JP5310109B2 - Brushless motor rotor, brushless motor, electric power steering apparatus, and method for manufacturing brushless motor rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely fix a magnet to the periphery of a rotor core at low cost. <P>SOLUTION: A rotor 10 includes: a rotor core 6, a plurality of magnets 5 which are provided around the rotor core 6 and arranged in the circumferential direction of the rotor core 6, and a rotor cover 20 to be attached to the periphery of the plurality of magnets 5. The rotor cover 20 includes a cylindrical drum 20S and regulating parts 20E1 and 20E2 provided at both ends of the drum 20S, and the regulating parts extending from the drum 20S toward the central axis Zr of the rotor core. Moreover, in the regulating part 20E1, an opening is formed at a part corresponding to a space between the adjacent magnets 5. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a structure for fixing a magnet to a rotor core of a brushless motor.

  The brushless motor has a structure in which a plurality of magnets are arranged on the outer peripheral portion of the rotor core, and it is necessary to fix the magnets to the rotor core. For example, Patent Document 1 discloses a rotor with a permanent magnet in which a resin bonding layer is provided on the outer peripheral surface of a rotor yoke. In Patent Document 2, an arm portion of a magnet holder is disposed in a gap between magnets disposed along an outer peripheral surface of a spacer, and an inner peripheral claw of a rotor cover is elastically contacted with an arm portion of the magnet holder. A rotor that presses and fixes a magnet to a spacer is disclosed.

Japanese Patent Laid-Open No. 6-80350 (FIG. 1, claim 1) Japanese Patent Laying-Open No. 2007-288877 (0007, 0008, FIG. 7)

  The technique disclosed in Patent Document 1 requires a mold for providing a resin bonding layer on the outer peripheral surface of the rotor yoke, which increases the manufacturing costs of the rotor and the motor. The technique disclosed in Patent Document 2 is a structure in which a magnet holder is provided as a holding member between magnets, and high accuracy is required for the magnet holder, the spacer, and the magnet, so that the manufacturing cost of the rotor and motor increases.

  The present invention has been made in view of the above, and an object of the present invention is to reliably fix a magnet attached to the outer peripheral portion of a rotor core at low cost.

In order to solve the above-described problems and achieve the object, a brushless motor rotor according to the present invention includes a rotor core and a plurality of rotor cores arranged on the outer periphery of the rotor core and arranged in the circumferential direction of the rotor core. A cylindrical side portion is disposed on the outer periphery of the magnet and the plurality of magnets, and a restriction portion for restricting the movement of the side portion in the central axis direction of the rotor core is provided at both ends of the side portion. together is, at least one restricting portion, seen including a rotor cover an opening in a portion corresponding to between the magnets adjacent is formed, wherein the restricting portion, the rotor core from both ends of the side Extending to the position of the rotor core toward the center of rotation, and the space between the rotor core, the plurality of magnets, and the rotor cover is filled from the opening. A filler is provided, and the opening has a cross section in which the area of the opening is perpendicular to the central axis direction of the rotor core in a space formed between the rotor core, the plurality of magnets, and the rotor cover. It is characterized by being formed smaller than the area .

  According to the present invention, a restricting portion is provided at both ends of the rotor cover, and an opening is formed in the restricting portion corresponding to between adjacent magnets. This opening is an opening for injecting a filler from the outside of the rotor cover between adjacent magnets. And a magnet is reliably fixed with respect to a rotor core with the filler provided between a rotor cover and a magnet by flowing a filler into a magnet from this opening part and solidifying. In this case, a region for providing the filler is formed in the rotor cover, so that a complicated mold for the filler is not required, a holding member between the magnets is not required, and the rotor core and the magnet are excessive. Precision is not required. As a result, the magnet can be securely fixed and the manufacturing cost of the rotor can be reduced.

  In addition, unlike the prior art, there is no need to provide a holding member between the magnets, so that the manufacturing cost can be reduced. Furthermore, since it is not necessary to prepare different holding members for changing the rotor specifications, it is possible to respond flexibly and at low cost to changing the rotor specifications.

In addition , since the restricting portion extends to a position where it engages with the rotor core, if the rotor cover moves relative to the central axis direction of the rotor core, the restricting portion of the rotor core engages to suppress the displacement of the rotor cover. it can. Further, since the restricting portion is supported by the rotor core, when the filler is injected from the opening provided in the restricting portion, the force with which the filler pushes the restricting portion is supported by the rotor core. Thereby, the position shift of the rotor cover in the central axis direction of the rotor core is suppressed at the time of filling the filler. As a result, even when the filler injection conditions and the like change, the positional accuracy between the magnet and the rotor core and the positional accuracy between the rotor core and the rotor cover can be maintained, so that the quality of the rotor is stabilized.

  Since the restricting portion extends toward the rotation center of the rotor core, the restricting portion and the side portion of the rotor cover have an angle. This improves the strength of the rotor cover. Moreover, it is preferable that a control part is integrally formed in cyclic | annular form toward the circumferential direction of a rotor cover. In this way, it is more preferable that the restricting portion is formed integrally without being divided in the circumferential direction of the rotor cover, since a decrease in strength of the restricting portion is suppressed. Further, it is preferable that the restricting portion is molded integrally with the side portion. As a result, the restricting portion can be easily formed, and the strength of the rotor cover is improved. Moreover, it is preferable that the opening part formed in a control part is a hole drilled in the control part. Thus, since the opening is a hole, the outer periphery of the hole is necessarily a restricting portion, so that the restricting portion can be prevented from being completely divided in the circumferential direction. As a result, it is possible to minimize the strength reduction of the restricting portion due to the formation of the opening.

Moreover, the magnet provided in the outer peripheral part of the rotor core can be more reliably fixed by providing a filler between rotors. Further, the filler can surely fix the magnet and the strength of the entire rotor is improved.

Moreover, a filler can be easily provided between magnets by inject | pouring a filler from an opening part.

  As a desirable mode of the present invention, in the present invention, it is preferable that the plurality of magnets are arranged stepwise toward the central axis direction of the rotor core. By arranging the magnet in this way, the torque fluctuation of the brushless motor is reduced.

  As a desirable mode of the present invention, in the present invention, it is preferable that a groove formed by the magnets adjacent in the circumferential direction is connected between one of the restricting portions and the other of the restricting portions. When the magnets are arranged stepwise toward the central axis direction of the rotor core, the grooves formed by adjacent magnets are configured to be continuous toward the central axis direction as in this aspect. As a result, the filler injected from the opening passes between the grooves adjacent in the central axis direction and spreads throughout. As a result, even in a structure in which the magnets are arranged stepwise, it is possible to reliably provide a filler between the magnets and fix the magnet with the rotor cover and the filler.

  As a desirable mode of the present invention, in the present invention, the rotor cover preferably restrains the plurality of magnets. According to this aspect, since the rotor cover restrains the magnet and the rotor core, it is possible to reduce the possibility that the position of the magnet is shifted due to the injection of the filler. As a result, a decrease in magnet mounting accuracy is suppressed. Also, since the rotor cover applies a force toward the central axis of the rotor core to restrain the magnet and the rotor core, the distance between the rotor core and the rotor cover should be kept at the magnet thickness (dimension in the radial direction of the rotor core). Can do. As a result, since the thickness of the filler provided between the adjacent magnet and the rotor core and the rotor cover can be made uniform, mass imbalance in the circumferential direction of the rotor can be suppressed.

