JP2019103321A - Inner rotor type motor - Google Patents

Abstract

To provide an inner rotor type motor which is inexpensive and in which the problem of a magnet coming into contact with a stator hardly occurs.SOLUTION: In an inner rotor type motor 1000, a stator 1020 is annularly disposed about a central axis 1100, and a rotor 1021 is disposed radially inward of the stator. In the rotor, a cylindrical portion of a covered cylindrical body 1102 faces the stator. A cylindrical rubber magnet 1103 is disposed radially inward of the inner peripheral surface of the cylindrical portion, along the inner peripheral surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inner rotor type motor.

  The inner rotor type motor comprises a stator and a rotor. The rotor is disposed radially inward of the stator. The stator serves as an armature to generate an armature magnetic field. The rotor becomes a field and generates a field magnetic field. The generated field magnetic field interlinks with the generated armature magnetic field. This generates torque that causes the rotor to rotate about the central axis.

  The rotor comprises a rotor core and a magnet. The magnet generates a field magnetic field.

  The inner rotor type motor is roughly classified into a surface magnet (SPM) type motor and an embedded magnet (IPM) type motor. In the SPM type motor, the magnet is held on the outer peripheral surface of the rotor core. The holding of the magnet on the outer peripheral surface of the rotor core may be performed using a member such as a magnet holder, or may be performed by adhesion. In an IPM type motor, a magnet is embedded in the rotor core.

  Magnets incorporated into the rotor of an SPM type motor are roughly classified into sintered magnets, plastic magnets and rubber magnets.

  When the magnet incorporated into the rotor is a sintered magnet or a plastic magnet, the magnet is deformed or moved toward the stator by magnetic interaction, heat, external force, etc. between the stator and the magnet, and the magnet is a tooth of the stator, etc. It is hard to occur the problem of touching. However, when the magnet incorporated into the rotor is a sintered magnet or a plastic magnet, the magnet is not inexpensive and storage, processing and incorporation into the rotor become difficult.

  On the other hand, when the magnet incorporated in the rotor is a rubber magnet, the above-mentioned problem is likely to occur. In particular, when the rubber magnet is a neodymium (Nd) rubber magnet, the above-mentioned problems are likely to be noticeable. However, if the magnet incorporated into the rotor is a rubber magnet, the magnet becomes inexpensive and storage, processing and incorporation into the rotor become easy.

The motor described in Patent Document 1 is an example of an SPM type motor. In the motor described in Patent Document 1, a cylindrical magnet is fixed to the outer peripheral surface of the rotor yoke assembly to form a rotor (paragraph 0031). In the motor described in Patent Document 1, it is unclear whether the magnet is a sintered magnet, a plastic magnet, or a rubber magnet.
Patent No. 4867671

  As described above, when the magnet incorporated in the rotor provided in the SPM type motor is a sintered magnet or a plastic magnet, the magnet is not inexpensive and storage, processing and incorporation into the rotor are not easy. On the other hand, when the magnet incorporated in the rotor provided in the SPM type motor is a rubber magnet, the problem of the magnet coming into contact with the stator tends to occur under high temperature environment.

  For this reason, in the prior art, it is difficult to obtain an inner rotor type motor which is an inexpensive rubber magnet and hardly causes a problem of contact with the stator.

  The present invention aims to solve this problem. The problem to be solved by the present invention is to provide an inner rotor type motor which is inexpensive and in which the problem of the magnet coming into contact with the stator hardly occurs.

  In an exemplary aspect of the present invention, in an inner rotor type motor, a stator is annularly disposed about a central axis, and a rotor is disposed radially inward of the stator. In the rotor, the cylindrical portion faces the stator, and a cylindrical rubber magnet is disposed radially inward of the inner peripheral surface of the cylindrical portion along the inner peripheral surface.

  According to one aspect of the motor of the present invention, a rubber magnet is incorporated into the rotor that is easy to store, machined and integrated into the rotor and is inexpensive. Thereby, an inexpensive inner rotor type motor can be provided.

  Further, according to one aspect of the motor of the present invention, the cylindrical portion is present radially outside the rubber magnet. As a result, it is restricted by the cylindrical portion that the rubber magnet is deformed or moved toward the stator by magnetic interaction between the stator and the rubber magnet, heat, external force or the like, and the rubber magnet contacts the stator. It can prevent.

