JP2007288977A - Rotor and brushless motor, and method of manufacturing rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor and a brushless motor, and a method of manufacturing the rotor that omits an adhesion step by fixing magnets without using adhesives to reduce the manufacturing cost, and ensures the fixing of the rotor magnets. <P>SOLUTION: An arm 26 of a magnet holder 24 is disposed in the clearance of magnets 23 disposed in a ring shape along the outer circumferential surface of a spacer 22 through which a shaft 21 has been inserted and fixed. An arm 26 is extended out and formed axially at the magnet 23 side from an annular ring 25 that abuts axially against one-side ends of the magnets 23. At the free end of the arm 26, there is formed an swaged portion 27 abuttable against the magnets 23 from an opposite direction with respect to the ring 25, the fallout of the magnets 23 in an axial direction is prevented by holding the magnets 23 between the swaged portion 27 and the ring 25. Since claws 30a, 30b at the inner circumferential surface of a rotor cover 30 comes into elastic contact with the arm 26, the magnets 23 can be pressed and fixed at all time to the spacer 22 via the arm 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotor, a brushless motor, and a rotor manufacturing method, and more particularly, a rotor in which a rotor magnet is fixed without using an adhesive, a brushless motor including the rotor, and a rotor for manufacturing the rotor. It relates to a manufacturing method.

Conventionally, in a rotating magnetic field type brushless motor using a permanent magnet as a rotor, the magnet is fixed to the surface of the rotor. As a fixing method, a method of fixing mainly using an adhesive is used.
However, in the method of fixing using an adhesive, an adhesive is applied to the magnet, the magnet is disposed on the rotor surface, the adhesive is dried and fixed, and the number of operation steps is large. In addition, since the work time is long, it is not efficient and the manufacturing cost is high. Adhesives have a problem of deterioration over time, but motors mounted on vehicles such as automobiles have severe environmental conditions and a long mounting period, so it is difficult to select an adhesive that meets such conditions. There was a problem that the material cost was also affected.

In addition, there is a method of securely fixing the magnet to the rotor by resin molding, but it is necessary to manufacture a mold for resin molding, and there is a disadvantage that the manufacturing cost increases.
There is also a method of pressing and fixing a magnet by press-fitting into the rotor cover (for example, see Patent Document 1). In Patent Document 1, a segmented rotor magnet is disposed on the outer periphery of a spacer, and a spacer arm extending in the axial direction of the rotor is provided between magnets adjacent in the circumferential direction. The spacer arm is formed with step portions at both ends in the circumferential direction, and the end portions of the rotor magnet are engaged with the step portions, and the rotor magnet is locked and positioned in the circumferential direction and the radial direction. And since the tubular rotor cover is armored so as to press the spacer arm from the outer peripheral side, the rotor magnet is fixed to the outer periphery of the spacer without using an adhesive by the binding force of the rotor cover.

Japanese Patent Laying-Open No. 2005-20887 (page 10-11, FIG. 2, FIG. 11)

  However, in the fixing method of Patent Document 1, the rotor magnet is locked in the circumferential direction and the radial direction and pressed and fixed to the spacer side. However, there is no structure for locking the rotor magnet in the axial direction. Therefore, when the rotor cover is loosened, the rotor magnet may move in the axial direction, and there is a problem that the fixing of the rotor magnet is not reliable.

  In view of the above problems, an object of the present invention is to reduce the manufacturing cost by fixing the magnet without using an adhesive to reduce the manufacturing cost, and to fix the rotor magnet securely and the rotor. A brushless motor provided with a rotor and a method of manufacturing the rotor.

  According to the present invention, the object is a rotor including a rotor shaft, a spacer into which the rotor shaft is inserted and fixed, and a plurality of rotor magnets arranged in an annular shape along the outer peripheral surface of the spacer. An annular ring portion that is in axial contact with one end of the rotor magnet, and a plurality of arm portions that extend in the axial direction from the ring portion and are disposed in gaps between the plurality of rotor magnets. A magnet holder, and a rotor cover that covers the rotor magnet and the magnet holder from the outside in the radial direction, and the magnet holder has a free end of the arm portion and a contact direction of the ring portion with the rotor magnet. Is formed with an engaging portion that can contact the other end of the rotor magnet from the opposite direction, and the rotor magnet is held between the engaging portion and the ring portion. It is solved by configured to be prevented from falling in the axial direction of the rotor magnet by.

Thus, in the rotor of the present invention, the ring portion abuts on one end side of the rotor magnet from the axial direction, and the engaging portion abuts on the other end side of the rotor magnet from the opposite direction to the ring portion. With such a configuration, the rotor magnet is held between the ring portion and the locking portion. As a result, the rotor magnet is locked in the axial direction and is prevented from falling off in the axial direction.
Further, since the arm portion extends in the gap between the rotor magnets arranged along the outer peripheral surface of the spacer, the rotor magnet is positioned in the circumferential direction. Furthermore, since the rotor cover that covers the rotor magnet and the magnet holder from the radially outer side is provided, the rotor magnet is prevented from falling off to the radially outer side. Further, the rotor magnet and the magnet holder can be pressed and fixed to the outer peripheral surface of the spacer by the binding force of the rotor cover.
In the present invention, such a configuration can prevent the rotor magnet from falling off without fixing the rotor magnet with an adhesive or the like. Therefore, the rotor magnet bonding process can be omitted in the rotor manufacturing process, and the number of processes and the manufacturing cost can be reduced.