  As a desirable mode of the present invention, in the present invention, it is preferable that the side portion is provided with a protruding portion toward the inside of the side portion at an arrangement interval of the magnets in the circumferential direction of the rotor core. In this aspect, when the rotor cover is attached to the rotor core, the protrusion is disposed between the adjacent magnets. As a result, the magnet is positioned in the circumferential direction of the rotor core, so that the displacement of the magnet can be suppressed. There is also an advantage that the magnet can be positioned simply by attaching the rotor cover to the rotor core.

  In a preferred aspect of the present invention, in the present invention, at least one of the restricting portions is configured such that after the rotor cover is attached to the outer peripheral portion of the magnet, the end portion of the side portion faces the rotation center of the rotor core. It is preferably formed by being bent. In this way, by forming the restricting portion by bending the side portion of the rotor cover, even if there is a variation in the size of the rotor core in the central axis direction, changing the place where the side portion is bent changes the size variation of the rotor core. Can be absorbed easily. As a result, the productivity of the rotor is improved. In addition, it is possible to easily cope with changes in the rotor specifications.

  As a desirable aspect of the present invention, in the present invention, one of the restricting portions is configured so that the rotation center of the rotor core is rotated from one end portion of the side portion before the rotor cover is attached to the outer peripheral portion of the magnet. It is preferable to extend in advance toward. In this aspect, since the rotor cover in which one of the restricting portions is formed in advance is used, the previously formed restricting portion can be used for positioning the rotor cover and the rotor core and positioning the rotor cover and the magnet. This makes it possible to easily position the rotor by simply attaching the rotor cover to the rotor core, thereby improving the productivity of the rotor.

  A brushless motor according to the present invention includes: the brushless motor rotor; a stator that is annularly arranged outside the brushless motor rotor; and a housing that holds the stator. It is characterized by. The present invention can manufacture a brushless motor having a rotor cover and having a rotor provided with a filler between magnets attached to the outer periphery of the rotor core at a low cost.

  The brushless motor according to the present invention is an electric power steering apparatus characterized in that an auxiliary steering torque is obtained by the brushless motor. According to the present invention, an electric power steering apparatus including a brushless motor having a rotor cover and having a filler provided between magnets attached to the outer peripheral portion of the rotor core can be manufactured at low cost.

In order to solve the above-described problems and achieve the object, a method for manufacturing a rotor for a brushless motor according to the present invention includes a rotation center of a rotor core from one end of the side part to one end part of a cylindrical member a step of mounting the rotor core and rotor cover, in which a plurality of magnets on an outer peripheral portion having a position regulating portion having a plurality of openings formed toward the extending therefrom, and the circumferential direction to the rotor core toward the A step of bending the end opposite to the regulating portion and extending the bent portion toward the rotation center of the rotor core to the position of the rotor core; the rotor core; the plurality of magnets; and the rotor cover. Of the space formed between the adjacent magnets that are smaller than the area of the cross section perpendicular to the central axis direction of the rotor core. Characterized in that the said opening formed in a portion corresponding including, a step of injecting the filling material into the space.

According to the present invention, the rotor cover provided with the restricting portions at both ends is attached to the rotor core provided with the magnet, the end opposite to the restricting portion is bent, and further, through the opening provided in the restricting portion. The filler is injected from the outside of the rotor cover into the space between adjacent magnets and solidified. Thereby, in this invention, a magnet can be reliably fixed with the rotor cover attached to the rotor core, and the filler provided between magnets. As a result, excessive accuracy is not required for the rotor core and the magnet, and a support member provided between the magnets is not necessary, so that the magnet can be fixed reliably at low cost. Moreover, since the area | region which provides a filler with a rotor cover is formed, the metal mold | die for complicated fillers becomes unnecessary. As a result, since the equipment for fixing the magnet is simple, the manufacturing cost of the rotor can be reduced. In addition, since the restricting portion extends to a position where it engages with the rotor core, if the rotor cover moves relative to the central axis direction of the rotor core, the restricting portion of the rotor core engages to suppress the displacement of the rotor cover. it can. Further, since the restricting portion is supported by the rotor core, when the filler is injected from the opening provided in the restricting portion, the force with which the filler pushes the restricting portion is supported by the rotor core. Thereby, the position shift of the rotor cover in the central axis direction of the rotor core is suppressed at the time of filling the filler. As a result, even when the filler injection conditions and the like change, the positional accuracy between the magnet and the rotor core and the positional accuracy between the rotor core and the rotor cover can be maintained, so that the quality of the rotor is stabilized. Moreover, the magnet provided in the outer peripheral part of the rotor core can be more reliably fixed by providing a filler between rotors. Further, the filler can surely fix the magnet and the strength of the entire rotor is improved. Moreover, a filler can be easily provided between magnets by inject | pouring a filler from an opening part.

  As a desirable aspect of the present invention, in the present invention, the side portion is provided with protrusions directed toward the inner side of the side portion at an arrangement interval of the magnets in the circumferential direction of the rotor core. When attaching to the rotor core, it is preferable to align the protrusion between the adjacent magnets and insert the rotor cover into the rotor core. Accordingly, the protrusion of the rotor cover is disposed between the adjacent magnets, so that the magnet is positioned in the circumferential direction of the rotor core. As a result, the displacement of the magnet can be suppressed. There is also an advantage that the magnet can be positioned simply by attaching the rotor cover to the rotor core.

  According to the present invention, the magnet attached to the outer peripheral portion of the rotor core can be reliably fixed at low cost.

FIG. 1 is a configuration diagram of an electric power steering including a brushless motor according to the first embodiment. FIG. 2 is a front view for explaining an example of a reduction gear provided in the electric power steering apparatus according to the first embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of the motor according to the first embodiment. 4 is a cross-sectional view taken along line XX in FIG. FIG. 5 is a perspective view of a rotor constituting the motor according to the first embodiment. FIG. 6 is a cross-sectional view illustrating a state where the rotor constituting the motor according to the first embodiment is cut along a plane including the central axis. FIG. 7 is a front view of a rotor constituting the motor according to the first embodiment. 8-1 is explanatory drawing which shows the attachment structure of a magnet and a rotor core. 8-2 is explanatory drawing which shows the attachment structure of a magnet and a rotor core. FIGS. 9-1 is explanatory drawing of the manufacturing method of the rotor for brushless motors concerning this embodiment. FIGS. 9-2 is explanatory drawing of the manufacturing method of the rotor for brushless motors concerning this embodiment. 9-3 is explanatory drawing of the manufacturing method of the rotor for brushless motors concerning this embodiment. FIG. 10A is a schematic diagram illustrating the rotor core after the filler is injected. FIG. 10-2 is a schematic diagram illustrating the rotor core after the filler is injected. FIG. 11 is a perspective view showing a first modification of the present embodiment. FIG. 12 is a perspective view showing a second modification of the present embodiment. FIG. 13 is a front view of a rotor according to a second modification of the present embodiment. FIG. 14 is a perspective view showing an example in which magnets are skewed. FIG. 15 is a plan view showing an arrangement example of magnets constituting the rotor according to the present embodiment. FIG. 16 is a plan view showing a groove formed by adjacent magnets. FIG. 17 is a perspective view showing an example in which a filler is injected into a rotor in which magnets are skew-arranged. FIG. 18 is a perspective view of a rotor according to the second embodiment. FIG. 19 is a cross-sectional view of the rotor cover shown in FIG. 20 is a cross-sectional view taken along the line XX of FIG. FIG. 21 is a cross-sectional view of the rotor according to the second embodiment cut at the position of a protrusion provided on the rotor cover. FIG. 22 is a perspective view of a rotor cover according to a modification of the second embodiment. FIG. 23 is a plan view illustrating an arrangement example of magnets constituting a rotor according to a modification of the second embodiment. FIG. 24 is a plan view showing a groove formed by adjacent magnets. In this modification, a protrusion is provided on the rotor cover when the magnet is skewed.