It is a sectional view which illustrates a motor of a 1st embodiment typically. FIG. 2 is a cross-sectional view schematically illustrating a rotor, a magnetic sensor, and a substrate provided in the motor of the first embodiment. It is a sectional view which illustrates a rubber magnet provided in a motor of a 1st embodiment typically. It is a sectional view which illustrates a motor of a 2nd embodiment typically. It is sectional drawing which illustrates typically the rotor provided in the motor of 2nd Embodiment, a magnetic sensor, and a board | substrate.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, a direction parallel to the central axis C of the motor is “axial direction”, a direction orthogonal to the central axis of the motor is “radial direction”, and a direction along an arc centered on the central axis C of the motor is “peripheral It is referred to as “direction”. Further, in the present application, the shape and the positional relationship of each part will be described with the axial direction as the vertical direction. However, the definition in the vertical direction is not intended to limit the direction at the time of manufacture and use of the motor according to the present invention.

  Further, in the present application, the “parallel direction” also includes a substantially parallel direction. Further, in the present application, the “orthogonal direction” also includes a substantially orthogonal direction.

1 First Embodiment 1.1 Outline of Motor FIG. 1 is a cross-sectional view schematically illustrating a motor according to a first embodiment.

  The motor 1000 illustrated in FIG. 1 is an inner rotor type, and includes a stator 1020, a rotor 1021, a case 1022, a bearing 1023, and a bearing 1024. Motor 1000 may comprise components other than these components.

  The case 1022 is a cylindrical member extending in the axial direction. The material of the case 1022 is not particularly limited, and, for example, aluminum (including an aluminum alloy), an iron alloy such as SUS, and the like are preferable. The case 1022 accommodates the stator 1020, the rotor 1021, and the like inside. The stator 1020 is coupled to the case 1022 without the bearings 1023 and 1024. Thus, the stator 1020 is held by the case 1022 in a fixed state with respect to the case 1022. The stator 1020 is fixed to, for example, the case 1022 by press fitting, shrink fitting, or the like.

  The axially lower bottom of the case 1022 is formed with a recess that is recessed downward in the axial direction. The bearing 1024 is held in the recess. A lid is disposed at the opening at the axially upper side of the case 1022. In the present embodiment, the lid is a substantially plate-like member. The lid and the case 1022 are fixed, for example, by screws (not shown). The lid has an axially penetrating through hole at its approximate center. The bearing 1023 is held in the through hole. In the present embodiment, the size of the bearing 1023 is larger than the size of the bearing 1024. However, the size of the bearing 1023 may be the same as the size of the bearing 1024, or the magnitude relationship may be reversed.

  The rotor 1021 is rotatably supported relative to the case 1022 by bearings 1023 and 1024. In the present embodiment, the bearings 1023 and 1024 are, for example, ball bearings. However, the types of bearings 1023 and 1024 are not particularly limited, and may be other types of bearings such as slide bearings.

  The stator 1020 serves as an armature to generate an armature magnetic field. The rotor 1021 becomes a field and generates a field magnetic field. The generated field magnetic field interlinks with the generated armature magnetic field. As a result, torque that causes the rotor 1021 to rotate around the central axis C is generated.

  The motor 1000 is an inner rotor type. For this reason, in the motor 1000, the rotor 1021 is disposed radially inward of the stator 1020. The stator 1020 is annular and disposed annularly around the central axis C.

1.2 Stator The stator 1020 comprises a stator core 1040 and a plurality of windings 1041 as illustrated in FIG. The stator core 1040 includes a core back 1060 and a plurality of teeth 1061.

  The core back 1060 is annular and disposed annularly around the central axis C. The plurality of teeth 1061 are distributed in the circumferential direction around the central axis C. In the present embodiment, the teeth 1061 are arranged at equal intervals in the circumferential direction. Each tooth 1061 protrudes radially inward from the inner circumferential surface 1080 of the core back 1060. A conductive wire is wound on each tooth 1061 through an insulator made of an insulating material such as a resin to form a winding 1041. The stator core 1040 is made of a magnetic material. In the present embodiment, the stator core 1040 is a laminated steel plate in which a plurality of electromagnetic steel plates are laminated in the axial direction. When current flows through the plurality of windings 1041, an armature magnetic field is generated according to the current. The stator core 1040 may be a powder magnetic core or the like instead of the laminated steel plate.

