JP2009284706A - Rotor and brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor which easily magnetizes a magnet while highly accurately maintaining the position of attaching a rotation angle detector for detecting the rotation angle of the rotor and reduces a manufacturing cost, and also to provide a brushless motor. <P>SOLUTION: The rotor 3 includes a magnet holder 34 for positioning a plurality of rotor magnets 33 in a circumferential direction, wherein the magnet holder 34 has a base section 52 externally fitted to a rotating shaft 18 and disposed on one end surface of the shaft direction of a rotor core 32, and a plurality of arm sections 55 extending along the shaft direction from the outside of diameter direction of the base section 52 and intervening between the plurality of rotor magnets 33. In the rotor 3, a magnet cover 35 for covering the outer surface of the plurality of rotor magnets 33 is provided, and mark holes 64 are provided on the positions corresponding to the portions where the plurality of rotor magnets 33 are disposed, on the base section 52 of the magnet holder 34 not covered by the magnet cover 35. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotor having a magnet holder for positioning a magnet disposed on an outer peripheral surface of a rotor core, and a brushless motor using the same.

2. Description of the Related Art Conventionally, there is known a brushless motor that includes a stator around which a coil is wound and a rotor that is rotatably provided with respect to the stator, and that rotates the rotor by controlling energization of the coil. The rotor includes a rotating shaft, a substantially cylindrical rotor core that is fitted and fixed to the rotating shaft, and a magnet that is provided on the outer peripheral surface of the rotor core.
As the magnet, a segment type magnet formed in a tile shape may be used. In this case, a plurality of magnets are arranged in parallel on the outer peripheral surface of the rotor core so that the magnetic poles change in order in the circumferential direction.

  Here, in order to perform the circumferential positioning of this kind of magnet, a magnet holder may be used. The magnet holder is composed of a holder base fixed to the rotating shaft and a plurality of holder arms extending in the axial direction from one end side of the holder base. Then, by positioning each holder arm between magnets, the segment magnets are positioned in the circumferential direction.

The rotor may be provided with a magnet cover that covers the periphery of the magnet. The outer surface of the magnet is covered with a magnet cover to prevent damage to the magnet. If the magnet is damaged, for example, if it is damaged, it is prevented from scattering around this piece. Locking can be prevented (see, for example, Patent Document 1).
International Publication No. 2007/080888 Pamphlet

  By the way, the brushless motor rotates the rotor by the magnetic attraction force or repulsive force generated between the magnetic field formed in the coil and the magnet by switching the energization timing to the coil wound around the stator. It is necessary to control the energization timing to the coil. For this reason, in the brushless motor as described above, a rotation angle detection device for detecting the rotation angle of the rotor is often provided.

  An example of the rotation angle detection device is a resolver. The resolver includes a resolver rotor that is fixed to a rotation shaft, and a resolver stator that is provided so as to surround the outer periphery of the resolver rotor. A resolver winding is wound around the resolver stator. The resolver winding is electrically connected to an external control device, and the rotation angle of the rotor is determined by measuring the gap permeance between the resolver rotor and the resolver stator. It can be detected. For this reason, the rotation angle detection result by the resolver is greatly influenced by the mounting accuracy of the resolver rotor.

  However, in the above-described prior art, since the magnet cover is covered around the magnet, the magnetic pole position of the magnet cannot be visually recognized from the outside. For this reason, there exists a subject that it is difficult to attach a resolver rotor accurately according to the position of a magnet.

Specifically, the magnet is often magnetized after the assembly of the rotor in consideration of mounting properties. For example, the resolver rotor is first attached with high accuracy, the resolver rotor is positioned, and then the magnetizing is performed. There is a case. In this case, due to the stress at the time of magnetization, a torsional load acts on the resolver rotor, and the attachment position of the resolver rotor may be shifted.
Further, for example, there is a case where a resolver rotor is attached with high accuracy, the resolver rotor is sensed by a detection device such as a laser, the rotation shaft is fixed, positioning is performed, and then magnetized. In this case, it is possible to prevent the resolver rotor from being displaced due to stress at the time of magnetization, but there is a problem that a separate detection device is required and the manufacturing cost increases.

