JP2010035354A - Electric motor and disk drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor equipped with an armature core which can adjust the natural frequency of the teeth portions, without modifying the width of the tooth where a conductor is wound or the surface facing the rotor magnet significantly, and to provide a disk drive unit which has this electric motor mounted. <P>SOLUTION: The armature core 321 in the armature 32 of an electric motor 10 comprises a core back portion 3211 and a tooth 3212. A hole 3213 is provided at a portion which connects the core back portion 3211 and the tooth 3212. A plurality of holes 3213 are separated apart from each other in the circumferential direction, and the adjacent holes 3213 have various differing shapes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thin motor and a disk drive using the same.

  2. Description of the Related Art Conventionally, along with the thinning of a disk drive device that records and reproduces an optical disk such as a DVD, there is an increasing demand for thinning a motor having a mounting portion for mounting the disk. In order to reduce the thickness of a motor, it is necessary to reduce the thickness of a stator that is a component constituting the motor and generates a magnetic field (see, for example, Patent Document 1 as an example of such a conventional thin motor).

JP 2006-129633 A

  The stator includes a stator core and a coil formed by winding a conductive wire around the stator core. When the stator core is thinned, the rigidity of a plurality of teeth portions around which the conductive wires of the stator core are wound is lowered. Moreover, since the teeth part receives reaction of the rotor magnet which comprises a magnetic circuit with a stator, it is easy to vibrate. In particular, when the natural frequencies of the teeth portions are the same, the vibrations of the teeth portions resonate, resulting in a problem that the vibrations of the stator increase. In particular, when only the vibration of the tooth portion resonates, the sound due to the vibration of the tooth portion is perceived as an annoying sound with respect to the sound due to other vibrations.

  In order to solve this problem, it is conceivable to greatly change the width around which the conductive wire of the tooth portion is wound or the surface facing the rotor magnet. However, if the width of the tooth portion is changed, the winding machine for winding the conductive wire around the tooth portion is an expensive type having a control device that can change the winding diameter of the winding nozzle for each tooth portion. Will be necessary. In addition, when the surface facing the rotor magnet is greatly changed, there arises a problem that the cogging torque of the motor increases.

  Accordingly, the present invention has been made in view of the above problems, and the object of the present invention is to make the teeth without greatly changing the width of the portion around which the conductive wire of the teeth is wound or the surface facing the rotor magnet. It is to provide a motor having a stator core capable of adjusting the natural frequency of a part and a disk drive device on which the motor is mounted.

According to the motor of the present invention,
A rotating body having a rotor magnet that rotates about a central axis, and a stationary body having a stator that faces the rotor magnet with a gap therebetween,
The stator is formed by laminating a plurality of magnetic core plates, and includes an annular core back portion and a plurality of teeth portions extending from the core back portion in the radial direction and spaced apart in the circumferential direction. A stator core, and a coil formed by winding a conductive wire around each tooth portion of the stator core,
At least one of the teeth portions in the stator core is provided with a hole in order to make the natural frequency of the teeth portion different from other teeth portions.

  According to the present invention, holes are formed in a plurality of teeth portions to change the rigidity of the teeth portions, and the natural frequencies of the teeth portions are made different from those of other teeth portions, so that all the teeth portions resonate at the same time. Can be prevented. Therefore, it is possible to reduce the vibration of the motor accompanying the vibration of the stator core and the noise resulting from this vibration.

  Further, by providing a hole in the tooth portion, the natural frequency can be easily adjusted by individually changing the longitudinal rigidity of the tooth portion. Therefore, the natural frequency of the entire teeth portion can be easily adjusted.

  In the motor of the present invention, among the plurality of teeth portions, at least two teeth portions provided with the holes are provided, and the shape, size, position, and number of the holes provided in the teeth portions are specified. Of these, at least one can be different.

  According to the present invention, the natural frequency of each of the teeth portions can be varied by varying at least one of the hole shape, size, position, and number of the teeth portions.

