JP6385854B2 - Brushless motor - Google Patents

Description

  The present invention relates to a resolver positioning structure which is a rotor position detecting means of a brushless motor, and more particularly to a resolver positioning structure in a magnetless brushless motor (IPM motor: Interior Permanent Magnet Motor).

  The brushless motor may require a position sensor that detects the rotor position. Examples of such position sensors include Hall ICs and resolvers. However, since they are strong against vibration and excellent in environmental resistance, the use of resolvers is increasing in motors for electric power steering devices. A resolver is a sensor that detects the angle of a rotating shaft by using an electromagnetic induction phenomenon, and generally includes a resolver rotor attached to a motor rotating shaft and a resolver stator in which a plurality of coils are arranged so as to surround the periphery. Composed.

  The resolver rotor is formed with a plurality of convex portions along the circumferential direction. When the convex portion approaches or separates from the stator side coil as the motor rotates, an AC signal is output from the coil. There is a predetermined positional relationship between the convex portion and the rotor (rotor magnet) of the motor, and the rotation angle (position) of the rotor is detected from the relationship between the convex portion position and the signal waveform. For this reason, in a brushless motor using a resolver, it is necessary to accurately match the positional relationship between the resolver rotor and the rotor of the motor (hereinafter referred to as motor rotor) and the center position of both.

JP 2006-320189 A JP 2003-32989 A JP 2014-54047 A JP2013-139085A

  However, in the conventional brushless motor, the assembly accuracy between the resolver rotor and the motor rotor is not necessarily high even when the assembly is performed using a jig, and the positional relationship between the two is readjusted after the motor is assembled as in Patent Document 1. Sometimes it was necessary. In addition, in order to assemble the resolver rotor and the motor rotor with high accuracy, as in Patent Document 2, a key is embedded in the shaft and the resolver rotor is positioned. However, when a key is used, it is necessary to provide a key groove on the shaft or to embed the key, which causes a problem that the manufacturing process becomes complicated.

  An object of the present invention is to provide a resolver positioning structure of a brushless motor that can accurately position a resolver rotor and a motor rotor of a motor while having a simple structure by effectively utilizing a member generated during magnet molding of an IPM motor. There is to do.

The brushless motor of the present invention includes a motor case, a stator fixed to the motor case, a rotor shaft rotatably disposed in the motor case, an inner side of the stator, and fixed to the rotor shaft. A rotor including a rotor core, a magnet attached to the rotor core, and a projecting portion projecting from an axial end surface of the rotor core and arranged in a predetermined positional relationship with the magnet, and attached to the rotor shaft And a resolver that includes a resolver rotor disposed on the outside of the resolver rotor and that detects a rotation angle of the rotor based on a rotation position of the resolver rotor. The brushless motor is attached to the axial end surface of the rotor and A resolver rotor mounting portion to which the resolver rotor is mounted is formed, and a resolver holder having a fitting hole to be fitted to the protruding portion is formed on the other end surface opposite to the resolver rotor mounting portion, The resolver rotor mounting portion is arranged in a predetermined positional relationship with the fitting hole, and is connected to a predetermined position of the resolver rotor, and the rotor core is a plurality of components arranged at equal intervals along the circumferential direction. A magnet housing hole, the magnet housing hole forming a plurality of sets of slits composed of a plurality of layers of curved slits, the magnet being housed and fixed in the magnet housing hole, It is arranged along the radial direction so as to straddle the magnet plurality of layers, characterized in Rukoto.

  In the present invention, the protruding portion arranged in a predetermined positional relationship with the magnet is provided on the axial end surface of the rotor core, and the resolver rotor mounting portion to which the resolver rotor is mounted on one end surface side is provided on the other end surface side. A resolver holder in which a fitting hole for fitting with the projecting portion is formed is attached to the axial end surface of the rotor. The resolver rotor mounting portion of the resolver holder is disposed in a predetermined positional relationship with the fitting hole and is connected to a predetermined position of the resolver rotor. Therefore, the magnet and the resolver rotor are accurately positioned by attaching the resolver holder to the rotor and fitting the resolver rotor mounting portion of the resolver holder and the resolver rotor while fitting the protruding portion and the fitting hole.