  Accordingly, the present invention has been made in view of the above-described circumstances, and easily magnetizes a magnet while accurately maintaining the mounting position of a rotation angle detection device for detecting the rotation angle of a rotor. It is possible to provide a rotor and a brushless motor that can reduce manufacturing costs.

In order to solve the above-described problem, the invention described in claim 1 includes a rotor core that is externally fitted and fixed to a rotating shaft, a plurality of magnets that are arranged in parallel along the circumferential direction on the outer peripheral surface of the rotor core, and A magnet holder for positioning the plurality of magnets in the circumferential direction, the magnet holder being externally fitted to the rotating shaft and disposed on one axial end surface of the rotor core, and a diameter of the base portion A rotor having a plurality of arm portions that extend along the axial direction from the outside in the direction and are interposed between the plurality of magnets, and a magnet cover that covers an outer surface of the plurality of magnets is provided; On the outer surface of the base portion of the magnet holder that is not covered, a mark is provided at a position corresponding to the arrangement location of the plurality of magnets. And features.
By configuring in this way, even when the magnet is covered with the magnet cover, the position of the magnet can be confirmed using the mark. For this reason, the magnet can be magnetized by positioning and fixing the rotor core. Since the rotor core is firmly fixed to the rotation shaft as compared with a rotation angle detection device such as a resolver rotor, the rotor core does not shift during magnetization.

According to a second aspect of the present invention, the mark is any one of a hole penetrating the base portion in the axial direction, a convex portion formed on the outer surface of the base portion, or a concave portion formed on the outer surface of the base portion. It is characterized by.
By configuring in this way, when positioning the rotor core, it becomes possible to use a jig that utilizes any of the holes, convex portions, or concave portions formed in the base portion. Positioning can be performed more accurately.

The invention described in claim 3 is characterized in that the mark is provided corresponding to a portion of the plurality of magnets where the magnet of the same magnetic pole is disposed.
By comprising in this way, it becomes unnecessary to provide a mark in a magnet holder more than necessary, and the position of a magnet can be confirmed efficiently.
Further, since the magnets are provided so that the magnetic poles are in order in the circumferential direction, the marks can be provided at equal intervals in the circumferential direction.

According to a fourth aspect of the present invention, the rotor according to any one of the first to third aspects, a stator disposed around the rotor and having a coil wound thereon, and a rotation angle of the rotor are detected. A brushless motor provided with a rotation angle detection device for performing the above operation.
With this configuration, the magnet can be easily magnetized while accurately maintaining the mounting position of the rotation angle detection device for detecting the rotation angle of the rotor, and the manufacturing cost can be reduced. The brushless motor which can be provided can be provided.

  According to the first aspect of the present invention, even when the magnet is covered with the magnet cover, the position of the magnet can be confirmed using the mark. For this reason, the magnet can be magnetized by positioning and fixing the rotor core. Since the rotor core is firmly fixed to the rotation shaft as compared with a rotation angle detection device such as a resolver rotor, the rotor core does not shift during magnetization. Therefore, for example, even when the rotation angle detection device is attached to the rotation shaft, the magnet can be easily magnetized while accurately maintaining the attachment position of the rotation angle detection device, Since a separate detection device is not required at the time of magnetization as in the prior art, the manufacturing cost can be reduced.

  According to the second aspect of the present invention, when positioning the rotor core, it is possible to use a jig that uses any one of the hole, the convex portion, or the concave portion formed in the base portion. Positioning in the circumferential direction can be performed more accurately. For this reason, the magnet can be magnetized more easily and accurately.

According to the third aspect of the present invention, it is not necessary to provide more marks than necessary on the magnet holder, and the position of the magnet can be confirmed efficiently. For this reason, it is possible to further reduce the manufacturing cost.
Further, since the magnets are provided so that the magnetic poles are in order in the circumferential direction, the marks can be provided at equal intervals in the circumferential direction. Here, for example, when the mark has a configuration that affects the weight of the magnet holder, the mark is provided at equal intervals in the circumferential direction, so that the dynamic balance of the rotor can be ensured.

  According to the fourth aspect of the present invention, the magnet can be easily magnetized while accurately maintaining the mounting position of the rotation angle detecting device for detecting the rotation angle of the rotor, and the manufacturing cost can be reduced. It is possible to provide a brushless motor that can be realized.

