). It is magnetized in a direction inclined by a predetermined angle θ with respect to (A direction). Specifically, the permanent magnet 23a adjacent to the core portion 21a is magnetized in a direction inclined to the outer peripheral side by a predetermined angle θ with respect to the direction orthogonal to the q axis (arrow A direction), while the core The permanent magnet 23b adjacent to the portion 21b is magnetized in a direction inclined toward the inner peripheral side by a predetermined angle θ with respect to a direction (arrow A direction) perpendicular to the q axis. That is, the magnetization directions of the permanent magnets 23a and 23b adjacent in the circumferential direction between the core portion 22a and the core portion 22b are substantially line symmetric with respect to the q axis.

  As shown in FIGS. 1 and 4, the q-axis of the electric motor 100 according to the present embodiment coincides with a line where the permanent magnets 23a and 23b adjacent in the circumferential direction are in contact with each other. In addition, the q axis of the electric motor 100 according to the present embodiment has a rotation center O of the rotor 2 (see FIG. 1) and a magnetic pole (refer to FIG. 1) adjacent to the reference magnetic pole in the circumferential direction when the core portion 22a shown in FIG. It coincides with a straight line (magnetic pole boundary line) connecting the magnetic boundary with the core portion 22b) shown in FIG.

  In the present embodiment, the inclination angle θ in the magnetization direction of the permanent magnet 23a (23b) is set in a range of 0 ° <θ ≦ 45 °. Thereby, compared with the case where the permanent magnet 23a (23b) is magnetized in the direction orthogonal to the q-axis (the direction of the arrow A (see FIG. 4)), the direction along the magnetization direction of the permanent magnet 23a (23b) Since the thickness can be increased, the operating point of the permanent magnet 23a (23b) can be increased. The angle θ is set within a certain range (0 ° <θ ≦ 45 °) even when the number of magnetic poles of the electric motor 100 (the number of core portions 22a and 22b (10 in this embodiment)) is changed. It is preferable to do this.

  As shown in FIG. 2, the permanent magnet 23a is disposed between two plates 24 sandwiching the rotor core 22 and the permanent magnet 23a (23b) from both sides in the axial direction, and is formed to extend in the axial direction. Has been. Further, as shown in FIG. 5, the permanent magnet 23b is also formed to extend in the axial direction similarly to the permanent magnet 23a. As shown in FIGS. 2 and 5, the axial lengths of the permanent magnets 23 a and 23 b are formed to be substantially equal to the axial length of the rotor core 22.

  As shown in FIGS. 1 and 2, the plate 24 is formed in a plate shape having a substantially annular shape when viewed from the axial direction. The plate 24 is made of a nonmagnetic material such as stainless steel or resin. As shown in FIG. 1, the diameter of the plate 24 is formed to be smaller than the outer diameter of the rotor 2. Further, as shown in FIG. 2, the plate 24 is formed so as to cover both end surfaces of the rotor core 22 and the permanent magnets 23a (23b) in the axial direction without exposing them.

  Further, as shown in FIG. 1, a shaft insertion portion 24 a formed of an opening is provided on the inner peripheral portion (near the central portion) of the plate 24. A gear-like engagement portion 24b is formed in the shaft insertion portion 24a. Here, a gear-like (see FIG. 1) engaging portion 21a corresponding to the engaging portion 24b of the plate 24 is formed in a portion (see FIG. 2) protruding from the rotor core 22 on the outer peripheral surface of the shaft 21 in the axial direction. Has been. In this embodiment, the plate 24 and the shaft 21 are fixed by engaging (meshing) the gear-shaped engaging portion 24 b of the plate 24 and the gear-shaped engaging portion 21 a of the shaft 21. The engaging portion 21a is an example of the “first engaging portion” in the present invention, and the engaging portion 24b is an example of the “second engaging portion” in the present invention.

