JP6259805B2 - Rotor and motor - Google Patents

Description

  The present invention relates to a rotor and a motor.

  As a rotor used in a motor, a pair of rotor cores each having a plurality of claw-shaped magnetic poles in the circumferential direction are combined, and field magnets are arranged between them to alternately change the claw-shaped magnetic poles to different magnetic poles. There is a so-called permanent magnet field Landell-type rotor that functions in the same manner (for example, see Patent Document 1).

Japanese Utility Model Publication No. 5-43749

  By the way, in the rotor as described above, as shown in FIG. 8, an assembly SA10 in which a pair of rotor cores 101, 102 having the same shape is assembled, and an assembly SA20 in which a pair of rotor cores 103, 104 having the same shape are assembled. Can be a so-called tandem structure in which a plurality of layers are stacked in the axial direction (two steps in FIG. 8). By configuring the rotor 100 in this way, it is possible to improve the motor output. However, in a so-called permanent magnet field rundel-type rotor, the surface magnetic flux of the rotor is likely to contain harmonics, which may increase the cogging torque.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a rotor and a motor that can reduce cogging torque.

A rotor that solves the above problems includes a plurality of pairs of rotor cores arranged along a rotation axis, and a field magnet that is arranged between each pair of rotor cores and is magnetized along the axial direction. The rotor core has a plurality of claw-shaped magnetic poles protruding from the outer peripheral portion of the disk-shaped core base and extending in opposite directions along the axial direction with a constant circumferential width, and arranged alternately along the circumferential direction. Each of the claw-shaped magnetic poles is formed so that a gap between circumferential end faces of the claw-shaped magnetic poles is linear along the axial direction, and the plurality of pairs of rotor cores are arranged adjacent to each other, are arranged in a manner deviated in the circumferential direction between the rotor core of each pair, the so axially opposite poles do not contact between each pair of rotor cores are offset the circumferentially between each pair of rotor cores, each Circumferential direction between a pair of rotor cores The shift angle θ is 180 ° × n / MS−5 ° ≦ θ ≦ 180 ° ×, where MS is the least common multiple of the number of magnetic poles and the number of slots of the stator facing the rotor, and n = 1 or 2. It is set in the range of n / MS + 5 ° .

A rotor that solves the above problems includes a plurality of pairs of rotor cores arranged along a rotation axis, and a field magnet that is arranged between each pair of rotor cores and is magnetized along the axial direction. The rotor core has a plurality of claw-shaped magnetic poles that protrude from the outer periphery of the disk-shaped core base and extend in opposite directions along the axial direction, and are alternately arranged along the circumferential direction, The plurality of pairs of rotor cores are arranged in such a manner that rotor cores having the same magnetic pole are adjacent to each other and are displaced in the circumferential direction between each pair of rotor cores, and different poles do not contact in the axial direction between each pair of rotor cores. as such, the are displaced in the circumferential direction between each pair of the rotor core, each pair of tips of the claw-shaped magnetic poles of the same polarity are displaced between the rotor core abuts said same-polarity between each pair of rotor core The claw-shaped magnetic pole With proximal to each other is in contact offset, wherein the offset angle θ in the circumferential direction between each pair of the rotor core, the least common multiple of the number of slots magnetic poles and the rotor facing the stator and MS, n = In the case of 1 or 2, it is set in the range of 180 ° × n / MS−5 ° ≦ θ ≦ 180 ° × n / MS + 5 ° .

A rotor that solves the above problems includes a plurality of pairs of rotor cores arranged along a rotation axis, and a field magnet that is arranged between each pair of rotor cores and is magnetized along the axial direction. The rotor core has a plurality of claw-shaped magnetic poles that protrude from the outer peripheral portion of the disk-shaped core base and extend in opposite directions along the axial direction, and are alternately arranged along the circumferential direction. The pair of rotor cores includes an interpole magnet magnetized between the claw-shaped magnetic poles adjacent in the circumferential direction so as to have the same polarity as that of the claw-shaped magnetic pole adjacent in the circumferential direction. A back auxiliary magnet magnetized so that the same polarity as that of the claw-shaped magnetic pole is opposed to the radially inner side surface of the magnetic pole, and the plurality of pairs of rotor cores are arranged adjacent to each other. Between each pair of rotor cores The rotor cores are arranged in such a manner that they are shifted in the circumferential direction, and are offset in the circumferential direction between the pair of rotor cores so that different polarities do not contact each other in the axial direction between the pair of rotor cores. The interpole magnets magnetized in the direction and axially adjacent to each other are displaced in the circumferential direction, and the deviation angle θ in the circumferential direction between the pair of rotor cores is the circumferential direction of the interpole magnets. When the width is θm, the range is set to 0 <θ ≦ θm / 2 .

