JP2013021844A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine that prevents a reduction in amount of magnetic flux that reaches a stator core from a rotor core.SOLUTION: A motor 100 (rotary electric machine) includes: a rotor core 22; stator teeth 11 that are arranged so as to face an outer edge of the rotor core 22; and permanent magnets 23a and 23b that extend radially from the vicinity of an inner edge, to the vicinity of the outer edge, of the rotor core 22 and that also extend axially so as to have respective portions projecting from axial end surfaces of the rotor core 22.

Description

  The present invention relates to a rotating electrical machine, and more particularly, to a rotating electrical machine including a permanent magnet extending in the axial direction.

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

  Patent Document 1 discloses a magnetic pole member (rotor core), a stator core disposed so as to face the outer periphery of the magnetic pole member, and a magnet (permanent magnet) embedded in the magnetic pole member so as to extend in the axial direction. A rotor structure of a permanent magnet type electric motor (rotating electric machine) including the above is disclosed. In this permanent magnet type electric motor, the end portion in the axial direction of the magnet is formed so as to be flush with the end surface in the axial direction of the magnetic pole member.

Japanese Patent Laid-Open No. 1-144337

  However, in the permanent magnet type electric motor (rotary electric machine) disclosed in Patent Document 1, the portion (end portion in the axial direction) where the magnetic flux of the magnet (permanent magnet) easily leaks is the end face in the axial direction of the magnetic pole member (rotor core). Since they are formed so as to be flush with each other, magnetic flux leakage occurs near the end in the axial direction of the magnetic pole member. For this reason, there exists a problem that the quantity of the magnetic flux which reaches | attains a stator core from a magnetic pole member (rotor core) reduces.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to provide a rotating electrical machine capable of suppressing a reduction in the amount of magnetic flux reaching the stator core from the rotor core. Is to provide.

  To achieve the above object, a rotating electrical machine according to one aspect of the present invention includes a rotor core, a stator core disposed so as to face the outer periphery of the rotor core, and a radial direction from the vicinity of the inner periphery of the rotor core to the vicinity of the outer periphery. And a permanent magnet extending in the axial direction so as to have a portion protruding from the end surface in the axial direction of the rotor core.

  In the rotating electrical machine according to one aspect of the present invention, as described above, the permanent magnet is formed so as to extend in the axial direction so as to have a portion protruding from the end surface in the axial direction of the rotor core. It is possible to dispose the easy portion (the end portion in the axial direction) so as to protrude outward from the end surface in the axial direction of the rotor core. As a result, magnetic flux leakage in the vicinity of the end of the rotor core in the axial direction can be reduced, so that it is possible to suppress a decrease in the amount of magnetic flux reaching the stator core from the rotor core. As a result, the output of the rotating electrical machine can be increased.

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 the figure 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 an enlarged 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 state which removed the shaft and plate from the rotor of the electric motor by one Embodiment of this invention. It is the perspective view which showed the plate of the rotor of the electric motor by one Embodiment of this invention. It is sectional drawing along the axial direction of the electric motor by the modification of one Embodiment of this invention.

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

  First, with reference to FIGS. 1-6, 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 plurality of electromagnetic steel plates (see FIG. 2) stacked in the axial direction. The shaft 21 is an example of the “rotating shaft” in the present invention.

  Here, in the present embodiment, as shown in FIG. 2, the axial length L <b> 1 of the rotor core 22 is formed to be smaller than the axial length L <b> 2 of the stator teeth 11. In addition, it is preferable that the distance D of the direction along the axial direction between the axial direction edge part of the rotor core 22 and the axial direction edge part of the stator teeth 11 shall be 1 mm or more and 5 mm or less.

  In the present embodiment, as shown in FIGS. 3 to 5, the rotor core 22 includes a plurality of (in this embodiment, five) core portions 22 a that function as the N poles of the rotor 2 and the S poles of the rotor 2. And a plurality of (in the present embodiment, five) core portions 22b. 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 (in the present embodiment, approximately 36 ° intervals). In addition, a bar insertion hole 22c into which a bar 30 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.