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the brushless motor 1 is a so-called inner rotor type brushless motor used in, for example, a power steering apparatus, and includes a stator 2 and a rotor 3 disposed in the stator 2. A rotor 3 is rotatably supported by a bracket 4 fixed to 2.

The stator 2 includes a bottomed cylindrical stator housing 11 having one end opened, and a stator core 12 that is press-fitted and fixed to the inner periphery of the stator housing 11.
The stator core 12 has an annular outer peripheral portion 31, and a plurality of teeth 14 are provided on the outer peripheral portion 31 to wind the coil 16 toward the center in the radial direction. A plurality of dovetail-shaped slots (not shown) are formed between adjacent teeth 14 on the inner peripheral side of the stator core 12. A coil 16 is wound around each of the teeth 14 by, for example, a concentrated winding method after the insulator 15 is mounted.

  The stator core 12 may be configured by joining a plurality of core units each having teeth 14 divided in the circumferential direction, or may be integrally formed without being divided in the circumferential direction. In the stator core 12 having the core unit divided and configured, first, after winding the coil 16 around each core unit, the plurality of core units are joined to form the stator core 12.

At the bottom of the stator housing 11, a boss portion 11B is formed at the substantially center in the radial direction, and a bearing 25b that rotatably supports one end of the rotating shaft 18 of the rotor 3 is press-fitted and fixed thereto.
On the opening side of the stator housing 11, an inlay portion 11 </ b> A that is used when the stamper is joined to the bracket 4 is formed. A bracket 4 for closing the opening is provided in the opening of the stator housing 11.

  The bracket 4 has a substantially cylindrical shape, and is fastened and fixed to the stator housing 11 by screws (not shown). On the end surface of the bracket 4 on the side of the stator housing 11, there is provided a joint portion 4 </ b> A that fits into the inlay portion 11 </ b> A when abutting against the stator housing 11. A packing 23 such as an O-ring is attached to the outer peripheral surface of the joint portion 4A so as to be sandwiched between the joint portion 4A and the spigot portion 11A.

  In the bracket 4, a bearing 25 a that rotatably supports the other end of the rotating shaft 18 of the rotor 3 is press-fitted and fixed in an opening opposite to the stator housing 11. A resolver stator 26A that constitutes one of the resolvers 26 that detects the rotational position of the rotor 3 is fixed to the stator core 12 side of the bearing 25a. The resolver stator 26 </ b> A is housed in a bottomed cylindrical resolver holder 40. The resolver holder 40 is used for positioning the resolver stator 26 </ b> A in the circumferential direction and fixing the resolver stator 26 </ b> A in the bracket 4, and is fastened and fixed to the bracket 4 by bolts 41. A connector 27 for taking out an electrical signal from the resolver stator 26A is fixed to the outer peripheral surface of the bracket 4.

  The rotor 3 is used, for example, as a power source of a column assist type power steering device, and has a role of applying an operation assisting force to a steering shaft of an automobile (not shown). That is, the rotor 3 is attached to a speed reduction mechanism (not shown) provided on a steering shaft (not shown) so that the rotation of the brushless motor 1 is decelerated via the speed reduction mechanism and transmitted to the steering shaft. It has become.

  As shown in FIGS. 1 to 3, the rotor 3 has a substantially cylindrical rotor core 32 that is externally fitted and fixed at a position facing the stator core 12 of the rotating shaft 18. A press-fitting hole 32 a for press-fitting the rotary shaft 18 is formed at the approximate center in the radial direction of the rotor core 32. In this embodiment, the rotor core 32 is formed by laminating with a metal plate. However, the present invention is not limited to this, and a magnetic powder body may be formed under pressure.

  On the outer circumferential surface of the rotor core 32, a plurality of (six in this embodiment) segment-type rotor magnets 33 formed in a tile shape are arranged in parallel along the circumferential direction. Each rotor magnet 33 is arranged so that the magnetic poles change in order in the circumferential direction. Each rotor magnet 33 is positioned in the circumferential direction by a magnet holder 34, and the outer peripheral surface is covered with a magnet cover 35.