That is, the resolver holder is attached to the rotor in such a manner that the protruding portion of the rotor is fitted into the fitting hole of the resolver holder, and the resolver rotor is attached to the resolver rotor attachment portion, thereby The rotor and the magnet are arranged in a predetermined positional relationship. In addition, the rotor core is provided with a plurality of magnet housing holes arranged at equal intervals along the circumferential direction, the magnets are housed and fixed in the magnet housing holes, and the magnets are housed in the rotor core to thereby obtain a surface of the rotor core. Unlike a motor of a type in which a magnet is disposed on a magnet, a magnet holder for holding the magnet on the surface of the rotor core becomes unnecessary, and the number of parts can be reduced accordingly.

  The resolver rotor mounting portion protrudes from the one end face side of the resolver holder and extends along the axial direction, and is a recess formed in a predetermined positional relationship with a convex portion formed on the outer periphery of the resolver rotor. You may make it fit with a groove | channel.

The projecting portion may be formed integrally with the magnet so that the magnet in the magnet housing hole does not come out of the end of the rotor core opposite to the projecting portion. It may be prevented from coming off. Further, the protruding portion may be arranged at a position where the magnetic balance of the rotor is not lost.

  In addition, the magnet may be filled and formed by pressurizing and supplying a bond magnetic material to the rotor core disposed in the mold. At this time, the magnet is formed on the end surface of the rotor core integrally with the magnet. A convex portion may be used as the protruding portion. As a result, the magnet and the projecting portion can be easily formed, and the convex portion removed after molding can be effectively used for positioning the resolver rotor, so that both the removal man-hours can be reduced and the mounting accuracy can be improved. In addition, since the protruding part is formed integrally with the magnet, it is not necessary to separately provide the protruding part on the end surface of the rotor core, such as separately manufacturing and laminating plates with protrusions, reducing the type of parts and the number of manufacturing steps. Figured.

  According to the brushless motor of the present invention, a resolver in which a protruding portion arranged in a predetermined positional relationship with a magnet is provided on the axial end surface of the rotor core, and a resolver rotor is attached to one end surface side of the axial end surface of the rotor. The rotor mounting portion is attached to a resolver holder in which a fitting hole is formed on the other end surface side to be fitted with the protruding portion, and at that time, the resolver rotor mounting portion is arranged in a predetermined positional relationship with the fitting hole, Since the resolver rotor is connected to a predetermined position, it is possible to accurately and easily position the resolver rotor with respect to the magnet by attaching the resolver holder to the rotor and attaching the resolver rotor to the resolver rotor mounting portion.

It is sectional drawing of the brushless motor which is one Embodiment of this invention. It is sectional drawing along the AA line of FIG. It is explanatory drawing which shows the structure of a rotor. It is a simplified explanatory drawing which shows the formation process of a rotor. It is explanatory drawing which shows the attachment state of a resolver holder. It is explanatory drawing which shows the attachment state of a resolver holder. It is explanatory drawing which shows the modification of a bridge | bridging part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a brushless motor 1 (hereinafter abbreviated as motor 1) according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 1, the motor 1 is an inner rotor type brushless motor in which a stator (stator) 2 is disposed outside and a rotor (rotor) 3 is disposed inside. The motor 1 is an IPM (Interior Permanent Magnet) type brushless motor in which a magnet is embedded in the rotor 3 and the rotor is rotated by magnet torque and reluctance torque.

  The motor 1 in FIG. 1 is used, for example, as a power source of a column assist type electric power steering apparatus, and is attached to a speed reduction mechanism portion (not shown) provided on a steering shaft. The rotation of the motor 1 is decelerated and transmitted to the steering shaft by the deceleration mechanism, and an operation assisting force is applied to the steering shaft of the automobile. The IPM structure motor has a smaller magnetic friction than the SPM structure motor, and the viscous torque can be kept small. Therefore, the handle has good convergence and is suitable for an electric power steering apparatus.

  The stator 2 includes a bottomed cylindrical housing 4, a stator core 5, a field coil 6 (hereinafter abbreviated as coil 6) wound around the teeth of the stator core 5, and a bus bar unit 7. The bus bar unit 7 is attached to the stator core 5 and is electrically connected to the coil 6. The housing 4 is formed in a bottomed cylindrical shape with iron or the like, and also serves as a motor case. A bracket 8 made of synthetic resin is attached to the opening of the housing 4 with a fixing screw 10. A synthetic resin insulator 11 is attached to the stator core 5. A coil 6 is wound around the outside of the insulator 11. An end portion 6 a of the coil 6 is drawn out at one end side of the stator core 5.

