JP6521137B2 - motor - Google Patents

Description

  The present invention relates to an inner rotor type motor.

  In the inner rotor type motor, recently, a small and high output motor is required.

  In order to increase the output of the motor, it is necessary to increase the stack thickness of the armature or to increase the thickness of the winding.

  In Patent Document 1, the lids 5 and 6 and the ring-shaped stator 1 are fastened to each other by a fixing screw 7 penetrating the ring-shaped stator 1 in the axial direction.

Further, in Patent Document 2, the stator core 13 and the base 16 are attached by passing the metal screw 9 having high thermal conductivity, the rivet 10 and the burring 11 through the hole 8. At that time, an insulator 14 which is an insulator, that is, a convex portion 17 is provided between the metal component and the winding 5 so as not to make contact with each other.
Patent No. 3862844 Japanese Patent Application

  In the conventional motor, when attaching the motor to the main body of the apparatus, parts such as screws or screws made of metal are used. However, when such parts are rubbed at the mounting portion of the motor, metal powder may be generated, and metal components may intrude inside the motor.

  The present invention provides an inner rotor type motor having a structure that solves the problems of the above technology.

  A motor according to a first aspect of the present invention includes a shaft, a rotor magnet, an armature, and a casing. The shaft is rotatably supported by the bearing member about a vertically extending central axis. The rotor magnet rotates with the shaft. The armature is located radially outward of the rotor magnet. The casing fixes the armature and holds an upper bearing and a lower bearing rotatably supporting the shaft in the radial center. The armature has a stator core, an insulator, and a coil. The stator core includes an annular core back and a plurality of pole teeth projecting radially inward from the core back. The insulator covers at least the upper and lower surfaces of the pole teeth of the stator core. The coil is configured by winding a conductive wire around the pole teeth via an insulator. The casing has an opening which is an axially penetrating hole at the axial end face. It further has a cover member disposed at a position facing the opening between the casing and the armature. The top surface of the cover member contacts at least a portion of the armature.

  According to the present invention, it is possible to prevent the entry of foreign matter into the motor. As a result, the reliability of the motor can be improved.

FIG. 1 is an external perspective view of a motor. FIG. 2 is an external perspective view of the motor. FIG. 3 is a cross-sectional view of the motor. FIG. 4 is a plan view of the motor with the upper bracket removed. FIG. 5 is a perspective view of the upper insulator. FIG. 6 is a plan view of the upper insulator. FIG. 7 is a perspective view of the lower insulator. FIG. 8 is a cross-sectional view of a motor according to a modification. FIG. 9 is a cross-sectional view of a motor according to a modification. FIG. 10 is a cross-sectional view of a motor according to a modification. FIG. 11 is a cross-sectional view of a motor according to a modification. FIG. 12 is a plan view of a cover member according to a modification.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Hereinafter, the direction along the central axis of the motor is referred to as the vertical direction. The shape and positional relationship of each part will be described with the circuit board side up with respect to the stator core. However, this is merely defining the vertical direction for the convenience of description, and does not limit the posture when using the motor according to the present invention.

<1. Overall configuration of motor>
The motor according to the present embodiment is mounted on, for example, a home appliance such as an air conditioner, an air cleaner, or a refrigerator, and is used as a drive source of a fan or a pump. Moreover, it is used as a drive source of industrial equipment, such as a sorter. However, the motor of the present invention may be a motor used for other applications. For example, the motor of the present invention may be mounted on an OA (Office Automation) device, a medical device, an automobile or the like to generate various driving forces. Below, the apparatus by which the motor 1 is mounted is called a "drive device."

  1 and 2 are external perspective views of a motor 1 according to the present embodiment. FIG. 3 is a cross-sectional view of the motor 1. As shown in FIG. 1, FIG. 2, and FIG. 3, the motor 1 includes a stationary unit 2 and a rotating unit 3. The stationary unit 2 is fixed to a frame of a drive device (not shown). The rotating unit 3 is rotatably supported relative to the stationary unit 2.

  The stationary portion 2 of the present embodiment includes an upper bracket 21, a lower bracket 22, a stator core 23, a coil 24, an upper insulator 25, a lower insulator 26, a circuit board 27, and a bearing portion 28.

  The upper bracket 21 holds the stator core 23 and the bearing portion 28 (upper bearing 281). The upper bracket 21 has a substantially cylindrical shape with a lid. The upper bracket 21 is a metal member. The upper bracket 21 is obtained by a so-called pressing method in which a steel plate is punched and formed. In addition, the manufacturing method may be processed not with a press method but with another processing method such as a die casting method. The upper bracket 21 may be made of resin instead of metal.

  The lower bracket 22 holds the stator core 23 and the bearing portion 28 (lower bearing 282). The lower bracket 22 has a bottomed substantially cylindrical shape. The lower bracket 22 is a metal member.

  The lower bracket 22 is obtained by a so-called pressing method in which a steel plate is punched out and molded. In addition, the manufacturing method may be processed not with a press method but with another processing method such as a die casting method. The lower bracket 22 may be made of resin instead of metal. Further, in the present embodiment, the stator core 23 and the bearing portion 28 (lower bearing 282) are held by the lower bracket 22 which is a single member. Therefore, the stator core 23 and the shaft 31 described later can be positioned with high accuracy.

  The stator core 23 and the coil 24 are portions functioning as an armature of the motor 1. The stator core 23 is a laminated steel plate in which electromagnetic steel plates such as silicon steel plates are laminated in the axial direction (direction along the central axis J1. The same applies to the following). The stator core 23 has an annular core back 231 and a plurality of magnetic pole teeth 232 protruding radially inward from the core back 231. The core back 231 is held by being sandwiched between the upper bracket 21 and the lower bracket 22. The outer circumferential surface of the core back 231 is the outer circumferential surface of the motor 1 except for the axially upper portion and the axially lower portion. The circumferential width of the portion of the magnetic pole teeth 232 of the stator core 23 where the coil 24 is wound is equal to or less than twice the radial width of the core back 231. Further, in the present embodiment, the number of magnetic pole teeth 232 is six.

  Here, the outer peripheral surface of the stator core 23 is not covered by the lower bracket 22 and the upper bracket 21 except near the upper end and the lower end, and is exposed from the lower bracket 22 and the upper bracket 21. That is, compared with the case where the entire outer peripheral surface of stator core 23 is covered with lower bracket 22 and upper bracket 21, in the present embodiment, the diametrically opposed areas of outer peripheral surface of stator core 23 and lower bracket 22 and upper bracket 21 are small. For this reason, even if the lower bracket 22 and the upper bracket 21 are magnetic members, the leakage of the magnetic flux from the outer peripheral surface of the stator core 23 to the lower bracket 22 and the upper bracket 21 is unlikely to occur. Therefore, the iron loss by lower bracket 22 and upper bracket 21 can be reduced, and the energy efficiency of motor 1 can be improved.