  The stator 1020 having the structure illustrated in FIG. 1 may be replaced with a stator having a structure different from the structure. The above-mentioned stator core 1040 is a round core whose core back is annular. However, stator core 1040 is not limited to a round core, and may be either a split core or a straight core, or may be a core of another shape. The winding method of the plurality of windings 1041 may be either concentrated winding or distributed winding, or may be other winding method.

1.3 Rotor FIG. 2 is a cross-sectional view schematically illustrating a rotor, a magnetic sensor, and a substrate provided in the motor of the first embodiment. FIG. 2 is an enlarged view of a part of FIG.

  The rotor 1021 includes a shaft 1100, a rotor core 1101, a lidded cylindrical body 1102 and a rubber magnet 1103 as illustrated in FIGS. 1 and 2.

  Shaft 1100 is coupled to an inner ring 1120 of bearing 1023 and an inner ring 1140 of bearing 1024, as illustrated in FIG. The inner rings 1120 and 1140 can rotate relative to the outer ring 1121 of the bearing 1023 and the outer ring 1141 of the bearing 1024, respectively. The outer rings 1121 and 1141 are coupled to the case 1022. Thereby, the shaft 1100 can rotate around the central axis C in a state along the central axis C.

  In the present embodiment, the rotor core 1101 is a laminated steel plate in which a plurality of electromagnetic steel plates are laminated in the axial direction. The shaft 1100 is threaded through holes 1160 formed in the rotor core 1101 as illustrated in FIG. The holes 1160 pass through the rotor core 1101 in the axial direction. The rotor core 1101 is coupled to the inserted shaft 1100, and is accommodated in an in-cylinder space 1170 formed in the covered cylindrical body 1102. In the present embodiment, the covered cylindrical body 1102 is coupled to the housed rotor core 1101. The rubber magnet 1103 is housed in the in-cylinder space 1170 and attached to the covered cylindrical body 1102. Thus, the rubber magnet 1103 can rotate integrally with the shaft 1100. The shaft 1100 may be indirectly coupled to the rotor core 1101 via a member such as resin or metal. That is, the shaft 1100 is fixed to the rotor core 1101 directly or indirectly. In the present embodiment, the rotor core 1101 may be a dust core or the like instead of the laminated steel plate.

  In the present embodiment, the rubber magnet 1103 has a tubular shape, and is disposed in a tubular shape centered on the central axis C. The magnet outer peripheral surface 1180 of the rubber magnet 1103 is multipolarly magnetized to be a multipolar magnetized surface. Thereby, the magnet outer peripheral surface 1180 generates a field magnetic field.

1.4 Advantages of Rubber Magnets The cylindrical rubber magnet 1103 illustrated in FIGS. 1 and 2 can be easily obtained by a business operator of the motor 1000 or the like by deforming a flat rubber magnet into a cylindrical shape. . Moreover, the flat rubber magnet does not require, for example, a large space for storage, and can be easily stored. Furthermore, when a flat rubber magnet is deformed into a cylindrical shape, a dedicated mold is not necessary. For this reason, when the magnet incorporated into the rotor 1021 is a rubber magnet 1103, storage, processing, and incorporation into the rotor 1021 are easy. Moreover, the binding material which binds magnetic powder mutually in the rubber magnet 1103 is cheap. For this reason, when the magnet incorporated in the rotor 1021 is the rubber magnet 1103, the manufacturing cost of the magnet and the like are reduced. Therefore, when the magnet incorporated in the rotor 1021 is the rubber magnet 1103, an inexpensive motor 1000 can be provided.

  During driving of the motor, a radial electromagnetic force is generated between the teeth and the magnet. Due to the electromagnetic force, vibrations occur in the teeth and the magnet, and noise may be generated from the motor. In particular, when the magnet incorporated in the rotor 1021 is a plastic magnet or a sintered magnet, the noise is difficult to suppress. Further, in the case where the magnet incorporated in the rotor 1021 is a plastic magnet or a sintered magnet, there is also a possibility that the resonance noise may be changed by the amount of adhesive bonding the magnet to the rotor main body. On the other hand, the rubber magnet 1103 in the present embodiment has elasticity. Thereby, the vibration generated by the electromagnetic force in the radial direction generated between the teeth 1061 and the rubber magnet 1103 when the motor is driven is attenuated by the rubber magnet 1103, and the noise generated from the motor 1000 is suppressed.