  Further, a plurality of (10 in this embodiment) bar insertion holes 24c are provided in the vicinity of the outer peripheral portion of the plate 24 so as to correspond to the bar insertion holes 22c of the core portion 22a (22b). The plurality of bar insertion holes 24c are provided in the vicinity of the outer peripheral portion of the plate 24 at substantially equal angular intervals along the circumferential direction (in the present embodiment, approximately 36 ° intervals). As shown in FIG. 2, a columnar bar 50 extending in the axial direction is inserted into the bar insertion hole 24c of the plate 24 and the bar insertion hole 22c of the core portion 22a (22b).

  Next, with reference to FIGS. 1-5, the assembly procedure of the rotor 2 of the electric motor 100 by one Embodiment of this invention is demonstrated.

  First, as shown in FIGS. 3 to 5, the rotor core 22 is configured on the outer peripheral surface of the shaft 21 by alternately arranging a plurality of core portions 22 a and a plurality of core portions 22 b one by one in a circumferential shape. Then, a plurality of permanent magnets 23 a and 23 b extending in the radial direction and extending in the axial direction are attached inside the rotor core 22. Specifically, as shown in FIGS. 3 and 4, the inner peripheral surface of the permanent magnet 23a (23b) and the outer peripheral surface of the shaft 21 are spaced apart in the radial direction, and the outer peripheral surface of the permanent magnet 23a (23b) Permanent magnets 23a and 23b are attached to the inside of the rotor core 22 so that the inner peripheral surface of the magnet covering portion 22d of the core portion 22a (22b) is in contact. Then, the adhesive layer 40 is filled into a space (gap 30) formed between the inner peripheral surfaces of the permanent magnets 23a and 23b and the outer peripheral surface of the shaft 21. At this time, a gap between the permanent magnet 23a (22b) and the core portion 22a (22b) adjacent in the circumferential direction, a gap between the permanent magnet 23a and the permanent magnet 23b adjacent in the circumferential direction, and permanent An adhesive layer (not shown) is also filled in the gap between the outer peripheral surface of the magnet 23a (23b) and the inner peripheral surface of the magnet covering portion 22d of the core portion 22a (22b).

  Next, as shown in FIG. 2, a disk-like plate 24 is attached from both sides in the axial direction to the shaft 21 to which the rotor core 22 and the permanent magnets 23a (23b) are attached as described above. Specifically, first, the shaft 21 is inserted into the shaft insertion portion 24 a on the inner peripheral portion of the plate 24. Then, as shown in FIG. 1, the gear-like engagement portion 21 a provided on the outer peripheral portion of the shaft 21 is engaged with the gear-like engagement portion 24 b provided on the shaft insertion portion 24 a of the plate 24. As a result, the shaft 21 and the plate 24 are fixed. At this time, the positions of the bar insertion holes 24c of the plate 24 and the bar insertion holes 22c of the core portion 22a (22b) are aligned.

  Finally, as shown in FIG. 2, the bar 50 is inserted in the axial direction into the bar insertion hole 24c of the plate 24 aligned as described above and the bar insertion hole 22c of the core portion 22a (22b). Then, the plate 24 and the core portion 22a (22b) are fixed. Thus, the rotor 2 of the electric motor 100 according to the embodiment of the present invention is assembled.

  In the present embodiment, as described above, the air gap 30 is provided on the inner peripheral surface side of the permanent magnets 23a and 23b. Thus, when a plurality of permanent magnets 23a and 23b are provided radially from the inner peripheral side of the rotor core 22 toward the outer peripheral side, two permanent magnets 23a adjacent in the circumferential direction via the rotor core 22 (soft magnetic body). Since the distance between the ends on the inner peripheral surface side of (23b) (for example, the distance D1 between the points P1 and P3 in FIG. 4) can be increased, the inner peripheral surface side of the permanent magnets 23a and 23b It is possible to suppress the occurrence of irreversible demagnetization at the end of each. Unlike the case where the inner peripheral surfaces of the permanent magnets 23a and 23b are formed so as to be close to the outer peripheral surface of the shaft 21 (soft magnetic body), the permanent magnets are formed by the gaps 30 on the inner peripheral surface side of the permanent magnets 23a and 23b. Since the magnetic resistance of the magnetic circuit formed on the inner peripheral surface side of 23a and 23b can be increased, the leakage magnetic flux leaking from the inner peripheral surface side of the permanent magnets 23a and 23b can also be reduced.

