JP5801693B2 - motor - Google Patents

Description

  The present invention relates to a motor having a so-called permanent magnet Rundel type rotor.

  A rotor of this type of motor is configured by arranging a field magnet between a first core member and a second core member constituting a rotor core, as shown in Patent Document 1, for example. Each of the first and second core members includes a plurality of first claw-shaped magnetic poles and second claw-shaped magnetic poles in the circumferential direction, and the first and second claw-shaped magnetic poles are alternately provided in the circumferential direction. Yes. The field magnet is magnetized in the axial direction, thereby causing the first claw-shaped magnetic pole to function as the first magnetic pole and the second claw-shaped magnetic pole to function as the second magnetic pole.

Japanese Utility Model Publication No. 5-43749

  In the motor as described above, when magnetic saturation occurs in the rotor core, the effective magnetic flux contributing to the motor torque is reduced, and as a result, there is a concern that the motor output decreases. There was room.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor that can suppress the occurrence of magnetic saturation and contribute to higher output.

In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a plurality of first claw-shaped magnetic poles are projected radially outward at equal intervals on the outer periphery of the substantially disk-shaped first core base. A plurality of second claw-shaped magnetic poles protrude outward in the radial direction and extend in the axial direction on the outer periphery of the first core member extending in the direction and the substantially disk-shaped second core base. A rotor core comprising a second core member formed and disposed between the first claw-shaped magnetic poles of the first core member to which the second claw-shaped magnetic poles respectively correspond; and the first core base and the second core The first claw-shaped magnetic pole functions as a first magnetic pole and the second claw-shaped magnetic pole functions as a second magnetic pole by being arranged between the base and the axial direction and being magnetized in the axial direction. A rotor having a field magnet and an annular stator core around which windings are wound A motor, which is composed of a stator disposed outer peripheral side of the axial length of the rotor core is set to be larger than the axial length of the stator core, the first and second claw-shaped magnetic poles Auxiliary magnets are respectively disposed on the rear surfaces of the first claw-shaped magnetic poles, and the first claw-shaped magnetic poles extend to the end surface of the second core base opposite to the field magnets in the axial direction. Is extended to the end surface of the first core base opposite to the field magnet in the axial direction, and the auxiliary magnet is connected to the axial end of the rotor at the end of the rotor in the axial direction. The end face of the auxiliary magnet on the side protrudes in the axial direction from the end face in the axial direction of the stator core .

  In the present invention, since the axial length of the rotor core is set to be larger than the axial length of the stator core, the axial thickness of the first and second core members can be increased. Further, by increasing the thickness of the first and second core members in the axial direction, a margin can be created in the magnetic path, and the occurrence of magnetic saturation can be suppressed. As a result, it is possible to contribute to higher output of the motor.

  In the present invention, the auxiliary magnet disposed on the back surface of each claw-shaped magnetic pole can be configured to extend to the axial end surface of the rotor core without protruding from the claw-shaped magnetic pole in the axial direction. It is possible to ensure a sufficient length in the axial direction of the magnet, and as a result, it is possible to further contribute to higher output of the motor.

The invention described in claim 2, in the motor according to claim 1, wherein the rotor has the configuration set of field magnet and the rotor core has a plurality of axially stacked, a plurality of aligned axially Of the first and second core bases, the axial thickness of the core bases disposed at both ends in the axial direction is set to be thicker than the axial thickness of the core bases disposed inside the axial direction. It is characterized by being.

  In this invention, the rotor has a so-called tandem structure in which a plurality of pairs of rotor cores and field magnets are laminated in the axial direction. And in the rotor of the tandem structure, among the plurality of first and second core bases arranged in the axial direction, the axial thickness of the core base at both ends in the axial direction is larger than the axial thickness of the core base disposed inside. It is set to be thick. Since the core end at both ends in the axial direction has the outer end surface in the axial direction facing the outside, leakage of magnetic flux tends to occur from the outer end surface, but in the present invention, the axial thickness of the core base at both ends in the axial direction By increasing the thickness, magnetic saturation at the core base can be suppressed, and as a result, generation of leakage magnetic flux from the outer end face of the core base can be suppressed.