1.5 Preventing Contact of Rubber Magnet to Stator When the magnet incorporated in the rotor 1021 shown in FIGS. 1 and 2 is a rubber magnet 1103, the magnetic interaction between the stator 1020 and the rubber magnet 1103 The rubber magnet 1103 may be deformed or moved toward the stator 1020 by heat, external force or the like. Therefore, these deformation or movement must be restricted to prevent the rubber magnet 1103 from contacting the stator 1020. Below, the structure for that is demonstrated.

  The rotor core 1101 and the covered cylindrical body 1102 do not deform so much as to contact the stator 1020 even when the rotor 1021 rotates when the motor is driven.

  The covered cylindrical body 1102 includes a cylindrical portion 1200 as illustrated in FIG. In the present embodiment, the cylindrical portion 1200 constituting the covered cylindrical body 1102 is a nonmagnetic material. When the material of the cylindrical portion 1200 is nonmagnetic, the material of the cylindrical portion 1200 is, for example, aluminum (including an aluminum alloy) or the like, but is not particularly limited.

  The cylindrical portion 1200 is disposed in a cylindrical shape with the central axis C as a center, and faces the stator 1020 in the radial direction.

  The rubber magnet 1103 is attached to the inner circumferential surface 1220 of the cylindrical portion 1200. For this reason, the rubber magnet 1103 is held by the inner circumferential surface 1220, disposed radially inward of the inner circumferential surface 1220, and along the inner circumferential surface 1220.

  A cylindrical portion 1200 is present radially outside the rubber magnet 1103. Thus, the cylindrical portion 1200 restricts the rubber magnet 1103 from being deformed or moved toward the stator 1020. As a result, the rubber magnet 1103 can be prevented from contacting the stator 1020. In particular, when the rotor 1021 rotates at high speed, the cylindrical portion 1200 regulates that the rubber magnet 1103 is deformed and scattered toward the stator 1020 by centrifugal force.

1.6 Coupling of the cylindrical part to the shaft The covered cylindrical body 1102 further includes a plate-like part 1201 as illustrated in FIG.

  The plate-like portion 1201 is a lid-like portion that closes a part of the upper opening of the cylindrical portion 1200. For this reason, the cylindrical portion 1200 extends axially downward from the plate end portion 1260 on the outer peripheral side of the plate portion 1201. In the present embodiment, the plate-like portion 1201 has a disk shape. The plate-like portion 1201 is integrally formed with the cylindrical portion 1200. The plate-like portion 1201 can be formed with the cylindrical portion 1200 by, for example, pressing, cutting, casting or the like. In addition, the shape of the plate-like-part 1201 is not restricted to the above-mentioned thing, It does not specifically limit.

  Rotor core 1101 is coupled to shaft 1100. The rotor core 1101 is fixed to the shaft 1100 by, for example, press fitting. In the present embodiment, the plate-like portion 1201 is coupled to the rotor core 1101. In this case, the plate-like portion 1201 can be fixed to the rotor core 1101 by, for example, caulking, adhesion, welding or the like. The upper cylindrical end portion 1240 of the cylindrical portion 1200 is coupled to the plate end portion 1260 on the outer peripheral side of the plate portion 1201. As a result, the rotor core 1101 and the plate-like portion 1201 become a coupling portion 1280 that couples the cylindrical portion 1200 to the shaft 1100, and the cylindrical portion 1200 can rotate integrally with the shaft 1100. In addition, as long as the plate-like portion 1201 is coupled to the shaft 1100, the plate-like portion 1201 may not necessarily be fixed to the rotor core 1101. In this case, the plate-like portion 1201 may face the rotor core 1101 in the axial direction via contact or a gap. Further, the coupling portion 1280 composed of the rotor core 1101 and the plate-like portion 1201 may be replaced with a coupling portion having another structure. The example is mentioned in the description of the second embodiment.

1.7 Detection of circumferential position of rotor The cylindrical rubber magnet 1103 has a first multipole magnetization surface facing the radially outer side and a second multipole magnetization surface facing the direction different from the radial outer side. Have. More specifically, the magnet outer peripheral surface 1180 of the rubber magnet 1103 illustrated in FIG. 2 faces the radially outer side and is a first multipolar magnetized surface that generates a field magnetic field.

  Further, in motor 1000, lower end face 1300 of rubber magnet 1103 is directed to the lower side in the axial direction, and becomes a second multipolar magnetized surface that generates a magnetic field used to detect the circumferential position of rotor 1021. ing.