  In the motor, it is preferable that the holes are provided in all of the plurality of tooth portions, and at least one of the specifications of the shape, size, position, and number of the holes of the tooth portions is different from each other.

  According to the present invention, since the natural frequencies of all the tooth portions are different, resonance of vibrations of the tooth portions can be reliably prevented.

  In the motor of the present invention, the holes may be provided in at least two of the plurality of teeth portions, and the radial lengths of the holes may be different from each other.

  According to the present invention, the natural frequency of the teeth portion can be changed by changing the radial lengths of the holes respectively provided in the at least two teeth portions. Therefore, the natural frequency of the tooth portion can be changed without forming a large hole, and the magnetic flux can be efficiently passed through the tooth portion. As a result, it is possible to provide a motor with high magnetic efficiency while reducing vibration and noise caused by the vibration.

  In the motor of the present invention, the shape of the surface of the teeth portion facing the rotor magnet and the shape of the portion around which the conductive wire forming the coil is wound can be made equal.

  According to the present invention, since the shape of the surface of the teeth portion facing the rotor magnet is equal, the radial excitation force acting on the surface side by the rotor magnet and this surface can be made uniform in the circumferential direction. The cogging torque can be reduced. In addition, since the shape of the portion around which the conductive wire of the tooth portion is wound is equal, the coil can be formed by an inexpensive winding machine.

  In the motor of the present invention, the coils formed in the teeth portion of the stator are three-phase, and coils of different phases are arranged in each tooth portion adjacent in the circumferential direction. At least two teeth portions adjacent to each other in the circumferential direction may be smaller in size than the other teeth portions or may not be formed.

  Alternatively, according to the present invention, the coils formed in the teeth portion of the stator have three phases, and coils of different phases are arranged in each of the teeth portions adjacent in the circumferential direction, and the plurality of teeth portions Of these, at least two teeth portions adjacent to each other in the circumferential direction may have different lengths in the axial direction of the holes compared to other teeth portions.

  According to the present invention, by reducing the size of the holes provided in at least two teeth portions adjacent to each other in the circumferential direction, or by not providing the holes, or by reducing the size of the holes in the axial direction. These teeth portions can make a magnetic flux easier to flow than other teeth portions. Therefore, the rotor magnet is strongly attracted by these tooth portions, and a lateral pressure can be applied to the rotating body.

  According to the disk drive device of the present invention, the chuck is provided with the above-described motor, and a disc-shaped disk having a mounting hole in the center is detachably mounted on the rotating body of the motor, and the disk is mounted. And a mounting portion.

  Furthermore, the disk drive device of the present invention is characterized by comprising an optical pickup mechanism that optically reads and writes information from and to the disk, and a moving mechanism that allows the optical pickup mechanism to move.

  According to the present invention, by reducing the vibration of the motor, it is possible to prevent a recording and reproduction error with respect to the disk and to provide a highly reliable disk drive device.

  According to the present invention, a motor including a stator core capable of adjusting the natural frequency of the tooth portion without greatly changing the width around which the conductive wire of the tooth portion is wound or the surface facing the rotor magnet, and the motor Can be provided.

<Overall structure of motor>
The overall structure of the motor 10 of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view of the motor 10 of the present invention, taken along a plane including the central axis J1 along the central axis J1. FIG. 2 is a plan view of the motor 10 of the present invention as viewed from the upper side in the axial direction. The motor 10 of the present invention is a three-phase brushless motor. Hereinafter, along the central axis J1, the rotating body 20 side is defined as the upper side in the axial direction, and the stationary body 30 side is defined as the lower side in the axial direction. The central axis J1 does not necessarily coincide with the direction of gravity.

  The motor 10 includes a rotating body 20 having a rotor magnet 22 that rotates about a central axis J1, a stationary body 30 having a stator 32 that faces the rotor magnet 22 via a gap in the radial direction, and the rotating body 20 as a stationary body. And a bearing mechanism 40 that is rotatably supported with respect to 30.