  Therefore, according to the above-described invention, it is possible to suppress the occurrence of magnetic saturation and contribute to high output of the motor.

Sectional drawing of the motor of embodiment. (A) The perspective view which looked at the rotor of embodiment from the 1st core member side, (b) The perspective view which looked at the rotor from the 2nd core member side. Sectional drawing of the rotor of embodiment. The schematic diagram for demonstrating the dimension structure of the bottom part of a rotor, an armature core, and a cylindrical housing. The graph which shows the relationship between the ratio G2 / G1 of the gap width G2 of a rotor core and a cylindrical housing, and the gap width G1 of the radial direction of a rotor core and an armature core, and a flux linkage. Sectional drawing of the rotor in another example.

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 includes a metal 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 made of resin. A circuit housing box 5 that houses a power supply 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 has an annular armature core 7 (stator core) having a plurality of teeth extending radially inward, and a segment conductor winding 8 (SC winding) 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 supported by the bearing 13 accommodated in the bearing accommodating portion 3b formed at the center of the bottom portion 3a on the rear side of the cylindrical housing 3, and the front end plate 4. The bearing 14 is rotatably supported. The bearing housing 3 b has a concave shape that opens to the inside of the cylindrical housing 3.

  As shown in FIGS. 2A, 2B, and 3, the rotor 11 includes a rotor core R composed of a first core member 21 and a second core member 22, and an annular magnet 23 as a field magnet (see FIG. 3). And first and second back auxiliary magnets 24, 25 and first and second interpole magnets 26, 27. The magnets 23, 24, 25, 26, and 27 are permanent magnets, and the arrows shown by solid lines in FIGS. 2A and 2B and FIG. 3 indicate the magnetizations of the magnets 23, 24, 25, 26, and 27. The direction (from the S pole to the N pole) is shown.

  As shown in FIG. 2 (a), the first core member 21 of the rotor core R has a plurality of (seven in this embodiment) first claws on the outer periphery of the substantially disk-shaped first core base 21a. A magnetic pole 21b is formed. The first claw-shaped magnetic pole 21b is formed in a rectangular shape when viewed from the radial direction. 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 in the axial direction from the protrusion 21c. 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. In addition, the circumferential cross section of the protrusion 21c is formed in a rectangular shape. A claw portion 21d is formed in the axial direction with a constant circumferential width at the radially outer end portion of the protruding portion 21c. The circumferential width (angle) of each first claw-shaped magnetic pole 21b, that is, the width (angle) between the circumferential end faces 21e and 21f is smaller than the angle of the gap between the first claw-shaped magnetic poles 21b adjacent in the circumferential direction. Is set.

  As shown in FIG. 2B, the second core member 22 has the same shape as the first core member 21, and a plurality of the second core members 22 are arranged at regular intervals on the outer periphery of the substantially disk-shaped second core base 22a (this embodiment). Seven (7) claw-shaped magnetic poles 22b are formed. The protrusion 22c of the second claw-shaped magnetic pole 22b has a fan-shaped cross section in the direction perpendicular to the axis, and a claw 22d is formed in the axial direction at the end portion on the radially outer side. The second core member 22 is arranged so that the claw portions 22d of the second claw-shaped magnetic poles 22b are disposed between the claw portions 21d of the first claw-shaped magnetic poles 21b corresponding to the first core base 21a. The annular magnet 23 (see FIG. 3) is disposed (sandwiched) between the first core member 21 and the second core base 22a in the axial direction.

  As shown in FIG. 3, the outer diameter of the annular magnet 23 is set to be the same as the outer diameter of the first and second core bases 21a and 22a, and the first claw-shaped magnetic pole 21b is used as the first magnetic pole (this embodiment). 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 the present embodiment). That is, the rotor 11 of the present embodiment is a so-called Landell type rotor having the annular magnet 23. As the annular magnet 23, for example, a neodymium magnet can be used. The axial thickness of the annular magnet 23 is set to be smaller than the axial thicknesses of the first and second core bases 21a and 22a.