In the present invention, more specifically, the locking portion includes a protruding portion formed so as to protrude in the circumferential direction from the free end of the arm portion, and between the protruding portion and the ring portion. The rotor magnet may be held in the structure.
In the present invention, the projecting portion is formed so as to project in two directions from the free end of the arm portion toward both sides in the circumferential direction, and between the projecting portion and the ring portion projecting in two directions. Can be configured such that the two rotor magnets arranged on both sides of the arm portion in the circumferential direction are respectively held.
In this manner, if the protruding portions are formed in two directions from the arm portion toward both sides in the circumferential direction, the two rotor magnets on both sides can be held by one locking portion. Further, when the projecting portions are extended in two directions from the arm portions arranged on both sides of each rotor magnet, each rotor magnet is held at two locations from both sides in the circumferential direction. Therefore, the rotor magnet can be held in the axial direction more reliably.

Further, in the present invention, the circumferential surface of the rotor magnet is formed so as to form a tapered surface inclined radially outward, and the arm portion is in contact with the circumferential surface and radially inward of the rotor cover. It can be set as the structure arrange | positioned so that it may contact | abut from.
As described above, when the arm portion is in contact with the tapered surface of the rotor magnet and this arm portion is in contact with the rotor cover from the inside in the radial direction, the rotor cover is externally mounted so as to press the arm portion from the outside in the radial direction. Thus, the rotor magnet can be pressed to the spacer side via the arm portion by the binding force of the rotor cover. Further, the tapered surface is pressed from the outside in the radial direction, whereby the rotor magnet is pressed from both sides in the circumferential direction. Therefore, the rotor magnet is positioned in the circumferential direction. Therefore, it is possible to prevent the rotor magnet from moving in the circumferential direction and falling off radially outward.

Moreover, in this invention, it can be set as the structure by which the press-contact part which elastically contacts from the radial direction outer side to the said arm part was provided in the inner peripheral side of the said rotor cover.
In this way, if a pressure contact portion that is elastically contacted from the outside in the radial direction is provided, a pressing force inward in the radial direction can be constantly applied to the arm portion. Therefore, it is possible to prevent the arm portion from being lifted outward in the radial direction, and the rotor magnet can be constantly pressed and fixed to the spacer via the arm portion. Therefore, the holding force of the rotor magnet can be improved.
Even if there is a manufacturing error in the rotor cover, arm portion, rotor magnet, etc., the contact state between the rotor cover and the arm portion can be ensured by elastic deformation of the pressure contact portion. Therefore, the rotor magnet can be more reliably pressed and fixed to the spacer at all times, and the holding force of the rotor magnet can be improved more reliably.

In the present invention, more specifically, the press contact portion is an extended piece extending from a predetermined position of the rotor cover, or a cut-and-raised piece formed by cutting a predetermined position of the rotor cover, Any of the above can be configured to be folded back to the inner peripheral side of the rotor cover.
Thus, with a simple configuration in which claw-like pieces such as extended pieces and cut-and-raised pieces formed on the rotor cover are turned back to the inner peripheral side, the folded-back portion can be made spring-like and have spring properties. Therefore, such a folded portion can be used as the pressure contact portion, and can be appropriately formed at a position corresponding to the arm portion, so that it can be brought into elastic contact with the arm portion.

In the present invention, the press contact portion includes a first press contact portion that elastically contacts the proximal end side of the arm portion, and a second press contact portion that elastically contacts the free end side of the arm portion. It can be.
In this way, if the arm portion is pressed radially inward by the pressure contact portion at two points of the base end portion and the free end portion, the arm portion is prevented from tilting with respect to the axial direction by being pressed at two points separated in the axial direction. The axial distribution of the pressing force applied to the rotor magnet via the arm portion can be made uniform.

  Moreover, according to the brushless motor of this invention, the said subject is solved by the brushless motor provided with the rotor of said each structure. As described above, the brushless motor of the present invention can prevent the rotor magnet from dropping off in the axial direction without fixing the rotor magnet with an adhesive or the like by providing each of the above-described configurations. Therefore, the rotor magnet bonding step can be omitted, and the number of steps and the manufacturing cost can be reduced. In addition, it is possible to more reliably prevent the rotor magnet from moving in the circumferential direction and falling off radially outward.