  In the present embodiment, as described above, the permanent magnets 23 a and 23 b are formed so as to have a rectangular cross section in which the circumferential width gradually increases from the inner peripheral portion of the rotor core 22 toward the outer peripheral portion. As a result, the circumferential width of the end portions of the permanent magnets 23a and 23b on the outer peripheral side of the rotor core 22 is increased, and the magnetization direction of the end portions of the permanent magnets 23a and 23b on the outer peripheral side of the rotor core 22 (the electric motor 100 Since the thickness in the direction along the direction crossing the q axis of the permanent magnets 23a and 23b can be increased. As a result, the output of the electric motor 100 can be increased, and the irreversible demagnetization at the end portions of the permanent magnets 23a and 23b on the outer peripheral side of the rotor core 22 that is easily affected by the demagnetizing field due to the armature reaction can be suppressed. .

  Further, by gradually increasing the circumferential width of the permanent magnets 23a and 23b from the inner peripheral portion of the rotor core 22 toward the outer peripheral portion, the end portions of the permanent magnets 23a and 23b on the inner peripheral portion side of the rotor core 22 are increased. Since the surface area of the permanent magnets 23a and 23b in contact with the inner peripheral portion of the rotor core 22 increases as the circumferential width decreases, the output of the electric motor 100 can be further increased. Further, by forming the permanent magnets 23a and 23b so as to have a rectangular cross section, the permanent magnets 23a and 23b are formed in shapes other than the rectangular shape (for example, the circumferential width is changed from the inner peripheral portion of the rotor core 22 to the outer peripheral portion). Permanent magnets 23a and 23b whose width in the circumferential direction gradually increases from the inner peripheral portion to the outer peripheral portion of the rotor core 22 as compared with the case where the cross section is formed to have a fan-shaped cross section that gradually increases toward the outer periphery. Can be easily manufactured.

  In the present embodiment, as described above, the shaft 21 to be attached to the inner peripheral portion of the rotor core 22 is provided, and the circumferential end portions of the inner peripheral surfaces of the permanent magnets 23a and 23b (see points P1 to P3 in FIG. 4). Is disposed at a position spaced outward from the outer peripheral surface of the shaft 21 in the radial direction, thereby providing a gap 30 on the inner peripheral surface side of the permanent magnets 23a and 23b. Thereby, the edge parts (for example, refer to points P1 and P3 in FIG. 4) of the two peripheral magnets 23a (23b) adjacent in the circumferential direction via the rotor core 22 can be easily separated from each other. Therefore, it is possible to easily suppress the occurrence of irreversible demagnetization at the end portions on the inner peripheral surface side of the permanent magnets 23a and 23b.

  Moreover, in this embodiment, as mentioned above, the edge part (for example, FIG. 4 of FIG. 4) rather than the center part (for example, see the point Q of FIG. 4) of the circumferential direction of the internal peripheral surface of the permanent magnets 23a and 23b. (See points P1 and P2) is further separated from the shaft 21 so that the gap 30 increases from the center of the inner peripheral surface of the permanent magnets 23a and 23b toward the end in the circumferential direction. A gap 30 is provided on the inner peripheral surface side of 23b. Thereby, compared with the case where the magnitude | size of the space | gap 30 does not change with the center part of the internal peripheral surface of permanent magnet 23a and 23b, and the edge part of the circumferential direction, two permanent magnets adjacent to the circumferential direction via the rotor core 22 The distance between the end portions on the inner peripheral surface side of 23a (23b) (for example, the distance D1 between the point P1 and the point P3 in FIG. 4) can be further increased. As a result, it is possible to further suppress the occurrence of irreversible demagnetization at the ends on the inner peripheral surface side of the permanent magnets 23a and 23b.