  As shown in FIGS. 3-5, the outer peripheral surface of the permanent magnet 23a (23b) which adjoins the core part 22a (22b) in the circumferential direction both ends of each outer peripheral part of several core part 22a (22b). A magnet covering portion 22d is provided to cover a portion of the core portion 22a (22b). In addition, as shown in FIG. 1, the part which is not covered with the magnet coating | coated part 22d of the outer peripheral surface of the permanent magnet 23a (23b) is exposed to the stator 1 side.

  As shown in FIG. 2, the permanent magnet 23a is formed so as to extend in the axial direction between two plates 24 that sandwich the rotor core 22 from both sides in the axial direction. 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. In this embodiment, as shown in FIGS. 2 and 5, the permanent magnets 23 a and 23 b extend in the axial direction so as to have portions (protruding portions 23 c) that protrude outward from both axial end surfaces of the rotor core 22. Is formed. Note that the protrusion height H1 of the protrusion 23c is preferably set to 3 mm or more and 7 mm or less.

  As shown in FIGS. 1 to 5, the permanent magnets 23 a and 23 b are provided so as to extend in the radial direction from the inner peripheral portion of the rotor core 22 to the vicinity of the outer peripheral portion. As shown in FIGS. 3 and 4, the permanent magnets 23 a and 23 b have inner peripheral surfaces of the permanent magnets 23 a and 23 b between the adjacent core portions 22 a and 22 b of the plurality of core portions 22 a and 22 b. It arrange | positions so that the outer peripheral surface of the shaft 21 may be contact | connected. Further, the permanent magnets 23a and 23b are arranged so as to be adjacent to each other in the circumferential direction without interposing the core portions 22a and 22b.

  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. Specifically, as shown in FIG. 4, the permanent magnet 23 a (23 b) is a corner portion adjacent to the core portion 22 a (22 b) of the end portions on the outer peripheral portion side of the rotor core 22 of the permanent magnet 23 a (23 b). And the corner | angular part adjacent to permanent magnet 23b (23a) among the edge parts by the side of the inner peripheral part of rotor core 22 of permanent magnet 23a (23b) is formed so that it may become 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 FIGS. 1, 2, and 6, the plate 24 is formed in a plate shape having an 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. As shown in FIG. 2, the thickness t1 of the plate 24 is formed to be larger than the protruding height H1 of the permanent magnet 23a (23b) from the end surface of the rotor core 22 in the axial direction. Further, the thickness t1 of the plate 24 is preferably set to 5 mm or more and 10 mm or less.

  Further, as shown in FIG. 2, two plates 24 are provided so as to sandwich the rotor core 22 and the permanent magnets 23a and 23b from both sides in the axial direction. Specifically, the plate 24 covers both end surfaces of the rotor core 22 in the axial direction, and does not expose the surfaces of the portions (projecting portions 23c) of the permanent magnets 23a and 23b that protrude from the end surfaces of the rotor core 22 in the axial direction. It is formed to cover. In the present embodiment, as shown in FIGS. 2 and 6, the surface of the plate 24 covering the rotor core 22 has the shape of the protrusions 23c of the permanent magnets 23a and 23b (the shape of a prism having a height H1 (see FIG. 5)). ) Corresponding to () is formed. The recess 24a of the plate 24 has a depth d corresponding to the protrusion height H1 of the protrusion 23c of the permanent magnets 23a and 23b. That is, the protrusions 23 c of the permanent magnets 23 a and 23 b are configured to be fitted into the recesses 24 a of the plate 24.

  As shown in FIGS. 1 and 6, a shaft insertion portion 24 b having an opening is provided on the inner peripheral portion of the plate 24 (near the central portion of the disk-shaped plate 24). A gear-like engagement portion 24c is formed in the shaft insertion portion 24b. Here, a gear-like (see FIG. 1) engaging portion 21a corresponding to the engaging portion 24c 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-like member 24c and the shaft 21 are fixed by engaging (meshing) the gear-like engaging portion 24c of the plate 24 and the gear-like engaging portion 21a of the shaft 21. The engaging portion 21a is an example of the “first engaging portion” in the present invention, and the engaging portion 24c is an example of the “second engaging portion” in the present invention.