  Further, according to the method of manufacturing a rotor of the present invention, the above-described problem is that a rotor shaft, a spacer in which the rotor shaft is inserted and fixed, and a plurality of rotor magnets arranged in an annular shape along the outer peripheral surface of the spacer, And an annular ring portion that axially contacts one end side of the rotor magnet, and a plurality of arm portions that extend from the ring portion in the axial direction and are disposed in gaps between the plurality of rotor magnets And a locking portion formed at the free end of the arm portion, and the locking portion of the rotor magnet from a direction opposite to a contact direction of the ring portion with the rotor magnet. Rotor manufacture for manufacturing a rotor in which the rotor magnet is held between the ring portion and the locking portion and prevented from falling off in the axial direction by contacting the other end. A first step of inserting and fixing the rotor shaft in a through-hole penetrating the spacer, and fitting the ring portion to the spacer and arranging the plurality of arms on the outer peripheral surface of the spacer. And a second step of disposing the rotor magnet between adjacent arm portions, and after the second step, the free end of the arm portion is pressed from the tip side and caulked in the circumferential direction. This is solved by performing the third step of forming the locking portion having a protruding portion and holding the rotor magnet between the protruding portion and the ring portion.

  As described above, the rotor manufacturing method of the present invention is used when manufacturing a rotor that can prevent the rotor magnet from dropping off in the axial direction without fixing the rotor magnet with an adhesive or the like, as in the above-described configurations. It is what And in this invention, it has the characteristics in the formation process of the latching | locking part which contact | abuts to a rotor magnet from a direction opposite to a ring part especially. That is, after the rotor magnet is disposed between the arm portions of the magnet holder, the free end of the arm portion is pressed and crimped from the distal end side to form a locking portion having a projecting portion projecting in the circumferential direction. . If it does in this way, since the latching | locking part is not formed at the time of arrangement | positioning of a rotor magnet, an assembly | attachment is easy. In addition, if the overhanging portion is formed by caulking, the ring portion and the rotor magnet, and the rotor magnet and the overhanging portion are in contact with each other without gaps due to pressing during caulking. Therefore, the rotor magnet does not rattle between the ring portion and the overhang portion.

The present invention has the following effects.
(1) By using a magnet holder that can hold the rotor magnet between the ring part and the engaging part formed at the tip of the arm part extending in the axial direction from the ring part, the rotor magnet is axially Is prevented from falling off in the axial direction. With such a configuration, it is possible to prevent the rotor magnet from dropping off in the axial direction without fixing the rotor magnet with an adhesive or the like. Therefore, the rotor magnet bonding process can be omitted in the rotor manufacturing process, and the number of processes and the manufacturing cost can be reduced.
(2) By providing the pressure contact portion that elastically contacts the arm portion from the radially outer side on the inner peripheral side of the rotor cover, it is possible to always apply a pressing force radially inward to the arm portion. Further, due to the elastic deformation of the pressure contact portion, the contact state between the rotor cover and the arm portion can be ensured even if there is a manufacturing error or the like. Therefore, the arm portion can be prevented from being lifted outward in the radial direction, and the rotor magnet can be more surely pressed and fixed to the spacer via the arm portion, and the holding force of the rotor magnet can be improved.

(3) The circumferential surface of the rotor magnet is a tapered surface that is inclined outward in the radial direction, and the tapered surface is pressed from the radially outer side by the binding force of the rotor cover via the arm portion, thereby rotating the rotor magnet in the circumferential direction. It is possible to prevent the dropout in the radial direction while preventing the movement in the circumferential direction.
(4) By forming an overhanging portion at the free end of the arm portion by caulking to form a locking portion, the assembly of the rotor magnet can be facilitated. Further, rattling of the rotor magnet can be prevented.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.
1 to 9 relate to an embodiment of the present invention, FIG. 1 is a cross-sectional explanatory view of a brushless motor, FIG. 2 is a side view of the rotor, FIGS. 3 and 4 are cross-sectional views of the rotor (of FIG. 2). FIG. 5 is a front view of the rotor (viewed in the direction of arrow C in FIG. 2), and FIG. 6 is a cross-sectional view of the rotor (DD cross-sectional view in FIG. 2). 7 is a side view of the rotor with the rotor cover removed, FIG. 8 is a front view of the rotor with the rotor cover removed (as viewed in the direction of arrow E in FIG. 7), FIG. 9 is an exploded perspective view of the magnet holder and magnet, and FIG. FIG. 5 is a partially enlarged sectional view of the rotor (region F in FIG. 4).

An embodiment in which the present invention is applied to an inner rotor type brushless motor 1 will be described.
As shown in FIG. 1, the brushless motor 1 of the present example mainly includes a stator 10, a rotor 20 that is rotatably supported on the inner peripheral side of the stator 10, and a housing 50 that accommodates the stator 10 and the rotor 20 therein. As a component.

  The stator 10 of this example includes a stator core 11 fixed to the inner peripheral side of the housing body 51 and a winding 12 wound around the stator core 11. The stator core 11 has, for example, a configuration in which a plurality of core sheets made of a thin silicon steel plate are stacked, and is arranged so as to protrude radially inward from the annular outer core portion and the outer core portion at substantially equal angular intervals. It has a tooth part. The winding 12 is wound around the tooth portion. The stator 10 generates a rotating magnetic field for rotating the rotor 20 by energizing the winding 12.