  In the present embodiment, as described above, the mutually opposing side surfaces of the two permanent magnets 23a (23b) adjacent to each other in the circumferential direction via the rotor core 22 are moved from the outer peripheral side to the inner peripheral side of the rotor core 22. It is formed to extend in a straight line in the radial direction so as to gradually approach each other and to be separated in a state of being close to each other at end portions on the inner peripheral surface side (see points P1 to P3 in FIG. 4). And the space | gap 30 is provided in the edge part vicinity of the inner peripheral surface side of the side surface of the permanent magnet 23a (23b). Thereby, the edge parts (for example, refer to points P1 and P3 in FIG. 4) of the two peripheral magnets 23a (23b) adjacent in the circumferential direction via the rotor core 22 can be reliably separated from each other. Therefore, it is possible to reliably suppress the occurrence of irreversible demagnetization at the end portions on the inner peripheral surface side of the permanent magnets 23a and 23b.

  In the present embodiment, as described above, the rotor core 22 is configured to include a plurality of core portions 22a and 22b arranged at intervals in the circumferential direction, and the outer peripheral portion of the core portion 22a (22b) A magnet covering portion 22d is provided to cover the core portion 22a (22b) side portion of the outer peripheral surface of the permanent magnet 23a (23b) adjacent to the core portion 22a (22b). Then, the permanent magnets 23a and 23b are provided so as to have a gap 30 on the inner peripheral surface side of the permanent magnets 23a and 23b and to expose a portion of the outer peripheral surface of the permanent magnets 23a and 23b that is not covered with the magnet covering portion 22d. It arrange | positions between adjacent core parts 22a and 22b. Thereby, the rotor core 22 is completely separated into a plurality of core portions 22a and 22b arranged at intervals in the circumferential direction, so that the rotor core 22 is formed to be continuous in the outer peripheral portion or the inner peripheral portion. Unlike the case where the permanent magnets 23a and 23b are different from each other, a part of the magnetic flux generated from the permanent magnets 23a and 23b is not circulated through the outer peripheral portion or the inner peripheral portion of the rotor core 22 without flowing to the stator teeth 11 side. be able to. As a result, the leakage magnetic flux can be reduced, so that the output of the electric motor 100 can be further increased.

  In addition, a magnet covering portion 22d that covers a portion of the outer peripheral surface of the permanent magnet 23a (23b) adjacent to the core portion 22a (22b) on the core portion 22a (22b) side is provided on the outer peripheral portion of the core portion 22a (22b). Thus, the magnetic flux flowing toward the stator teeth 11 on the outer peripheral surface of the rotor core 22 (core portions 22a and 22b) while suppressing the permanent magnet 23a (23b) from detaching to the outer peripheral side due to centrifugal force when the rotor 2 rotates. It is possible to increase the area of the region through which is passed. Thereby, since the change of the magnetic flux which flows through the gap 3 between the rotor core 22 (core part 22a and 22b) and the stator teeth 11 when the rotor 2 rotates can be made smoother, the cogging torque of the electric motor 100 can be reduced. It can be further reduced. Further, by exposing the portions of the outer peripheral surfaces of the permanent magnets 23a and 23b that are not covered with the magnet covering portion 22d, the portions of the outer peripheral surfaces of the permanent magnets 23a and 23b that are not covered with the magnet covering portion 22d are magnetic bodies, etc. Compared with the case where it covers, leakage magnetic flux can be reduced more. Thereby, the output of the electric motor 100 can be further increased.

  In the present embodiment, as described above, the gap 30 is filled with the nonmagnetic material (adhesive layer 40). Thereby, the space | interval of the edge parts by the side of the internal peripheral surface of the two permanent magnets 23a (23b) adjacent to the circumferential direction via the rotor core 22 (for example, the space | interval D1 between the point P1 and the point P3 of FIG. 4). It is possible to prevent the permanent magnets 23a and 23b from being displaced in the radial direction due to the centrifugal force when the rotor 2 rotates, while maintaining a desired size. Further, by using the adhesive layer 40 as a nonmagnetic material, the permanent magnets 23a and 23b can be bonded to the inside of the rotor core 22, so that the permanent magnets 23a and 23b have a radius due to centrifugal force when the rotor 2 rotates. Shifting in the direction can be further suppressed.