  The motor 1000 further comprises at least one magnetic sensor 1320 and a substrate 1321. In the present embodiment, the substrate 1321 is, for example, a plate-like member. Various electronic components such as a capacitor are electrically connected to at least one surface in the axial direction one side and the axial other side of the substrate 1321. Although not shown, the substrate 1321 is supported and held by, for example, the case 1002 or a stator. The substrate 1321 is connected to an external power supply (not shown) via a connector or the like. In addition, the substrate 1321 is connected to the winding directly or indirectly via a conductive member such as a lead, for example. Thereby, power can be supplied to the motor (i.e., the stator) through the external power supply. Note that the substrate 1321 is not limited to a so-called printed circuit board (PCB), and may be a flexible printed circuit (FPC) or the like. The number of substrates 1321 is not limited to one, and may be two or more. The substrate 1321 may be a single-sided substrate on which an electronic component or the like is mounted on one side, or may be a double-sided substrate on which an electronic component or the like is mounted on both sides.

  The magnetic sensor 1320 is a position sensor that detects the circumferential position of the rotor 1021. In the present embodiment, the magnetic sensor 1320 is mounted on the substrate 1321. The magnetic sensor 1320 faces the lower end surface 1300 of the rubber magnet 1103 at a specific position in the circumferential direction. Thereby, the magnetic sensor 1320 can detect the magnetic field generated by the end surface 1300, and can output an electric signal according to the detected magnetic field. The output electric signal is used, for example, to detect the circumferential position of the rotor 1021. That is, the motor 1000 further includes a magnetic sensor that faces the second multipolar magnetization surface and detects a magnetic field generated by the second multipolar magnetization surface. The magnetic sensor 1320 may be either a Hall element or a magnetoresistive element, or may be another element. In addition to the magnetic field generated by the end face 1300, the magnetic sensor 1320 may detect the magnetic field generated by the magnet inner circumferential surface 1181 of the rubber magnet 1103 or the like. The number of magnetic sensors 1320 may be one or three or more, and can be appropriately changed in accordance with the number of magnetic poles of the rotor, the number of phases, and the like.

  When the magnet is a sintered magnet having strong anisotropy, it is necessary to provide a sensor magnet independent of the sintered magnet that generates a field magnetic field and a magnetic sensor that detects the magnetic field generated by the sensor magnet. become. As a result, the cost and the number of mounting steps of the sensor magnet and the like increase.

  On the other hand, in the present embodiment, the rubber magnet 1103 is desirably an isotropic magnet or an anisotropic magnet having weak anisotropy that can be magnetized in a direction different from the direction in which the magnetization easy axis extends. More preferably, they are isotropic magnets. When the rubber magnet 1103 is an isotropic magnet or an anisotropic magnet having weak anisotropy, the lower side in the axial direction different from the magnet outer peripheral surface 1180 of the rubber magnet 1103 facing radially outward and the radially outer side It becomes easy to magnetize both end faces 1300 on the lower side of the rubber magnet 1103 that faces. This makes it unnecessary to provide a sensor magnet independent of the rubber magnet 1103 to detect the circumferential position of the rotor 1021 and a magnetic sensor for detecting the magnetic field generated by the sensor magnet, and the manufacturing cost of the motor 1000 Can be lowered.

  The lower end surface 1300 of the rubber magnet 1103 protrudes axially downward from the cylindrical portion 1200 as illustrated in FIG. 2. That is, the second multipolar magnetized surface protrudes from the cylindrical portion 1200 in the axial direction and faces in the axial direction. Accordingly, the magnetic sensor 1320 can be easily disposed near the end surface 1300, and the magnetic field generated by the end surface 1300 can be efficiently detected by the magnetic sensor 1320.

  A plate end portion 1260 on the outer peripheral side of the plate portion 1201 is coupled to a lower tube end portion 1241 of the tubular portion 1200. An upper end surface 1301 of the rubber magnet 1103 that faces the axial direction upper side protrudes from the cylindrical portion 1200 to the axial direction upper side. The end face 1301 is a multipolar magnetized surface that generates a magnetic field used to detect the circumferential position of the rotor 1021. The magnetic sensor 1320 faces the end face 1301.

1.8 Mounting of Rubber Magnet The rubber magnet 1103 shown in FIG. 2 is mounted on the inner circumferential surface 1220 of the cylindrical portion 1200 by any mounting method. For example, the rubber magnet 1103 is attached to the inner circumferential surface 1220 by drawing it into the cylindrical portion 1200 and press-fitting it onto the inner circumferential surface 1220. According to such a mounting method, the rubber magnet 1103 is mounted by a mounting process which is simpler than the mounting process in the case of mounting the sintered magnet in the SPM type motor or the IPM type motor. The rubber magnet 1103 may be attached to the inner circumferential surface 1220 of the cylindrical portion 1200 by another method such as adhesion.