The rotor 20 of this example includes a shaft 21 serving as a rotation axis of the rotor 20, a substantially cylindrical spacer 22 (see FIGS. 4 and 6) into which the shaft 21 is inserted and fixed by press-fitting or the like, and an outer peripheral surface of the spacer 22. And a comb-like magnet having a plurality of rod-like arm portions 26 respectively disposed between adjacent magnets 23 and a segment-like magnet 23 (see FIGS. 4, 7, and 8) attached in a ring shape along A holder 24 (see FIGS. 4 and 7) and a rotor cover 30 mounted so as to cover the magnet 23 and the magnet holder 24 from the outer periphery are provided.
In this example, the magnet 23 is not bonded and fixed to the spacer 22 by an adhesive or the like, is held by the magnet holder 24 so as not to fall off in the axial direction, and is radially inward by the rotor cover 30 via the magnet holder 24. By being pressed, the spacer 22 is fixed.

The housing 50 of this example includes a bottomed cylindrical housing main body 51 and an end plate 52 that closes the opening of the housing main body 51. The housing main body 51 and the end plate 52 are provided with bearings 53 and 54 that rotatably support the shaft 21, respectively. The end plate 52 is provided with a power supply device (not shown) for supplying a driving voltage from the outside to the winding 12 of the stator 10.
As shown in FIG. 1, when the stator 10 and the rotor 20 are disposed in the housing 50, the inner peripheral surface of the annular stator 10 and the outer peripheral surface of the rotor 20 are arranged in the radial direction via a slight air gap. They are facing each other.

  Further, in the brushless motor 1 of this example, a resolver 40 is disposed in order to detect the rotational position of the rotor 20. That is, the resolver rotor 41 is attached to the output side of the shaft 21. Further, a resolver stator 42 around which a winding 44 is wound is fixed to the end plate 52, and a resolver connector (not shown) connected to the winding 44 is disposed.

The resolver rotor 41 is configured by laminating a plurality of core sheets formed of, for example, a thin metal plate. The resolver stator 42 includes a substantially annular core 43 and a winding 44 wound around the core 43. The core 43 is configured by laminating a plurality of core sheets formed of a thin metal plate material.
The annular resolver stator 42 and resolver rotor 41 are opposed to each other in a radial direction through a slight air gap when the stator 10 and the rotor 20 are disposed in the housing 50. A variable reluctance type resolver 40 for detecting the rotational position of the rotor 20 is configured.

In the brushless motor 1 configured as described above, a rotating magnetic field is generated in the stator 10 when a driving voltage is supplied to the stator 10 from a driving circuit (not shown) via a power feeding device. The rotor 20 is rotated by the magnetic interaction.
That is, the drive circuit of the brushless motor 1 detects the rotational position of the rotor 20 based on the output of the resolver 40 and supplies a drive voltage to the winding 12 according to the detected rotational position. Thereby, the stator 10 can generate a rotating magnetic field corresponding to the rotational speed (rotational position) of the rotor 20. A detector such as a hall sensor may be provided in place of the resolver 40, and the drive voltage may be controlled by detecting the rotational position using the hall sensor or the like.

Next, based on FIGS. 2-10, the structure of the rotor 20 of this example is demonstrated. Note that the cross-sectional position shown in FIG. 6 (the DD cross-sectional view in FIG. 2) is a cross-section with the dd line in FIG. 3 as the cutting position.
As shown in FIGS. 4 and 6, the shaft 21 is fitted and fixed in a through hole provided in the center of the spacer 22. For example, an axial groove is formed on the outer peripheral surface of the spacer 21 on the shaft 21 at the attachment position. In addition, a protrusion is formed on the inner peripheral surface of the through hole in the spacer 22 corresponding to the groove. If it does in this way, the groove | channel of the shaft 21 and the processus | protrusion of the spacer 22 can be engaged, and the positioning and rotation prevention of the spacer 22 can be performed.

In this example, a flange portion 21 a is formed at a predetermined position on the shaft 21 so as to extend outward in the radial direction. The spacer 22 has an end face on one end side in the axial direction in contact with the flange portion 21a. Since the flange portion 21 a has a diameter larger than that of the spacer 22, the outer peripheral end of the flange portion 21 a projects outward in the radial direction from the spacer 22. The flange portion 21 a may be formed integrally with the spacer 22 on one end side of the spacer 22.
Further, as shown in FIG. 3, the flange portion 21a is notched in a straight line so as to form end surfaces 21b that are substantially perpendicular to the radial direction, at two positions shifted by 180 degrees on the outer periphery.