  In the present embodiment, as described above, the permanent magnets 23a and 23b are magnetized in a direction inclined by a predetermined angle θ with respect to the direction orthogonal to the q axis. Thereby, compared with the case where the permanent magnets 23a and 23b are magnetized in the direction orthogonal to the q-axis (direction of arrow A (see FIG. 4)), the thickness in the direction along the magnetization direction of the permanent magnets 23a and 23b is reduced. Since it can be made larger, the operating point of the permanent magnets 23a and 23b can be made higher. As a result, the output of the electric motor 100 can be further increased, and the irreversible demagnetization of the permanent magnets 23a and 23b can be further suppressed. Further, by inclining the magnetization direction of the permanent magnets 23a and 23b with respect to the direction orthogonal to the q-axis (direction of arrow A), the gap 3 between the rotor core 22 and the stator teeth 11 when the rotor core 22 rotates is set. The change of the flowing magnetic flux can be smoothed. As a result, the cogging torque of the electric motor 100 can be reduced.

  In the present embodiment, as described above, the inclination angle θ in the magnetization direction of the permanent magnets 23a and 23b is set in a range of 0 ° <θ ≦ 45 °. By setting the angle θ to this angle range, the thickness in the direction along the magnetization direction of the permanent magnets 23a and 23b can be easily increased, and the rotor core 22 and the stator teeth when the rotor core 22 rotates. 11 can be smoothly changed in the magnetic flux flowing through the gap 3 between them.

  In the present embodiment, as described above, the rotor core 22 is composed of a plurality of electromagnetic steel plates laminated in the axial direction, and the plate 24 attached so as to cover the end surface of the rotor core 22 in the axial direction is provided. Then, the engaging portion 21 a is formed on the outer peripheral portion of the shaft 21, and the engaging portion 24 b that engages with the engaging portion 21 a of the shaft 21 is formed on the inner peripheral portion of the plate 24. Thereby, by engaging the engaging portion 21a of the shaft 21 and the engaging portion 24b of the plate 24, the plate 24 and the shaft 21 can be firmly fixed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, the example in which the air gap is provided only on the inner peripheral surface side of the permanent magnet (between the inner peripheral surface of the permanent magnet and the outer peripheral surface of the shaft (rotating shaft portion)) is shown. Not limited to. In this invention, you may provide a space | gap in both the inner peripheral surface side of a permanent magnet, and the outer peripheral surface side (between the outer peripheral surface of a permanent magnet, and the inner peripheral surface of a magnet coating | coated part) of a permanent magnet.

  Moreover, in the said embodiment, the example which comprises a space | gap by separating the inner peripheral surface of a permanent magnet and the outer peripheral surface of a shaft (rotating shaft part) over the full length of the inner peripheral surface of a permanent magnet in the circumferential direction is shown. However, the present invention is not limited to this. In the present invention, the inner peripheral surface of the permanent magnet and the outer peripheral surface of the rotary shaft portion do not have to be separated over the entire circumferential length of the inner peripheral surface of the permanent magnet. For example, by forming the outer peripheral surface of the rotating shaft portion into an uneven shape so as to have a portion that contacts (contacts) the inner peripheral surface of the permanent magnet, the permanent magnet in the outer peripheral surface of the uneven shaft portion You may comprise a space | gap between parts other than the part contact | abutted to the inner peripheral surface, and the inner peripheral surface of a permanent magnet.

  In the above embodiment, an example is shown in which the permanent magnet is formed so that the circumferential width gradually increases from the inner peripheral side to the outer peripheral side of the rotor core. The invention is not limited to this. In the present invention, the permanent magnet may be formed so as to have a fan-shaped cross section in which the circumferential width gradually increases from the inner peripheral portion to the outer peripheral portion of the rotor core.

  Moreover, although the said embodiment showed the example which comprises a space | gap so that it might become large toward the edge part of the circumferential direction from the center part of the circumferential direction of the internal peripheral surface of a permanent magnet, this invention is not limited to this. In the present invention, the air gap may be configured so that the size is equal between the circumferential center portion and the circumferential end portion of the inner circumferential surface of the permanent magnet.