  The stator core 5 is formed by laminating a large number of steel plate materials (for example, electromagnetic steel plates). As shown in FIG. 2, the outer ring portion 5a of the stator core 5 is formed with a plurality of (here, 24) teeth 5b extending inward in the radial direction along the circumferential direction. Slots 19 are formed between adjacent teeth 5b. In the motor 1, 24 teeth 5b are provided and have a 24-slot configuration. The coil 6 is accommodated in the slot 19. A bus bar unit 7 that is electrically connected to the coil 6 is attached to one end side of the stator core 5. The stator core 5 is press-fitted and fixed in the housing 4 after the bus bar unit 7 is attached.

  The bus bar unit 7 has a structure in which a copper bus bar 9 is insert-molded in a synthetic resin main body. The bus bar 9 has a plurality of power feeding terminals 12 protruding in the radial direction. Around the bus bar unit 7, the power supply terminals 12 project radially. When the bus bar unit 7 is attached, the coil end 6 a is welded to the power feeding terminal 12. In the bus bar unit 7, the bus bar 9 is provided in a number corresponding to the number of phases of the motor 1 (in this case, three for the U phase, V phase, W phase and one for connecting each phase). It has been. Each coil 6 is electrically connected to a power supply terminal 12 corresponding to the phase. On the other hand, the end of the bus bar 9 extends in the axial direction from the end face of the bus bar unit 7 to form a bus bar terminal 33.

  A power terminal 31 is also insert-molded in the bracket 8. The power terminal 31 is provided for each of the U, V, and W phases, and one end side 31 a thereof is disposed in the opening 32. The other end 31 b of the power terminal 31 is disposed in the power connector 34. When the bracket 8 is assembled to the housing 4, the bus bar terminal 33 extending in the axial direction from the bus bar unit 7 faces the power terminal 31 in parallel. In the motor 1, after the bracket 8 is attached to the housing 4, the bus bar terminal 33 and the power terminal 31 are fixed by welding in the opening 32.

  A rotor 3 is inserted inside the stator 2. The rotor 3 has a shaft 13 that serves as a motor rotation shaft. A rotor core 16 formed by laminating electromagnetic steel plates is fixed to the shaft 13. The shaft 13 is rotatably supported by ball bearings (hereinafter abbreviated as bearings) 14a and 14b. The rear bearing 14 a is press-fitted and fixed to a bearing housing portion 4 a formed at the center of the bottom of the housing 4. The front-side bearing 14 b is fixed to the center portion of the bracket 8 by a metal bearing holder 15.

  FIG. 3 is an explanatory diagram showing the configuration of the rotor 3. The motor 1 has an IPM configuration, and the rotor core 16 is formed with a plurality of sets of slit groups 17 each having an arcuate (bow-shaped) hole. Each of the slits 17 a to 17 c of the slit group 17 is provided along an arc centered on a virtual point (not shown) set outside the outer periphery of the rotor 3. The slit group 17 is formed in three layers along the radial direction so that the convex side portion thereof faces the center side of the rotor 3. That is, the set of slit groups 17 includes an outermost first slit 17a, an intermediate second slit 17b, and an innermost third slit 17c.

  The slit group 17 is filled with a bond magnet (bond magnetic material), and a rotor magnet 18 is formed. By filling the bond magnet, an arc-shaped rotor magnet 18 is built in the rotor 3, and the motor 1 becomes a brushless motor having an IPM structure. As the bond magnet, for example, a material obtained by mixing magnetic powder of a rare earth magnet such as a neodymium magnetic material, such as an anisotropic neodymium bond magnetic material, with a synthetic resin such as epoxy is used. The bond magnetic material is formed by filling the slit group 17 by injection molding and performing predetermined magnetization.

  In the rotor 3, the magnetic pole portion 20 formed of a layered magnet group is formed by the rotor magnet 18 in the slit group 17. The magnetic pole part 20 is provided with a rotor magnet 18s whose outer peripheral side is an S pole and a rotor magnet 18n whose outer peripheral side is an N pole. The magnetic pole part 20 is arranged with two S poles and N poles alternately (four in total) along the circumferential direction. As a result, the motor 1 has a 4-pole 24-slot (4P24S) structure. As described above, the rotor magnets 18 of the magnetic pole portions 20 are arranged in three layers along the radial direction. In the rotor 3, a plurality of d-axes in the direction of the magnetic flux created by the magnetic poles and q-axiss that are magnetically orthogonal to the d-axis are alternately formed in the circumferential direction by the magnetic pole portion 20. The rotor 3 is provided with an arc-shaped slit group 17 so that the q-axis magnetic flux easily passes.