  Through holes 233 are formed at the boundaries between some of the core backs 231 of the stator core 23 and the pole teeth 232. In the present embodiment, the number of through holes 233 is three. It is desirable that the through holes 233 be arranged at equal intervals in the circumferential direction around the central axis. In the present embodiment, the through holes 233 are arranged at an interval of 120 degrees as viewed from the central axis. The through hole 233 is not limited to this, and may be a groove recessed inward in the radial direction.

  An axially extending longitudinal groove is formed on the outer peripheral surface of the stator core 23. The protrusions of the upper bracket 21 and the protrusions of the lower bracket 22 are inserted or fitted into the vertical grooves. Thereby, positioning of the upper bracket 21 and the lower bracket 22 in the radial direction and the circumferential direction is performed.

  The coil 24 is constituted by a conductive wire wound around the pole teeth 232. The coil 24 is wound around the pole tooth 232 via the insulator. In the present embodiment, the conductors are connected by so-called star connection. Therefore, four ends of the U phase, the V phase, the W phase, and the common are drawn from the coil 24. The drawn out ends are respectively soldered to the circuit board 27. When a drive current is applied to the coil 24 through the circuit board 27, a magnetic flux in the radial direction is generated in the magnetic pole teeth 232 which is a magnetic core. And, by the action of the magnetic flux between the magnetic pole teeth 232 and the rotor magnet 33 on the rotating portion 3 side, torque in the circumferential direction is generated. As a result, the rotating unit 3 rotates around the central axis J1 with respect to the stationary unit 2.

  The insulator includes an upper insulator 25 and a lower insulator 26. The upper insulator 25 and the lower insulator 26 are members made of resin that electrically insulate the stator core 23 from the coil 24. The upper insulator 25 is disposed on the upper side of the stator core 23. The lower insulator 26 is disposed below the stator core 23. In other words, the stator core 23 is sandwiched between the upper insulator 25 and the lower insulator 26. The upper insulator 25 covers the top surfaces of the magnetic pole teeth 232. The lower insulator 26 covers the lower surface of the pole tooth 232. Further, the upper insulator 25 and the lower insulator 26 cover the side surfaces of the magnetic pole teeth 232. The upper insulator 25 and the lower insulator 26 constitute an insulator. In the present embodiment, the coil 24 is wound on the pole teeth 232 from above the upper insulator 25 and the lower insulator 26, whereby the insulator is fixed to the stator core 23.

  The upper insulator 25 and the lower insulator 26 have a portion interposed between the magnetic pole teeth 232 and the coil 24 to electrically insulate the magnetic pole teeth 232 from the coil 24. Further, the upper insulator 25 has an annular core back insulating portion 252 continuous in the circumferential direction on the radial outside of the coil 24. The core back insulator 252 is disposed radially outward of the coil 24. The core back insulating portion 252 is a portion that performs insulation with another member when the coil 24 is broken. An assembly of the stator core 23, the coil 24, the upper insulator 25, and the lower insulator 26 is defined as an armature 29. Details of the upper insulator 25 and the lower insulator 26 will be described later.

  FIG. 4 is a plan view of a state in which the upper bracket 21 is removed from the motor 1 according to the present embodiment. Referring to FIG. 4, circuit board 27 is a board having a wire for applying a drive current to coil 24 from an external power supply. The circuit board 27 has a substantially disc shape in a plan view. The outer shape of the circuit board 27 substantially matches the outer shape of the upper insulator 25 described later. The circuit board 27 is fixed on a bearing surface which is the upper surface of the upper insulator 25. Further, a magnetic sensor 271 for detecting the number of rotations of the rotating portion 3 is provided on the lower surface of the circuit board 27. For the magnetic sensor 271, for example, a Hall element is used.

  Referring to FIG. 3, the bearing unit 28 is a member that rotatably supports the shaft 31 of the rotating unit 3. The bearing portion 28 is composed of an upper bearing 281 and a lower bearing 282. The upper bearing 281 is held by the inner circumferential surface 2121 of the holding portion 212 of the upper bracket 21. The lower bearing 282 is held by the lower bracket 22. For the bearing portion 28, for example, a ball bearing that relatively rotates the outer ring and the inner ring via a ball is used. However, other types of bearings such as slide bearings and fluid bearings may be used for the bearing portion 28.

  The rotating portion 3 of the present embodiment has a shaft 31, a rotor holder 32, and a rotor magnet 33. The shaft 31 is a substantially cylindrical member extending in the vertical direction along the central axis J1. The shaft 31 rotates about the central axis J1 while being supported by the bearing 28 described above. The lower end portion of the shaft 31 protrudes downward of the lower bracket 22. Further, the upper end portion of the shaft 31 protrudes above the circuit board 27. The lower end portion or the upper end portion of the shaft 31 is connected to the drive portion of the drive device via a power transmission mechanism such as a gear. However, the drive unit of the drive device may be directly driven by the shaft 31.

  The rotor holder 32 is a member that rotates with the shaft 31 inward of the stator core 23 and the coil 24 in the radial direction. The rotor holder 32 of the present embodiment is configured by arranging the upper rotor holder member 323 and the lower rotor holder member 324 having a bottomed cylindrical shape in a back-to-back relationship. That is, the bottom surface of the upper rotor holder member 323 and the bottom surface of the lower rotor holder member 324 are disposed to face each other via a minute gap. The upper rotor holder member 323 and the lower rotor holder member 324 are each obtained by a so-called pressing method in which a steel plate is punched out and molded.

  In the present embodiment, although the rotor holder 32 is disposed so that the upper rotor holder member 323 and the lower rotor holder member 324 are in a back-to-back relationship, the present invention is not limited to this. The rotor holder 32 may be configured by a single member. Alternatively, it may be obtained by cutting free-cutting steel. Alternatively, the rotor holder 32 may be obtained by laminating magnetic steel plates. Alternatively, the rotor holder 32 may be obtained by sintering. Alternatively, the rotor holder 32 may be obtained by combining a member obtained by laminating magnetic steel sheets with a member having a substantially cylindrical shape and obtained by pressing. Alternatively, the rotor holder 32 may be obtained by resin molding. Moreover, although it is a so-called SPM type | mold (Surface-permanent magnet, surface magnet type | mold) rotor in this embodiment, it is not restricted to this. It may be a so-called IPM (interior permanent-magnet, embedded magnet) rotor. In the case of an IPM type rotor, it is desirable that the rotor holder 32 be obtained by laminating magnetic steel plates.