  Moreover, although the example which provides a space | gap over the full length of the circumferential direction of the internal peripheral surface of a permanent magnet was shown in the said embodiment, this invention is not limited to this. In the present invention, it is sufficient that a gap is provided in the vicinity of the end portion on the inner peripheral surface side of the side surfaces facing each other of at least two permanent magnets adjacent in the circumferential direction via the rotor core. That is, if a gap is provided in the vicinity of the end portion on the inner peripheral surface side of the mutually facing side surfaces of two permanent magnets adjacent in the circumferential direction via the rotor core, the inner peripheral surface of the permanent magnet and the outer peripheral surface of the shaft May be close to each other. In this way, when the inner peripheral surface of the permanent magnet and the outer peripheral surface of the shaft are close to each other, if the shaft is formed of a non-magnetic material such as stainless steel, the leakage magnetic flux leaking from the inner peripheral surface side of the permanent magnet can be further reduced. Can do.

  Moreover, in the said embodiment, as shown in FIG.3 and FIG.4, the inside of the space | gap 30 by the side of the internal peripheral surface of permanent magnet 23a and 23b is filled only using the adhesive bond layer 40 which is a nonmagnetic material. Although shown, the present invention is not limited to this. In the present invention, as in the first modified example shown in FIG. 6, in addition to the adhesive layer 41 that is a nonmagnetic material, a ring member 42 that is made of a resin that is a nonmagnetic material is also used, so that the permanent magnets 23a and 23b are used. The inside of the space 31 on the inner peripheral surface side may be filled (may be filled).

  In the first modification, as shown in FIG. 6, an annular ring member 42 having an inner peripheral surface in contact with the outer peripheral surface of the shaft 21 inside the gap 31 on the inner peripheral surface side of the permanent magnets 23 a and 23 b. Is provided. In addition, the outer peripheral surface of the ring member 42 is arrange | positioned so that the inner peripheral surface of the some core parts 122a and 122b which comprise the rotor core 122, and a part of inner peripheral surface of the permanent magnets 23a and 23b may be contact | connected. An adhesive layer 41 is filled in a space (gap 31) formed between the outer peripheral surface of the ring member 42 and the inner peripheral surfaces of the permanent magnets 23a and 23b.

  In the first modification, when filling the gap 31 on the inner peripheral surface side of the permanent magnets 23a and 23b, a ring member 42 made of a resin having a certain shape (annular shape) is used. Unlike the case where the inside of the space 31 is filled using only the adhesive layer 41 that does not have a certain shape, the inside of the space 31 can be filled effectively.

  Moreover, in the said embodiment, although the example which comprises the rotor core 22 so that division | segmentation into the some core parts 22a and 22b was shown, this invention is not limited to this. In the present invention, as in the second modification shown in FIG. 7, the rotor core 222 may be configured as one component by connecting the inner peripheral portions of the plurality of core portions 222a and 222b.

  In the second modification, as shown in FIG. 7, the inner peripheral portions of the core portions 222 a and 222 b that constitute the rotor core 222 are connected to the inner peripheral portions of the core portions 222 a and 222 b that are adjacent to each other in the circumferential direction. An annular connection core part 222e is provided for connection along the inner periphery of the ring. The inner peripheral surface of the connecting core part 222e is disposed so as to contact the outer peripheral surface of the shaft 21. Moreover, the outer peripheral surface of the connection core part 222e is arrange | positioned in the position spaced apart to the inner side of radial direction from the inner peripheral surface of permanent magnet 23a and 23b. An adhesive layer 43 is filled in a space (gap 32) formed between the outer peripheral surface of the connecting core portion 222e and the inner peripheral surfaces of the permanent magnets 23a and 23b.

  In the second modification, the strength of the rotor core 222 can be increased by providing the connecting core portion 222e that connects the core portions 222a and 222b adjacent in the circumferential direction along the inner periphery of the rotor core 222. Further, since the gap 32 on the inner peripheral surface side of the permanent magnets 23a and 23b can be reduced by the thickness of the connecting core portion 222e in the radial direction, the adhesive used for the adhesive layer 43 filled in the gap 32 The amount of can be reduced.