  Hereinafter, the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited by the modes for carrying out the invention (hereinafter referred to as embodiments). In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art and those that are substantially the same. In the present embodiment, an example in which the torque detection device according to the present invention is applied to an electric power steering device (EPS) will be described, but the application target of the present invention is not limited to the electric power steering device. . Even when the present invention is applied to an electric power steering apparatus, the method is not limited.

(Embodiment 1)
FIG. 1 is a configuration diagram of an electric power steering including a brushless motor according to the first embodiment. First, an outline of an electric power steering apparatus including a brushless motor according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the electric power steering apparatus 100 detects a steering torque generated in the steering shaft 102 by the operation of the steering wheel 101 with a torque sensor 110 that is a torque detection means, and based on the detection signal, the ECU ( An electric control unit (50) assists the steering force of the steering wheel 101 by driving and controlling a brushless motor (hereinafter referred to as a motor if necessary) 1 to generate an auxiliary steering torque.

  A steering shaft 102 connected to the steering wheel 101 has an input shaft 102a to which a driver's steering force is input and an output shaft 102b to output the input steering force. In the present embodiment, the input shaft 102a and the output shaft 102b are made of a magnetic material such as iron. A torque sensor 110 and a speed reducer 111 are provided between the input shaft 102a and the output shaft 102b.

  The driver's steering force transmitted to the output shaft 102b of the steering shaft 102 is transmitted to the steering mechanism. Specifically, the driver's steering force transmitted to the output shaft 102 b is transmitted to the lower shaft 105 via the universal joint 104 and further transmitted to the pinion shaft 107 via the universal joint 106. The steering force transmitted to the pinion shaft 107 is transmitted to the tie rod 109 via the steering gear 108 to steer the steered wheels.

  The steering gear 108 is configured as a rack and pinion type having a pinion 108a connected to the pinion shaft 107 and a rack 108b meshing with the pinion 108a. By such a steering gear 108, the rotational motion transmitted to the pinion 108a is converted into a straight motion by the rack 108b.

  An auxiliary steering mechanism 103 that transmits auxiliary steering torque to the output shaft 102b is connected to the output shaft 102b of the steering shaft 102. The auxiliary steering mechanism 103 includes a reduction gear 111 connected to the output shaft 102b and a motor 1 connected to the reduction gear 111 and generating auxiliary steering torque. A steering column is constituted by the steering shaft 102, the torque sensor 110, and the speed reducer 111, and the motor 1 applies auxiliary steering torque to the output shaft 102b of the steering column. That is, the electric power steering apparatus 100 in this embodiment is a column assist system.

  The torque sensor 110 detects a driver's steering force transmitted to the input shaft 102a via the steering wheel 101 as a steering torque. Electric power is supplied from an electric power source (for example, a vehicle-mounted battery) 115 to the ECU 50 that controls the driving of the motor 1. Note that power is supplied from the power supply 115 to the ECU 50 with the ignition switch 114 being on. The ECU 50 calculates an assist steering command value of the assist command based on the steering torque T detected by the torque sensor 110 and the traveling speed V detected by the vehicle speed sensor 116, and the motor based on the calculated assist steering command value. The supply current value to 1 is controlled.

  FIG. 2 is a front view for explaining an example of a reduction gear provided in the electric power steering apparatus according to the present embodiment. FIG. 2 shows a part in cross section. The speed reducer 111 is a worm speed reducer. The worm 121 spline-coupled to the rotating shaft 1 </ b> S of the motor 1 is held by the speed reducer housing 120 so as to be rotatable by a ball bearing 122 and a ball bearing 123 held by a holder 125. Worm teeth 121 a formed on a part of the worm 121 mesh with worm wheel teeth 124 a formed on a worm wheel 124 that is rotatably held by the speed reducer housing 120. The rotational force of the motor 1 is transmitted to the worm wheel 124 via the worm 121 to rotate the worm wheel 124. The torque of the motor 1 is increased by the worm 121 and the worm wheel 124, and an auxiliary steering torque is applied to the output shaft 102b of the steering column shown in FIG. Next, the configuration of the motor 1 will be described.

  FIG. 3 is a cross-sectional view showing the configuration of the motor according to the present embodiment. 4 is a cross-sectional view taken along line XX in FIG. As shown in FIG. 3, the motor 1 includes a substantially cylindrical housing 2A formed of a magnetic material, and a substantially disc-shaped front bracket 2B that closes one open end of the housing 2A. Yes. At the end of the housing 2A opposite to the side where the front bracket 2B is provided, a bottom 2Ab is formed integrally with the housing 2A so as to close the end. As the magnetic material forming the housing 2A, for example, a general steel material such as SPCC (Steel Plate Cold Commercial), electromagnetic soft iron, or the like can be applied. The front bracket 2B serves as a flange when the brushless motor 1 is attached to a desired device.

  Inside the housing 2A, a bearing 3 is provided at a substantially central portion of the front bracket 2B, and a bearing 4 is provided at a substantially central portion of the bottom portion 2Ab. The bearing 3 rotatably supports one end of the rotating shaft 1S disposed inside the housing 2A, and the bearing 4 rotatably supports the other end of the rotating shaft 1S. The rotation center of the rotation shaft 1S is Zr shown in FIG. 3, and corresponds to the center axis of the rotation shaft 1S. Hereinafter, the rotation center and the center axis of the rotation shaft 1S are represented by Zr. Since the rotating shaft 1S is supported by the bearings 3 and 4, the rotation center of the bearings 3 and 4 is also Zr.

  A cylindrical rotor core 6 is disposed around the rotation shaft 1S. The rotating shaft 1S may be molded integrally with the rotor core 6, or the rotating shaft 1S may be press-fitted into the rotor core 6. A plurality of (5 × n, n is an integer) magnets 5 for driving the motor are provided on the outer periphery of the rotor core 6. The magnet 5 is a permanent magnet that is attached to the outer peripheral portion of the rotor core 6 and has S and N poles alternately magnetized in the circumferential direction of the rotor core 6 at equal intervals, as shown in FIG. In the present embodiment, the magnet 5 has a divided shape (segment structure).