  According to each of the above configurations, the plurality of pairs of rotor cores are arranged in such a manner that the rotor cores having the same magnetic pole are adjacent to each other and shifted in the circumferential direction between each pair of rotor cores. Therefore, the cogging torques out of phase can cancel each other out, and the combined cogging torque can be reduced to suppress the occurrence of vibration.

A motor that solves the above problem includes the rotor described above.
According to this configuration, a motor capable of reducing cogging torque can be provided.

  Therefore, according to the above described invention, it is possible to provide a rotor and a motor that can reduce cogging torque.

Sectional drawing of the motor in embodiment. The perspective view of the rotor in the same as the above. Sectional drawing of the rotor in the same as the above. The graph which shows the relationship between the shift | offset | difference angle (theta) between rotor cores in the same as above, and the amount of flux linkages. The graph which shows the relationship between deviation angle (theta) between rotor cores in the same as above, and cogging torque. The perspective view of the rotor in another example. The graph which shows the relationship between the shift | offset | difference angle (theta) between rotor cores in another example, and the amount of flux linkages. The perspective view for demonstrating the conventional rotor structure.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, a motor case 2 of a motor 1 closes a cylindrical housing 3 formed in a bottomed cylindrical shape and an opening on the front side (left side in FIG. 1) of the cylindrical housing 3. And a front end plate 4. A circuit housing box 5 that houses a power circuit such as a circuit board is attached to an end of the cylindrical housing 3 on the rear side (right side in FIG. 1).

  A stator 6 is fixed to the inner peripheral surface of the cylindrical housing 3. The stator 6 includes an armature core 7 having a plurality of teeth extending radially inward, and a segment conductor (SC) winding 8 wound around the teeth of the armature core 7. The rotor 11 of the motor 1 has a rotating shaft 12 and is disposed inside the stator 6. The rotating shaft 12 is a non-magnetic metal shaft, and is rotatably supported by bearings 13 and 14 supported by the bottom 3 a of the cylindrical housing 3 and the front end plate 4.

As shown in FIGS. 2 and 3, the rotor 11 includes first and second assemblies SA1 and SA2.
2 and 3, the first assembly SA1 includes a pair of first and second rotor cores 21 and 22, a ring magnet 23 as a field magnet, a back auxiliary magnet 24, and an interpole magnet 25. With. 2 and 3 indicate the magnetization directions (from the S pole to the N pole) of the magnets 23, 24, and 25.

  As shown in FIG. 2, the first rotor core 21 of the first assembly SA1 has a plurality of (five in this embodiment) first claws at an equal interval on the outer periphery of a substantially disk-shaped first core base 21a. A magnetic pole 21b is formed. The first claw-shaped magnetic pole 21b has a protrusion 21c that protrudes radially outward with respect to the first core base 21a, and a claw 21d that extends from the protrusion 21c in the axial direction.

  The circumferential end surfaces 21e, 21f of the first claw-shaped magnetic pole 21b are flat surfaces extending in the radial direction (not inclined with respect to the radial direction when viewed from the axial direction), and the projecting portion 21c has a fan-shaped cross section in the direction perpendicular to the axis. It is said that. A claw portion 21d is formed at the end portion on the radially outer side of the protruding portion 21c so as to extend along the axial direction with a constant circumferential width. The circumferential angle of each first claw-shaped magnetic pole 21b, that is, the angle between the circumferential end surfaces 21e and 21f is set to be smaller than the angle of the gap between the first claw-shaped magnetic poles 21b adjacent in the circumferential direction.

  As shown in FIGS. 2 and 3, the second rotor core 22 has protrusions 22 c of a plurality of second claw-shaped magnetic poles 22 b formed at equal intervals on the outer periphery of a substantially disk-shaped second core base 22 a. . The projecting portion 22c has a fan-shaped cross section in the direction perpendicular to the axis, and a claw portion 22d is formed to extend along the axial direction at the radially outer end portion.

  The circumferential end surfaces 22e and 22f of the second claw-shaped magnetic pole 22b are flat surfaces extending in the radial direction, and the second claw-shaped magnetic pole 22b has a fan-shaped cross section in the direction perpendicular to the axis. The circumferential angle of each second claw-shaped magnetic pole 22b, that is, the angle between the circumferential end faces 22e and 22f is set smaller than the angle of the gap between the second claw-shaped magnetic poles 22b adjacent in the circumferential direction.