  The rotating body 20 includes a shaft 21 arranged coaxially with the central axis J1, a covered cylindrical rotor holder 23 fixed to the shaft 21, a cylindrical rotor magnet 22 held on the inner surface of the cylindrical portion of the rotor holder 23, A chucking device 24 disposed on the upper surface side of the lid portion of the rotor holder 23. The upper end portion of the shaft 21 is fixed to the center portion of the lid portion of the rotor holder 23.

  The chucking device 24 includes a center case 241 that is coaxially fixed to the rotor holder 23, a plurality of chuck claws 242 that are partly accommodated in the center case 241 and hold a disk (not shown), and the chuck claws 242 in the radial direction. It comprises an elastic member 243 that biases outward, and a mounting portion 244 that is provided on the rotor holder 23 and on which the lower surface of the disk is mounted. As shown in FIG. 2, three chuck claws 242 and three elastic members 243 are provided. Further, the mounting portion 244 of the present embodiment is formed of an annular rubber member for the purpose of preventing slippage in the disk mounting portion 244. The center case 241 is integrally provided with a plurality of centering claws 2411 that are spaced apart in the circumferential direction. The aligning claw 2411 plays a role of making the center of the center mounting hole (not shown) of the disc coincide with the center of the center case 241. In the present embodiment, three alignment claws 2411 are provided.

  The stationary body 30 includes a stator 32, a housing 31 having a holding cylindrical portion 311 and a bottom portion 312 that hold the stator 32, and a substantially flat mounting plate that is disposed axially below the stator 32 of the holding cylindrical portion 311. 33 and a circuit board 34 attached to the upper surface of the attachment plate 33. In addition, the housing 31 of the present embodiment is configured by a separate member from the holding cylindrical portion 311 and the bottom portion 312.

  The bearing mechanism 40 includes a first bearing portion 41 held on the inner peripheral surface of the holding cylindrical portion 311 of the housing 31 and a second bearing portion 42 disposed on the upper surface of the bottom portion 312. The first bearing portion 41 has a cylindrical shape having a through hole into which the shaft 21 is inserted. The first bearing portion 41 is made of an oil-containing sintered material. The 2nd bearing part 42 is comprised from the resin material excellent in the slidability of the substantially disc shape.

<Structure of stator>
Next, the configuration of the stator 32 of the present invention will be described with reference to FIGS. FIG. 3 is a schematic plan view of the stator 32 of the present invention as viewed from the upper side in the axial direction. FIG. 4 is a diagram in which the coil 322 is removed from the stator 32 of FIG. 3.

  Referring to FIG. 3, the stator 32 is formed by winding a plurality of core plates, which are thin plates made of a magnetic material, in the axial direction, and winding a plurality of conductive wires around the stator core 321. A plurality of coils 322. The stator core 321 of the present embodiment is formed by stacking six core plates.

  The stator core 321 includes an annular core back portion 3211 having a center concentric with the central axis J1 and a plurality of teeth portions 3212 extending radially outward from the core back portion 3211. The teeth portions 3212 are arranged at equal intervals in the circumferential direction (in the present embodiment, twelve teeth portions 3212 are provided).

  Each of the tooth portions 3212 is formed with a coil 322 by winding a conductive wire (in this embodiment, 12 coils 322 are provided). In this embodiment, each coil 322 is constituted by three conductive wires of U phase, V phase, and W phase (one conductive wire for each phase). And these three conductive lines comprise one neutral point 322c by star-connecting the edge part of these conductive lines. As shown in FIG. 3, the coil 322 includes a U-phase coil 322u, a V-phase coil 322v, and a W-phase coil 322w. Each phase coil 322u, 322v, 322w is composed of one conductive wire. Moreover, the coils 322u, 322v, and 322w of each phase are configured in the order shown in FIG. Ends of the phase coils 322u, 322v, 322w and the neutral point 322c are connected to the circuit board 34 (see FIGS. 1 and 2), respectively.