  A first 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. The first back auxiliary magnet 24 has a fan-shaped cross section in the direction perpendicular to the axis, and the second core base has a side that is in contact with the back surface 21g of the first claw-shaped magnetic pole 21b and has the same polarity as the first claw-shaped magnetic pole 21b. The side abutting on the outer peripheral surface 22h of 22a is magnetized in the radial direction so as to be the S pole having the same polarity as the second core base 22a.

  Similarly to the first claw-shaped magnetic pole 21b, the second back auxiliary magnet 25 is disposed on the back surface 22g of each second claw-shaped magnetic pole 22b. As the 1st back auxiliary magnet 24 and the 2nd back auxiliary magnet 25, a ferrite magnet can be used, for example. The second back auxiliary magnet 25 has a fan-shaped cross section in the direction perpendicular to the axis, and the side in contact with the back 22g is the S pole and the side in contact with the outer peripheral surface 21h of the first core base 21a is the N pole. Is magnetized.

  The first back auxiliary magnet 24 and the second back auxiliary magnet 25 overlap each other in the axial direction at the axial position of the rotor 11 on which the annular magnet 23 is arranged, in other words, the axial end surface (the first end face of the rotor core R). And the axial length is set so as to be arranged from the second end face Ra, Rb) until reaching the axial position where the annular magnet 23 is arranged.

  As shown in FIGS. 2 (a) and 2 (b), first and second interpole magnets 26 and 27 are disposed between the circumferential directions of the first claw-shaped magnetic pole 21b and the second claw-shaped magnetic pole 22b. Yes. Specifically, the first interpole magnet 26 includes a flat surface formed by one circumferential end surface 21e of the first claw-shaped magnetic pole 21b and a circumferential end surface of the first back auxiliary magnet 24, and a second claw-shaped magnet. It is fitted and fixed between the other circumferential end face 22f of the magnetic pole 22b and a flat face formed by the circumferential end face of the second back auxiliary magnet 25.

  The second interpole magnet 27 has the same shape as the first interpole magnet 26, and is formed by the other circumferential end face 21 f of the first claw-shaped magnetic pole 21 b and the circumferential end face of the first back auxiliary magnet 24. And a flat surface formed by one circumferential end surface 22e of the second claw-shaped magnetic pole 22b and a circumferential end surface of the second back auxiliary magnet 25. The first and second interpole magnets 26 and 27 are opposite in polarity to the first and second claw-shaped magnetic poles 21b and 22b (the first claw-shaped magnetic pole 21b side is N-pole and the second claw-shaped It is magnetized in the circumferential direction (so that the magnetic pole 22b side becomes the S pole).

Here, the dimension structure in the motor 1 of this embodiment is demonstrated according to FIG.
The axial length Hr of the rotor core R is set to be larger than the axial length Hs of the armature core 7. The axial length Hr of the rotor core R is equal to that of the annular magnet 23 in the second core base 22a from the axial end surface (first end surface Ra of the rotor core R) opposite to the annular magnet 23 in the first core base 21a. Is the axial length to the opposite axial end face (second end face Rb of the rotor core R). Thus, since the axial length Hr of the rotor core R is set to be larger than the axial length Hs of the armature core 7, the first and second core members 21 and 22 (mainly the first and It is possible to increase the axial thickness of the second core bases 21a, 22a). In the present embodiment, the center line in the axial direction of the rotor core R and the center line in the axial direction of the armature core 7 are configured to coincide (shown as the center line L in FIG. 4). That is, the rotor core R is wider than the armature core 7 by the same dimension (overlap width G3) on both sides in the axial direction. This overlap width G3 is the amount of protrusion in the axial direction with respect to the armature core 7 at each of both axial ends of the rotor core R, and in this embodiment, the axial length Hr of the rotor core R and the axial direction of the armature core 7 The dimension is half the difference in length Hs.