  The second rotor core 22 is disposed between the first core base 21a and the first core base 21a so that the claw portions 22d of the second claw-shaped magnetic poles 22b are disposed between the claw portions 21d of the corresponding first claw-shaped magnetic poles 21b. The annular magnet 23 (see FIG. 3) is disposed (sandwiched) between the two core bases 22a in the axial direction and assembled to the first rotor core 21. At this time, one end surface 21e of the first claw-shaped magnetic pole 21b and the other circumferential end surface 22f of the second claw-shaped magnetic pole 22b are formed so as to be parallel to each other in the axial direction. , 22f is formed so as to be substantially linear along the axial direction. Since the other circumferential end face 21f of the first claw-shaped magnetic pole 21b and one circumferential end face 22e of the second claw-shaped magnetic pole 22b are formed so as to be parallel along the axial direction, the end faces 21f, The gap between 22e is formed so as to be substantially linear along the axial direction.

  Here, the outer diameter of the annular magnet 23 is set to be the same as the outer diameters of the first and second core bases 21a and 22a, and the first claw-shaped magnetic pole 21b is the first magnetic pole (N pole in this embodiment). And the second claw-shaped magnetic pole 22b is magnetized in the axial direction so as to function as a second magnetic pole (S pole in this embodiment).

  A back auxiliary magnet 24 is disposed between the back surface 21g (radially inner surface) of each first claw-shaped magnetic pole 21b and the outer peripheral surface 22h of the second core base 22a. Similarly to the first claw-shaped magnetic pole 21b, a back auxiliary magnet 24 is disposed on the back surface 22g of each second claw-shaped magnetic pole 22b. Each of the back auxiliary magnets 24 has a fan-shaped cross section in the direction perpendicular to the axis, and the side contacting the back surface 21g of the first claw-shaped magnetic pole 21b and the side contacting the outer peripheral surface 21h of the first core base 21a are N poles. It is magnetized to become. Each of the back auxiliary magnets 24 has the same polarity as the second core base 22a on the side contacting the outer peripheral surface 22h of the second core base 22a and the side contacting the back surface 22g of the second claw-shaped magnetic pole 22b. It is magnetized so that

  The back auxiliary magnets 24 overlap each other in the axial direction at the axial position of the rotor 11 where the annular magnet 23 is arranged, in other words, from both sides of the rotor 11 until reaching the axial position where the annular magnet 23 is arranged. The axial length is set so as to be arranged.

  Further, as shown in FIG. 2, an interpole magnet 25 is arranged between the first claw-shaped magnetic pole 21b and the second claw-shaped magnetic pole 22b in the circumferential direction. More specifically, the interpole magnet 25 of the present embodiment is disposed between one circumferential end surface 21e of the first claw-shaped magnetic pole 21b and the other circumferential end surface 22f of the second claw-shaped magnetic pole 22b. . The other interpolar magnet 25 is disposed between the other circumferential end face 21f of the first claw-shaped magnetic pole 21b and one circumferential end face 22e of the second claw-shaped magnetic pole 22b. Each inter-pole magnet 25 has the same polarity as the first and second claw-shaped magnetic poles 21b and 22b (the first claw-shaped magnetic pole 21b side is the N pole, and the second claw-shaped magnetic pole 22b side is the S pole. Like) is magnetized in the circumferential direction. A gap K for preventing leakage magnetic flux is provided on the rotating shaft 12 side of each interpolar magnet 25 (inside in the radial direction of the rotor 11).

  The second assembly SA2 has substantially the same shape as the first assembly SA1, a pair of third and fourth rotor cores 31, 32, an annular magnet 33 as a field magnet, a back auxiliary magnet 34, And an inter-pole magnet 35. 2 and 3 indicate the magnetization directions (from the S pole to the N pole) of the magnets 33, 34, and 35.

  As shown in FIGS. 2 and 3, the third rotor core 31 constituting the second assembly SA <b> 2 is obtained by inverting the second rotor core 22 with respect to the direction perpendicular to the axis, and has a substantially disc-shaped third core base. A plurality (five in the present embodiment) of third claw-shaped magnetic poles 31b are formed at equal intervals on the outer periphery of 31a. The third claw-shaped magnetic pole 31b has a protrusion 31c that protrudes radially outward with respect to the third core base 31a, and a claw 31d that extends from the protrusion 31c in the axial direction.

  As shown in FIG. 3, the third rotor core 31 is assembled to the rotary shaft 12 such that the end surface on one end side in the axial direction is in contact with the end surface on the other end side in the axial direction of the second rotor core 22. For this reason, the said claw part 31d is comprised so that the claw part 22d of the 2nd rotor core 22 may be extended to an axial direction opposite side.