The magnet 23 is formed in a plate shape curved in an arc shape as shown in FIGS. 4, 8, and 9, and is magnetized so that the magnetic flux is directed in the plate thickness direction. The magnets 23 are arranged at substantially equal intervals in the circumferential direction along the substantially cylindrical outer peripheral surface of the spacer 22. More specifically, eight magnets 23 of different polarities are alternately arranged in the circumferential direction on the outer peripheral surface of the spacer 22, and the positions of the magnets 23 are positions shifted by 45 degrees with the rotation angle of the rotor 20. It is said that. The number of magnets 23 may be other than 8, and is not particularly limited.
Further, as shown in FIG. 10, the magnet 23 is formed such that both side surfaces 23a in the circumferential direction are inclined by a predetermined angle (angle θ) with respect to the radial direction, and a tapered surface that is inclined outward in the radial direction. It has become. An arm portion 26 of a magnet holder 24 described later is in contact with the side surface 23a.

  The magnet holder 24 is attached to the outer periphery of the spacer 22 as shown in FIG. 4, FIG. 6, FIG. That is, the magnet holder 24 includes an annular ring portion 25 that is positioned and fitted on one end side of the spacer 22, and an axis of the shaft 21 from the annular surface of the ring portion 25 toward the other end side of the spacer 22. And eight arm portions 26 extending in the direction. The magnet holder 24 of this example has a comb shape in which the base end portions of the eight substantially parallel arm portions 26 are joined to the ring portions 25, respectively. A caulking portion 27 is formed at the free end of each arm portion 26.

  As shown in FIG. 6, the ring portion 25 has an annular surface opposite to the side on which the arm portion 26 extends so as to contact a flange portion 21 a projecting radially outward from the outer peripheral surface of the spacer 22. By being in contact, the spacer 22 is positioned on one end side. Further, as shown in FIGS. 3 and 6, the outer peripheral end of the ring portion 25 projects outward in the radial direction from the flange portion 21 a. As will be described later, an engaging portion 30c of the rotor cover 30 is engaged with a portion that protrudes radially outward from the flange portion 21a.

On the ring portion 25, protrusions 25a are formed to project at two locations on the annular surface on the flange portion 21a side. The protrusion 25a is formed at a position shifted by 180 degrees so as to correspond to the end surface 21b of the notched portion of the flange portion 21a, and is in contact with the end surface 21b. In this way, the flange portion 21a is sandwiched between the protrusions 25a, thereby preventing the ring portion 25, that is, the magnet holder 24 from rotating.
The ring portion 25 has one end of the magnet 23 in contact with an annular surface (axial surface) on which the arm portion 26 is extended. That is, in this example, the ring portion 25 is in contact with the one end side of the magnet 23 in the axial direction.

The arm portion 26 is formed in a rod shape, and is assembled so as to be disposed in the gap between the adjacent magnets 23 as shown in FIGS. 4 and 7. That is, each arm portion 26 is extended to a position shifted by 45 degrees at equal intervals in the circumferential direction, that is, at the rotation angle of the rotor 20 so as to correspond to the arrangement of the magnets 23.
The arm portion 26 is in contact with the spacer 22 on the inner peripheral surface facing the radially inner side. Further, the outer circumferential surface facing the radially outer side is located on the radially inner side than the outer circumferential surface of the magnet 23. Further, both side surfaces 26 a in the circumferential direction are in contact with the adjacent magnets 23. That is, the side surface 26a is formed to be inclined with respect to the radial direction at substantially the same angle θ as the side surface 23a of the magnet 23 described above. Further, the interval between the adjacent arm portions 26 is substantially the same as the circumferential width of the magnet 23, and is an interval at which the magnet 23 can be inserted in a press-fit manner.

Further, as shown in FIGS. 6 to 8, the arm portion 26 is formed with a caulking portion 27 on the free end side. As shown in FIGS. 7 and 8, the caulking portion 27 is formed wider in the circumferential direction than the linear arm portion 26. That is, the projecting portions 27a that project from the side surfaces 26a (circumferential surfaces) of the arm portions 26 are formed on both sides in the circumferential direction. FIG. 8 is a view of the rotor 20 with the rotor cover 30 removed as viewed from the caulking portion 27 side. Further, as shown in FIG. 6, the caulking portion 27 extends radially inward from the arm portion 26, and the extended portion is in contact with the spacer 22 from the axial direction.
In this example, since the magnet holder 24 is made of a nonmagnetic metal (copper, stainless steel, aluminum, etc.), the free end of the arm portion 26 can be deformed by caulking.

The caulking part 27 has such an overhang part 27a, so that the adjacent magnets 23 can be locked. That is, the overhanging portion 27 a abuts the two magnets 23 adjacent in the circumferential direction from the direction opposite to the ring portion 25 to lock the magnet 23 in the axial direction. In this example, the magnet 23 is held between the caulking portion 27 and the ring portion 25 by such a configuration. In other words, the two magnets 23 on both sides in the circumferential direction can be locked to prevent the axial direction (the free end direction of the arm portion 26) from falling off.
The caulking portion 27 of this example corresponds to the locking portion of the present invention.