  In the rotor core R, the tip end portion of the first claw-shaped magnetic pole 21b extends to the first end surface Ra of the rotor core R in the axial direction, and the tip portion of the second claw-shaped magnetic pole 22b extends in the axial direction of the rotor core R. It extends to the two end faces Rb. That is, the axial length of each claw-shaped magnetic pole 21b, 22b (the axial length of the outer peripheral surface parallel to the inner peripheral surface of the armature core 7 in each claw-shaped magnetic pole 21b, 22b) is the axial length of the rotor core R. Is set to be equal to Hr. The first and second back auxiliary magnets 24 and 25 arranged inside the first and second claw-shaped magnetic poles 21b and 22b have first and second claw-shaped magnetic poles 21b and 22b at the outer ends in the axial direction, respectively. It extends to a position coinciding with the tip of the shaft. That is, the axially outer end face of the first back auxiliary magnet 24 and the second end face Rb of the rotor core R are flush with each other, and the axially outer end face of the second back auxiliary magnet 25 and the first end face Ra of the rotor core R are flush with each other. Is the same. In this way, the axial end surfaces (first and second) of the rotor core R in a state where the first and second back auxiliary magnets 24 and 25 do not protrude outward in the axial direction from the first and second claw-shaped magnetic poles 21b and 22b. By extending to the end faces Ra and Rb), it is possible to sufficiently secure the axial length of each of the back auxiliary magnets 24 and 25. Of course, the annular magnet 23 can be thickened in the axial direction, and the output can be increased by thickening the annular magnet 23.

Next, the operation of this embodiment will be described.
In the motor 1 configured as described above, when a drive current is supplied to the segment conductor winding 8 via the power supply circuit in the circuit housing box 5, a magnetic field for rotating the rotor 11 by the stator 6 is generated. The rotor 11 is rotationally driven.

  In the rotor 11 of this embodiment, the axial length Hr of the rotor core R is set to be larger than the axial length Hs of the armature core 7, so that the first and second core members 21 and 22 (mainly The axial thickness of the first and second core bases 21a and 22a) can be increased. Further, by increasing the axial thickness of the first and second core members 21 and 22, a margin can be created in the magnetic path and the occurrence of magnetic saturation can be suppressed. As a result, the axial direction of the annular magnet 23 can be suppressed. The output of the motor 1 can be increased without increasing the length.

  In addition, the first and second back auxiliary magnets 24 and 25 of the rotor 11 do not protrude outward in the axial direction from the first and second claw-shaped magnetic poles 21b and 22b. It extends to the second end face Ra, Rb). For this reason, it is possible to secure a sufficient length in the axial direction of each of the back auxiliary magnets 24 and 25, and as a result, it is possible to further contribute to higher output of the motor 1.

  In addition, the rotor 11 of the present embodiment is not a type of rotor in which permanent magnets are arranged on the outer peripheral surface of the rotor core, but is a Landel type having an annular magnet 23 inside the rotor core R. In a rotor in which a permanent magnet is arranged on the outer peripheral surface of the rotor core, when the axial length is larger than the axial length of the armature core 7, if the permanent magnet protrudes in the axial direction from the stator core, the permanent magnet There is a possibility that the magnetic flux cannot be used effectively. In the configuration in which the axial length Hr of the rotor core R is larger than the axial length Hs of the armature core 7 in the Landel-type rotor 11 as in the present embodiment, the portion facing the armature core 7 is a magnet. And the cores (first and second claw-shaped magnetic poles 21b and 22b), the first and second claw-shaped magnetic poles 21b and 22b are forced into the air from the portion protruding from the armature core 7 in the axial direction. As a result, the effective magnetic flux contributing to the motor torque is hardly reduced. Therefore, by making the axial length Hr of the rotor core R larger than the axial length Hs of the armature core 7 in the Landel type rotor 11, the motor output can be improved more effectively. .

  Next, the radial gap width G1 between the rotor core R and the armature core 7 (the radial interval between the outer peripheral surface of the rotor core R and the inner peripheral surface of the armature core 7), and the rotor core R and the cylindrical housing 3 The influence of the gap width G2 in the axial direction on the motor output will be described. The gap width G <b> 2 is an axial distance between the first end surface Ra of the rotor core R and the bottom 3 a of the cylindrical housing 3. In the present embodiment, the gap width G2 is defined as the distance between the bearing housing portion 3b that extends most to the rotor core R side at the bottom 3a of the cylindrical housing 3 and the first end surface Ra of the rotor core R.