  A plurality of (10 in this embodiment) bar insertion holes 24d 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 24d are provided at substantially equal angular intervals in the vicinity of the outer peripheral portion of the disk-shaped plate 24 (approximately 36 ° intervals in this embodiment) along the circumferential direction. As shown in FIG. 2, a columnar bar 30 extending in the axial direction is inserted into the bar insertion hole 24d of the plate 24 and the bar insertion hole 22c of the core portion 22a (22b).

  In the present embodiment, between the permanent magnet 23a (22b) and the core portion 22a (22b), between the permanent magnet 23a and the permanent magnet 23b, and between the permanent magnet 23a (23b) and the shaft 21, , Filled with an adhesive (not shown).

  Next, with reference to FIGS. 1-6, the assembly procedure of the rotor 2 of the electric motor 100 by one Embodiment of this invention is demonstrated.

  First, as shown in FIG. 3, 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. A plurality of permanent magnets 23 a and 23 b extending in the radial direction and extending in the axial direction are attached to the inside of the motor 22. At this time, as shown in FIGS. 2 and 5, the permanent magnets 23 a and 23 b have permanent magnets inside the rotor core 22 so that both end portions in the axial direction protrude from both end surfaces in the axial direction of the rotor core 22. Install 23a and 23b. At this time, as shown in FIGS. 3 and 4, the inner peripheral surfaces of the permanent magnets 23a and 23b are in contact with the outer peripheral surface of the shaft 21, and the permanent magnets 23a and 23b are between the adjacent core portions 22a and 22b. Permanent magnets 23a and 23b are attached to the inside of the rotor core 22 so as to be adjacent in the circumferential direction. At this time, the adhesive is between the permanent magnet 23a (23b) and the core portion 22a (22b), between the permanent magnet 23a and the permanent magnet 23b, and between the permanent magnet 23a (23b) and the shaft 21. Fill.

  Next, as shown in FIG. 2, a disk-shaped plate 24 (see FIG. 6) is attached from the outside in the axial direction to the shaft 21 to which the rotor core 22 and the permanent magnets 23a and 23b are attached. Specifically, first, the shaft 21 is inserted into the shaft insertion portion 24 b 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 c provided on the shaft insertion portion 24 b of the plate 24. As a result, the shaft 21 and the plate 24 are fixed. At this time, as shown in FIG. 2, a portion (protruding portion) protruding from the axial end surface of the rotor core 22 of the permanent magnets 23 a and 23 b inside the concave portion 24 a formed on the surface of the plate 24 on the rotor core 22 side. 23c) is inserted. At this time, the positions of the bar insertion holes 24d 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 30 is inserted in the axial direction with respect to the bar insertion hole 24d 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 permanent magnets 23a and 23b are formed so as to extend in the axial direction so as to have portions protruding from the axial end surfaces of the rotor core 22 (projecting portions 23c). And the part (axial direction edge part) which magnetic flux of 23b tends to leak can be made to protrude outside the axial direction end surface of the rotor core 22 and can be arrange | positioned. As a result, magnetic flux leakage in the vicinity of the end portion of the rotor core 22 in the axial direction can be reduced, so that the amount of magnetic flux reaching the stator teeth 11 from the rotor core 22 can be suppressed from decreasing. As a result, the output of the electric motor 100 can be increased.

  In the present embodiment, as described above, the permanent magnets 23a and 23b are formed so as to extend in the axial direction so as to have portions (protruding portions 23c) protruding from both end surfaces of the rotor core 22 in the axial direction. As a result, magnetic flux leakage in the vicinity of both end portions of the rotor core 22 in the axial direction can be reduced, so that the amount of magnetic flux reaching the stator teeth 11 from the rotor core 22 can be further suppressed.