  The rotor 3 has a structure with a large inductance Lq. In the reluctance motor, the reluctance torque increases as the difference between Lq and Ld increases. The difference between Lq and Ld is larger in the case of three layers than in the case of one or two magnet layers, but there is not much change when the number of layers is three or more. Therefore, the rotor 3 employs three layers that can effectively increase the reluctance torque as the number of layers of the rotor magnet 18 from the balance with the slit width.

  FIG. 4 is a simplified explanatory view showing the forming process of the rotor 3. As shown in FIG. 4, the rotor 3 is formed using a magnetic field orientation mold 42 in which a plurality of magnetic field orientation magnets 41 are arranged. As the magnetic field orientation magnet 41, for example, a rare earth magnet such as a samarium cobalt magnet is used. The rotor core 16 is accommodated in a cavity 43 formed inside the magnetic field orientation magnet 41. An upper mold 44 connected to a nozzle (not shown) of the injection molding machine is placed on the cavity 43. The upper die 44 is formed with a sprue 45 connected in communication with the nozzle, a plurality (four in this case) of first runners 46 that radiate from the sprue 45, and the first runners 46, and each slit is formed. A second runner 47 is provided for supplying a molten bond magnetic material to 17a to 17c.

  A connecting portion (opening) between each of the slits 17 a to 17 c of the slit group 17 and the second runner 47 is a gate 48. In the case of forming the rotor 3, first, the rotor core 16 that has completed the lamination process is accommodated in the cavity 43 of the magnetic field orientation mold 42. Next, the upper mold 44 is placed on the rotor core 16, and the slit group 17 of the rotor core 16 and the gate 48 are connected. In this state, a molten bond magnetic material is injected into the sprue 45 from a nozzle (not shown) of the injection molding machine. The bond magnetic material supplied under pressure to the sprue 45 flows into the slits 17 a to 17 c from the first and second runners 46 and 47 through the gate 48.

  On the other hand, the bond magnetic material that has flowed into the slit group 17 is magnetized by controlling the direction of the magnetic powder by the magnetic field orientation magnet 41 to form the magnetic pole portion 20 having the polarity as shown in FIG. That is, the rotor magnet 18 is molded while being magnetized by the magnetic field orientation magnet 41. In the magnetic field orientation mold 42, the magnetic field orientation magnet 41 magnetizes the bond magnetic material using anisotropic magnetic powder with polar anisotropy, and aligns the directionality of the magnetic powder. In the case of polar anisotropic magnetization, the magnets in each layer are magnetized so that the magnetization vector is directed toward the center inside the arc.

  Thus, after the rotor core 18 is filled with the rotor magnet 18, the sprue 45 and the first runner 46 are removed. At this time, as shown in FIG. 3, the resin of the portion of the second runner 47 remains as a protruding bridge portion (projecting portion) 49 on the end surface 16 a of the rotor core 16 after molding. In the motor 1, the bridge portion 49 is formed at the center of the magnetic pole portion 20, that is, at the center of the arc-shaped slits 17a to 17c, and extends along the radial direction so as to straddle each slit. . In this case, if several bridge portions other than the magnetic pole center are provided, the magnetic balance is lost, the cogging torque is deteriorated, and the bridge portion needs to be removed. In this respect, since the bridge portion 49 of the motor 1 exists at the center of the magnetic pole portion 20, it is not easily affected by the magnetic flux. For this reason, the bridge portion 49 can be left as it is as a member for preventing the rotor magnet 18 from coming off in the axial direction without adversely affecting the motor characteristics.

  A resolver holder 51 made of a non-magnetic material (for example, made of synthetic resin) is attached to the axial end of the rotor core 16. A resolver 21 serving as a rotation angle detection means is disposed on the left side of the rotor 3 in FIG. 1, and a rotor (resolver rotor) 22 of the resolver 21 is integrally attached to the left end side of the resolver holder 51. 5 and 6 are explanatory diagrams showing the configuration of the resolver holder 51. FIG. As shown in FIGS. 5 and 6, two resolver rotor mounting pieces (resolver rotor mounting portions) 52 project from the one end surface 51 a of the resolver holder 51 in the axial direction. On the other hand, a concave groove 53 into which the resolver rotor mounting piece 52 is fitted is formed on the inner diameter side of the resolver rotor 22. The resolver rotor 22 is fixed on the shaft 13 in a form in which the resolver rotor mounting piece 52 is fitted and mounted in the concave groove 53.