  As shown in FIGS. 2 to 6, the rotor cover 30 is formed in a cup shape by closing one end of a thin, hollow cylindrical body with a thin, substantially circular bottom. An insertion hole having a diameter that allows the shaft 21 to be inserted is opened at the center of the substantially circular bottom. The rotor cover 30 can be attached to the outer periphery of the magnet 23 and the magnet holder 24 by inserting the shaft 21 through the insertion hole. In this example, the rotor cover 30 is positioned in the axial direction with respect to the spacer 22 and the shaft 21 by the bottom portion being in contact with and fixed to the end surface of the spacer 22. The rotor cover 30 is formed in such a size that the cylindrical body covers up to the outer peripheral surface of the ring portion 25 when positioned in this way.

As shown in FIGS. 5 and 6, the rotor cover of this example is provided with claw portions 30 a and 30 b on the inner peripheral side of the cylindrical portion. The claw portion 30a is provided on the bottom side (caulking portion 27 side) of the cylindrical portion, and the claw portion 30b is provided on the opening side (ring portion 25 side) of the cylindrical portion.
The claw portion 30a is formed by making a substantially U-shaped cut at the outer peripheral end of the bottom portion to form a claw-like cut-and-raised piece and folding the cut-and-raised piece back to the inner circumference side of the cylindrical portion at a predetermined angle. Yes. By folding the nail-like cut and raised pieces in this way, the folded portion becomes a leaf spring shape and has spring properties. That is, the claw portion 30a can be brought into elastic contact with an object that abuts from the radially inner side.

  In this example, as shown in FIG. 5, the claw portions 30 a are formed in eight radial positions along the outer periphery of the bottom portion, and the claw portions 30 a are provided at all positions corresponding to the arm portions 26 of the magnet holder 24. ing. That is, all the claw portions 30a are in elastic contact with the arm portion 26 from the outside in the radial direction, and due to the spring property of the claw portion 30a, a pressing force inward in the radial direction can be constantly applied to the arm portion 26. . Therefore, the arm portion 26 can be prevented from being lifted outward in the radial direction, and the magnet 23 can be constantly pressed and fixed to the spacer 22 via the arm portion 26. Thereby, the holding force of the magnet 23 can be improved. Further, when the claw portion 30a has a spring property in this way, even if there is a manufacturing error in the rotor cover 30, the arm portion 26, the magnet 23, etc., the arm portion 26 and the arm portion 26a are elastically deformed. Can be ensured.

Further, the claw portion 30b is formed by folding back a claw-like extension piece formed from a predetermined position of the opening end of the cylindrical portion at a predetermined angle to the inner peripheral side of the cylindrical portion, like the claw portion 30a. ing. Therefore, the claw part 30b is a leaf spring like the claw part 30a and has a spring property, and can be elastically brought into contact with an object that abuts from the radially inner side. Therefore, similarly to the claw portion 30a, the arm portion 26 can be prevented from being lifted outward in the radial direction.
In addition, the nail | claw parts 30a and 30b of this example are corresponded to the press-contact part (1st press-contact part, 2nd press-contact part) of this invention.

In this example, four claw portions 30b are formed at substantially equal intervals along the opening of the cylindrical portion. In other words, the claw portions 30b are provided at positions corresponding to the arm portions 26, but are arranged every other one in the circumferential direction and are not provided at positions corresponding to all the arm portions 26.
The arm portion 26 that is in contact with the claw portion 30b is pressed radially inward at two points on the base end side (ring portion 25 side) and the free end side (caulking portion 27 side). Thus, when the arm portion 26 is pressed at two points separated in the axial direction, the inclination of the arm portion 26 with respect to the axial direction is prevented, and the axial direction of the pressing force applied to the magnet 23 via the arm portion 26 is prevented. Distribution can be made uniform.

Further, at the opening end of the cylindrical portion of the rotor cover 30, there is an engaging portion 30c that can be engaged with the flange portion 21a at a position corresponding to the arm portion 26 and not provided with the claw portion 30b. Is formed. That is, the engaging portions 30c are formed in four locations alternately with the claw portions 30b along the opening of the cylindrical portion.
The engaging portion 30c is a substantially right angle so that the claw-like extension piece formed in the same manner as the claw portions 30a and 30b extends from the opening end of the cylindrical portion of the rotor cover 30 so that the tip is directed radially inward. It is formed by bending. When formed in this way, the bent claw-like piece can be engaged with the outer peripheral portion of the flange portion 21a. Thus, the rotor cover 30 is mounted so that the opening end of the rotor cover 30 is engaged with the flange portion 21a and the rotor cover 30 is not detached.

With the configuration as described above, in the rotor 20 of this example, the arm portions 26 of the magnet holder 24 are respectively disposed in the gaps between the adjacent magnets 23, and both side surfaces 26 a in the circumferential direction thereof are adjacent to each other. Abut. Therefore, the magnet 23 is positioned in the circumferential direction by the arm portion 26. In addition, since the contact surface between the arm portion 26 and the magnet 23 is a tapered surface inclined with respect to the radial direction, the magnet 23 is moved to the spacer via the arm portion 26 from the outside in the radial direction by the binding force of the rotor cover 30. It is the structure which can be pressed to 22 side.
In this example, since the claw portions 30a and 30b formed on the inner peripheral side of the rotor cover 30 are in elastic contact with the arm portion 26, the arm portion 26 is prevented from being lifted outward in the radial direction. Thus, the magnet 23 can be reliably pressed and fixed to the spacer 22 side. Further, since the tapered surface is pressed from the outside in the radial direction, the magnet 23 is pressed from both sides in the circumferential direction, and positioning in the circumferential direction is also ensured. Therefore, the holding force of the magnet 23 can be improved.