  Referring to FIG. 4, holes 3213 a to 3213 k are provided in a portion where stator core 321 is connected with core back portion 3211 and teeth portion 3212. Here, when a specific hole is not designated, or when the entire hole is comprehensively expressed, “hole 3213” is set. Moreover, the hole 3213 is comprised by the substantially elliptical shape extended to radial direction. Further, one of the teeth portions 3212 is not provided with a hole.

  The teeth portion 3212 includes a base portion 3214 extending in the radial direction from the core back portion 3211 and a surface facing the rotor magnet 22 (see FIG. 1) in the radial direction on the outer surface, and extends from the base portion 3214 to both sides in the circumferential direction. And an umbrella part 3215. Here, the width W1 of the base portion 3214 of each tooth portion 3212 is equal. And the shape of the umbrella part 3215 of each teeth part 3212 is respectively equal. The hole 3213 is provided at the center of the base portion 3214 of the teeth portion 3212. The central portion of the base portion 3214 is a region where a small amount of magnetic flux passes when the teeth portion 3212 and the rotor magnet 22 form a magnetic circuit. Therefore, by providing the hole 3213 in the central portion of the base portion 3214, the influence on the magnetic efficiency of the motor can be reduced.

  Since the shape of each umbrella part 3215 in each teeth part 3212 is formed equally, the magnetic characteristics of the motor can be kept uniform in the circumferential direction. Therefore, the vibration of the motor due to the cogging torque can be reduced. Further, since the width W1 of the base portion 3214 is equal in each tooth portion 3212, the winding machine (not shown) can be changed from an expensive type having a control device to an inexpensive type not having a control device. Therefore, the stator 31 can be manufactured at a low cost.

  In the stator core 321 of this embodiment, holes 3213 are arranged symmetrically with respect to the line AA (see FIG. 4). In other words, the holes 3213b and 3213k, the holes 3213c and 3213j, the holes 3213d and 3213i, the holes 3213e and 3213h, the holes 3213f and the holes 3213g are formed in the same shape. Here, when the natural frequency of the teeth portion 3212 is substantially the same value for all the teeth portions 3212, when the teeth portions 3212 vibrate, the vibrations of the teeth portions 3212 overlap. Therefore, the noise resulting from the vibration of the teeth part 3212 increases. However, by providing each of the holes 3213 in the stator core 321, the natural frequency of the teeth portion 3212 can be changed. Therefore, it can reduce that the vibration of the teeth part 3212 overlaps. As a result, it is possible to reduce noise due to the vibration of the tooth portion 3212. In particular, when the motor 10 is started, the vibration of the tooth portion 3212 becomes large, which is effective in reducing noise when the motor 10 is started.

  By arranging the shape of the hole 3213 symmetrically with respect to the line AA, at least the shapes of the holes 3213 of the six teeth portions 3212 are different. Therefore, the shape of each hole 3213 can be largely changed as compared with the case where all the shapes of the holes 3213 of the twelve teeth portions 3212 are changed. Thereby, the natural frequency of the teeth part 3212 can be changed greatly. Therefore, the overlapping of vibrations of the teeth portion 3212 can be significantly suppressed, and noise resulting from the vibration of the teeth portion 3212 can be reduced.

  3 and 4, only the teeth portion 3212 in which the U-phase coil 322u is formed has the same shape by arranging the holes 3213 symmetrically with respect to the line AA. Although it has the hole 3213d and the hole 3213i, the teeth part 3212 in which the coil 322 of the other phase is formed does not have the hole 3213 having the same shape. Therefore, since the natural frequencies of the teeth portion 3212 that vibrate simultaneously differ except for one set, the overlapping of vibrations of the teeth portion 3212 can be more reliably reduced.