  After arranging the plurality of magnets 5 on the outer periphery of the rotor core 6, in this embodiment, as shown in FIG. 3, the rotor cover 20 is attached to the outer periphery of the magnet 5 by press-fitting or shrink fitting. Here, the rotor cover 20 is made of a nonmagnetic material. As will be described later, a filler such as a resin or an adhesive is provided between the magnet 5, the rotor core 6, and the rotor cover 20. In the present embodiment, the rotating shaft 1S, the rotor core 6, the magnet 5, and the rotor cover 20 constitute the rotor 10 of the motor 1. Since the rotation shaft 1S, the rotor core 6, the magnet 5, and the rotor cover 20 all rotate around the rotation center Zr, the rotation center of the rotor 10 is also Zr.

  As shown in FIG. 4, the core 7 is fixed to the inner peripheral surface of the housing 2 </ b> A in a state where the core 7 is entirely surrounded. In the core 7, for example, a three-phase exciting coil 8 is concentrated and wound via an insulator 11 so as to surround the magnets 5 arranged in the circumferential direction of the rotor core 6. These core 7 and exciting coil 8 constitute a stator 9 of the motor 1. The stator 9 is annularly arranged outside the rotor 10 with a predetermined interval.

  The core 7 is composed of, for example, a plurality of (12 in this embodiment) divided cores 7A that are equally divided. Each of the divided cores 7A has an arc-shaped divided yoke 17 that becomes a cylindrical yoke portion when assembled to form the core 7, and one piece that extends from the inner peripheral surface of the divided yoke 17 toward the rotor 10. The teeth 18 are provided. The exciting coils 8 are concentratedly wound around the teeth 18 of each divided core 7A. Then, the plurality of divided cores 7A are combined and press-fitted into the housing 2A to constitute the annular core 7. In this way, the split core 7A is press-fitted into the housing 2A and fastened to the housing 2A to constitute the core 7. The core 7 and the housing 2A may be fixed by adhesion, shrink fitting, or the like in addition to press-fitting.

  In the present embodiment, the core 7 is configured by combining the split core 7A, but is not limited thereto. For example, the core 7 may be configured integrally or by sintering. The exciting coil 8 is wound around the core 7 to which the insulator 11 is attached after the insulator 11 is attached to the core 7. A terminal block is provided at one end of the stator. The bus bar (which may be a power harness) inserted into or inserted into the terminal block and the exciting coil 8 in each layer are electrically connected by fusing, resistance welding, or the like.

  The end of the rotary shaft 1S on the front bracket 2B side protrudes to the outside, and the rotation output of the motor 1 can be taken out by connecting a desired shaft or the like to the end protruding to the outside. In the present embodiment, the end of the rotating shaft 1S that protrudes toward the front bracket 2B is splined to the worm 121 of the speed reducer 111 shown in FIG. The rotating shaft 1S and the worm 121 may be elastic couplings. A resolver 14 that detects the rotational position of the rotor 10 and a terminal block 15 that supports the resolver 14 are provided on the front bracket 2B side of the rotating shaft 1S. The resolver 14 includes a resolver rotor 12 that is attached to the circumferential surface of the rotating shaft 1S by press-fitting or the like, and a resolver stator 13 that is opposed to the resolver rotor 12 with a predetermined gap therebetween. Next, the rotor 10 constituting the motor 1 will be described in more detail.

  FIG. 5 is a perspective view of a rotor constituting the motor according to the first embodiment. FIG. 6 is a cross-sectional view illustrating a state where the rotor constituting the motor according to the first embodiment is cut along a plane including the central axis. FIG. 7 is a front view of a rotor constituting the motor according to the first embodiment. As described above, the rotor 10 is configured by attaching the rotor cover 20 to the outer peripheral portion of the rotor core 6 provided with the magnet 5 on the outer peripheral portion. The rotor cover 20 is used for fixing the magnet 5 to the rotor core 6. The rotor cover 20 is a thin cylindrical member made of a nonmagnetic material such as SUS, aluminum, or aluminum alloy. The rotor cover 20 is manufactured by, for example, deep drawing, but the manufacturing method of the rotor cover 20 is not limited to this.

  As shown in FIG. 6, the rotor cover 20 includes a side portion 20S and restriction portions 20E1 and 20E2 provided at both ends of the side portion 20S. As shown in FIG. 5, the side portion 20S is a cylindrical member. The restricting portions 20E1 and 20E2 restrict the movement of the side portion 20S in the direction of the central axis Zr of the rotor core 6. For this reason, in the present embodiment, as shown in FIGS. 6 and 7, the restricting portions 20E1 and 20E2 are arranged so that the end portions 20T1 and 20T2 of the side portion 20S move toward the rotation center Zr of the rotor core 6 from the both ends 20T1 and 20T2. Extend to position. In this case, as shown in FIGS. 6 and 7, the distance R1 from the central axis Zr to the restricting portion 20E1 is smaller than the distance R2 from the central axis Zr to the outer peripheral portion of the rotor core 6. The restriction unit 20E2 is the same as the restriction unit 20E1. With this structure, when the rotor cover 20 moves in the direction of the central axis Zr, the restricting portions 20E1 and 20E2 are engaged with the rotor core 6 and the side portions 20S and the rotor cover 20 move in the direction of the central axis Zr of the rotor core 6. To regulate. Since R1 <R2, openings 24A and 24B through which the rotation shaft 1S provided in the rotor core 6 passes are formed in the restricting portions 20E1 and 20E2 as shown in FIG.

  An opening 21 is formed in at least one of the restricting portions 20E1 and 20E2 constituting the rotor cover 20. As shown in FIG. 7, the opening 21 is formed in a portion corresponding to a portion between adjacent magnets 5 (portion indicated by M in FIG. 7) among the magnets 5 arranged in the circumferential direction of the rotor core 6. For this reason, the interval at which the openings 21 are arranged in the circumferential direction of the rotor cover 20 is the interval at which the magnets 5 are arranged in the circumferential direction of the rotor core 6.

  As shown in FIGS. 5 and 7, in the present embodiment, the opening 21 is provided in the restricting portion 20E1. The opening 21 penetrates the restricting portion 20E1. Thus, when the rotor cover 20 is attached to the rotor core 6, the opening 21 and the space formed by the adjacent magnet 5, rotor cover 20, and rotor core 6 are communicated. Therefore, resin, adhesive, or the like can be injected from the opening 21 into the space.

  The opening 21 is provided corresponding to each space. Since the rotor 10 shown in FIG. 7 includes eight magnets 5, eight spaces are formed. In the present embodiment, the opening 21 is a circular hole. The shape of the opening 21 is not limited to this, and may be a polygonal hole such as a quadrangle or a hexagon. Here, the attachment structure of the magnet 5 and the rotor core 6 will be described.

  FIGS. 8-1 and FIGS. 8-2 are explanatory drawings showing the attachment structure of the magnet and the rotor core. In the mounting structure shown in FIG. 8A, a plurality of protrusions 6T parallel to the central axis Zr of the rotor core 6 are formed on the outer periphery of the rotor core 6 in the circumferential direction. And the magnet 5 is arrange | positioned and attached between adjacent projection parts 6T. With this protrusion 6T, the magnet 5 can be positioned and the magnet 5 can be temporarily fixed. The mounting structure shown in FIG. 8A is the same as the mounting structure shown in FIG.

  In the mounting structure shown in FIG. 8B, a plurality of groove portions 6U parallel to the central axis Zr of the rotor core 6 are formed on the outer peripheral portion of the rotor core 6 in the circumferential direction. And the magnet 5 is arrange | positioned and attached between the adjacent groove parts 6U on the basis of the groove part 6U. In this embodiment, any mounting structure may be used. Next, a method for manufacturing a brushless motor rotor according to the present embodiment (that is, a method for assembling the rotor 10) will be described.