  The circumferential end surfaces 31e and 31f of the third claw-shaped magnetic pole 31b are flat surfaces extending in the radial direction (not inclined with respect to the radial direction when viewed from the axial direction), and the projecting portion 31c has a fan-shaped cross section in the direction perpendicular to the axis. It is said that. A claw portion 31d is formed at the end portion on the radially outer side of the protruding portion 31c so as to extend along the axial direction with a constant circumferential width. The circumferential angle of each third claw-shaped magnetic pole 31b, that is, the angle between the circumferential end surfaces 31e and 31f is set to be smaller than the angle of the gap between the third claw-shaped magnetic poles 31b adjacent in the circumferential direction.

  On the other hand, the fourth rotor core 32 constituting the second assembly SA2 is obtained by inverting the first rotor core 21 with respect to the direction perpendicular to the axis, and has substantially the same shape as the third rotor core 31 and is substantially disc-shaped. Projections 32c of a plurality of fourth claw-shaped magnetic poles 32b are formed at equal intervals on the outer periphery of the fourth core base 32a. The projecting portion 32c has a fan-shaped cross section in the direction perpendicular to the axis, and a claw portion 32d extends along the axial direction at an end portion on the radially outer side.

  The circumferential end surfaces 32e and 32f of the fourth claw-shaped magnetic pole 32b are flat surfaces extending in the radial direction, and the fourth claw-shaped magnetic pole 32b has a fan-shaped cross section in the direction perpendicular to the axis. The circumferential angle of each fourth claw-shaped magnetic pole 32b, that is, the angle between the circumferential end faces 21e and 32f is set smaller than the angle of the gap between the fourth claw-shaped magnetic poles 32b adjacent in the circumferential direction.

  The fourth rotor core 32 is arranged so that the claw portions 32d of the fourth claw-shaped magnetic poles 32b are disposed between the claw portions 31d of the corresponding third claw-shaped magnetic poles 31b. The annular magnet 33 (see FIG. 3) is disposed (sandwiched) between the four core bases 32a in the axial direction and assembled to the third rotor core 31. At this time, one end surface 31e of the third claw-shaped magnetic pole 31b and the other circumferential end surface 32f of the fourth claw-shaped magnetic pole 32b are formed so as to be parallel to each other along the axial direction. , 32f is formed so as to be substantially linear along the axial direction. Further, since the other circumferential end face 31f of the third claw-shaped magnetic pole 31b and one circumferential end face 32e of the fourth claw-shaped magnetic pole 32b are formed so as to be parallel along the axial direction, each end face 31f, The gap between 32e is formed to be substantially linear along the axial direction. In addition, the fourth claw-shaped magnetic pole 32b has the third rotor core 31 and the claw portion 32d so that the axial tip surface 32i abuts the axial tip surface 21i of the claw portion 21d of the first claw-shaped magnetic pole 21b in the axial direction. The rotary shaft 12 is assembled.

  At this time, the pair of first and second rotor cores 21 and 22 constituting the first assembly SA1 and the pair of third and fourth rotor cores 31 and 32 constituting the second assembly SA2 are arranged in the circumferential direction. The rotary shaft 12 is assembled so as to be shifted by a shift angle θ which is a predetermined angle. Here, the deviation angle θ is 0 <θ ≦ 10 ° (indicated as X1 in FIG. 4), where 0 <θ ≦ 50 ° / P when the number of pole pairs is P (5 in this embodiment). It is desirable to set the deviation angle θ to 0 <θ ≦ 7 ° (indicated as X2 in FIG. 4), which is in the range of 0 <θ ≦ 35 ° / P. More preferably, it is desirable to set the deviation angle θ to 0 <θ ≦ 4 ° (indicated as X3 in FIG. 4) in the range of 0 <θ ≦ 20 ° / P.

  The annular magnet 33 is provided so that the annular magnet 23 and the magnetization direction thereof are opposite to each other. The outer diameter of the annular magnet 33 is set to be the same as the outer diameters of the third and fourth core bases 31a and 32a, and the third claw-shaped magnetic pole 31b functions as a second magnetic pole (S pole in this embodiment). The fourth claw-shaped magnetic pole 32b is magnetized in the axial direction so as to function as a first magnetic pole (N pole in this embodiment).