  Further, in the rotor 20 of this example, the ring portion 25 abuts on one end side of the magnet 23 in the axial direction (axial direction of the shaft 21), and the other end side of the magnet 23 is opposite to the ring portion 25. The protruding portion 27a of the crimping portion 27 is in contact with the direction. That is, since the magnet 23 is sandwiched and held between the ring portion 25 and the overhang portion 27a, the magnet 23 does not fall off from the magnet holder 24 in the axial direction. Accordingly, it is possible to prevent the magnet 23 from falling off in the axial direction without fixing the magnet 23 with an adhesive or the like. Therefore, the bonding process of the magnet 23 can be omitted in the manufacturing process of the rotor 20, and the number of processes and the manufacturing cost can be reduced.

  Further, the rotor 20 of this example is formed such that the protruding portion 27a of the crimping portion 27 protrudes in two directions from the free end of the arm portion 26 toward both sides in the circumferential direction. Thereby, the two magnets 23 on both sides can be held by one caulking portion 27. Moreover, if each crimping part 27 has the overhang | projection part 27a extended in 2 directions, respectively, each magnet 23 will be hold | maintained at two places from the circumferential direction both sides, respectively. Accordingly, the magnet 23 can be held in the axial direction more reliably.

FIG. 9 is an exploded perspective view showing the magnet 23 and the magnet 23 having the arm portion 26A before caulking, the free end portion of which has not yet been deformed by caulking. In FIG. 9, the shaft 21 and the spacer 22 are not shown.
In the magnet holder 24A, the arm portion 26A before caulking has a straight shape without a projecting portion in the circumferential direction. Therefore, the magnet 23 can be inserted in the direction of the arrow in FIG. 9 and disposed between the arm portions 26A. it can. The magnet 23 may be disposed by lifting the arm portion 26A outward in the radial direction. Then, after the magnets 23 are disposed, the free end side of the arm portion 26A is pressed and deformed in the axial direction to form a crimping portion 27 at the free end of the arm portion 26, and the magnet 23 is removed. Can be held to not.

The rotor 20 of this example can be manufactured by such a manufacturing method that performs the following steps using the magnet holder 24A.
First, the first step of inserting and fixing the shaft 21 into the through hole of the spacer 22 is performed. At this time, the flange portion 21 a is brought into contact with one end side of the spacer 22.
Next, the ring portion 25 of the magnet holder 24A is externally fitted to the spacer 22, and a plurality of arm portions 26A are disposed on the outer peripheral surface of the spacer 22, and the magnet 23 is interposed between the adjacent arm portions 26A as described above. And a second step of arranging the magnet 23 so that one end side of the magnet 23 abuts against the ring portion 25 is performed. At this time, the magnet 23 is inserted between the adjacent arm portions 26A.

Subsequently, by pressing and crimping the free end of the arm portion 26 </ b> A from the distal end side, a caulking portion 27 having an overhanging portion 27 a that protrudes on both sides in the circumferential direction is formed, and between the overhanging portion 27 a and the ring portion 25 A third step of holding the magnet 23 is performed. As a result, the magnet 23 does not fall off from the magnet holder 24 in the axial direction.
Subsequently, a fourth step of inserting the shaft 21 through the insertion hole of the rotor cover 30 and mounting the rotor cover 30 so as to cover the outer periphery of the magnet 23 and the magnet holder 24 is performed. At this time, the claws 30 a and 30 b are assembled so as to abut on the radially outer surface of the arm 26. Thereby, the rotor cover 30 presses the magnet 23 via the magnet holder 24 from the outside in the radial direction due to the spring property of the claw portions 30a and 30b. Therefore, the magnet 23 is pressed and fixed to the spacer 22.

  As described above, the manufacturing method of the rotor 20 of this example can omit the bonding process of the magnet 23 with an adhesive or the like, so the number of processes can be reduced and the time required for drying the adhesive can be shortened. Yes. Further, the magnet holder 24A is easy to assemble because the crimping portion 27 is not formed when the magnet 23 is disposed. Further, if the overhanging portion 27a is formed by caulking, the ring portion 25 and the magnet 23, and the magnet 23 and the overhanging portion 27a abut each other without gaps due to pressing during caulking. Therefore, the magnet 23 does not rattle between the ring portion 25 and the overhang portion 27a.

  In the above embodiment, the magnet holder 24 is made of a non-magnetic metal (copper, stainless steel, aluminum, etc.), and the overhanging portion 27a is formed by caulking the free end of the arm portion 26. The protruding portion 27a may be formed by deforming the free end of the portion 26 by bending or the like. When the magnet holder 24 is made of resin, the free end of the arm portion 26 may be heated and deformed to form the protruding portion 27a.