  9A to 9C are explanatory diagrams of the method for manufacturing the brushless motor rotor according to the present embodiment. 10A and 10B are schematic diagrams illustrating the rotor core after the filler is injected. First, the magnet 5 is disposed on the outer periphery of the rotor core 6. As shown in FIG. 9A, the rotor cover 20 is attached to the rotor core 6 on which the magnets 5 are arranged from the end opposite to the end where the restricting portion 20E1 of the rotor cover 20 is provided.

  When the rotor cover 20 is inserted into the rotor core 6 and the rotor cover 20 is moved in a direction parallel to the rotation axis 1S of the rotor core 6, the restricting portion 20E1 of the rotor cover 20 contacts the rotor core 6 as shown in FIG. . As a result, the restricting portion 20E1 and the rotor core 6 are engaged with each other. Therefore, even if the rotor cover 20 is moved in the direction of the end opposite to the end where the restricting portion 20E1 is formed, the rotor cover 20 moves further. Can not. In this state, as shown in FIG. 9B, the portion F that is opposite to the restricting portion 20 </ b> E <b> 1 and protrudes from the rotor core 6 is bent toward the end 6 h of the rotor core 6. Thereby, the rotor cover 20 is attached to the rotor core 6. As shown in FIG. 9C, the bent portion of the rotor cover 20 becomes a restricting portion 20E2 that extends to the position of the rotor core 6 toward the central axis Zr of the rotor core 6.

  In this way, by attaching the rotor cover 20 to the rotor core 6 and then bending the rotor cover 20 to form the restricting portion 20E2, even when there are variations in the dimensions of the rotor core 6 and the magnet 5 in the central axis Zr direction, The variation can be absorbed by shifting the folding position. As a result, it is possible to flexibly cope with dimensional variations of parts, and thus the productivity of the rotor 10 is improved.

  Here, the angle at which the portion F protruding from the rotor core 6 is bent is close to 90 degrees, preferably 90 degrees or more, and desirably at least 80 degrees or more. Thus, the restricting portion 20E2 can be reliably formed and the rotor cover 20 can be attached to the rotor core 6. Further, the movement of the rotor cover 20 in the direction of the central axis Zr can be reliably restricted.

  The positioning of the rotor cover 20 and the rotor core 6 in the direction of the central axis Zr can be performed by the restricting portion 20E2. In addition, since the movement of the magnet 5 in the direction of the central axis Zr is restricted by the restriction portions 20E1 and 20E2, the rotor core 6 and the magnet 5 can be positioned in the direction of the central axis Zr. Further, when the rotor cover 20 is moved in a direction parallel to the rotation axis 1S of the rotor core 6, the restricting portion 20E1 comes into contact with the rotor core 6, and thus the rotor cover 20 cannot be moved any more. At this position, the portion F protruding from the rotor core 6 on the side opposite to the restricting portion 20E1 may be bent. Therefore, the restricting portion 20E1 also has a function of determining a position where the portion F1 protruding from the rotor core 6 is bent.

  Here, the regulating portion 20E1 is not formed in advance, and after attaching a cylindrical member to the rotor core 6, one end portion of the cylindrical member is bent toward the central axis Zr of the rotor core 6 to form the regulating portion 20E1. May be. However, as described above, by forming the restricting portion 20E1 in advance at one end of the rotor cover 20, the restricting portion 20E1 can be used for positioning when the portion that forms the restricting portion 20E2 is bent. Further, by forming the restricting portion 20E1 in advance at one end of the rotor cover, when attaching the rotor cover 20 to the rotor core 6, the rotor cover 20 is moved to a position where the restricting portion 20E1 contacts the rotor core 6. Then, the attachment of the rotor cover 20 and the positioning at the time of bending the portion forming the restricting portion 20E2 are completed. This facilitates the work of attaching the rotor cover 20 to the rotor core 6. Therefore, before attaching the rotor cover 20 to the rotor core 6, it is preferable to previously form the restricting portion 20 </ b> E <b> 1 on the rotor cover 20.

  Further, if the restricting portion 20E1 is formed in advance, the step of forming the restricting portion 20E1 becomes unnecessary as compared with the method of forming both the restricting portions 20E1 and 20E2 after the rotor cover 20 is attached to the rotor core 6. . Therefore, since the positioning and bending operations for forming the restricting portion 20E1 after the rotor cover 20 is attached to the rotor core 6 can be omitted, the productivity of the rotor 10 is improved.

  When the rotor cover 20 is attached to the rotor core 6 and the restriction portion 20E2 is formed and the rotor cover 20 is fixed to the rotor core 6, the magnet 5 provided on the outer peripheral portion of the rotor core 6 is restrained by the rotor cover 20. In this state, as shown in FIG. 9C, the filler P is injected from the opening 21 provided in the restricting portion 20E1. The filler P is injected from the opening 21 between the rotor core 6, the plurality of magnets 5, and the rotor cover 20 shown in FIG. 7.

  As the filler P, a resin, an adhesive, a hot melt, an elastic body, an elastomer, or the like can be used. The filler P is injected between the rotor core 6, the plurality of magnets 5, and the rotor cover 20 in a state in which these are heated to have fluidity. Thus, in this embodiment, since the area | region where the filler P is inject | poured by the rotor cover 20 is formed, the metal mold | die for injection | pouring of a filler which is complicated and expensive becomes unnecessary. As a result, the manufacturing cost of the motor 1 can be reduced.

  The filler P injected from the opening 21 flows between the rotor core 6, the plurality of magnets 5, and the rotor cover 20. At this time, the restricting portion 20E2 (that is, the restricting portion on the side opposite to the restricting portion 20E1 where the opening 21 is formed) and the rotor core 6 are not completely in close contact with each other, and a slight gap exists. Therefore, air between the rotor core 6, the plurality of magnets 5, and the rotor cover 20 flows out from the gap, so that the filler P is formed between the rotor core 6, the plurality of magnets 5, and the rotor cover 20. Spread throughout. In the present embodiment, the magnet 5 is constrained by the rotor cover 20 in the radial direction and the central axis Zr direction of the rotor core 6, so that even when the mounting structure of the rotor core 6 and the magnet 5 shown in FIG. The positional deviation of the magnet 5 due to the injection of P can be suppressed.

  Thus, since the rotor cover 20 holds the magnet 5 on the rotor core 6 until the filler P is injected, a mold for injecting the filler becomes unnecessary, and the manufacturing equipment for the motor 1 can be simplified. . Further, by holding the magnet on the rotor core 6 with the rotor cover 20, the magnet 5 can be reliably held on the rotor core 6 without making the dimensional tolerances of the magnet 5, the rotor core 6 and the rotor cover 20 highly accurate. Furthermore, since the magnet 5 is held by the rotor cover 20 from the outside in the radial direction of the rotor core 6, it is not necessary to provide a holding member between the magnets 5 as in the prior art. By these actions, in this embodiment, the magnet 5 can be reliably fixed to the rotor core 6 easily and at low cost.