On the other end side of the rotating shaft 18, a resolver rotor 26B constituting the other of the resolver 26 is fixed at a position facing the resolver stator 26A. The resolver rotor 26B is formed in a substantially annular shape by laminating a plurality of metal plates, and is press-fitted and fixed to the rotary shaft 18.
A plurality of salient poles 28 (three poles in this embodiment, see FIG. 3) are formed on the outer peripheral surface of the resolver rotor 26B. Accordingly, when the resolver rotor 26B rotates together with the rotating shaft 18, the gap permeance between the resolver rotor 26B and the resolver stator 26A changes. On the inner peripheral surface of the resolver rotor 26B, three concave portions 29 into which a projection 51 of a magnet holder 34 described later is inserted are formed at three equal intervals in the circumferential direction.

  As shown in FIGS. 4A and 4B, the magnet holder 34 has a substantially disc-shaped base portion 52 that is disposed on the end surface of the rotor core 32 on the resolver rotor 26 </ b> B side and is fitted around the rotary shaft 18. is doing. A cylindrical portion 53 projects from the base portion 52 in the radial direction toward the resolver rotor 26 </ b> B, and a rotary shaft insertion hole 54 is formed on the radially inner side of the cylindrical portion 53. Yes. Further, at the tip of the cylindrical portion 53, three protruding portions 51 extending in the axial direction are integrally formed at equal intervals in the circumferential direction. The protrusion 51 is formed so as to correspond to the recess 29 of the resolver rotor 26 </ b> B, and is inserted into a hole formed by the recess 29 and the outer peripheral surface of the rotary shaft 18. By inserting the protrusion 51 into this hole, the relative position between the resolver rotor 26B and the magnet holder 34 is determined.

  On the outer peripheral edge of the base portion 52, a plurality of arm portions 55 are projected toward the rotor core 32 at equal intervals in the circumferential direction. The arm portion 55 includes an arm main body 56 interposed between the rotor magnets 33 and a bridge portion 57 that connects the arm main body 56 and the base portion 52. The circumferential width W1 of the bridge portion 57 is set smaller than the circumferential width W2 of the arm main body 56. Cutout portions 58 are formed on both sides of the bridge portion 57 in the circumferential direction, and a peripheral wall portion 59 constituting the outer periphery of the base portion 52 is formed between the adjacent bridge portions 57.

  The arm body 56 is formed in a substantially T-shaped cross section, and a pair of magnet holding pieces 60 extending in the axial direction are formed on both sides of the outer peripheral side in the circumferential direction. Between the magnet holding pieces 60 formed on the adjacent arm portions 55 and facing each other in the circumferential direction, a magnet housing portion 61 is formed by the magnet holding pieces 60 and the outer peripheral surface of the rotor core 32.

  When each rotor magnet 33 is disposed on the outer peripheral surface of the rotor core 32, the rotor magnet 33 is press-fitted into the magnet housing portion 61 along the axial direction from the bottom side of the stator housing 11. Thereby, the rotor magnet 33 is held by the magnet holder 34 in the magnet housing part 61. Therefore, in this embodiment, since six rotor magnets 33 are arranged side by side, six magnet housing portions 61 are formed.

  The bridge portion 57 is formed to be narrower than the arm main body 56 in order to securely house the rotor magnet 33 in the magnet housing portion 61 (see FIG. 4A). That is, the circumferential width W1 of the bridge portion 57 is set to be smaller than the circumferential width W2 of the arm body 56, and the notch portions 58 are formed on both sides of the bridge portion 57 in the circumferential direction. It is designed to bend elastically. As a result, when the rotor magnet 33 is press-fitted into the magnet housing portion 61, the bridge portion 57 is elastically bent, so that the rotor magnet 33 can be surely pushed in and the rattle of the rotor magnet 33 can be suppressed, and the arm body 56 can be prevented. Thus, the rotor magnet 33 can be securely held.