  In particular, when the motor 10 is driven, when the U-phase / W-phase energization is performed, the first set of the tooth portion 3212 having the hole 3213b and the tooth portion 3212 having the hole 3213k, and the tooth portion 3212 having the hole 3213f and the hole 3213h The second pair with the teeth portion 3212 having the same vibrates simultaneously. However, since the first set and the second set of teeth 3212 have different natural frequencies, only one set of teeth 3212 having the same natural frequency vibrates at the same time when the U-phase and W-phase are energized. is there. Similarly, when the V-phase-W-phase energization and the V-phase-U-phase energization, the pair of the tooth portion 3212 having the hole 3213d and the tooth portion 3212 having the hole 3213i only vibrates simultaneously. Therefore, even when the motor 10 is driven, the vibrations of only one pair of the teeth portions 3212 only overlap, so that the vibrations of the teeth portions 3212 can be greatly reduced. That is, in the stator core 321 of the present embodiment, the natural frequency of each tooth portion 3212 is greatly changed except for one set while the natural frequency of each tooth portion 3212 is greatly changed. The overlap of vibration can be greatly reduced. Therefore, it is possible to provide a motor in which noise caused by vibration of the tooth portion 3212 is significantly reduced.

<Second Embodiment of Stator>
Next, a second embodiment of the stator will be described with reference to FIGS. FIG. 5 is a schematic plan view of the stator core 321a of the stator according to the second embodiment of the present invention as seen from the upper side in the axial direction. FIG. 6 is a schematic cross-sectional view showing a cross section of the base portion 3214 of each tooth portion 3212a. Hereinafter, the same reference numerals are used for the same parts as those of the stator 32 according to the first embodiment of the stator, and the description thereof is omitted. In addition, in the same part, parts having different shapes are denoted by the symbol “a”. However, the reference numeral “l” is attached to the holes. Further, “T1” to “T12” are given to the respective tooth portions 3212a.

  Referring to FIGS. 5 and 6, in stator core 321 a, the axial length of hole 3213 l is different in each tooth portion 3212 a. The shape of the hole 3213l is also different from the shape of the hole 3213 of the stator 31. Other than that, it is the same shape as the stator 32.

  The stator core 321a has a core plate in which holes 3213l are provided in all of the teeth portions 3212a as a plurality of stacked core plates, and a portion 3212a of the teeth portions 3212a is not provided with holes 3213l. And a core plate. Therefore, the axial length of the hole 3213l in the predetermined tooth portion 3212a is determined by the number of stacked core plates provided with the hole 3213l on the predetermined tooth portion 3212a. Further, the shape of the hole 3213l may be only one type. The length of the hole 3213l in the axial direction is provided to be symmetric with respect to the line BB. That is, as shown in FIG. 6 and FIG. 7, among the sections T1 to T12 of the tooth portion 3212a, the sets of T2 and T12, T3 and T11, T4 and T10, T5 and T9, T6 and T8 are holes, respectively. The axial lengths of 3213l are equal. Thereby, the natural frequency of each teeth part can be changed greatly similarly to the stator core 321 of the stator 32. Therefore, the stator core 321a has the same effect as the stator core 321.

<Side pressure>
Next, the side pressure generated in the stator will be described with reference to FIGS. 7 and 8 are the same as FIGS. 4 and 5, respectively. 7 and 8, T1 to T12 are given to the teeth portions 3212 and 3212a in the same manner as in FIG.

  7 and 8, in both stator cores 321 and 321a, teeth portion groups T5 to T9 (hereinafter referred to as a first group) in which magnetic flux easily flows in teeth portions 3212 and 3212a and teeth portion group in which magnetic flux does not easily flow. It can be divided into T1 to T3, T10 and T11 (hereinafter referred to as a second group). Thereby, the rotor magnet 22 (refer FIG. 1) is attracted | sucked magnetically strongly with respect to the 1st group side, and approaches this. As a result, the shaft 21 serving as the rotation axis moves to the second group side as shown in FIGS. 7 and 8 (see the dotted arrows in FIGS. 7 and 8). In particular, the rotor magnet 22 approaches T6 to T8 centering on T7 of the first group. Therefore, by providing the hole 3213, the vibration of the teeth portions 3212 and 3212a can be reduced and the shaft 21 can be moved in one direction. Thereby, it is possible to suppress the occurrence of swinging of the rotating body 20 caused by the radial gap between the shaft 21 and the first bearing portion 41. As a result, a motor with reduced vibration can be provided.