  The rotor magnet 33 has a cylindrical shape, and is fixed to the outer peripheral surface of the rotor holder 32. The radially outer surface of the rotor magnet 33 is a magnetic pole surface radially opposed to the stator core 23 and the coil 24. The rotor magnet 33 is magnetized such that the magnetic pole surface of the N pole and the magnetic pole surface of the S pole are alternately arranged in the circumferential direction. In addition, about the rotor magnet 33, it may replace with a cylindrical-shaped magnet, and you may arrange | position a some magnet so that N pole and S pole may be alternately located in a line with the circumferential direction. Further, as described above, the rotor magnet 33 may be embedded in the rotor holder 32 as an IPM type rotor.

<2. About circuit board>
FIG. 5 is an external perspective view of the upper insulator 25 according to the present embodiment. Referring to FIGS. 4 and 5, circuit board 27 has a substantially disc shape in plan view. The outer peripheral surface of the circuit board 27 is provided with a notch which is recessed inward in the radial direction from the outer periphery. This notch is a positioning portion 272. In the positioning portion 272, a positioning convex portion 254 of the upper insulator 25 described later is inserted. Thereby, when the circuit board 27 tries to move relative to the upper insulator 25, the convex portion 254 contacts the positioning portion 272, and the movement is restricted. As a result, positioning in the circumferential direction and radial direction of the upper insulator 25 and the circuit board 27 can be performed with high accuracy.

  In addition, a connector 273 is provided on the top surface of the circuit board 27. The motor 1 obtains drive current via the connector 273.

  Further, the outer peripheral surface of the circuit board 27 is provided with a notch which is recessed inward in the radial direction from the outer periphery. This notch is a buttock insertion portion 274. The collar part insertion part 274 comprises a part of permeation | transmission part. Lands are disposed in a region adjacent to the ridge insertion portion 274 on the top surface of the circuit board 27. A collar portion 255 of the upper insulator 25 described later is inserted into the collar portion insertion portion 274. The buttock insertion portion 274 is positioned adjacent to the buttock insertion width narrow portion 2741 having a short width in the radial direction of the notch and the buttock insertion width narrow portion 2741, and is in the radial direction than the buttock insertion width narrow portion 2741. And a wide buttocks insertion wide portion 2742. More specifically, the collar portion 255 is inserted into the collar portion insertion narrow portion 2741.

  The outer peripheral surface of the circuit board 27 is provided with a notch which is recessed inward in the radial direction from the outer periphery. This notch is a wire extraction portion 277. The winding wire extraction portion 277 constitutes a part of the transmission portion. A land is disposed in a region adjacent to the winding wire extraction portion 277 on the upper surface of the circuit board.

  At the center of the circuit board 27, an axially opening central opening 276 is located. The shaft 31 is located radially inward of the central opening.

  The wiring pattern needs to be spaced apart from the edge of the circuit board 27 by a fixed distance. Therefore, the wiring area of the circuit board 27 can be wider if the number of holes and notches provided in the circuit board 27 is smaller. In the present embodiment, the portion (transmissive portion) into which the convex portion such as the collar portion insertion portion 274 is inserted is enlarged to be a notch for lead wire extraction. Thereby, the wiring area of the circuit board 27 can be widened.

  In particular, when mounting large electronic components such as control ICs, AC-DC converters, encoders, connectors, etc. on a circuit board, or when widening the wiring pattern to flow a large current through the board, the area of the circuit board itself is narrowed. The present technology is useful when necessary.

<3. About upper bracket and upper insulator>
First, the upper bracket 21 will be described in detail. The upper bracket 21 has a lid portion 211, a holding portion 212, an upper projecting portion 213, a through hole 214, and an opening 215. The lid portion 211 is flat and is located on the axial direction upper side of the circuit board 27. The holding portion 212 is a concave portion located radially inward of the lid portion 211 and opening upward in the axial direction. The holding portion 212 has a cylindrical inner circumferential surface 2121 and an annular top surface 2122. The inner circumferential surface 2121 contacts the outer circumferential surface of the outer ring of the upper bearing 281. The top surface 2122 contacts the upper end surface of the outer ring of the upper bearing 281. Thus, the holding portion 212 holds the upper bearing 281. Further, the outer circumferential surface of the upper bearing 281 is smaller than the diameter of the central opening 276 of the circuit board 27. Thereby, interference of the upper bearing 281 with respect to the circuit board 27 can be prevented, and the motor 1 can be thinned.

  The upper protruding portion 213 protrudes axially downward from the radially outer side of the lid portion 211. The protrusion 213 is substantially annular. Moreover, the upper protrusion part 213 is a substantially cylindrical shape. The inner peripheral surface of the upper protruding portion 213 contacts the upper outer peripheral surface of the stator core 23. Thereby, the coaxial accuracy of the central axis J1 and the upper bearing 281 can be improved. In addition, the rigidity of the upper bracket 21 can be improved. In the present embodiment, the stator core 23 is fixed to the upper bracket 21 by being pressed into the upper protrusion 213. However, it may be fixed not only by press fitting but by insertion adhesion. When the upper bracket 21 and the stator core 23 are fixed by insertion bonding, the inner peripheral surface of the protrusion 213 may be in contact with the outer peripheral surface of the circuit board 27 or the outer peripheral surface of the upper insulator 25. The rigidity of the upper bracket 21 can be improved by the inner circumferential surface of the projecting portion 213 being in contact with the circuit board 27 and the upper insulator 25.

  A plurality of through holes 214 are circumferentially arranged at the radially outer side on the lid portion 211. In the present embodiment, the number of through holes 214 is six.

  Further, when an electronic component having a large amount of heat generation is mounted on the circuit board 27, it is preferable to dispose it so as to face the electronic component. Thereby, the distance between the electronic component and the upper bracket 21 can be reduced. As a result, the heat generated from the electronic component can be dissipated from the upper bracket 21. In addition, a heat conductive material such as silicon may be interposed between the electronic component and the lid portion 211. Thereby, the heat dissipation from the electronic component is further promoted. In addition, a field effect transistor (FET) is mentioned as an example of electronic component with a large emitted-heat amount.

  The opening 215 is a through hole disposed in the lid portion 211. The connector 273 mounted on the circuit board 27 is exposed from the opening 215. By connecting with the connector 273 through the opening 215, power is supplied to the motor 1.