  A fitting projection 62 is formed on the inner peripheral side of the arm body 56, while a dovetail groove 63 is formed on the outer peripheral surface of the rotor core 32 at a portion corresponding to the fitting projection 62. The fitting protrusion 62 has a substantially trapezoidal cross section so as to correspond to the dovetail groove 63 of the rotor core 32. That is, when the fitting protrusion 62 and the dovetail groove 63 are fitted, the displacement of the arm body 56 outward in the radial direction is restricted. For this reason, the arm main body 56 can hold the rotor magnet 33 more reliably.

  Here, in the base portion 52 of the magnet holder 34, three mark holes 64 for recognizing the position of the rotor magnet 33 are formed. Each mark hole 64 is formed at a position corresponding to the substantially central portion in the circumferential direction of the magnet housing portion 61 and at a position corresponding to every other magnet housing portion 61 present in the circumferential direction, and is equally spaced in the circumferential direction. It is in the state where it is arranged. That is, since the rotor magnets 33 are arranged so that the magnetic poles change in order in the circumferential direction, each mark hole 64 corresponds to the position of the rotor magnet 33 that is the same magnetic pole among the six rotor magnets 33. Will be formed.

  As shown in FIGS. 2, 5 (a), and 5 (b), the magnet cover 35 is formed in a bottomed cylindrical shape. The magnet cover 35 has an opening 36 having a large opening at the center of the bottom 35 a, and can be attached to the rotor core 32 from the bottom side of the stator housing 11. That is, the bottom 35a of the magnet cover 35 is disposed on the end surface of the rotor core 32 opposite to the resolver rotor 26B side. The diameter E1 of the opening 36 formed in the bottom 35a of the magnet cover 35 is such that the bottom 35a is at least one end surface of the rotor magnet 33 (the bottom surface side end surface of the stator housing 11) and the tip of the arm body 56 of the magnet holder 34. It is set to a size that can be covered.

  Here, in the present embodiment, the side plate 42 is provided on the end surface of the rotor core 32 opposite to the resolver rotor 26B side (see FIG. 1). That is, when the magnet cover 35 is attached to the rotor core 32, the end surface side plate 42 opposite to the resolver rotor 26B side of the rotor core 32 is placed in advance, and then the magnet cover 35 is attached to the rotor core 32. ing. For this reason, when the magnet cover 35 is attached to the rotor core 32, the end surface of the rotor core 32 opposite to the resolver rotor 26 </ b> B side is entirely covered with the side plate 42 and the bottom 35 a of the magnet cover 35. Yes.

  A caulking portion 37 is integrally formed on the opening edge of the peripheral wall 35 b of the magnet cover 35. The caulking portion 37 is formed so as to expand toward the outer side in the axial direction. The caulking portion 37 is a portion where caulking is performed in such a manner that the rotor core 32 is held after the magnet cover 35 is attached to the rotor core 32. The length L1 in the axial direction of the caulking portion 37 is set to a length that can cover the other end surface (the end surface on the resolver rotor 26B side) of the rotor magnet 33 after caulking (FIGS. 1 and 5B). )reference).

  Therefore, when the magnet cover 35 is attached, the outer surface of the rotor magnet 33 is completely covered by the magnet cover 35 and is not visible from the outside. On the other hand, since the mark hole 64 formed in the base portion 52 of the magnet holder 34 is formed near the center in the radial direction, the mark hole 64 is not covered with the magnet cover 35 and is exposed to the outside ( (See FIG. 3).

Next, a procedure for attaching the rotor 3 will be described with reference to FIGS.
First, the rotor core 32 is press-fitted into the rotating shaft 18. Next, the magnet holder 34 is inserted from the resolver rotor 26 </ b> B side of the rotating shaft 18. At this time, the arm body 56 of the magnet holder 34 is inserted toward the rotor core 32, and the magnet holder 34 is fitted so that the fitting protrusion 62 formed on the arm body 56 and the dovetail groove 63 of the rotor core 32 are fitted. Match the circumferential direction.
Subsequently, the rotor magnet 33 is press-fitted into a magnet housing portion 61 formed by the arm portion 55 of the magnet holder 34 and the rotor core 32. At this time, the rotor magnet 33 is in an unmagnetized state, and the unmagnetized rotor magnet 33 is press-fitted into the magnet housing portion 61 from the end opposite to the resolver rotor 26B of the rotating shaft 18.