<Overall structure of disk drive>
One embodiment of the disk drive apparatus according to the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view taken along the axial direction showing an embodiment of the disk drive device of the present invention.

  Referring to FIG. 9, the disk drive device 50 aligns the disk 60 by inserting the chucking device 24 into the center mounting hole 61 of the disk-shaped disk 60, and the disk 60 is centered on the central axis J1. A spindle motor 51 that rotates, an optical pickup mechanism 52 that irradiates light to the disk 60 and receives reflected light from the disk 60, a moving mechanism 53 that moves the optical pickup mechanism 52 in the rotational radial direction of the disk 60, and these And a housing 54 for housing the housing.

  The spindle motor 51 and the optical pickup mechanism 52 are held by the chassis 55. When the chassis 55 moves at least in the axial direction, the mounting hole 61 of the disk 60 is mounted in the chucking device 24 of the spindle motor 51. In addition, an opening hole is formed in the chassis 55, and the optical pickup mechanism 52 is disposed inside the opening hole.

  The moving mechanism 53 includes a motor 531 having a gear on an output shaft, and a transmitted side gear 532 that transmits the rotational torque of the motor 531.

  The housing 54 is provided with a boundary plate 541 formed of a thin plate that separates the movement of the disk 60 and the moving mechanism 53. An opening hole 542 for inserting and removing the disk 60 is formed in the housing 54.

  The pickup mechanism 52 is provided, for example, perpendicular to the light emitting / receiving unit 521 that receives laser light that is emitted from or reflected from the disk 60 and the moving direction of the light emitting / receiving 521 in the rotational radial direction of the disk 60. And a moving unit 522 that moves the light emitting / receiving unit 521. The moving part 522 has a meshing part 522 a that meshes with the transmitted side gear 532. The light emitting / receiving unit 521 moves in the radial direction by meshing with the moving unit 522.

  When the gear portion 531a attached to the motor 531 and the transmitted side gear 532 are engaged with each other, the transmitted side gear 532 is rotated, and when the transmitted side gear 532 is engaged with the engaging portion 522a of the moving unit 522, the moving unit 522 is rotated. Move in the radial direction. The light emitting / receiving unit 521 moves in the rotational radial direction by the movement of the moving unit 522.

  By applying the brushless motor 10 of the present invention to the spindle motor 51 of the disk drive device 50, a highly reliable disk drive device that achieves low vibration and noise and prevents errors in recording and reproduction on the disk is provided. can do.

  Although the embodiment of the motor of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the claims.

  For example, in the stator core 321 of the present invention, the hole 3213 is not provided in one tooth portion 3212, but the present invention is not limited to this. You may make it the form by which a hole is provided with respect to all the teeth parts 3212. FIG.

  For example, the holes 3213 provided in the stator core 321 of the present invention are arranged symmetrically with respect to the line AA, but the present invention is not limited to this. Since it is only necessary to change the natural frequency of each tooth portion 3212, the shapes of the holes provided in each tooth portion may be all different.

  For example, in the stator core 321a of the above embodiment, the axial length of the hole 3213l is continuously changed, but the present invention is not limited to this. The length of the hole 3213l should just differ with respect to the predetermined teeth part 3212a. Therefore, the hole 3213l may be formed apart from the axial direction. Moreover, although the hole 3213l of this Embodiment was provided from the lower end surface side of the axial direction of the teeth part 3212a, this invention is not limited to this. For example, a hole 3213l may be provided in the central portion of the teeth portion 3212a in the axial direction. In this case, except for T1 of the teeth portion 3212a, the holes 3213l are not provided in both axial end surfaces of the teeth portion 3212a.

  Moreover, although the stator cores 321 and 321a mentioned above showed the case where the hole 3213 was provided in the teeth parts 3212 and 3212a except one teeth part 3212 and 3212a, this invention is not limited to this. There may be at least one teeth portion 3212 and 3212a having the holes 3213. Moreover, although the one hole 3213 was provided in each teeth part 3212 and 3212a, this invention is not limited to this. A plurality of holes may be provided.