  A back auxiliary magnet 34 is disposed between the back surface 31g (radially inner surface) of each third claw-shaped magnetic pole 31b and the outer peripheral surface 32h of the fourth core base 32a. Similarly to the third claw-shaped magnetic pole 31b, a back auxiliary magnet 34 is disposed on the back surface 32g of each fourth claw-shaped magnetic pole 32b. Each of the back auxiliary magnets 34 has a fan-shaped cross section in the direction perpendicular to the axis, and the side that contacts the back surface 31g of the third claw-shaped magnetic pole 31b and the side that contacts the outer peripheral surface 31h of the third core base 31a are S poles. It is magnetized to become. Each of the back auxiliary magnets 34 has the same polarity as the fourth core base 32a on the side contacting the outer peripheral surface 32h of the fourth core base 32a and the side contacting the back surface 32g of the fourth claw-shaped magnetic pole 32b. It is magnetized so that

  The back auxiliary magnets 34 overlap each other in the axial direction at the axial position of the rotor 11 where the annular magnet 33 is arranged, in other words, from both sides of the rotor 11 until reaching the axial position where the annular magnet 23 is arranged. The axial length is set so as to be arranged.

  An inter-pole magnet 35 is disposed between the circumferential direction of the third claw-shaped magnetic pole 31b and the fourth claw-shaped magnetic pole 32b. More specifically, the interpole magnet 35 of the present embodiment is disposed between the other circumferential end surface 31f of the third claw-shaped magnetic pole 31b and one circumferential end surface 32e of the fourth claw-shaped magnetic pole 32b. . The other interpole magnet 35 is disposed between one circumferential end face 31e of the third claw-shaped magnetic pole 31b and the other circumferential end face 32f of the fourth claw-shaped magnetic pole 32b. The interpolar magnets 35 are opposite in polarity to the third and fourth claw-shaped magnetic poles 31b and 32b (the fourth claw-shaped magnetic pole 24b side is the N pole, and the third claw-shaped magnetic pole 23b side is the S pole. Is magnetized in the circumferential direction. A gap (not shown) for preventing leakage magnetic flux is provided on the rotating shaft 12 side of each interpolar magnet 35 (in the radial direction of the rotor 11).

The first assembly SA1 and the second assembly SA2 configured as described above are configured such that the axial lengths L1 and L2 are the same as shown in FIG.
When the drive current is supplied to the segment conductor (SC) winding 8 via the power supply circuit in the circuit housing box 5, the motor 1 configured as described above has a magnetic field for rotating the rotor 11 by the stator 6. Is generated, and the rotor 11 is rotationally driven.

Next, the operation of the motor 1 configured as described above will be described.
The rotor 11 of the motor 1 according to the present embodiment includes a first assembly SA1 including a pair of first and second rotor cores 21 and 22, and a second group including a pair of third and fourth rotor cores 31 and 32. A so-called tandem structure in which the appendage SA2 is laminated. The pair of first and second rotor cores 21 and 22 and the pair of third and fourth rotor cores 31 and 32 are arranged in a manner that they are shifted in the circumferential direction. Here, in the so-called permanent magnet field Landell-type rotor, the surface magnetic flux of the rotor is likely to contain harmonics, which may increase the cogging torque. For this reason, the cogging torque generated in each of the pair of rotor cores 21 and 22 and the pair of rotor cores 31 and 32 is out of phase, so that the cogging torques out of phase can cancel each other, and the combined cogging torque is reduced. To suppress the occurrence of vibration.

  The deviation angle θ between the pair of rotor cores 21 and 22 and the pair of rotor cores 31 and 32 is 0 <θ ≦ 50 ° / P (P = 5), where P is the number of pole pairs (5 in the present embodiment). By setting to the range, the cogging torque is reduced while suppressing the decrease in the amount of flux linkage within 10% as the range of X1 in FIG. Further, by setting the deviation angle θ in the range of 0 <θ ≦ 35 ° / P, the decrease of the flux linkage can be suppressed to within 5% within the range of X2 in FIG. Furthermore, by setting the deviation angle θ in the range of 0 <θ ≦ 20 ° / P, the decrease of the flux linkage can be suppressed to within 1% within the range of X3 in FIG.

Next, characteristic effects of the present embodiment will be described.
(1) The first and second rotor cores 21 and 22 and the third and fourth rotor cores 31 and 32, which are a plurality of pairs of rotor cores, are arranged so that the rotor cores 22 and 31 having the same magnetic pole are adjacent to each other. , 22, 31 and 32 are arranged in a manner shifted in the circumferential direction, so that the phases of the cogging torque generated in the pair of rotor cores 21 and 22 and the pair of rotor cores 31 and 32 are out of phase. Cogging torques can be canceled out, and the combined cogging torque can be reduced to suppress the occurrence of vibration.