Next, the magnet cover 35 is attached to the rotor core 32. At this time, the caulking portion 37 of the magnet cover 35 is inserted from the end opposite to the resolver rotor 26 </ b> B of the rotating shaft 18 toward the rotor core 32, and attached to the rotor core 32.
Then, after the bottom portion 35 a of the magnet cover 35 is brought into contact with the end surface of the rotor core 32, the crimping portion 37 is crimped. When the magnet cover 35 is mounted, the side plate 42 is placed in advance on the end surface of the rotor core 32 opposite to the resolver rotor 26B. As a result, the outer surface of the rotor magnet 33 is completely covered with the magnet cover 35.

  Subsequently, the resolver rotor 26 </ b> B is press-fitted and fixed to the rotary shaft 18. At this time, the circumferential direction of the resolver rotor 26B is adjusted so that the concave portion 29 of the resolver rotor 26B is positioned at a position corresponding to the protrusion 51 of the magnet holder 34. Then, the resolver rotor 26B is press-fitted so that the protrusion 51 of the magnet holder 34 is inserted between the concave portion 29 formed in the resolver rotor 26B and the outer peripheral surface of the rotary shaft 18.

  Next, the rotor magnet 33 is magnetized. At this time, since the mark hole 64 formed in the base portion 52 of the magnet holder 34 is exposed in the rotor 3, the rotor 3 is positioned using the mark hole 64. Since the mark hole 64 is exposed, the position of the rotor magnet 33 covered with the magnet cover 35 can be easily confirmed.

  As a more specific positioning method of the rotor 3, for example, a method using a jig having a positioning pin that can be fitted into the mark hole 64 may be used. If such a jig is used, when the rotor 3 is set on the jig, the positioning of the rotor 3 can be completed only by setting the positioning pin and the mark hole 64 to be fitted.

  After the positioning of the rotor 3 is completed, the rotor magnet 33 is magnetized. At this time, for example, when the rotor 3 is positioned using a jig, the rotor magnet 33 can be surely magnetized by associating the relative positions of the jig and the magnetizing device. It can be carried out. Further, even when no jig is used, the position of each rotor magnet 33 can be recognized, so the direction of the rotor magnet 33 in the circumferential direction with respect to the magnetizing device can be easily adjusted, and the rotor can be reliably connected. The magnet 33 can be magnetized. As described above, when the magnetization of the rotor magnet 33 is completed, the attachment of the rotor 3 is completed.

  Therefore, according to the above-described embodiment, the arrangement position of the rotor magnet 33 can be confirmed using the mark hole 64 even when the rotor magnet 33 is covered with the magnet cover 35. For this reason, it is possible to magnetize the rotor magnet 33 by positioning and fixing the rotor core 32 with a jig or the like. Since the rotor core 32 is firmly fixed to the rotating shaft 18 as compared with the resolver rotor 26B, the rotor core 32 does not shift during magnetization. Therefore, it is possible to easily magnetize the rotor magnet 33 while accurately maintaining the mounting position of the resolver 26, that is, the mounting position of the resolver rotor 26B. Thus, the manufacturing cost can be reduced.

In addition, by forming the mark hole 64 in the base portion 52 of the magnet holder 34, for example, a positioning pin that can be fitted to the mark hole 64 is provided on the positioning jig of the rotor 3 or the like. Positioning in the circumferential direction can be performed accurately. For this reason, it becomes possible to magnetize the rotor magnet 33 more easily and accurately.
Furthermore, since the mark hole 64 is formed so as to correspond to the position of the rotor magnet 33 that is the same magnetic pole among the six rotor magnets 33, it is not necessary to form the mark hole 64 in the magnet holder 34 more than necessary. The position of the rotor magnet 33 can be confirmed efficiently. For this reason, it is possible to further reduce the manufacturing cost.

  And each rotor magnet 33 is arrange | positioned so that a magnetic pole may change in order in the circumferential direction. For this reason, the weight balance of the magnet holder 34 is changed by forming the mark holes 64. However, since the mark holes 64 are formed at equal intervals in the circumferential direction, the dynamic balance of the rotor 3 is ensured. It becomes possible.