  The shape of the upper insulator 25 will be described in detail with reference to FIG. The upper insulator 25 has a magnetic pole tooth insulating portion 251 and a core back insulating portion 252. The pole tooth insulators 251 cover the top and side surfaces of each pole tooth 232. The core back insulator 252 is annular, and connects the respective pole tooth insulators 251. At the radially inner end of each of the magnetic pole tooth insulating portions 251, a plate portion 2511 protruding upward in the axial direction is provided. The core back insulator 252 extends axially upward at the radially outer side of the coil 24. The upper end surface of the core back insulator 252 is located axially above the coil 24. This can prevent interference between the coil 24 and the circuit board 27, the upper bracket 21, and other members.

  The core back insulating portion 252 has an annular wall portion 253, a positioning convex portion 254, and a collar portion 255. The annular wall portion 253 is a substantially annular wall that protrudes in the axial direction from the radial outer end of the core back insulating portion 252. The upper surface of the annular wall portion 253 is a seating surface 2531 and is a flat surface substantially perpendicular to the central axis. The seating surface 2531 contacts the lower surface of the circuit board 27. More specifically, the seating surface 2531 contacts the lower surface near the outer edge of the circuit board 27. The outer end of the annular wall portion 253 is located radially inward of the outer end of the stator core 23. Therefore, the portion of the stator core 23 located radially outward of the annular wall portion 253 is the upper core back exposed portion 41 exposed upward in the axial direction.

  The positioning convex portion 254 is located at substantially the same position in the radial direction as the annular wall portion 253 and protrudes axially upward with respect to the seat surface 2531. Further, the positioning convex portion 254 is located axially lower than the upper surface of the circuit board 27. Therefore, the positioning convex portion 254 is accommodated in the positioning portion 272 of the circuit board 27. Thus, even when the lower surface of the projecting portion 213 of the upper bracket 21 contacts the upper surface of the circuit board 27 as described later, the positioning convex portion 254 does not contact the upper bracket 21. Therefore, the circuit board 27 is firmly fixed.

  Further, in the present embodiment, the positioning convex portions 254 are provided at one place at intervals in the circumferential direction. Although three positioning projections 254 are provided in the present embodiment, the present invention is not limited to this, and two or more positioning projections may be provided.

  The shape of the positioning convex portion 254 in a plan view is substantially the same as that of the positioning portion 272, that is, the positioning convex portion 254 has a shape along the contour of the positioning portion 272. Thereby, the circuit board 27 can be accurately positioned with respect to the upper insulator 25.

  More preferably, both circumferential end surfaces of the positioning convex portion 254 contact the circumferential end surface of the positioning portion 272. Further, the radial end surface of the positioning convex portion 254 contacts the radial end surface of the positioning portion 272. Thereby, the circuit board 27 can be accurately positioned with respect to the upper insulator 25. However, if the end face of a part of the positioning convex part 254 is in contact with the end face of the positioning part 272, accurate positioning can be performed. If the circuit board 27 can be accurately positioned with respect to the upper insulator 25, the lead may be soldered without being sandwiched between the upper insulator 25 and the circuit board 27 in the step of soldering the lead described later. it can.

  Adjacent to the circumferential direction of the positioning convex portion 254, a first window portion 2541 which is notched downward in the axial direction is located. The axial position of the lower end of the first window portion 2541 is located lower than the upper end of the plate portion 2511 of the magnetic pole tooth insulating portion 251.

  The collar portion 255 is located at a position overlapping the annular wall portion 253 in the radial direction, and protrudes axially from the core back insulating portion 252. The flange portion 255 is located at a position different from the magnetic pole tooth insulating portion 251 in the circumferential direction. The upper end in the axial direction of the collar portion 255 is located above the upper surface of the circuit board 27 and protrudes axially upward beyond the seating surface 2531 and the positioning projection 254. The ridge portion 255 has a ridge-like portion 2551 on the upper side thereof. The bowl-shaped portion 2551 protrudes radially inward. The lower surface of the bowl-shaped portion 2551 is in contact with the upper surface of the circuit board 27 or faces the gap via a gap.

  A second window portion 2552 is located at a position adjacent to the collar portion 255 in the circumferential direction, in which the collar portion 255 and the annular wall portion 253 are cut downward in the axial direction. The axial position of the lower end of the second window 2552 is located lower than the upper end of the plate 2511 of the magnetic pole tooth insulator 251.

  In addition, the positioning convex part 254 and the collar part 255 are convex parts.

  Further, in the annular wall portion 253 of the upper insulator 25, a third window portion 2531 cut downward in the axial direction is located. The axial position of the lower end of the third window portion 2531 is located below the upper end of the plate portion 2511 of the magnetic pole tooth insulating portion 251.

  In the present embodiment, the window portions 2531 and 2255 are disposed at a total of five places at four points every 60 degrees and three places at every 120 degrees (two places of which overlap with those arranged every 60 degrees). ing. Thereby, in either case of connecting by star connection or connecting by delta connection, the conducting wire can be drawn out. Therefore, even in the case of changing the connection method, the common upper insulator 25 can be used. However, if connection is performed only by star connection, the window portions 2531 and 252 may be disposed at four places in the circumferential direction.

<4. About lower bracket and lower insulator>
First, the lower bracket 22 will be described in detail. The lower bracket 22 has a lower lid portion 221, a lower holding portion 222, and a lower protruding portion 223. The lower bracket 22 has a cylindrical shape with a lid. The lower lid portion 221 has a substantially annular flat plate shape. The lower holding portion 222 is a recess that is located radially inward of the lower lid portion 221 and opens downward in the axial direction. The lower holding portion 222 has a cylindrical inner circumferential surface 2221 and an annular top surface 2222. The inner circumferential surface 2221 contacts the outer circumferential surface of the outer ring of the lower bearing 282. The top surface 2222 contacts the lower end surface of the outer ring of the lower bearing 281 via a spring. Thus, the lower holding portion 222 holds the lower bearing 282.

  The lower protrusion 223 protrudes axially upward from the radially outer side of the lower lid 221. The lower protrusion 223 is substantially annular. Further, the lower protruding portion 223 has a substantially cylindrical shape. The upper end of the lower protrusion 223 is in contact with the outer peripheral surface of the stator core 23. Thereby, the coaxial accuracy of the central axis J1 and the lower bearing 282 can be improved. Further, the lower bracket 22 and the stator core 23 can be firmly fixed. In the present embodiment, the stator core 23 is fixed to the lower bracket 22 by being pressed into the lower protrusion 223. However, it may be fixed not only by press fitting but by insertion adhesion. In addition, the lower protrusion 223 has a positioning step 2231 with a smaller inner diameter. The top surface of the positioning step 2231 is in direct contact with the core back 231 of the stator core 23. Thus, the reduction in accuracy due to the axial positioning of the lower bracket 22 with respect to the stator core 23 is suppressed.