1.9 Types of Magnets The rubber magnet 1103 illustrated in FIGS. 1 and 2 is either a ferrite rubber magnet composed of a composition containing ferrite or an Nd rubber magnet composed of a composition containing neodymium (Nd) Although it may be good or another rubber magnet, it is preferably an Nd rubber magnet. Nd rubber magnets have the same magnetic force as ferrite rubber magnets occupying a larger volume. Therefore, in the case of generating the same magnetic force, when the rubber magnet 1103 is an Nd rubber magnet, the volume of the magnet can be reduced to reduce the volume of the rotor as compared to the case where the ferrite rubber magnet is used. it can. As a result, the motor 1000 can be miniaturized.

  Nd rubber magnets are less expensive than Nd plastic magnets containing Nd and Nd sintered magnets. Therefore, when the magnet incorporated into the rotor 1021 is an Nd rubber magnet, the inexpensive motor 1000 can be provided. The Nd plastic magnet is more expensive than the Nd rubber magnet because it is necessary to use epoxy, polyamide (PA), poniphenylene sulfide (PPS) or the like as a binder in the Nd plastic magnet. The reason why the Nd sintered magnet is more expensive than the Nd rubber magnet is that the Nd content in the Nd sintered magnet is larger than the Nd content in the Nd rubber magnet.

  In a general Nd rubber magnet, magnetic particles made of NeFeB-based magnetic material are bound to one another by nitrile rubber. However, the force with which the nitrile rubber fixes the magnetic powder is not sufficient for the magnetic force of the magnetic powder. Therefore, when a general Nd rubber magnet is simply incorporated into a rotor provided in a conventional SPM type motor, there arises a problem due to the insufficient force. For example, when an inner rotor type motor including a rotor incorporating a Nd rubber magnet magnetized to a stator and 10 poles is left as assembled, the magnetic powder is attracted to the stator core and the Nd rubber magnet is located at 10 places. There may be a problem of contact with the stator core. However, in the motor 1000, the rubber magnet 1103 is attached to the inner circumferential surface 1220 of the cylindrical portion 1200, which can prevent the occurrence of the problem.

1.10 Halbach Arrangement FIG. 3 is a cross-sectional view schematically illustrating a rubber magnet provided in the motor of the first embodiment.

  The rubber magnet 1103 illustrated in FIG. 3 is magnetized in eight poles. The number of magnetic poles in the rubber magnet 1103 may be other than eight.

  The rubber magnet 1103 is desirably an isotropic magnet. In the present embodiment, the rubber magnet 1103 is magnetized in a Halbach arrangement, and includes a plurality of magnetized portions 1400 arranged in a Halbach arrangement as illustrated in FIG. 3. The rubber magnet 1103 has a magnet inner circumferential surface 1181 and a magnet outer circumferential surface 1180. Thus, the magnetic flux is concentrated on the magnet outer peripheral surface 1180 of the rubber magnet 1103, and the magnetic field generated by the magnet outer peripheral surface 1180 of the rubber magnet 1103 becomes stronger than the magnetic field generated by the magnet inner peripheral surface 1181 of the rubber magnet 1103. The fact that the magnetic field generated by the magnet outer circumferential surface 1180 is intensified by the magnetization of the Halbach arrangement contributes to the increase of the torque generated by the motor 1000 while maintaining the volume, shape and material of the rubber magnet 1103. The fact that the magnetic field generated by the magnet inner circumferential surface 1181 is weakened by the magnetization of the Halbach arrangement eliminates the need for the magnetic path from the teeth 1061 to the stator 1020 via the rotor core, and the radially inner side of the magnet inner circumferential surface 1181 It is unnecessary to provide a rotor core that functions as a yoke. Therefore, the rotor core 1101 described above can be made of a nonmagnetic material.

  As described above, when the rotor 1021 is not provided with a rotor core, the assembly process of the rotor 1021 is simplified. When the rotor core is not provided on the rotor 1021, the inertia of the rotor 1021 is reduced, and the responsiveness of the motor 1000 to the control command is improved.