  Since the cylindrical housing 3 is made of metal, there is a concern about leakage magnetic flux from the first end face Ra of the rotor core R generated by the influence of the cylindrical housing 3 when the gap width G2 is small. Here, the relationship between the ratio G2 / G1 of the gap width G2 and the gap width G1 and the amount of flux linkage (the amount of effective magnetic flux contributing to the motor torque) is shown in FIG. In the figure, the amount of interlinkage magnetic flux when the gap width G2 is sufficiently larger than the gap width G1 (when G2 / G1 is 8) is used as a reference (ie, 100%). As shown in the figure, the amount of flux linkage decreases as G2 / G1 decreases from 8. Specifically, G2 / G1 is approximately 5.8, the flux linkage is 99%, G2 / G1 is approximately 4.0, the flux linkage is 98%, and G2 / G1 is approximately 1.9. The amount of magnetic flux is 95%.

Next, characteristic effects of the present embodiment will be described.
(1) The rotor 11 includes a rotor core R including first and second core members 21 and 22 having first and second claw-shaped magnetic poles 21b and 22b, respectively, and axial directions of the first and second core members 21 and 22. And an annular magnet 23 that is magnetized in the axial direction so that the first claw-shaped magnetic pole 21b functions as the first magnetic pole and the second claw-shaped magnetic pole 22b functions as the second magnetic pole. . The axial length Hr of the rotor core R is set to be larger than the axial length Hs of the armature core 7 of the stator 6. Thereby, the axial thickness of the first and second core members 21 and 22 can be increased. Further, by increasing the axial thickness of the first and second core members 21 and 22, a margin can be created in the magnetic path, and the occurrence of magnetic saturation can be suppressed. Can contribute.

  (2) First and second back auxiliary magnets 24 and 25 are disposed on the back surfaces 21g and 22g of the first and second claw-shaped magnetic poles 21b and 22b, respectively. The first claw-shaped magnetic pole 21b extends to the end surface (second end surface Rb) opposite to the annular magnet 23 in the second core base 22a in the axial direction, and the second claw-shaped magnetic pole 22b extends in the axial direction. The first core base 21a extends to the end surface (first end surface Ra) opposite to the annular magnet 23. Thus, the axial end surfaces (first and second end surfaces) of the rotor core R in a state where the first and second back auxiliary magnets 24, 25 do not protrude in the axial direction from the first and second claw-shaped magnetic poles 21b, 22b. Ra, Rb) can be extended. For this reason, the axial lengths of the first and second back auxiliary magnets 24 and 25 can be sufficiently secured, and as a result, the motor 1 can further contribute to higher output.

In addition, you may change embodiment of this invention as follows.
-From the rotor 11 of the above embodiment, the first and second back auxiliary magnets 24, 25 are omitted, the first and second interpole magnets 26, 27 are omitted, or both are omitted. It may be changed.

  In the rotor 11 of the above embodiment, the rotor core R and each of the magnets 23, 24, 25, 26, and 27 are configured by one, but this is not particularly limited, and the set is axially A plurality of so-called tandem rotors may be used. For example, in the rotor 31 shown in FIG. 6, each of the magnets 23, 24, 25, 26, and 27 of the rotor core R is composed of two sets. That is, the first and second core members 21 and 22 of the rotor core R are provided in two, the two second core members 22 abut against each other in the axial direction, and the first core member 21 is in the axial direction. It is laminated so that it may be arranged outside. The first and second claw-shaped magnetic poles 21b and 22b are configured to have the same polarity in the axial direction. 6, the axial length Hr of the entire rotor core R (from the axially outer end surface of the upper first core member 21 in the drawing to the axially outer end surface of the lower first core member 21 is also shown. Is set larger than the axial length Hs of the armature core 7 of the stator 6, and the same effect as in the above embodiment can be obtained.