  Further, in this embodiment, since it is not necessary to provide a holding member between the magnets 5 as in the prior art, for example, the specification of the motor 1 is changed, for example, the shape of the magnet 5 is changed, or the central axis Zr direction of the rotor core 6 is changed. Even if the length increases, it can be easily dealt with by changing the length (dimension in the direction of the central axis Zr) and the diameter of the rotor cover 20. For this reason, unlike the prior art, there is no need to newly install a holding member between the magnets 5, so that the manufacturing cost of the motor 1 can be reduced.

  10-1 and 10-2 both show the rotor 10 after the filling material P has been injected. As shown in FIGS. 10A and 10B, when the filler P is injected and solidified, the filler solidified between the rotor core 6, the plurality of magnets 5, and the rotor cover 20 (solidified filler). 30 is provided. The magnet 5 is fixed and held between the rotor cover 20 and the rotor core 6 by the rotor cover 20 and the solidified filler 30. Thereby, the rotor 10 is completed. Thereafter, the rotor 10 is assembled to the bearings 3 and 4 or disposed in the housing 2A, whereby the motor 1 is completed.

  In this embodiment, the magnet 5 is held on the rotor core 6 by the rotor cover 20, and a filler is provided between the rotor core 6, the magnet 5, and the rotor cover 20. Thus, the magnet 5 can be securely attached and fixed to the rotor core 6 and the centrifugal force acting on the magnet 5 can be received by the rotor cover 20, so that the reliability with respect to heat and centrifugal force is improved. Furthermore, since the magnet 5 is held on the rotor core 6 by the rotor cover 20 when the rotor 10 is manufactured, an injection mold and a holding member are not required, and the rotor 10 can be manufactured simply and at low cost with high accuracy. Thus, in this embodiment, the rotor 10 with high accuracy and high reliability can be manufactured at a low cost.

(First modification)
FIG. 11 is a perspective view showing a first modification of the present embodiment. This modified example has substantially the same configuration as that of the above-described embodiment, but openings are provided at positions corresponding to between adjacent magnets provided on the rotor core in both restricting parts provided on both ends of the rotor cover. The point to provide is different. Other configurations are the same as those of the above-described embodiment.

  As shown in FIG. 11, in the present modification, an opening 22 is provided in a portion F that is opposite to the restricting portion 20E1 and protrudes from the rotor core 6, that is, a portion that is bent to become the restricting portion 20E2. The opening 22 is provided at a portion corresponding to between adjacent magnets 5 provided in the rotor core 6. Thus, after the rotor cover 20a is attached to the rotor core 6, the protruding portion F is bent toward the end of the rotor core 6 to form the restricting portion 20E2. When the restricting portion 20E2 is formed, the opening 22 of the restricting portion 20E2 It faces between adjacent magnets 5 provided on 6. And the opening part 22 connects the space enclosed by the adjacent magnet 5, the rotor cover 20a, and the rotor core 6 with the exterior of the control part 20E2. With such a configuration, the space surrounded by the adjacent magnet 5, the rotor cover 20a, and the rotor core 6 communicates with the outside of the rotor cover 20a through the opening 21 of the restricting portion 20E1 and the opening 22 of the restricting portion 20E2. To do.

  When the filler is injected from the opening 21 of the restricting portion 20E1, the air in the space surrounded by the adjacent magnet 5, the rotor cover 20a, and the rotor core 6 flows out from the opening 22 of the restricting portion 20E2. This makes it easier for the filler to flow in the space surrounded by the adjacent magnet 5, the rotor cover 20a, and the rotor core 6 as compared with the rotor cover 20 of the above-described embodiment. Spread throughout the space. As a result, the manufacturing time of the rotor is shortened and the productivity is improved.

(Second modification)
FIG. 12 is a perspective view showing a second modification of the present embodiment. FIG. 13 is a front view of a rotor according to a second modification of the present embodiment. Since the rotor is symmetrical with respect to the plane containing the central axis, FIG. 13 shows only half of the rotor. This modification is different in that a plurality of restricting portions are provided at both ends of the rotor cover 20.

  As shown in FIG. 12, a plurality of restricting portions 20E1b are formed at one end of the rotor cover 20b. The restricting portion 20E1b extends from one end portion of the rotor cover 20b toward the central axis Zr of the rotor core 6. The plurality of restricting portions 20E1b are arranged at predetermined intervals in the circumferential direction of the rotor cover 20b. As illustrated in FIG. 13, an opening 21 b is formed between the adjacent restricting portions 20 </ b> E <b> 1. The opening 21b is provided in a portion corresponding to a portion between the adjacent magnets 5 (portion indicated by M in FIG. 7) among the magnets 5 arranged in the circumferential direction of the rotor core 6. Further, the restricting portion 20E1b is formed corresponding to the position of each magnet 5, and restricts the movement of each magnet 5 in the direction of the central axis Zr.

  The opening 21 provided in the restricting portion 20E1 of the rotor cover 20 of the embodiment described above is a hole, and the size thereof depends on the width of the restricting portion 20E1 (the dimension in the radial direction of the rotor cover 20). Moreover, since the opening 21 is formed by perforation, the shape is also limited. Thus, in the rotor cover 20 of the above-described embodiment, the size and shape of the opening 21 are limited.

  In this modification, a plurality of restricting portions 20E1b are formed in the circumferential direction of the rotor cover 20b, and an opening 21 is defined between adjacent restricting portions 20E1b. With such a configuration, the size and shape of the opening 21b are less restricted than the opening 21 of the above-described embodiment. For this reason, by increasing the area of the opening 21b, the space surrounded by the adjacent magnet 5, the rotor cover 20a, and the rotor core 6 can be opened larger. As a result, since the filler can be injected into the space from a larger area, the time for injecting the filler is shortened and the production efficiency is improved. Further, since the filler is more easily spread throughout the space, the magnet 5 can be fixed more firmly.

  As shown in FIG. 13, in this modification, the portion F that protrudes from the rotor core 6 on the side opposite to the restricting portion 20E1, that is, the portion that is bent to become the restricting portion 20E2 also faces the circumferential direction of the rotor cover 20b. Multiple. As a result, a plurality of restricting portions 20E2 are formed at the end of the rotor cover 20b opposite to the end where the restricting portions 20E1 are formed. The restricting portions 20E2b are formed corresponding to the positions of the respective magnets 5 and restrict the movement of the respective magnets 5 in the central axis Zr direction. Further, the opening formed between the adjacent restricting portions 20 </ b> E <b> 2 is provided at a portion corresponding to between the adjacent magnets 5.

  With such a configuration, the space surrounded by the adjacent magnet 5, the rotor cover 20a, and the rotor core 6 can be opened larger, so that when the filler is injected, the filler in the space is more It becomes easy to flow. As a result, the time for injecting the filler is shortened, the production efficiency is improved, and the filler is more easily spread throughout the space, so that the magnet 5 can be fixed more firmly. In this modification, a plurality of both restriction portions 20E1b and 20E2b are provided, but a plurality of any one of the restriction portions may be provided, and the other may have an annular integrated configuration.

(Example of magnet arrangement)
FIG. 14 is a perspective view showing an example in which magnets are skewed. FIG. 15 is a plan view showing an arrangement example of magnets constituting the rotor according to the present embodiment. FIG. 16 is a plan view showing a groove formed by adjacent magnets. FIG. 17 is a perspective view showing an example in which a filler is injected into a rotor in which magnets are skew-arranged.