  The lower cover 221 is provided with an opening 228. The openings 228 are a plurality of holes that penetrate the lower lid 221 in the axial direction. A thread groove is formed on the inner circumferential surface of the opening 228. When attaching the motor to the device body, it is fixed by screwing a screw into the opening 228.

  Here, an annular cover member 71 is disposed between the opening 228 and the armature 29. In the present embodiment, the cover member 71 is formed of an elastic body such as rubber, and the outer peripheral surface thereof is press-fit and fixed to the inner peripheral surface of the lower protruding portion 223. However, the cover member 71 may be disposed at a position facing at least the opening 228. By interposing the cover member 71 between the lower cover portion 221 and the armature 29, it is possible to prevent foreign matter from entering the inside of the motor. In particular, when the motor is attached to the apparatus main body, it is possible to prevent the ingress of metal powder generated by rubbing the screw and the opening 228. Therefore, the reliability of the motor can be improved. Further, in the present embodiment, the upper surface of the cover member 71 is in contact with the coil 24 of the armature 29. The cover member 71 has elasticity. Therefore, since the cover member 71 is in contact with the coil 24, vibration and noise generated from the armature 29 can be reduced.

Further, in the present embodiment, the cover member 71 has a collar 711 extending axially downward at the inner side in the radial direction of the opening 228 and a thick portion 712 having a thick axial direction at the outer side in the radial direction of the opening 228 And a foot portion 713 located radially outward of the thick portion 712 and thinner in the axial direction than the thick portion 712. The collar 711 contacts the lower lid 221 of the lower bracket 22. This can prevent dust from entering the lower bearing 282 or the rotor holder 32 side. A part of the inner peripheral surface of the collar portion 711 has an inclined portion whose axial height decreases as it goes radially inward. Thereby, the contact between the cover member 71 and the rotating unit 3 is avoided. Further, the cover member 71 is inserted into the inner peripheral surface of the lower projecting portion 223 at the skirt portion 713. That is, the cover member 71 is inserted not at the thick thick portion 712 but at the thin hem portion 713. Thereby, insertion of the cover member 71 can be performed smoothly. Further, a thick portion 712 is provided on the inside of the skirt portion 713, so that deformation of the entire cover member 71 can be suppressed. Therefore, dust can be effectively prevented from entering the interior of the motor. The cover member 71 may be made of plastic or other material instead of rubber. Further, although the cover member 71 is inserted, it may be press-fit. Further, the cover member 71 may be disposed not on the lower bracket 22 side but on the upper bracket 21 side, or may be disposed on both the upper bracket 21 side and the lower bracket 22 side.
As described above, in the conventional inner rotor type motor, in order to obtain the upper bracket 21 and the lower bracket 22 by the press method, the opening 228 needs to be a through hole. As a result, there is a concern that dust may intrude inside the motor. However, by using the above-described cover member 71, it is possible to prevent the entry of foreign matter such as dust.

  FIG. 6 is a plan view of the lower insulator 26. FIG. FIG. 7 is a perspective view of the lower insulator 26. FIG. The shape of the lower insulator 26 will be described in detail with reference to FIGS. 6 and 7. The lower insulator 26 has a lower magnetic pole tooth insulating portion 261 and a lower core back insulating portion 262. The lower magnetic pole tooth insulating portion 261 covers the lower surface and the side surface of each magnetic pole tooth 232. The lower core back insulating portion 262 is annular, and connects the lower magnetic pole tooth insulating portions 261. The lower magnetic pole tooth insulating portion 261 has an axially projecting plate portion 2611 at its radially inner end. The plate portion 2611 is a plate-like wall extending in the circumferential direction. The plate portion 2611 radially faces the inner end of the coil 24. The lower core back insulating portion 262 has a core back insulating protruding portion 2621 which protrudes in a direction away from the surface covering the core back 231 in the axial direction. The lower core back insulating protrusion 2621 is provided to be a wall in the circumferential direction.

  The lower core back insulating protrusion 2621 has a notch 2622, a coil guide wall 2623, a connecting wire guide wall 2624, a continuous wall 2625, and a connecting wire holding portion 2626. The notch portion 2622 points to a portion where the lower core back insulating protrusion portion 2621 continuously cuts in the circumferential direction to be a wall. In the present embodiment, portions in which the lower core back insulating protruding portion 2621 is continuous in the circumferential direction and which is a wall are the coil guide wall 2623, the connecting wire guide wall 2624, and the continuous wall 2625. The notched portion 2622 is provided in the lower core back insulating protruding portion 2621 at a position radially opposed to the lower magnetic pole tooth insulating portion. Coil guide walls 2623 are disposed at both circumferential ends of the notch 2622. The circumferential width of the notch 2622 is set to be narrower than the circumferential width of the magnetic pole teeth 232 on which the conducting wire is wound. In other words, the lower core back insulating protruding portion 2621 is continuously formed at the location excluding the notch 2622. Thereby, the rigidity of the lower insulator 26 can be improved.

The coil guide wall 2623 is located radially outward of the magnetic pole tooth insulating portion 261. The coil guide wall 2623 is located radially inward of a crossover wire guide wall 2624 described later. The radially inner surface of the coil guide wall 2623 is opposed to the radially outer side of a coil 24 configured by winding a wire around the magnetic pole teeth 232. Preferably, the radially inner surface of the coil guide wall 2623 is in contact with the radially outer side with the coil 24. The coil 24 has a plurality of lead wires wound around the pole teeth 232. That is, it is necessary to prevent the winding collapse with an insulator or another member so as to prevent the winding of the multiple conductive wires. By providing the coil guide wall 2623, the radially outward winding collapse of the coil 24 is prevented.
The crossover guide wall 2624 is connected to the coil guide wall 2623 and integrally provided. That is, the coil guide wall 2623 and the crossover guide wall 2624 are provided to be connected via the continuous wall 2625. By connecting the coil guide wall 2623 and the crossover wire guide wall 2624 with the continuous wall 2625, the rigidity of the coil guide wall 2623 is enhanced. As a result, even if the lead is wound and tension is applied to the core back insulating protruding portion 2621, the core back insulating protruding portion 2621 can be prevented from falling down. Coil guide wall 2623 is located radially inward of crossover wire guide wall 2624. The radial thickness of the crossover guide wall 2624 is smaller than the radial thickness of the coil guide wall 2623.