  (2) The circumferential shift angle θ between each pair of rotor cores 21, 22, 31, 32 is 0 <θ ≦ 50 ° / P, where P is the number of pole pairs, 0 < Since it is set in the range of θ ≦ 10 °, the cogging torque can be reduced while suppressing a decrease in the amount of flux linkage, that is, a decrease in torque as shown in FIG. Further, by setting the deviation angle θ in the range of 0 <θ ≦ 35 ° / P, for example, 0 <θ ≦ 7 °, the amount of interlinkage magnetic flux, that is, the torque is reduced as shown in FIG. The cogging torque can be reduced while further suppressing. Furthermore, by setting the deviation angle θ in the range of 0 <θ ≦ 4 °, where 0 <θ ≦ 20 ° / P, as shown in FIG. 4, the amount of interlinkage magnetic flux decreases, that is, the torque decreases. The cogging torque can be reduced while further suppressing the above.

  (3) Since the first assembly SA1 and the second assembly SA2 have the same axial length L1, L2, the magnetic circuit (path) is completed for each pair of rotor cores 21, 22, 31, 32. Therefore, the short-circuit magnetic flux between the magnetic poles of the pair of rotor cores 21, 22, 31, 32 becomes small.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, although not particularly mentioned, for example, when the least common multiple of the number of magnetic poles of the rotor 11 and the number of slots of the stator 6 is MS and n = 1 or 2, 180 ° × n / MS− It is desirable to set in the range of 5 ° ≦ θ ≦ 180 ° × n / MS + 5 °. For example, when the least common multiple MS = 12, and n = 1, the shift angle θ is set in a range of 10 ° ≦ θ ≦ 20 ° (Y1 in FIG. 5). When the least common multiple MS = 12, and n = 2, the deviation angle θ is set in a range of 40 ° ≦ θ ≦ 50 ° (Y1 in FIG. 5). With such a configuration, the cogging torque can be reduced to 50% as shown in FIG.

  In the above embodiment, the assembly SA1 including the pair of rotor cores 21 and 22 and the assembly SA2 including the pair of rotor cores 31 and 32 are stacked to form a so-called tandem structure of two stages. For example, as shown in FIG. 6, the number of stacked layers may be appropriately changed to three levels or more.

  In the above embodiment, the axial length of the first assembly SA1 including the pair of rotor cores 21 and 22 (the length of the axial end surfaces of the rotor cores 21 and 22) and the second including the pair of rotor cores 31 and 32 Although the configuration is such that the axial length of the assembly SA2 (the length of the axial end surfaces of the rotor cores 31 and 32) is the same, this is not restrictive. For example, a configuration in which the axial length of the first assembly SA1 and the axial length of the second assembly SA2 are different may be employed. Further, for example, even in a configuration in which three or more assemblies SA3, SA4, and SA5 including the pair of rotor cores 41, 42, 43, 44, 45, and 46 are stacked, the axial length is similarly different. May be. Here, the rotor 11 shown in FIG. 6 will be described. The rotor cores 41, 42, 43, 44, 45, and 46 of the rotor 11 protrude from the outer peripheral portion of the core base and extend in opposite directions along the axial direction, and are alternately arranged along the circumferential direction. A plurality of claw-shaped magnetic poles 41b, 42b, 43b, 44b, 45b, 46b are provided. Between the circumferential directions of the claw-shaped magnetic poles 41b, 42b, 43b, 44b, 45b, 46b, inter-pole magnets 50, 51, 52 are provided. The circumferential shift angle θ between the pair of rotor cores 41, 42, 43, 44, 45, 46 (the shift angle θ between the assembled bodies SA 3, SA 4, SA 5) is the interpolar magnets 50, 51. , 52 is set in the range of 0 <θ ≦ θm. Here, when the axial length is the same for each pair of rotor cores 41, 42, 43, 44, 45, 46, the magnetic circuit (path) is completed for each pair of rotor cores and balanced with each other. The short-circuit magnetic flux between the magnetic poles of the rotor core is small. However, when the axial lengths L3, L4, and L5 are different for each pair of rotor cores 41, 42, 43, 44, 45, and 46 as in this configuration, the short-circuit magnetic flux tends to increase. Therefore, by setting the deviation angle θ within the circumferential width θm of the interpole magnets 50, 51, and 52, the magnetic flux rectification effect by the interpole magnets 50, 51, and 52 causes other magnetic poles as shown by Z1 in FIG. The short-circuit magnetic flux to the magnetic pole can be suppressed. Further, by setting the deviation angle θ in the range of 0 <θ ≦ θm / 2, the magnetic flux is rectified by the interpole magnets 50, 51, and 52, so that from the magnetic pole to another magnetic pole as indicated by Z2 in FIG. Short-circuit magnetic flux can be further suppressed.