  In the embodiment described above, the magnets are arranged at predetermined intervals in the circumferential direction of the rotor core, but are arranged in a row in the central axis direction of the rotor core. In the present embodiment, as in the rotor 10c shown in FIG. 14, magnets 5A, 5B, etc. are arranged stepwise in the central axis Zr direction of the rotor core 6, and a plurality of rows of magnets are also arranged in the central axis Zr direction of the rotor core 6. Etc. are arranged. Such a magnet arrangement is called skew arrangement. The torque variation of the motor can be reduced by arranging the magnets in a skewed manner.

  In the skew arrangement, for example, like the rotor 10c shown in FIG. 15, the magnets 5A, 5B, 5C, and 5D are arranged so as to be shifted from each other in the circumferential direction toward the central axis Zr. As a result, the rotor 10c is arranged in a staircase pattern in the direction of the central axis Zr of the rotor core 6. A plurality of magnets 5 </ b> A, 5 </ b> B, 5 </ b> C, 5 </ b> D are arranged in the circumferential direction of the rotor core 6. Therefore, grooves 40A, 40B, 40C, and 40D are provided between magnets 5A and 5A adjacent in the circumferential direction, between magnets 5B and 5B, between magnets 5C and 5C, and between magnets 5D and 5D, respectively. It is formed.

  In the present embodiment, as shown in FIG. 16, a groove 40A or the like formed by magnets 5A and 5B adjacent in the circumferential direction is continuously connected between one restricting portion 20E1 and the other restricting portion 20E2. To do. That is, the adjacent grooves 40A and 40B, the grooves 40B and 40C, and the grooves 40C and 40D are connected to each other with an overlapping portion, and there is no connection between the restricting portion 20E1 and the other restricting portion 20E2. Continuous as two grooves. With such a structure, the filler P injected from the opening 21 provided in the restricting portion 20E1 flows through the grooves 40A, 40B, 40C, and 40D and reaches all the grooves.

  Thus, when the filler P is solidified, a solidified filler (solidified filler) 30 is provided between the rotor core 6, the plurality of magnets 5A, 5B, and the rotor cover 20, as shown in FIG. . Thus, in the skew arrangement of the magnets, even when the magnets are skew-arranged by continuing the groove formed between the magnets adjacent in the circumferential direction between one restricting portion and the other restricting portion. The filler can be spread between the magnets.

(Embodiment 2)
FIG. 18 is a perspective view of a rotor according to the second embodiment. FIG. 19 is a cross-sectional view of the rotor cover shown in FIG. 20 is a cross-sectional view taken along the line XX of FIG. FIG. 21 is a cross-sectional view of the rotor according to the second embodiment cut at the position of a protrusion provided on the rotor cover. The second embodiment is substantially the same as the first embodiment, except that the side portions of the rotor cover are provided with protrusions that are directed toward the inside of the side portions at intervals of the arrangement of magnets in the circumferential direction of the rotor core. Other configurations are the same as those of the first embodiment.

  As illustrated in FIG. 18, the rotor cover 20d provided in the rotor 10d includes a plurality of protrusions 23 on the side portion 20Sd. The protrusions 23 are dot-like protrusions, and are provided at corresponding portions between the plurality of magnets 5 attached to the rotor core 6. For this reason, in the direction parallel to the central axis Zr, each opening 21 provided in the restricting portion 20E1 of the rotor cover 20d and each projection 23 are on the same straight line, and in the circumferential direction of the rotor cover 20 Each opening 21 and each projection 23 are at the same position.

  As shown in FIGS. 19 and 20, the protrusion 23 provided on the side 20Sd of the rotor cover 20d protrudes inside the side 20Sd, that is, toward the central axis Zr. Since the rotor cover 20d is composed of a thin plate made of a nonmagnetic material, the protrusion 23 can be formed by plastically deforming the side portion 20Sd with a punch or the like, for example. In addition, the formation method of the projection part 23 is not limited to this.

  As shown in FIG. 21, the rotor cover 20 d is attached to the rotor core 6 so that the protrusion 23 is positioned between the adjacent magnets 5. Accordingly, the magnet 5 can be positioned with high accuracy because the magnet 5 can be positioned in the circumferential direction of the rotor core 6 by the rotor cover 20d. Further, as shown in FIG. 18, the protrusion 23 has the same position in the circumferential direction as the opening 21, and therefore, if the protrusion 23 is provided between the adjacent magnets 5, the protrusion 23 is interposed between the adjacent magnets 5. The opening 21 is located. Thus, the filler can be reliably injected between the adjacent magnets 5.

  As shown in FIG. 21, the protrusions 23 are provided at an arrangement interval of the magnets 5 in the circumferential direction of the rotor core 6. Here, the arrangement interval of the magnets 5 is the interval between the centers of the magnets 5 in the circumferential direction, and is θpm in terms of the central angle about the central axis Zr. The interval at which the protrusions 23 are arranged is θpt in terms of a central angle with the central axis Zr as the center. In the present embodiment, the protrusion 23 is formed so that θpm = θpt. Thereby, each protrusion 23 can be reliably disposed between adjacent magnets 5.

  In this embodiment, when attaching the rotor cover 20 d to the rotor core 6, the protrusion 23 is aligned between the adjacent magnets 5, and the rotor cover 20 d is inserted into the rotor core 6. Thereby, even if the position of the magnet 5 in the circumferential direction of the rotor core 6 is slightly deviated, it is corrected to the correct position by the protrusion 23. In particular, in the above-described attachment structure of the magnet and the rotor core shown in FIG. 8-2, the magnet 5 tends to be displaced from a predetermined position of the rotor core 6. Therefore, the effect of correcting the position of the magnet 5 by the protrusion 23 is effective. is there. In addition, it is preferable to determine the dimension and shape of the projection part 23 in consideration of the flow of the filler in the space formed by the magnet 5 adjacent to the rotor core 6 and the rotor cover 20d (the same applies hereinafter).

  The protrusion may be provided with a plurality of dot-like protrusions in the central axis Zr direction, or may extend in the central axis Zr direction. In this way, since the position of the magnet 5 can be defined in a wider area in the direction of the central axis Zr, the positional deviation of the magnet 5 can be more effectively suppressed.

(Modification)
FIG. 22 is a perspective view of a rotor cover according to a modification of the second embodiment. FIG. 23 is a plan view illustrating an arrangement example of magnets constituting a rotor according to a modification of the second embodiment. FIG. 24 is a plan view showing a groove formed by adjacent magnets. In this modification, a protrusion is provided on the rotor cover when the magnet is skewed.

  As shown in FIG. 23, when the magnets 5A, 5B, 5C, and 5D are skewed, the magnets 5A and 5A adjacent in the circumferential direction, the magnets 5B and 5B, the magnets 5C and 5C, the magnets Grooves 40A, 40B, 40C, and 40D are formed between 5D and 5D, respectively. As shown in FIG. 22, in this modification, protrusions 23A, 23B, 23C, and 23D are provided on the side portion 20Sd of the rotor cover 20d corresponding to the respective grooves 40A, 40B, 40C, and 40D.