  Moreover, in the said embodiment, as shown in FIG.3 and FIG.4, although the example which provides the space | gap 30 in the inner peripheral surface side of the permanent magnet 23a (23b) which has a rectangular-shaped cross section extended in radial direction was shown, The invention is not limited to this. In the present invention, as in the third modification shown in FIG. 8, the permanent magnet 123 a (123 b) whose corners on the core 22 a (22 b) side of the end on the inner peripheral side of the rotor core 22 are chamfered. You may provide the space | gap 33 in the inner peripheral surface side.

  In the third modified example, as shown in FIG. 8, the permanent magnets 123 a and 123 b formed by the chamfered portion 123 c and the non-chamfered portion 123 d are formed between the inner peripheral surface and the outer peripheral surface of the shaft 21. The space (the gap 33) is filled with an adhesive layer 44 that is a nonmagnetic material. Further, in the third modified example, the mutually opposing side surfaces of the two permanent magnets 123a adjacent to each other in the circumferential direction via the core portion 22a are in contact with the end portion on the inner peripheral surface side (the chamfered portion 123c and the core portion 22a). The portions (see points P4 and P5 in FIG. 8) are separated from each other by a predetermined distance D2. Similarly, although not shown in FIG. 8, the mutually opposing side surfaces of the two permanent magnets 123b adjacent in the circumferential direction via the core portion 22b are also separated from each other by a predetermined distance D2 at the end on the inner peripheral surface side. Only separated.

  In the third modification, the inner peripheral surface of the permanent magnet 123a (123b) is constituted by a chamfered portion 123c and a non-chamfered portion 123d. As a result, the end portions on the inner peripheral surface side of the two permanent magnets 123a (123b) adjacent in the circumferential direction via the rotor core 22 (the portion where the chamfered portion 123c and the core portion 22a are in contact (for example, the point P4 in FIG. (Refer to P5)) While keeping the distance D2 between each other in a desired size, the non-chamfered portion 123d of the gap 33 formed between the inner peripheral surface of the permanent magnet 123a (123b) and the outer peripheral surface of the shaft 21 Corresponding portions can be made smaller. As a result, the amount of the adhesive used for the adhesive layer 44 filled in the gap 33 is reduced while suppressing the occurrence of irreversible demagnetization at the end on the inner peripheral surface side of the permanent magnet 123a (123b). Can do.

  Moreover, although the example which magnetizes a permanent magnet in the direction inclined with respect to the direction orthogonal to the q axis | shaft of an electric motor (rotating electric machine) was shown in the said embodiment, this invention is not limited to this. In the present invention, the permanent magnet may be magnetized in a direction orthogonal to the q axis of the rotating electrical machine.

  Moreover, in the said embodiment, two permanent magnets from which the circumferential width | variety becomes gradually large as it goes to an outer peripheral part from the inner peripheral part of a rotor core between two adjacent core parts among several core parts. Although an example of arrangement is shown, the present invention is not limited to this. In the present invention, the number of permanent magnets arranged between two adjacent core portions may be one, or may be three or more.

  Moreover, in the said embodiment, the engaging part 21a (1st engaging part) of the outer peripheral part of the shaft 21 (rotating shaft part), the engaging part 24b (2nd engaging part) of the inner peripheral part of the plate 24, and However, the present invention is not limited to this. In the present invention, the first engaging portion and the second engaging portion may be formed in a shape other than the gear shape.