  In the rotor 31 having such a tandem structure, the first core base 21a of the first core member 21 and the second core base 22a of the second core member 22 are aligned in the axial direction. In the configuration shown in FIG. 6, the axial thickness T1 of the first core bases 21a arranged at both axial ends of the first and second core bases 21a and 22a arranged in the axial direction is the inner side in the axial direction. It is set to be thicker than the axial thickness T2 of the second core base 22a disposed at the position. The first core base 21a has an outer end surface in the axial direction facing the outside, so that magnetic flux leaks easily from the outer end surface. However, in the configuration shown in FIG. 6, the axial direction of the first core base 21a By increasing the thickness, magnetic saturation in the first core base 21a is suppressed, and as a result, generation of leakage magnetic flux from the outer end surface of the first core base 21a can be suppressed.

  In the configuration shown in FIG. 6, the axial thickness T1 of the first core base 21a is set to be thicker than the axial thickness T2 of the second core base 22a. The directional thickness T1 may be set to be thinner than the axial thickness T2 of the second core base 22a. In the same configuration, the rotor core R and each of the magnets 23, 24, 25, 26, and 27 are configured by two, but the number of the sets is not limited to this, and may be configured by three or more. In the same configuration, the first and second back auxiliary magnets 24 and 25 are omitted, the first and second interpole magnets 26 and 27 are omitted, or both are omitted. May be.

In the above embodiment, the shape and number of the first and second claw-shaped magnetic poles 21b and 22b may be changed as appropriate according to the configuration.
-In the said embodiment, although the winding method to the teeth of the stator 6 is not referred in particular, concentrated winding and distributed winding may be used.

  -Although not mentioned in particular in the said embodiment, you may comprise the 1st and 2nd core members 21 and 22 and the armature core 7 by lamination | stacking of a magnetic metal plate material, and shaping | molding of magnetic powder, for example.

  DESCRIPTION OF SYMBOLS 1 ... Motor, 6 ... Stator, 7 ... Armature core (stator core), 8 ... Segment conductor winding (winding), 11 ... Rotor, 21 ... 1st core member, 21a ... 1st core base, 21b ... 1st Claw-shaped magnetic poles, 21g, 22g ... back surface, 22 ... second core member, 22a ... second core base, 22b ... second claw-shaped magnetic pole, 23 ... annular magnet (field magnet), 24 ... first back auxiliary magnet ( Auxiliary magnets), 25 ... second back auxiliary magnet (auxiliary magnet), R ... rotor core, Hr ... axial length of the rotor core, Hs ... axial length of the armature core.

Claims (2)

A first core member having a plurality of first claw-shaped magnetic poles projecting radially outward and extending in the axial direction on the outer periphery of a substantially disc-shaped first core base; A plurality of second claw-shaped magnetic poles projecting radially outward at equal intervals on the outer periphery of the second core base and extending in the axial direction, and each of the second claw-shaped magnetic poles corresponding to each of the first claw-shaped magnetic poles. A rotor core comprising a second core member disposed between the first claw-shaped magnetic poles of the core member;
The first claw-shaped magnetic pole is arranged between the first core base and the second core base and is magnetized in the axial direction so that the first claw-shaped magnetic pole functions as the first magnetic pole, and the second claw-shaped A rotor including a field magnet that causes the magnetic pole to function as a second magnetic pole;
An annular stator core around which a winding is wound is a motor configured with a stator disposed on the outer peripheral side of the rotor,
The axial length of the rotor core is set larger than the axial length of the stator core ,
Auxiliary magnets are respectively disposed on the back surfaces of the first and second claw-shaped magnetic poles,
The first claw-shaped magnetic pole extends in the axial direction to an end surface of the second core base opposite to the field magnet,
The second claw-shaped magnetic pole extends in the axial direction to the end surface of the first core base opposite to the field magnet,
In the axial end portion of the rotor, the auxiliary magnet has an end surface of the auxiliary magnet on the axial end portion side of the rotor protruding beyond the axial end surface of the stator core in the axial direction. motor. The motor according to claim 1 ,
The rotor has a configuration in which a plurality of sets of the rotor core and the field magnet are stacked in the axial direction;
Of the plurality of first and second core bases arranged in the axial direction, the axial thickness of the core bases arranged at both ends in the axial direction is thicker than the axial thickness of the core bases arranged inside in the axial direction. A motor characterized by being set to be.