Furthermore, the shape, size, and number of the holes 3213 provided in the teeth 3212 and 3212a of the stator cores 321 and 321a are not limited to the above. What is necessary is just to set so that it may become the shape of the hole 3213, a dimension, and the number which adjust each natural frequency of the teeth parts 3212 and 3212a.

It is the schematic cross section which cut the axial direction which showed the motor of this invention. It is the model top view seen from the axial direction upper side which showed the motor of this invention. It is the model top view seen from the axial direction upper side which showed the stator of this invention. It is the figure which showed the state which removed the coil from FIG. It is the model top view seen from the axial direction upper side which showed the stator core in the stator of the 2nd Embodiment of this invention. It is the schematic diagram which showed the cross section of the base part of each teeth part of this invention. It is the model top view seen from the axial direction upper side which showed the stator core of this invention. It is the model top view seen from the axial direction upper side which showed the stator core of the 2nd Embodiment of this invention. It is the schematic cross section which cut the axial direction which showed the disk drive device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motor 20 Rotating body 21 Shaft 22 Rotor magnet 24 Chucking device 244 Mounting part 30 Stationary body 32, 32a Stator 321, 321a Stator core 3211 Core back part 3212, 3212a Teeth part 3213 Holes 3213a to 3213l Hole 322 Coil 40 Bearing mechanism 41 First bearing portion 50 Disk drive device 52 Optical pickup mechanism 53 Moving mechanism J1 Center axis D Disk

Claims (9)

A motor,
A rotating body having a rotor magnet that rotates about a central axis;
A stationary body having a stator facing the rotor magnet via a gap;
With
The stator is
A stator core formed by laminating a plurality of magnetic core plates, and comprising a ring-shaped core back portion and a plurality of teeth portions extending in a radial direction from the core back portion and spaced apart in the circumferential direction; ,
A coil formed by winding a conductive wire around each tooth portion of the stator core;
With
At least one of the teeth portions in the stator core is provided with a hole in order to make the natural frequency of the teeth portion different from other teeth portions,
A motor characterized by Among the plurality of teeth portions, there are at least two teeth portions provided with the holes, and at least one of the specifications of the shape, size, position, and number of the holes provided in the teeth portions is Different,
The motor according to claim 1. The holes are provided in all of the plurality of tooth portions,
At least one of the specifications of the shape, size, position, and number of the holes of the teeth portions is different from each other;
The motor according to claim 2. Among the plurality of tooth portions, at least two of the tooth portions are provided with the holes, and the axial lengths of the holes are different from each other,
The motor according to any one of claims 1 to 3, wherein: The shape of the surface facing the rotor magnet in the plurality of teeth portions, and the shape of the portion around which the conductive wire forming the coil is wound are equal,
The motor according to any one of claims 1 to 3, wherein: The coils formed in the teeth portion of the stator are three-phase, and coils of different phases are arranged in adjacent teeth portions,
Among the plurality of tooth portions, at least two of the tooth portions adjacent to each other in the circumferential direction are smaller in size of the hole or formed with the hole as compared with the other tooth portions. Not,
The motor according to claim 1 or 2, characterized by the above-mentioned. The coils formed in the teeth portion of the stator are three-phase, and coils of different phases are arranged in adjacent teeth portions,
Among the plurality of tooth portions, at least one of the tooth portions has a different length in the axial direction of the hole compared to other tooth portions.
The motor according to claim 4. The rotating body has a chucking device that allows a disk-shaped disc having a mounting hole in the center to be attached and detached, and a placement portion on which the disc is placed,
The motor according to claim 1, wherein: A disk drive device on which the motor according to claim 8 is mounted,
An optical pickup mechanism for optically reading and writing information on the disc;
A movement mechanism that enables movement of the optical pickup mechanism;
Providing
A disk drive characterized by the above.

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