  In the above embodiment, one annular magnet 23, 33 is provided as a field magnet in each of the pair of first and second rotor cores 21, 22 and the pair of third and fourth rotor cores 31, 32. Not limited to this. For example, a plurality of permanent magnets are arranged between the core bases 21 a and 22 a of the pair of rotor cores 21 and 22 and the core bases 31 a and 32 a of the pair of rotor cores 31 and 32 around the rotation shaft 12. You may employ | adopt the structure to do.

  In the above embodiment, although not particularly mentioned, the first to fourth rotor cores 21, 22, 31, 32 and the armature core 7 are configured by, for example, lamination of magnetic metal plate materials or molding of magnetic powder. May be.

The technical idea is described below.
(Supplementary Note 1) A plurality of pairs of rotor cores arranged along the rotation axis, and a field magnet that is arranged between each pair of rotor cores and is magnetized along the axial direction. The plurality of pairs of rotor cores, each having a plurality of claw-shaped magnetic poles protruding from the outer peripheral portion of the core-shaped core base and extending in opposite directions along the axial direction, and alternately arranged along the circumferential direction Are arranged in such a manner that the rotor cores of the same magnetic pole are adjacent to each other and are shifted in the circumferential direction between the respective pairs of rotor cores, and the respective different polarities are not adjacent to each other in the axial direction between the respective pairs of rotor cores. A rotor characterized by being displaced in a circumferential direction between a pair of rotor cores.

  In this configuration, the plurality of pairs of rotor cores are arranged so that the rotor cores having the same magnetic pole are adjacent to each other and are shifted in the circumferential direction between each pair of rotor cores, so that the phase of cogging torque generated in the pair of rotor cores is Therefore, the cogging torques that are out of phase can cancel each other, and the combined cogging torque can be reduced to suppress the occurrence of vibration.

(Supplementary Note 2) A rotor displacement angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ 50 ° / P where P is the number of pole pairs. .
In this configuration, the circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ 50 ° / P where P is the number of pole pairs, and as shown in FIG. In addition, the cogging torque can be reduced while suppressing the decrease in the amount of flux linkage, that is, the decrease in torque.

(Supplementary Note 3) A rotor having a circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ 35 ° / P.
In this configuration, the circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ 35 ° / P. Therefore, as shown in FIG. The cogging torque can be reduced while further suppressing the decrease in torque.

(Supplementary Note 4) A rotor having a circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ 20 ° / P.
In this configuration, the circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ 20 ° / P. Therefore, as shown in FIG. The cogging torque can be reduced while further suppressing the decrease in torque.

  (Supplementary Note 5) The circumferential shift angle θ between each pair of rotor cores is expressed as follows: MS is the least common multiple of the number of magnetic poles and the number of stator slots facing the rotor, and n = 1 or 2. A rotor that is set in a range of 180 ° × n / MS−5 ° ≦ θ ≦ 180 ° × n / MS + 5 °.

  In this configuration, the circumferential shift angle θ between each pair of rotor cores is 180 when the least common multiple of the number of magnetic poles and the number of stator slots facing the rotor is MS, and n = 1 or 2. It is set in the range of ° × n / MS-5 ° ≦ θ ≦ 180 ° × n / MS + 5 °. Therefore, the cogging torque can be further reduced as shown in FIG.

  (Supplementary Note 6) The plurality of pairs of rotor cores are configured so that the lengths in the axial direction are different for each pair of rotor cores, and are disposed between the claw-shaped magnetic poles adjacent in the circumferential direction and are adjacent in the circumferential direction. A magnetic pole magnetized so that the same polarity as that of the magnetic poles is opposed to each other, and the deviation angle θ in the circumferential direction between the pair of rotor cores is a circumferential width θm of the interpolar magnet, A rotor set in a range of 0 <θ ≦ θm.

  In this configuration, the plurality of pairs of rotor cores are configured to have different axial lengths for each pair of rotor cores, and are arranged between the claw-shaped magnetic poles adjacent to each other in the circumferential direction and are adjacent to each other in the circumferential direction. Between the pair of rotor cores, the circumferential shift angle θ between each pair of rotor cores is 0 <θ ≦ It is set in the range of θm. Here, when the axial length is the same for each pair of rotor cores, the magnetic circuit (path) for each pair of rotor cores is completed and balanced with each other, and the short-circuit magnetic flux between the magnetic poles of the pair of rotor cores is small. When the axial length differs for each pair of rotor cores, the short-circuit magnetic flux tends to increase. Therefore, by setting the deviation angle θ within the circumferential width θm of the interpole magnet, the magnetic flux rectification effect acts by the interpole magnet, and the short-circuit magnetic flux from the magnetic pole to another magnetic pole is suppressed as shown in FIG. Can do.