It is a section explanatory view of the brushless motor concerning one embodiment of the present invention. It is a side view of the rotor of this example. It is sectional drawing (AA sectional drawing of FIG. 2) of the rotor of this example. It is sectional drawing (BB sectional drawing of FIG. 2) of the rotor of this example. FIG. 3 is a front view of the rotor of this example (viewed in the direction of arrow C in FIG. 2). It is sectional drawing (DD sectional drawing of FIG. 2) of the rotor of this example. It is a side view of the rotor which removed the rotor cover. It is a front view of the rotor with the rotor cover removed (viewed in the direction of arrow E in FIG. 7). It is a disassembled perspective view of a magnet holder and a magnet. FIG. 5 is a partially enlarged sectional view of the rotor (region F in FIG. 4).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Brushless motor, 10 ... Stator, 11 ... Stator core, 12 ... Winding,
20 ... Rotor, 21 ... Shaft, 21a ... Flange, 21b ... End face 22 ... Spacer, 23 ... Magnet, 23a ... Side 24, 24A ... Magnet holder, 25 ... Ring, 25a ... Projection 26, 26A ... Arm, 26a ··· side, 27 ··· caulking portion, 27a ··· overhang portion 30 ··· rotor cover, 30a ··· claw portion, 30b · claw portion, 30c · engagement portion 40 · resolver, 41 · resolver rotor · 42 · resolver stator 43 ··· core , 44. Winding, 50. Housing, 51. Housing body 52. End plate, 53, 54.

Claims (9)

A rotor comprising a rotor shaft, a spacer through which the rotor shaft is inserted and fixed, and a plurality of rotor magnets arranged in an annular shape along the outer peripheral surface of the spacer,
A magnet holder having an annular ring portion axially contacting one end side of the rotor magnet, and a plurality of arm portions extending in an axial direction from the ring portion and disposed in gaps between the plurality of rotor magnets; A rotor cover that covers the rotor magnet and the magnet holder from outside in the radial direction,
The magnet holder is formed with a locking portion capable of abutting on the other end side of the rotor magnet from a direction opposite to the abutting direction of the ring portion on the rotor magnet at a free end of the arm portion, A rotor configured to prevent the rotor magnet from falling off in the axial direction by holding the rotor magnet between a locking portion and the ring portion.   The locking portion includes a protruding portion formed so as to protrude from the free end of the arm portion in the circumferential direction, and the rotor magnet is held between the protruding portion and the ring portion. The rotor according to claim 1.   The projecting portion is formed to project in two directions from the free end of the arm portion toward both sides in the circumferential direction, and between the projecting portion projecting in two directions and the ring portion, The rotor according to claim 2, wherein the two rotor magnets arranged on both sides in the circumferential direction are respectively held.   The circumferential surface of the rotor magnet is formed to form a tapered surface that is inclined outward in the radial direction, and the arm portion is disposed so as to contact the circumferential surface and to contact the rotor cover from the radial inner side. The rotor according to claim 1, wherein the rotor is provided.   The rotor according to claim 1, wherein a pressure contact portion that elastically contacts the arm portion from the radially outer side is provided on an inner peripheral side of the rotor cover.   The pressure contact portion is formed by either extending an extended piece extending from a predetermined position of the rotor cover or a cut-and-raised piece formed by cutting a predetermined position of the rotor cover on the inner peripheral side of the rotor cover. The rotor according to claim 5, wherein the rotor is formed by folding.   The said press contact part was provided with the 1st press contact part which elastically contacts the base end part side of the said arm part, and the 2nd press contact part which elastically contacts the free end side of the said arm part, It is characterized by the above-mentioned. The rotor according to claim 5.   The brushless motor provided with the rotor as described in any one of Claims 1 thru | or 7. A rotor shaft, a spacer in which the rotor shaft is inserted and fixed, and a plurality of rotor magnets arranged in an annular shape along the outer peripheral surface of the spacer, and is axially contacted with one end side of the rotor magnet. An annular ring portion in contact with each other; a plurality of arm portions extending in an axial direction from the ring portion and disposed in gaps between the plurality of rotor magnets; and a locking portion formed at a free end of the arm portion; , And the locking portion abuts the other end side of the rotor magnet from a direction opposite to the abutting direction of the ring portion to the rotor magnet, whereby the rotor magnet is And a rotor manufacturing method for manufacturing a rotor that is held between the locking portion and prevented from falling off in the axial direction,
A first step of inserting and fixing the rotor shaft in a through-hole penetrating the spacer;
A second step of externally fitting the ring portion to the spacer and disposing the plurality of arm portions on an outer peripheral surface of the spacer, and disposing the rotor magnet between adjacent arm portions;
After the second step, the locking portion having a protruding portion protruding in the circumferential direction is formed by pressing and crimping the free end of the arm portion from the distal end side, and between the protruding portion and the ring portion. And a third step of holding the rotor magnet in a rotor.

Images