  The plurality of magnetized portions 1400 are arranged in the circumferential direction. The plurality of magnetized portions 1400 includes a radially magnetized portion 1420 magnetized in the radial direction and a circumferential magnetized portion 1421 magnetized in the circumferential direction. In the plurality of magnetized portions 1400, the radially magnetized portions 1420 and the circumferentially magnetized portions 1421 are alternately arranged. The plurality of radially magnetized portions 1420 have a first radially magnetized portion 1440 whose S pole is exposed on the magnet outer peripheral surface 1180 of the rubber magnet 1103 and a N pole exposed on the magnet outer peripheral surface 1180 of the rubber magnet 1103. 2 radially magnetized parts 1441 are included. In the plurality of radially magnetized portions 1420, the first radially magnetized portions 1440 and the second radially magnetized portions 1441 are alternately arranged. In the two circumferential magnetization parts 1421 adjacent to the first radial magnetization part 1440, the direction from the S pole to the N pole is a direction away from the first radial magnetization part 1440. . In the two circumferential magnetization parts 1421 adjacent to the second radial magnetization part 1441, the direction from the S pole to the N pole is a direction approaching the second radial magnetization part 1441. .

  The rubber magnet 1103 disposed in a cylindrical shape about the central axis C may be replaced with a plurality of rubber magnets arranged in the circumferential direction about the central axis C. The plurality of rubber magnets are magnetized in the same manner as the plurality of magnetized portions 1400 provided in the rubber magnet 1103 respectively.

1.11 Shape and Application of Motor When the magnet incorporated in the rotor 1021 is a rubber magnet 1103, the torque generated by the motor 1000 can be increased without increasing the axial dimension of the stator 1020. Therefore, when the magnet incorporated in the rotor 1021 is the rubber magnet 1103, the motor is compact, has a flat shape in which the outer diameter φ of the stator 1020 is larger than the axial dimension of the stator 1020, and generates high torque. One thousand is easily obtained. The outer diameter φ of the stator 1020 that can be realized is, for example, about 85 mm, and the axial dimension of the stator 1020 that can be realized is, for example, 3 mm to 7 mm.

  The motor 1000 of such a size is suitably used, for example, as a power slide motor mounted on a car.

2 Second Embodiment FIG. 4 is a cross-sectional view schematically illustrating a motor according to a second embodiment.

  The motor 2000 illustrated in FIG. 4 is an inner rotor type, and includes a stator 1020, a rotor 2021, a case 1022, a bearing 1023, a bearing 1024, a magnetic sensor 1320, and a substrate 1321.

  The stator 1020, the case 1022, the bearing 1023, the bearing 1024, the magnetic sensor 1320 and the substrate 1321 are respectively provided in the motor 1000 of the first embodiment, the stator 1020, the case 1022, the bearing 1023, the bearing 1024, the magnetic sensor 1320 and the substrate 1321. It is the same thing, and the explanation is omitted.

  The rotor 2021 includes a shaft 2100, a covered double cylindrical body 2102 and a rubber magnet 1103.

  The rubber magnet 1103 is the same as the rubber magnet 1103 provided in the motor 1000 of the first embodiment.

  FIG. 5 is a cross-sectional view schematically illustrating a rotor, a magnetic sensor, and a substrate provided in the motor of the second embodiment. FIG. 5 is an enlarged view of a part of FIG. 4.

  As shown in FIG. 5, the covered double cylindrical body 2102 includes a cylindrical portion 2200, a plate-like portion 2201, and a cylindrical coupling portion 2202. The tubular portion 2200 has a first tubular end 2240. The coupling portion 2280 has a cylindrical shape 2202 having a second cylindrical end 2600 and coupled to the shaft 2100, and a plate-like portion 2201 coupled to the first cylindrical end 2240 and the second cylindrical end 2600. And. The details will be described below.

  The plate-like portion 2201 is a lid-like portion that closes at least a part of the upper opening of the cylindrical portion 2200. The cylindrical portion 2200 extends axially downward from the plate end 2260 on the outer peripheral side of the plate portion 2201. The cylindrical coupling portion 2202 extends axially downward from an inner peripheral plate end 2261 which is substantially at the center of the plate portion 2201.