  Further, in the present embodiment, as described above, the plate 24 that covers the axial end surface of the rotor core 22 is provided, and the surface of the rotor core 22 of the permanent magnets 23a and 23b on the surface of the plate 24 that covers the axial end surface of the rotor core 22 is provided. A concave portion 24a corresponding to the shape (prism shape) of the portion (protruding portion 23c) protruding from the end surface in the axial direction is formed. Thereby, since the part (protrusion part 23c) which protruded from the end surface of the axial direction of the rotor core 22 of the permanent magnets 23a and 23b can be engage | inserted inside the recessed part 24a, the plate 24 can be attached to the rotor core 22 easily. .

  In the present embodiment, as described above, the plate 24 is formed of a nonmagnetic material (stainless steel, resin, or the like), and the concave portion 24a of the plate 24 protrudes from the end face in the axial direction of the rotor core 22 of the permanent magnets 23a and 23b. It forms so that the surface of the part (protrusion part 23c) may be covered without exposing. As a result, the end face in the axial direction of the rotor core 22 and the surface of the portion of the permanent magnets 23a and 23b protruding from the end face in the axial direction of the rotor core 22 (projecting portion 23c) are covered with the plate 24 made of a nonmagnetic material. Therefore, magnetic flux leakage in the vicinity of the end portions on both sides in the axial direction of the rotor core 22 can be further reduced.

  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 engaging portion 21a is formed on the outer peripheral portion of the shaft 21 and is engaged with the engaging portion 21a of the shaft 21. The engaging portion 24b to be formed is formed on the inner peripheral portion of the plate. Thereby, the shaft 21 and the plate 24 can be firmly fixed by engaging the engaging portion 21 a of the shaft 21 and the engaging portion 24 b of the plate 24.

  Further, in the present embodiment, as described above, the axial length L1 of the rotor core 22 is formed to be smaller than the axial length L2 of the stator teeth 11. Accordingly, it is possible to easily suppress the magnetic flux from the rotor core 22 toward the stator teeth 11 from spreading outward in the axial direction and not reaching the stator teeth 11. That is, it is possible to easily suppress a decrease in the amount of magnetic flux reaching the stator teeth 11 from the rotor core 22.

  In the present embodiment, as described above, the permanent magnets 23 a and 23 b are formed so that 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, since the circumferential width of the end portions of the permanent magnets 23a and 23b on the inner peripheral side of the rotor core 22 is reduced, the surface areas of the permanent magnets 23a and 23b in contact with the inner peripheral portion of the rotor core 22 are increased. Output can be further increased.

  In the present embodiment, as described above, the permanent magnets 23a and 23b 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. To do. Thereby, the permanent magnets 23a and 23b are formed so as to have a cross section of a shape other than the rectangular shape (for example, a sector shape in which the circumferential width gradually increases from the inner peripheral portion toward the outer peripheral portion of the rotor core 22). Compared to the case, the permanent magnets 23a and 23b whose width in the circumferential direction gradually increases from the inner peripheral portion of the rotor core 22 toward the outer peripheral portion can be easily manufactured.

  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 configured so as to include the plurality of core portions 22a and 22b arranged at intervals in the circumferential direction, and the adjacent one of the plurality of core portions 22a and 22b. The permanent magnets 23 a and 23 b are arranged between the core portions 22 a and 22 b so that the inner peripheral surfaces of the permanent magnets 23 a and 23 b are in contact with the outer peripheral surface of the shaft 21. 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, it is possible to prevent a part of the magnetic flux generated from the permanent magnets 23a and 23b from circulating through the outer peripheral part or the inner peripheral part of the rotor core 22 without flowing to the stator teeth 11 side. it can. As a result, the leakage magnetic flux can be reduced, so that the output of the electric motor 100 can be further increased.

  In the present embodiment, as described above, the magnet covering portion 22d that covers the 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) is used as the core portion 22a. (22b) is provided on the outer periphery. In addition, the inner peripheral surfaces of the permanent magnets 23a and 23b are in contact with the outer peripheral surface of the shaft 21, and 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 exposed. 23b is disposed between adjacent core portions 22a and 22b. Thereby, it can suppress that permanent magnet 23a and 23b remove | deviate by the centrifugal force at the time of the rotor core 22 (core part 22a and 22b) rotating by the magnet coating | coated part 22d.