The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.
Moreover, although the above-mentioned embodiment demonstrated the case where the mark hole 64 was formed in the base part 52 of the magnet holder 34 as a means for confirming the position of the rotor magnet 33 after mounting | wearing with the magnet cover 35, in this, It is not limited, and it is only necessary that a mark capable of confirming the position of the rotor magnet 33 is provided.
For example, as indicated by a two-dot chain line in FIG. 4B, a convex portion 65 may be formed on the outer surface of the base portion 52 instead of the mark hole 64, or a concave portion 66 may be formed.
In the case where a convex portion is formed, when a jig for positioning the rotor 3 is used, it is desirable that a concave portion or a hole that can be fitted to the convex portion is formed in the jig. On the other hand, when the concave portion is formed, it is desirable to form a convex portion that can be fitted to the concave portion in the jig for positioning the rotor 3.

  Furthermore, in the above-described embodiment, the case where the six segment-type rotor magnets 33 are provided and the three mark holes 64 are formed in the base portion 52 of the magnet holder 34 has been described. However, the number of rotor magnets 33 is not limited to six and may be two or more. In this case, the number of the mark holes 64 may be changed according to the number of the same magnetic poles of the rotor magnet 33.

  In the above-described embodiment, the case where the mark hole 64 is formed only in the portion corresponding to the same magnetic pole of the six rotor magnets 33 in the base portion 52 of the magnet holder 34 has been described. However, the present invention is not limited to this, and the mark holes 64 may be formed at positions corresponding to all the rotor magnets 33.

  Further, in the above-described embodiment, the case where three salient poles 28 are formed on the outer peripheral surface of the resolver rotor 26B has been described. However, the present invention is not limited to this. For example, the salient poles 28 may be formed in four poles, or the resolver rotor 26B may be formed in an elliptical shape in the axial plan view.

  Further, in the above-described embodiment, the case where the rotor core 32, the magnet holder 34, the rotor magnet 33, the magnet cover 35, and the resolver rotor 26B are attached to the rotating shaft 18 in this order as the attachment procedure of the rotor 3 has been described. However, the present invention is not limited to this, and the rotor magnet 33 may be magnetized in the final process.

It is a longitudinal cross-sectional view which shows the structure of the brushless motor in embodiment of this invention. It is a disassembled perspective view of the rotor in embodiment of this invention. It is a partially notched top view of the rotor in embodiment of this invention. The magnet holder in embodiment of this invention is shown, (a) is a top view, (b) is a longitudinal cross-sectional view. The magnet cover in embodiment of this invention is shown, (a) is a top view, (b) is a partially notched side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brushless motor 2 Stator 3 Rotor 18 Rotating shaft 26 Resolver (Rotation angle detection device)
26A Resolver stator 26B Resolver rotor 32 Rotor core 33 Rotor magnet (magnet)
34 Magnet holder 35 Magnet cover 52 Base portion 55 Arm portion 56 Arm body 64 Marking hole (hole)
65 Convex part 66 Concave part

Claims (4)

A rotor core that is externally fixed to the rotary shaft;
A plurality of magnets arranged side by side along the circumferential direction on the outer peripheral surface of the rotor core;
A magnet holder for positioning the plurality of magnets in the circumferential direction;
The magnet holder is
A base portion fitted on the rotary shaft and disposed on one end surface in the axial direction of the rotor core;
In the rotor having a plurality of arm portions extending along the axial direction from the radially outer side of the base portion and interposed between the plurality of magnets,
Provide a magnet cover that covers the outer surface of the plurality of magnets,
The rotor according to claim 1, wherein a mark is provided on an outer surface of the base portion of the magnet holder that is not covered with the magnet cover at a position corresponding to an arrangement position of the plurality of magnets. The landmark is
2. The device according to claim 1, wherein the hole is one of a hole penetrating the base portion in the axial direction, a convex portion formed on the outer surface of the base portion, or a concave portion formed on the outer surface of the base. Rotor.   3. The rotor according to claim 1, wherein the mark is provided corresponding to a place where a magnet having the same magnetic pole is disposed among the plurality of magnets. The rotor according to any one of claims 1 to 3,
A stator disposed around the rotor and wound with a coil;
A brushless motor comprising a rotation angle detection device for detecting a rotation angle of the rotor.

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