  The crossover guide wall 2624 is a wall-like portion for guiding the crossover derived from the coil 2623. The crossover guide wall 2624 protrudes in a direction away from the surface covering the core back in the axial direction. A crossover holding portion 2626 is provided radially inward of the crossover guiding wall 2624. The crossover holding portion 2626 supports the crossover on the radial outer surface. The inner wall of the crossover guide wall 2624 and the crossover holding portion 2626 face in the radial direction. A conductor, which is a crossover, is disposed and guided between the crossover guide wall 2624 and the crossover holding portion 2626. In the crossover holding portion 2626, a slope is provided on the outer surface in the axial direction upper end. This is because when the lead wire, which is a crossover wire, is inserted between the crossover wire guide wall 2624 and the crossover wire holding portion 2626, the wire is guided by the slope, and the workability can be improved. Further, in the present embodiment, the crossovers are concentrated on the lower bracket 22 side. Therefore, a crossover is not formed on the upper bracket 21 side where the circuit board 27 is disposed. As a result, it is not necessary to consider crossovers in the arrangement of the wiring patterns of the circuit board 27, and the degree of freedom in circuit design is improved.

  The crossover guide wall 2624 has inclined portions 2628 whose axial height gradually decreases from both ends in the circumferential direction toward the center in the circumferential direction. The central portion 2629 located at the circumferential center of the crossover guide wall 2624 has a lower axial position than the inclined portion 2628. That is, the upper end of a portion (central portion 2629) radially facing the crossover holding portion 2626 of the crossover guiding wall 2624 has a lower position in the axial direction than the upper end of the crossover holding portion 2626. By this configuration, when winding the winding, the nozzle of the winding machine can be inserted to the back. As a result, the crossover can be reliably hooked to the crossover holding portion 2626. In addition, since the axial height of the central portion 2629 of the crossover guide wall 2624 is kept low, the axial height of the crossover holding portion 2626 can be made relatively low. Therefore, the moment load applied when the crossover is hooked to the winding holding portion 2626 can be reduced. As a result, it is possible to prevent the crossover holding portion 2626 from falling in the radial direction.

  The ratio of the width of the radial gap between the crossover guide wall 2624 and the crossover holding portion 2626 to the height of the crossover holding portion 2626 is preferably 1: 3 or less. This is because, in the present embodiment, the three-phase motor is used and three crossovers overlap. More preferably, one to four or less is desirable. This is because there is a possibility to further provide a crossover wire for adjusting the inductance, adjusting the extraction position of the winding, and the like. By setting in this manner, the crossover can be reliably held.

  Further, the axial height of the central portion 2629 of the crossover guide wall 2624 is lower than that of the coil guide wall 2623, the continuous wall 2625, and the crossover holding portion 2626. By this configuration, the axial thickness of the winding guide wall 2624 can be reduced. As a result, the lower insulator 26 can be thinned, and hence the motor can be thinned.

  The axial height of the crossover holding portion 2626 is lower than that of the coil guide wall 2623 and the continuous wall 2625. The axial height of the crossover holding portion 2626 is lower than the axial height of the plate portion 2611 of the lower insulator 26.

<5. About assembling the armature and the circuit board>
Next, an assembling process of the armature 29 and the circuit board 27 and the upper bracket 21 and the lower bracket 22 will be described. An assembly of the stator core 23, the coil 24, the upper insulator 25, and the lower insulator 26 is defined as an armature 29.

  First, the U, V, W, and common ends of the coil 24 are drawn radially outward from the window portions 2541 and 2255 of the upper insulator 25. Thus, even when the circuit board 27 is placed on the armature 29, the conducting wire is not pinched between the upper insulator 25 and the circuit board 27.

  Next, the circuit board 27 is placed on the bearing surface 2531 of the upper insulator 25 of the armature 29. At this time, the positioning convex portion 254 is inserted into the positioning portion 272 of the circuit board 27. Thereby, positioning of the circuit board 27 with respect to the armature 29 can be performed accurately. Thus, the magnetic sensor 271 mounted on the circuit board 27 can be accurately disposed. Further, the collar portion 255 is inserted into the collar portion insertion portion 274 of the circuit board 27. The collar portion 255 elastically deforms, and the portion 2551 contacts the upper surface of the circuit board 27 or axially opposes via a gap. Thereby, the axial movement of the circuit board 27 can be restricted with respect to the armature 29, and the circuit board 27 can be temporarily fixed.

  At this time, the circumferential positions of the window portions 2541 and 2552 and the buttocks insertion portion 274 coincide with each other. Preferably, the circumferential positions of the window portions 2541 and 2552 and the buttocks insertion wide portion 2742 coincide with each other. This improves the workability of the soldering described below.

  Next, the drawn out ends are soldered to lands located on the top surface of the circuit board 27. At this time, some of the lands are disposed adjacent to the buttocks insertion portion 274. Therefore, it can be soldered easily.

<3. Modified example>
Although the exemplary embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.

<3-1. Modification 1>
For example, FIG. 8 shows another embodiment of the present application. The following description will focus on differences from the above-described exemplary embodiments of the present invention. Referring to FIG. 8, lower bracket 22 </ b> A covers the outer peripheral surface of armature 29. More specifically, the axial length of the lower bracket 22A in the present embodiment is longer than the axial length of the stator core 23. Further, the axial length of the lower bracket 22A is longer than the total length of the upper insulator 25 and the lower insulator 26 in the axial direction. More specifically, the axial length of the lower protrusion 223A of the lower bracket 22A is longer than the total length of the upper insulator 25 and the lower insulator 26 in the axial direction. On the upper side of the lower projecting portion 223A of the lower bracket 22A, a caulking portion 224A for fixing an upper bracket 21A described later is formed. The upper bracket 21A has a substantially disc shape and does not have the upper projecting portion 213A. The upper bracket 21A is fixed to the lower bracket by plastic deformation of the caulking portion 224A. The casing may be formed in this manner.

  As described above, by covering the entire outside of the armature 29 with the casing, it is possible to suppress the vibration and noise generated inside the motor. In addition, it is possible to prevent dust from entering the inside of the motor.