  Further, by covering the portion of the outer peripheral surface of the permanent magnet 23a (23b) on the core portion 22a (22b) side with the magnet covering portion 22d, a region in which the magnetic flux flowing on the stator teeth 11 side on the outer peripheral surface of the rotor core 22 is generated is generated. Since the area can be increased, the change in magnetic flux flowing through the gap 3 between the rotor core 22 (core portions 22a and 22b) and the stator teeth 11 when the rotor core 22 (core portions 22a and 22b) rotates is smoother. Can be. Thereby, the cogging torque of the electric motor 100 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. As a result, the output of the electric motor 100 can be further increased.

  Further, in the present embodiment, as described above, the two permanent magnets 23a and 23b are arranged between the two adjacent core portions 22a and 22b so as to be adjacent in the circumferential direction without the core portions 22a and 22b being interposed. To do. Thereby, unlike the case where the permanent magnets 23a and 23b are adjacent to each other via the core portion 22a or 22b, the total distance of the gaps in the magnetic circuit composed of the permanent magnet 23a and the permanent magnet 23b can be reduced. The operating point of the permanent magnets 23a and 23b can be increased. 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.

  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, an example in which the permanent magnet is formed so as to have portions protruding from both end faces in the axial direction of the rotor core has been shown, but the present invention is not limited to this. In this invention, you may form a permanent magnet so that it may have a part which protrudes only from one end surface of the axial direction of a rotor core.

  Further, in the above embodiment, an example is shown in which a plate that covers the end face in the axial direction of the rotor core is provided, and the portion that protrudes from the end face in the axial direction of the rotor core of the permanent magnet is covered without being exposed. Not limited to this. In the present invention, it is not necessary to provide a plate that covers the axial end surface of the rotor core. That is, the part which protruded from the end surface of the axial direction of the rotor core of the permanent magnet may be exposed.

  Further, in the above embodiment, as shown in FIG. 2, the plate 24 is recessed so as to cover a portion (protruding portion 23c) protruding from the axial end surface of the rotor core 22 of the permanent magnet 23a (23b) without exposing it. Although the example which forms 24a was shown, this invention is not restricted to this. In the present invention, as in the modification shown in FIG. 7, the hole 124 a is formed in the plate 124 so as to expose the portion (protruding portion 23 f) that protrudes from the axial end surface of the rotor core 22 of the permanent magnet 23 d (23 e). It may be formed.

  As shown in FIG. 7, the permanent magnet 23 d (23 e) attached to the rotor 2 a of the electric motor 100 a (rotary electric machine) according to this modification is exposed at both ends in the axial direction through the holes 124 a of the plate 124. Thus, it is formed to extend in the axial direction. That is, the protrusion height H2 of the portion (protruding portion 23f) protruding from the end surface in the axial direction of the rotor core 22 of the permanent magnet 23d (23e) is formed to be larger than the thickness t2 of the plate 124.

  In this modified example, as described above, the permanent magnet 23d (23e) is exposed through the hole 124a of the plate 124. As a result, when the rotor 2a rotates, the air inside the electric motor 100a is agitated by the portion exposed through the hole 124a of the plate 124 of the permanent magnet 23d (23e). Can be cooled. As a result, the output of the electric motor 100a can be effectively increased. Further, since the portion exposed through the hole 124a of the plate 124 of the permanent magnet 23d (23e) is cooled by touching the air inside the electric motor 100a, the permanent magnet 23d (23e) is demagnetized by heat. Can be suppressed.

  In the above embodiment, the example in which the axial length of the rotor core is made smaller than the axial length of the stator teeth (stator core) is shown, but the present invention is not limited to this. In the present invention, the axial length of the rotor core may be equal to the axial length of the stator core.

  In the above embodiment, an example is shown in which the permanent magnet is 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 toward the outer peripheral portion. Is not limited to this. In the present invention, the permanent magnet may be formed to have a cross section of a shape other than a rectangular shape (for example, a sector shape in which the circumferential width gradually increases from the inner peripheral portion toward the outer peripheral portion of the rotor core). .