  The intervals at which the protrusions 23A, 23B, 23C, and 23D are arranged are the intervals at which the grooves 40A, 40B, 40C, and 40D are arranged, that is, the intervals at which the magnets 5A, 5B, 5C, and 5D are arranged. Are the same. As described above, in the skew arrangement, the groove 40A, the groove 40B, the groove 40C, and the groove 40D are connected in consideration of the injection of the filler. Therefore, as shown in FIG. 23, when the rotor cover 20e shown in FIG. 22 is attached to the rotor core, the protrusion 23D (the other protrusions 23A, 23B, and 23C are the same) have the groove 40A, the groove 40B, the groove 40C, It passes through the groove 40D in order and fits in the corresponding groove 40D.

  When attaching the rotor cover 20e to the rotor core, the protrusion 23D is inserted into the groove 40A, and the rotor cover 20e is moved in the circumferential direction and the central axis direction of the rotor core at the joint between the groove 40A and the groove 40B. Accordingly, the protrusion 23D is moved from the groove 40A to the groove 40B, and the next protrusion 23C is caused to enter the groove 40A. This operation is sequentially repeated to arrange all the protrusions 23A, 23B, 23C, and 23D in the corresponding grooves 40A, 40B, 40C, and 40D, respectively.

  Here, the protrusions 23B, 23C, and 23D that move between adjacent grooves are preferably point-like protrusions. Accordingly, the protrusions 23B, 23C, and 23D can easily move between adjacent grooves. Further, in this modification, the protrusions 23A, 23B, 23C, and 23D can be moved between adjacent grooves and the fillers can be reliably injected into the grooves 40A, 40B, 40C, and 40D. It is preferable to set dimensions and shapes. As described above, according to the present modification, even when the magnets are skew-arranged, the magnets 5A in the circumferential direction of the rotor core are formed by the protrusions 23A, 23B, 23C, and 23D provided on the side portion 20Se of the rotor cover 20e. 5B, 5C, 5D can be positioned.

(Appendix)
The following invention can be understood from the second embodiment and its modifications. The present invention includes a cylindrical rotor core, a plurality of magnets provided on an outer peripheral portion of the rotor core, a cylindrical side portion disposed on the outer peripheral portion of the plurality of magnets, and the side portion including the side portion And a rotor cover provided at intervals between the magnets in the circumferential direction of the rotor core.

  When the rotor cover is disposed on the outer periphery of the magnet provided on the rotor core, an opening formed at one end of the cylindrically formed rotor cover is generally inserted into the rotor core. Since the rotor cover is generally attached to the rotor core by press-fitting or shrink-fitting, it is difficult to repair the displacement of the magnet attached to the rotor core.

  Thus, as in the present invention, by disposing the protrusions provided on the rotor cover between the adjacent magnets, the positional deviation of the magnet (particularly the positional deviation in the circumferential direction of the rotor core) is suppressed. As a result, in the manufacture of a rotor and a brushless motor using this rotor, it is possible to reduce the occurrence of defects due to magnet misalignment, thereby improving productivity and reducing manufacturing costs.

  As described above, the brushless motor rotor, the brushless motor and the electric power steering device, and the brushless motor rotor manufacturing method according to the present invention are useful for a brushless motor in which a rotor cover is attached to a rotor core.

1 Motor (brushless motor)
1S Rotating shaft 2A Housing 2Ab Bottom 2B Front bracket 3, 4 Bearing 5, 5A, 5B, 5C, 5D Magnet 6 Rotor core 6T Protrusion 6U Groove 6h End 7 Core 7A Split core 8 Excitation coil 9 Stator 10, 10c, 10d Rotor 11 Insulator 17 Split yoke 18 Teeth 20, 20a, 20b Rotor cover 20E1, 20E1b, 20E2, 20E2b Restriction part 20S, 20Sd, 20Se Side part 20T1, 20T2 End part 21, 21b, 22 Opening part 23, 23A, 23B, 23C, 23D Protrusion part 24A, 24B Opening part 30 Solidified filler 40A, 40B, 40C, 40D Groove 100 Electric power steering apparatus 111 Reduction gear

Claims (11)

Rotor core,
A plurality of magnets provided on an outer peripheral portion of the rotor core and arranged in a circumferential direction of the rotor core;
Cylindrical side portions are arranged on the outer peripheral portions of the plurality of magnets, and both ends of the side portions are provided with restriction portions that restrict the movement of the side portions in the central axis direction of the rotor core, At least one of the restricting portions includes a rotor cover in which an opening is formed in a corresponding portion between the adjacent magnets;
Only including,
The restricting portion extends from both end portions of the side portion toward the rotation center of the rotor core to the position of the rotor core,
Between the rotor core, the plurality of magnets, and the rotor cover, a filler filled from the opening is provided,
The opening is formed such that an area of the opening is smaller than an area of a cross section perpendicular to a central axis direction of the rotor core in a space formed between the rotor core, the plurality of magnets, and the rotor cover. A rotor for a brushless motor. A plurality of said magnets, a brushless motor rotor according to claim 1 disposed toward the central axis direction of the rotor core in a stepwise manner. The rotor for a brushless motor according to claim 2 , wherein a groove formed by the magnets adjacent in the circumferential direction is connected between one of the restricting portions and the other restricting portion. The rotor cover, a brushless motor rotor according to any one of claims 1 to 3 for restraining a plurality of said magnets. The brushless motor rotor according to any one of claims 1 to 4 , wherein protrusions directed toward the inside of the side portion are provided on the side portion at an arrangement interval of the magnets in a circumferential direction of the rotor core. At least one of the regulating unit, after the rotor cover is attached to the outer peripheral portion of the magnet, claim 1 the ends of said side is formed by being bent toward the rotational center of the rotor core 5 The rotor for a brushless motor according to any one of the above. One of the restricting portion, before the rotor cover is attached to the outer peripheral portion of the magnet from claim 1, from one end of said side and out beforehand extending toward the rotation center of the rotor core 6 The rotor for a brushless motor according to any one of the above. The brushless motor rotor according to any one of claims 1 to 7 ,
A stator that is annularly arranged at a predetermined interval outside the brushless motor rotor;
A housing for holding the stator;
A brushless motor comprising: An electric power steering apparatus, wherein an auxiliary steering torque is obtained by the brushless motor according to claim 8 . A restricting portion having a plurality of openings formed in one end portion of the side portion of the cylindrical member extending from the one end portion of the side portion toward the position of the rotor core toward the rotation center of the rotor core and in the circumferential direction. a step of the rotor cover, attached to the rotor core in which a plurality of magnets on an outer peripheral portion having,
Bending the end opposite to the restricting portion, and extending the bent portion toward the rotor core toward the rotation center of the rotor core ; and
The space formed between the rotor core, the plurality of magnets, and the rotor cover is opened smaller than the area of the cross section perpendicular to the central axis direction of the rotor core, and corresponds between adjacent magnets. A procedure for injecting a filler into the space from the opening formed in the portion to be performed;
The manufacturing method of the rotor for brushless motors characterized by including these. The side portion is provided with protrusions directed toward the inside of the side portion at an arrangement interval of the magnets in the circumferential direction of the rotor core,
The method for manufacturing a brushless motor rotor according to claim 10 , wherein when the rotor cover is attached to the rotor core, the protrusion is aligned between the adjacent magnets, and the rotor cover is inserted into the rotor core.

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