<3-2. Modification 2>
For example, FIG. 9 shows another embodiment of the present application. Referring to FIG. 9, the lower holding portion 222B of the lower bracket 22B extends largely upward in the axial direction. The lower holding portion 222B holds the upper bearing 281B in addition to the lower bearing 282B. Further, in the present embodiment, there is no upper bracket, and the circuit board 27 is exposed. However, instead of the upper bracket, it is possible to arrange a member that covers the substrate.

  Further, as still another embodiment of the present application, as shown in FIG. 10, the lower bracket 22C may be provided by two members of an inner lower bracket 22C1 and an outer lower bracket 22C2.

<3-3. Modification 3>
For example, FIG. 11 is a diagram showing another embodiment of the present application. Referring to FIG. 11, in the present embodiment, upper bracket 21D and lower bracket 22D are fixed to armature 29D by fixing member 61D. First, the outer peripheral surface of the circuit board 27D is provided with a notch which is recessed inward in the radial direction from the outer periphery. This notch is a fixing member insertion portion 275D. The fixing member insertion portion 275D has a surface corresponding to a projected shape in a plan view of the screw portion of the fixing member (screw 61D). In the present embodiment, the upper bracket 21D and the lower bracket 22D are molded by die casting. Therefore, in the present embodiment, the opening 228 does not have to be a through hole. Therefore, even if the cover member 71 is omitted, the risk of dust entering the inside of the motor is small.

  The upper bracket 21D has a through hole 214D. A plurality of through holes 214D are circumferentially arranged at the radially outer side on the lid portion 211D. In the present embodiment, the number of through holes 214D is three. Screws 61D are inserted into the respective through holes 214D. A seating surface 2141D is disposed around the through hole 214D. The seat surface 2141D is located axially lower than the lid portion 211D. The head of the screw 61D comes in contact with the bearing surface 2141D. In other words, the screw 61D has a lower surface in contact with the upper surface of the upper bracket 21D. Thus, even when the screw 61D is inserted, the screw 61D can be prevented from protruding upward in the axial direction from the lid portion 211D. Thereby, the motor 1D can be thinned. The diameter of the screw portion of the screw 61D is the same as or slightly smaller than the diameter of the through hole 214D. Thereby, after screw 61D is inserted, movement of upper bracket 21D in the circumferential direction with respect to armature 29D is suppressed. Therefore, the upper bracket 21D and the armature 29D can be fixed firmly. The fixing member 61D may be a rivet. Also, a ground pattern may be formed at the edge of the fixing portion insertion portion 275D of the circuit board 27D. Thereby, it becomes possible to take a ground between the ground pattern of the circuit board 27D and the upper bracket 21D by the screw 61D.

  The upper insulator 25D is provided with a fixing member insertion recess 256D. The fixing member insertion recess 256D is a recess which is recessed inward in the radial direction from the outer edge of the core back insulating portion 252D. The screw 61D is inserted into the fixing member insertion recess 256D. The fixing member insertion recess 256D may not be a recess that is recessed inward in the radial direction, but may be a hole that opens upward in the axial direction.

  The lower bracket 22D has a lower fixing member accommodating portion 224D. A plurality of lower fixing member accommodating portions 224D are disposed circumferentially on the radially outer side on the lower cover portion 221D. In the present embodiment, the number of lower fixing member accommodating portions 224D is three. The arrangement of the lower fixing member accommodating portion 224D coincides with the circumferential position of the through hole 214D of the upper bracket. A screw 61D is inserted into each lower fixing member accommodating portion 224D. In the present embodiment, the lower fixing member accommodating portion 224D is a bag-like hole and is not penetrated but may be a through hole.

  The shape of the lower insulator 26 in the present embodiment is the same as that shown in FIGS. 5 and 6. With reference to FIGS. 6 and 7, the notch 2622 of the lower core back insulating protrusion 2621 in the present embodiment is a portion of the lower core back insulating protrusion 2621 facing the lower magnetic pole tooth insulating portion in the radial direction. Provided. The fixing member disposition portion 44D and the screw 61D of the stator core 23 are located radially outward of the notch portion 2622. That is, the notch portion 2622 radially faces the screw 61D. In other words, in the lower core back insulating projecting portion 2621, a portion facing the screw 61D in the radial direction is the cutout portion 2622 which is notched.

  The coil guide wall 2623 is located radially outward of the magnetic pole tooth insulating portion 261. The radially inner surface of the coil guide wall 2623 is in contact with the radially outer side of a coil 24D configured by winding a wire around the magnetic pole teeth 232D. The coil 24D has multiple lead wires wound around the pole teeth 232D. That is, it is necessary to prevent the winding collapse with an insulator or another member so as to prevent the winding of the multiple conductive wires. In particular, in the present embodiment, the fixing member disposition portion 44D and the screw 61D are located radially outward of the coil 24D. If the coil 24D collapses, the fixing member placement portion 44D and the coil 24D may overlap in plan view when the motor is assembled. That is, in this case, the screw 61D can not be inserted into the fixing member disposition portion 44D. When the coil 24D is broken due to a change in fixation after the screw 61D is inserted into the fixing member disposition portion 44D, there is a possibility that the coil 61D may come into contact with the screw 61D. When the screw 61D is formed of a conductor, the dielectric strength can not be maintained. By providing the coil guide wall 2623, the radially outward winding collapse of the coil 24 is prevented.

  A screw 61D is inserted into the fixing member disposition portion 44D to fix the upper bracket 21D, the armature 29D, and the lower bracket 22D. The radially inner end of the fixing member disposition portion 44D is located radially inward of the outer surface of the coil guide wall 2623D. The radially inner end of the fixing member disposition portion 44D is located radially outward of the inner surface of the coil guide wall 2623. Core back insulating portion 262D has a recess 2627. The recess 2627 is located at the periphery of the fixing member disposition portion 44D and is recessed radially inward. In other words, the recess 2627 is recessed radially inward along the peripheral edge of the fixing member placement portion 44D. The lower insulator 26D and the stator core 23D are molded in a state having a certain dimensional tolerance because they are mass-produced products. Therefore, when the two are combined, by providing the recess 2627, it is possible to prevent the lower core back insulating portion 262D and the fixing member disposition portion 44D from overlapping in a plan view. That is, when the screw 61D is inserted into the fixing member disposition portion 44D, the screw 61D can be prevented from contacting the lower insulator 26D. The radially inner end of the recess 2627 is located radially outward of the inner surface of the coil guide wall 2623. As a result, since the coil 24D is accommodated radially inward of the inner surface of the coil guide wall 2623, the coil 24D and the stator core 23D can be reliably insulated.