  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, although the example which comprises a rotor core by a some core part was shown, this invention is not limited to this. In this invention, you may comprise a rotor core as one component by connecting the outer peripheral part or inner peripheral part of a some core part.

  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, although the magnet coating | coated part was provided in the core part and the part by the side of the core part of the outer peripheral surface of a permanent magnet was covered with the magnet coating | coated part, this invention is not limited to this. In the present invention, it is not necessary to provide a magnet covering part in the core part.

  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 24c (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 Rotor core 22a, 22b Core portion 22d Magnet covering portion 23a, 23b, 23d, 23e Permanent magnet 24 Plate 24a Recessed portion 24c Engaging portion (second engaging portion)
124 Plate 124a Hole 100, 100a Electric motor (rotary electric machine)

Claims (14)

Rotor core,
A stator core disposed to face the outer periphery of the rotor core;
A rotating electrical machine comprising: a permanent magnet extending in a radial direction from the vicinity of an inner peripheral portion of the rotor core to the vicinity of an outer peripheral portion and extending in an axial direction so as to have a portion protruding from an end face in the axial direction of the rotor core.   2. The rotating electrical machine according to claim 1, wherein the permanent magnet is formed to extend in the axial direction so as to have portions protruding from both axial end surfaces of the rotor core. A plate attached so as to cover the axial end surface of the rotor core;
The surface of the plate covering the end face in the axial direction of the rotor core is formed with a recess or a hole corresponding to the shape of the portion of the permanent magnet protruding from the end face in the axial direction of the rotor core. 2. The rotating electrical machine according to 2. The plate is made of a non-magnetic material,
The concave portion is formed on the surface of the plate covering the end face in the axial direction of the rotor core,
The rotating electrical machine according to claim 3, wherein the concave portion is formed so as to cover a surface of a portion of the permanent magnet that protrudes from an end surface in the axial direction of the rotor core without exposing the concave portion. A rotating shaft portion attached to the inner peripheral portion of the rotor core;
A first engaging portion is formed on the outer peripheral portion of the rotating shaft portion,
The rotating electrical machine according to claim 3 or 4, 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.   The rotating electrical machine according to any one of claims 1 to 5, wherein the rotor core is formed such that an axial length thereof is smaller than an axial length of the stator core.   The rotating electric machine according to any one of claims 1 to 6, wherein the permanent magnet is formed so that a circumferential width gradually increases from an inner peripheral portion to an outer peripheral portion of the rotor core.   The rotating electrical machine according to claim 7, wherein the permanent magnet is formed to have a rectangular cross section in which a circumferential width gradually increases from an inner peripheral portion to an outer peripheral portion of the rotor core.   The rotating electrical machine according to claim 1, wherein the permanent magnet is magnetized in a direction intersecting with a q-axis of the rotating electrical machine.   The rotating electrical machine according to claim 9, 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 10, wherein the predetermined angle θ is set in a range of 0 ° <θ ≦ 45 °. A rotating shaft portion attached to the inner peripheral portion of the rotor core;
The rotor core is configured to include a plurality of core portions arranged at intervals in the circumferential direction,
The said permanent magnet is arrange | positioned so that the internal peripheral surface of the said permanent magnet may contact | connect the outer peripheral surface of the said rotating shaft part between the adjacent core parts among these core parts. The rotating electrical machine according to any one of the above. 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 has an inner peripheral surface of the permanent magnet that is in contact with an outer peripheral surface of the rotating shaft portion between adjacent core portions of the plurality of core portions, and the outer peripheral surface of the permanent magnet is covered with the magnet. The rotating electrical machine according to claim 12, wherein the rotating electric machine is disposed so that a portion not covered with the portion is exposed.   The said permanent magnet is arrange | positioned so that two may adjoin in the circumferential direction between the two adjacent core parts among these several core parts, without passing through the said core part. The rotating electrical machine described.

Images