  A stator (resolver stator) 23 of the resolver 21 is press-fitted and fixed in a metal resolver holder 24. The resolver holder 24 is formed in a bottomed cylindrical shape, and is lightly press-fitted into the outer periphery of the end portion of the rib 26 provided in the center portion of the bracket 8. The resolver holder 24 is accommodated in a bracket holder 25 made of synthetic resin fixed to the inside of the bracket 8. A metal resolver fixing nut 27 is attached to the bracket holder 25, and the bracket holder 25 and the bracket 8 are fixed by a resolver fixing screw 28 with a flange portion 24a of the resolver holder 24 interposed therebetween. The

  The flange portion 24 a of the resolver holder 24 is attached between the bracket holder 25 and the bracket 8 so as to be slightly movable in the circumferential direction. The resolver holder 24 is fixed to the bracket holder 25 by a resolver fixing screw 28 after the position of the resolver stator 23 is adjusted. At this time, a resolver fixing screw 28 is screwed into the resolver fixing nut 27 from the outside of the bracket 8, and the bearing holder 15 and the resolver holder 24 are fastened together with the bracket 8. Thereby, the resolver holder 24 is fixed to the inside of the bracket 8 in a state where the position in the circumferential direction is adjusted.

  On the other hand, the resolver rotor 22 is integrally attached to the one end surface side 51a of the resolver holder 51 as described above, and the bridge portion 49 protruding from the rotor core 16 is fitted and accommodated on the other end surface side 51b. A bridge fitting hole 54 is recessed. The bridge portion 49 protrudes from the end face of the rotor core 16, and one bridge portion 49 is provided for each magnetic pole portion 20 (four in total). The bridge fitting holes 54 are formed at four locations equally in the circumferential direction corresponding to the bridge portion 49. A predetermined positional relationship is set between the bridge fitting hole 54 and the resolver rotor mounting piece 52 in accordance with the positional relationship between the convex portion 22 a of the resolver rotor 22 and the magnetic pole portion 20. That is, when the bridge portion 49 is attached to the bridge fitting hole 54, the resolver rotor attachment piece 52 is disposed in a predetermined positional relationship with respect to the magnetic pole portion 20. Accordingly, the resolver holder 51 is attached to the rotor core 16 while the bridge portion 49 is fitted to the bridge fitting hole 54, and the resolver rotor attachment piece 52 and the concave groove 53 of the resolver rotor 22 are fitted to each other, The positional relationship with the rotor magnet 18 is set mechanically and automatically.

  As described above, in the motor 1, the bridge portion 49 is effectively used, and the bridge portion 49 and the bridge fitting hole 54, the resolver rotor mounting piece 52 and the concave groove 53 are fitted to each other, whereby the resolver rotor is engaged with the rotor magnet 18. 22 can be accurately positioned, and the positional relationship between the two can be set with high accuracy without using a jig or the like. That is, by the fitting operation of the bridge portion 49 and the like, the resolver rotor 22 and the rotor magnet 18 can be reliably positioned, the assembling operation of the resolver rotor 22 is facilitated, and the number of work steps can be reduced. In addition, the rotational position of the rotor 3 can be accurately detected, and motor control characteristics can be improved. Further, since the bridge portion 49 is accommodated in the bridge fitting hole 54, even if the bridge portion 49 is left as a retaining member for the rotor magnet 18, the bridge portion 49 itself is not dropped and scattered, and the product Reliability is improved.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the configuration in which the rotor magnet 18 is provided in three layers in the rotor 3 is shown, but the number of magnet layers is not limited to three, and the magnet configuration is less than three layers or four or more layers. There may be. The shapes of the slits 17a to 17c may be linear instead of arcuate (circular), and the present invention is applicable regardless of the number and shape of the rotor magnets 18. Furthermore, the bridge portion 49 that connects the rotor magnets 18 of each layer is not limited to the above-described configuration in which one piece is disposed at the center of the magnetic pole portion 20. Thus, a plurality (two in FIG. 7) may be provided at positions symmetrical with respect to the center of the magnetic pole part 20. In this case, the bridge fitting hole 54 of the resolver holder 51 is also arranged accordingly.