<3-4. Modification of cover member>
Moreover, FIG. 12 is a figure which showed the modification of the cover member which can be applied to the said embodiment. Referring to FIG. 12, the cover member 71E has an annular portion 714E, an outer peripheral portion 715E, and accommodation portions 716E and 717E. The cover member 71E in the present embodiment is made of resin. However, the cover member 71E may be made of rubber. The annular portion 714E has a doughnut-like disc shape, and connects the housing portions 716E and 717E. The outer circumferential portion 715E is located radially outward of the annular portion 714E. The outer peripheral portion 715E has a cylindrical shape. The cover member 71E in the present embodiment is press-fit and fixed to the projection 223 of the lower bracket 22.

  The housing portions 716E and 717E each have a bottomed cylindrical shape. The circumferential positions of the housing portions 716 E and 717 E coincide with the circumferential positions of the openings 228 of the lower bracket 22. In the present embodiment, the housing portions 716E and 717E are arranged point-symmetrically at three locations in the circumferential direction. Further, the radial position of each accommodation portion 716 E, 717 E coincides with the radial position of each opening 228 of the lower bracket 22. The respective accommodating portions 716 E and 717 E are opened toward the respective openings 228. Thus, when the screw is inserted into the opening 228, each housing portion 716E, 717E can accommodate the screw. Therefore, it is possible to prevent dust from entering the inside of the motor. Here, the circumferential positions of the accommodation portions 716E and 717E are located between the adjacent magnetic pole teeth 232 of the stator core 23, respectively. Further, the axial position of the bottom of the housing portions 716E and 717E is located closer to the stator core 23 than the axial position of the annular portion 714E. By this configuration, the screw inserted into the opening 228 can be elongated.

<3-5. Other Modifications>
In this embodiment, although it used for the three-phase brushless motor, it is not restricted to this. It may be a single-phase or two-phase brushless motor. In addition, a brushed motor having a brush and a commutator may be used. Also, it may be used for other types of motors such as stepping motors.

  In the present embodiment, although the protrusion is annular, it is not limited to this. Other shapes, such as flat plate shape, may be sufficient.

  Further, in the present embodiment, although the upper bearing is positioned radially inward of the central opening, the shape of the upper bracket 21 is not limited to this.

  Further, the rotating object may be fixed to either the upper side or the lower side of the shaft 31, or may be fixed to both. Also, the upper insulator 25 and the lower insulator 26 may be disposed in the opposite direction.

  In addition, each element appearing in the above-described embodiment and modification may be combined appropriately as long as no contradiction occurs.

  The present invention can be used for an inner rotor type motor.

DESCRIPTION OF SYMBOLS 1 motor 2 stationary portion 21 upper bracket 211 lid 212 holding portion 2121 inner circumferential surface 2122 top surface 213 protrusion 214 through hole 2141 seat surface 215 opening 216 protrusion 228 opening 23 stator core 231 core back 232 core tooth 233 through hole 234 Vertical groove 24 Coil 25 Upper insulator 251 Magnetic pole tooth insulating portion 252 Core back insulating portion 253 Annular wall portion 2531 Bearing surface 254 Positioning convex portion 2541 Window portion 255 (first) Window portion 2552 (second) Window portion 256 Fixing member Insertion recess 26 Lower insulator 261 Lower magnetic pole tooth insulating portion 2611 Plate portion 262 Lower core back insulating portion 2621 Lower core back insulating protrusion portion 2623 Coil guide wall 2624 Crossing wire guide wall 2625 Continuous wall 2626 Crossing wire holding portion 2628 Sloped portion 2629 Central portion 27 circuit board 271 magnetic cell Sa 272 positioning unit 273 Connector 274 hook insertion part 275 fixing member insertion portion 276 central opening 28 the bearing portion 281 above the bearing 282 lower bearing 29 armature 31 shaft 32 rotor holder 321 central 322 tubular portion 33 the rotor magnet 71 the cover member

Claims (9)

A shaft rotatably supported by a bearing member about a vertically extending central axis;
A rotor magnet that rotates with the shaft;
An armature positioned radially outward of the rotor magnet;
An upper bearing for rotatably supporting the shaft at a radial center and a casing for holding the lower bearing, the armature being fixed;
Have
The armature is
A stator core including an annular core back and a plurality of pole teeth projecting radially inward from the core back;
An insulator covering at least the upper and lower surfaces of the magnetic pole teeth of the stator core;
A coil configured by winding a conductive wire around the magnetic pole teeth through the insulator;
Have
The casing has an opening that is an axially penetrating hole at an axial end surface,
A cover member disposed at a position facing the opening between the casing and the armature;
An upper surface of the cover member is in contact with at least a part of the armature. The upper surface of the cover member contacts the coil,
The motor according to claim 1, wherein the cover member is formed of an elastic body. The casing has an upper bracket for holding an upper bearing and a lower bracket for holding a lower bearing.
The lower bracket is
A substantially annular flat lower lid;
A substantially cylindrical lower projection which projects axially upward from the radially outer side of the lower lid;
Have
The motor according to claim 1, wherein an outer peripheral surface of the cover member is fixed to an inner peripheral surface of the lower protrusion. The casing has an upper bracket for holding an upper bearing and a lower bracket for holding a lower bearing.
The lower bracket is
A substantially annular flat lower lid;
A substantially cylindrical lower projection which projects axially upward from the radially outer side of the lower lid;
Have
The cover member is
A collar extending axially downward at a radially inner side of the opening;
A thick-walled portion having a thick axial thickness on the radially outer side of the opening;
A skirt portion which is located radially outward of the thick portion and which is thinner in axial direction than the thick portion;
Have
The motor according to any one of claims 1 to 3, wherein the collar is in contact with the lower lid.   The motor according to claim 4, wherein a part of the inner circumferential surface of the collar has an inclined portion whose axial height decreases as it goes inward in the radial direction.   The motor according to claim 4, wherein the cover member is inserted into an inner circumferential surface of the lower protrusion at the skirt.   The cover member according to any one of claims 1 to 6, wherein the cover member has a plurality of accommodating portions having a cylindrical shape with a bottom, which is aligned with the radial and circumferential positions of the opening and opens toward the opening. The motor according to item 1 or 2. The cover member has a disk shape, and further includes an annular portion connecting a plurality of the housing portions,
The circumferential position of the housing portion is located between the adjacent magnetic pole teeth of the stator core,
The motor according to claim 7, wherein an axial position of a bottom of the housing portion is located closer to the stator core than an axial position of the annular portion. The motor according to any one of claims 1 to 8, wherein a thread groove is formed on an inner circumferential surface of the opening.

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