11 Stator Teeth (Stator Core)
21 Shaft (Rotating shaft)
21a Engagement part (first engagement part)
22, 122, 222 Rotor core 22a, 22b, 122a, 122b, 222a, 222b Core portion 22d Magnet covering portion 23a, 23b, 123a, 123b Permanent magnet 24 Plate 24b Engaging portion (second engaging portion)
30, 31, 32, 33 Gap 40, 41, 43, 44 Adhesive layer (non-magnetic material)
42 Ring member (non-magnetic material)
100 Electric motor (rotary electric machine)

Claims (13)

Rotor core,
A stator core disposed to face the outer periphery of the rotor core;
A permanent magnet provided inside the rotor core and formed so that a circumferential width increases from an inner peripheral side to an outer peripheral side of the rotor core;
Wherein the inner peripheral surface of the permanent magnet is void is provided,
The permanent magnets are provided so as to be adjacent to each other in the circumferential direction without passing through the rotor core, and the two adjacent permanent magnets have a length in the radial direction of the first side surfaces facing each other. A rotating electrical machine configured to be longer than a corresponding length of a second side surface opposite to the first side surface .   2. The rotation according to claim 1, wherein the permanent magnet is formed to have a substantially rectangular cross section in which a circumferential width gradually increases from an inner peripheral side to an outer peripheral side of the rotor core. Electric. A rotating shaft portion attached to the inner peripheral portion of the rotor core;
By arranging at least a circumferential end portion of the inner circumferential surface of the permanent magnet at a position spaced radially outward from the outer circumferential surface of the rotating shaft portion, the gap is formed on the inner circumferential surface side of the permanent magnet. The rotating electrical machine according to claim 1 or 2, which is provided.   The circumferential end of the inner circumference of the permanent magnet is spaced farther from the rotary shaft than the center of the circumference of the inner circumference of the permanent magnet. The rotating electrical machine according to claim 3, wherein the gap is provided on an inner peripheral surface side of the permanent magnet so that the gap becomes larger. The permanent magnet includes two permanent magnets adjacent in the circumferential direction via the rotor core,
The mutually opposing side surfaces of two permanent magnets adjacent in the circumferential direction via the rotor core gradually approach each other from the outer peripheral side to the inner peripheral side of the rotor core, and end portions on the inner peripheral surface side Extending in a straight line in the radial direction so as to be separated from each other in a state close to each other,
The rotating electrical machine according to any one of claims 1 to 4, wherein the gap is provided at least in the vicinity of the end portion on the inner peripheral surface side of the side surface of the permanent magnet. The rotor core is configured to include a plurality of core portions arranged at intervals in the circumferential direction,
The outer peripheral part of the core part is provided with a magnet covering part that covers a part on the core part side of the outer peripheral surface of the permanent magnet adjacent to the core part,
The permanent magnet, between adjacent core portions of the plurality of core portions, wherein both the that having a said gap on the inner circumferential surface of the permanent magnet, the magnet cover portion of the outer peripheral surface of the permanent magnet The rotating electrical machine according to any one of claims 1 to 5, wherein the rotating electrical machine is disposed so that a portion not covered with the exposed portion is exposed.   The rotating electrical machine according to claim 6, wherein the permanent magnets are provided so as to be adjacent to each other in the circumferential direction between the adjacent core portions of the plurality of core portions without using the core portion. .   The rotating electrical machine according to any one of claims 1 to 7, wherein the gap is filled with a nonmagnetic material.   The rotating electrical machine according to claim 8, wherein the nonmagnetic material includes an adhesive layer.   The rotating electrical machine according to any one of claims 1 to 9, wherein the permanent magnet is magnetized in a direction intersecting with a q-axis of the rotating electrical machine.   The rotating electric machine according to claim 10, wherein the permanent magnet is magnetized in a direction inclined by a predetermined angle θ with respect to a direction orthogonal to the q-axis.   The rotating electrical machine according to claim 11, wherein the predetermined angle θ is set in a range of 0 ° <θ ≦ 45 °. The rotor core is composed of a plurality of electromagnetic steel plates laminated in the axial direction,
A rotating shaft attached to the inner periphery of the rotor core;
A plate that surrounds the rotating shaft and is attached so as to cover an axial end surface of the rotor core made of the plurality of electromagnetic steel plates;
A first engaging portion is formed on the outer peripheral portion of the rotating shaft portion,
The rotating electrical machine according to any one of claims 1 to 12, wherein a second engaging portion that engages with the first engaging portion of the rotating shaft portion is formed on an inner peripheral portion of the plate. .

Images