On the other hand, in the above-described embodiment, the case where the brushless motor according to the present invention is used as a drive source of the electric power steering apparatus has been described.
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In addition, the reluctance torque can be utilized, so that its application is expanding as a high-efficiency and high-torque motor. The present invention is also applied to other in-vehicle electric devices, electric products such as hybrid cars, electric cars, and air conditioners. Widely applicable.

DESCRIPTION OF SYMBOLS 1 Brushless motor 2 Stator 3 Rotor 4 Housing 4a Bearing accommodating part 5 Stator core 5a Outer ring part 5b Teeth 6 Field coil 6a Coil end part 7 Bus bar unit 8 Bracket 9 Bus bar 10 Fixing screw 11 Insulator 12 Feed terminal 13 Shafts 14a, 14b Bearing 15 Bearing holder 16 End face 17 Slit group 17a First slit 17b Second slit 17c Third slit 18 Rotor magnet 18n Rotor magnet 18s Rotor magnet 19 Slot 20 Magnetic pole part 21 Resolver 22 Resolver rotor 22a Convex part 23 Resolver stator 24 Resolver Holder 24a Flange 25 Bracket holder 26 Rib 27 Resolver fixing nut 28 Resolver fixing screw 31 Power tower Null 31a One end side 31b The other end side 32 Opening portion 33 Bus bar terminal 34 Power connector 41 Magnetic field orientation magnet 42 Magnetic field orientation die 43 Hollow portion 44 Upper die 45 Sprue 46 First runner 47 Second runner 48 Gate 49 Bridge portion (projection) Department)
51 Resolver holder 51a One end surface side 51b The other end surface side 52 Resolver rotor mounting piece (resolver rotor mounting portion)
53 Concave groove 54 Bridge fitting hole

Claims (7)

A motor case,
A stator fixed to the motor case;
A rotor shaft rotatably disposed in the motor case;
A rotor core disposed on the inner side of the stator and fixed to the rotor shaft, a magnet attached to the rotor core, and a protrusion projecting from an axial end surface of the rotor core and disposed in a predetermined positional relationship with the magnet. A rotor provided with a configuration part;
A resolver rotor attached to the rotor shaft, and a resolver stator disposed outside the resolver rotor, the resolver detecting a rotation angle of the rotor based on a rotation position of the resolver rotor, A brushless motor,
The brushless motor
A resolver rotor mounting portion is formed on one end surface side of the rotor, and a resolver rotor mounting portion is formed on one end surface side of the rotor. The other end surface side opposite to the resolver rotor mounting portion is fitted with the protruding portion. Having a resolver holder in which a fitting hole is formed;
The resolver rotor mounting portion is disposed in a predetermined positional relationship with the fitting hole, and is connected to a predetermined position of the resolver rotor ,
The rotor core has a plurality of magnet housing holes arranged at equal intervals along the circumferential direction, and the magnet housing holes form a plurality of sets of slit groups each including a plurality of layers of curved slits. Is housed and fixed in the magnet housing hole,
The projecting portion is a brushless motor, wherein Rukoto disposed along the radial direction so as to straddle the magnet of the plurality of layers. The brushless motor according to claim 1,
The resolver holder is attached to the rotor in such a manner that the projecting portion of the rotor is fitted into the fitting hole of the resolver holder, and the resolver rotor is attached to the resolver rotor attachment portion, thereby The brushless motor, wherein the magnets are arranged in a predetermined positional relationship. The brushless motor according to claim 1 or 2,
The resolver rotor mounting portion projects from the one end face side of the resolver holder and extends along the axial direction, and a concave groove formed in a predetermined positional relationship with a convex portion formed on the outer periphery of the resolver rotor. A brushless motor characterized by being fitted. The brushless motor according to any one of claims 1 to 3,
The brushless motor , wherein the projecting portion is formed integrally with the magnet . The brushless motor according to claim 4,
The brushless motor according to claim 1, wherein the magnet in the magnet housing hole is retained by the projecting portion so as not to come out from an end portion of the rotor core opposite to the projecting portion . The brushless motor according to any one of claims 1 to 5,
The brushless motor, wherein the protruding portion is disposed at a position where the magnetic balance of the rotor is not lost . The brushless motor according to any one of claims 1 to 6,
The magnet is filled and formed by pressurizing and supplying a bond magnetic material to the rotor core disposed in a mold .

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