(Appendix 7) A rotor, wherein a circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ θm / 2.
In this configuration, since the circumferential shift angle θ between each pair of rotor cores is set in a range of 0 <θ ≦ θm / 2, a magnetic flux rectification effect is exerted by the interpole magnet, and FIG. As shown, the short-circuit magnetic flux from the magnetic pole to the other magnetic pole can be further suppressed.

  DESCRIPTION OF SYMBOLS 1 ... Motor, 6 ... Stator, 11 ... Rotor, 12 ... Rotary shaft, 21, 22, 31, 32, 41, 42, 43, 44, 45, 46 ... Rotor core, 21a, 22a, 31a, 32a ... Core base, 25, 35, 50, 51, 52 ... interpolar magnets, 41b, 42b, 43b, 44b, 45b, 46b ... claw-shaped magnetic poles, L1, L2, L3, L4, L5 ... axial lengths.

Claims (4)

A plurality of pairs of rotor cores arranged along a rotation axis;
A field magnet disposed between each pair of rotor cores and magnetized along an axial direction;
With
Each pair of rotor cores protrudes from the outer peripheral portion of the disk-shaped core base, and has a constant circumferential width and is formed to extend in opposite directions along the axial direction. The plurality of claws are alternately arranged along the circumferential direction. Each of the claw-shaped magnetic poles, the gap between the circumferential end faces of the claw-shaped magnetic pole is formed in a straight line along the axial direction,
The plurality of pairs of rotor cores are arranged such that the rotor cores of the same magnetic pole are adjacent to each other, and are arranged in a manner shifted in the circumferential direction between the pair of rotor cores,
The pair of rotor cores is displaced in the circumferential direction so that the different poles do not contact in the axial direction between the pair of rotor cores,
The circumferential deviation angle θ between each pair of rotor cores is 180 ° × n when MS is the least common multiple of the number of magnetic poles and the number of stator slots facing the rotor, and n = 1 or 2. / MS-5 ° ≦ θ ≦ 180 ° × n / MS + 5 °. A plurality of pairs of rotor cores arranged along a rotation axis;
A field magnet disposed between each pair of rotor cores and magnetized along an axial direction;
With
Each pair of rotor cores has a plurality of claw-shaped magnetic poles that protrude from the outer periphery of the disk-shaped core base, extend in opposite directions along the axial direction, and are alternately arranged along the circumferential direction. And
The plurality of pairs of rotor cores are arranged such that the rotor cores of the same magnetic pole are adjacent to each other, and are arranged in a manner shifted in the circumferential direction between the pair of rotor cores,
The pair of rotor cores is displaced in the circumferential direction so that the different poles do not contact in the axial direction between the pair of rotor cores,
The tips of the claw-shaped magnetic poles with the same polarity are in contact with each other between the pair of rotor cores, and the base ends of the claw-shaped magnetic poles with the same polarity are in contact with each other between the pairs of rotor cores.
The circumferential deviation angle θ between each pair of rotor cores is 180 ° × n when MS is the least common multiple of the number of magnetic poles and the number of stator slots facing the rotor, and n = 1 or 2. / MS-5 ° ≦ θ ≦ 180 ° × n / MS + 5 °. A plurality of pairs of rotor cores arranged along a rotation axis;
A field magnet disposed between each pair of rotor cores and magnetized along an axial direction;
With
Each pair of rotor cores has a plurality of claw-shaped magnetic poles that protrude from the outer periphery of the disk-shaped core base, extend in opposite directions along the axial direction, and are alternately arranged along the circumferential direction. And
In each pair of rotor cores, an interpole magnet magnetized so that the same polarity as the claw-shaped magnetic pole adjacent in the circumferential direction is disposed between the claw-shaped magnetic poles adjacent in the circumferential direction, and the claw A back auxiliary magnet magnetized so that the same polarity as the claw-shaped magnetic pole is opposed to the radially inner side surface of the magnetic pole,
The plurality of pairs of rotor cores are arranged such that the rotor cores of the same magnetic pole are adjacent to each other, and are arranged in a manner shifted in the circumferential direction between the pair of rotor cores,
The pair of rotor cores is displaced in the circumferential direction so that the different poles do not contact in the axial direction between the pair of rotor cores,
The interpole magnets magnetized in the same direction between each pair of rotor cores and adjacent in the axial direction are shifted in the circumferential direction, and
The rotor displacement angle θ between the pair of rotor cores is set in a range of 0 <θ ≦ θm / 2 when the circumferential width θm of the interpole magnet is set. . The motor provided with the rotor as described in any one of Claims 1-3 .