  The tubular coupling portion 2202 is formed, for example, by burring, and is disposed in a tubular shape around the central axis C. In the present embodiment, the tubular coupling portion 2202 is coupled via a knurled groove 2500 cut in the shaft 2100. The plate end 2261 on the inner peripheral side of the plate-like portion 2201 is coupled to the second cylindrical end 2600 on the upper side of the tubular coupling portion 2202. The upper cylindrical end 2240 of the cylindrical portion 2200 is coupled to the plate end 2260 on the outer peripheral side of the plate portion 2201. The rubber magnet 1103 is attached to the inner circumferential surface 2220 of the cylindrical portion 2200, disposed radially inward of the inner circumferential surface 2220, and along the inner circumferential surface 2220. In the present embodiment, the cylindrical coupling portion 2202, the cylindrical end portion 2600, and the plate-like portion 2260 are integrally formed by, for example, pressing or cutting. The cylindrical coupling portion 2202, the cylindrical end portion 2600, and the plate-like portion 2260 do not have to be formed of one member by, for example, press processing, and separate members are assembled to constitute one member. May be

  The plate-like portion 2201 and the cylindrical coupling portion 2202 form a coupling portion 2280 which couples the cylindrical portion 2200 to which the rubber magnet 1103 is attached to the shaft 2100. Also in the present embodiment, the material of the cylindrical coupling portion 2202, the cylindrical end portion 2600, and the plate-like portion 2260 is nonmagnetic. As a result, the rotor core is not necessary for the rotor 2021, and the assembly process of the rotor 2021 is simplified. Further, when the rotor core is not provided on the rotor, the inertia of the rotor 2021 is reduced, and the responsiveness of the motor 2000 to the control command is improved.

  Even when the coupling portion 1280 is replaced with the coupling portion 2280, an inexpensive motor 2000 is provided, and the rubber magnet 1103 can be prevented from coming into contact with the stator 1020 due to deformation or the like.

  The present invention can be widely used not only for power slides, but also for various devices equipped with various motors such as vacuum cleaners, dryers, ceiling fans, washing machines, refrigerators and electric power steering devices.

  Although the present invention has been described in detail, the above description is an exemplification in all aspects, and the present invention is not limited thereto. It is understood that countless variations not illustrated are conceivable without departing from the scope of the present invention.

1000, 2000 Motor 1020 Stator 1021, 2021 Rotor 1100, 2100 Shaft 1101 Rotor core 1102 Covered cylindrical body 1103 Rubber magnet 1200, 2200 Cylindrical portion 1201, 2201 Plate shaped portion 1280 Coupling portion 1320 Magnetic sensor 1400 Magnetization portion 2102 Covered double layer Tubular body 2202 Tubular joint C central axis

Claims (9)

A stator disposed annularly around a central axis;
A rotor disposed radially inward of the stator;
Equipped with
The rotor is
A cylindrical portion having an inner circumferential surface and facing the stator;
A cylindrical rubber magnet disposed radially inward of the inner circumferential surface and extending along the inner circumferential surface;
Inner rotor type motor with. The cylindrical rubber magnet has a first multipolar magnetized surface facing radially outward and a second multipolar magnetized surface facing in a direction different from the radially outer side.
The inner rotor type motor according to claim 1, wherein the inner rotor type motor further comprises a magnetic sensor that faces the second multipolar magnetization surface and detects a magnetic field generated by the second multipolar magnetization surface. Motor. The inner rotor type motor according to claim 2, wherein the second multipolar magnetized surface protrudes axially from the cylindrical portion and faces in the axial direction. The inner rotor type motor according to claim 2 or 3, wherein the cylindrical rubber magnet is an isotropic magnet. The cylindrical rubber magnet includes a plurality of magnetized portions arranged in a Halbach array, and has an inner circumferential surface and an outer circumferential surface of the magnet.
The inner rotor type motor according to any one of claims 1 to 4, wherein the magnetic field generated by the outer circumferential surface of the magnet is stronger than the magnetic field generated by the inner circumferential surface of the magnet. The rotor is
A shaft along the central axis,
A coupling portion coupling the tubular portion to the shaft;
The inner rotor type motor according to any one of claims 1 to 5, further comprising: The tubular portion has a first tubular end,
The connecting portion is
A tubular joint having a second barrel end and coupled to the shaft;
A plate-like portion coupled to the first cylinder end and the second cylinder end;
The inner rotor type motor according to claim 6, comprising: The inner rotor type motor according to any one of claims 1 to 7, wherein an outer diameter of the stator is larger than an axial dimension of the stator. The inner rotor type motor according to any one of claims 1 to 8, wherein the cylindrical portion is made of a nonmagnetic material.

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