JP2000023403A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which can suppress sudden fluctuation in driving torque and hence can reduce the vibration caused by the rotation. SOLUTION: A motor has a magnet 30 applied to a rotor hub and a stator which is attached to a stationary member so as to face the magnet 30 and has a cylindrical stator 42 and a cylindrical coil unit 44. The cylindrical coil unit 44 has a coil 48 to which a drive current is applied. The coil 48 has axial line direction parts 52 and 54 which are extended in the rotation axis line direction of the rotor hub and circumferential line direction parts 56 and 58 which are extended in the rotation direction of the rotor hub. The axial line direction parts 52 and 54 have inclined parts 52a, 52b, 54a and 54b which are extended in the axial direction but inclined in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor in which a cylindrical coil is disposed on the surface of a cylindrical stator core in order to reduce cogging.

[0002]

2. Description of the Related Art In general, a spindle motor as an example of a motor is rotatably supported by a mounting bracket as a stationary member and a mounting bracket via bearing means.
A hub as a rotor. An annular magnet is mounted on the rotor, and a stator is mounted on the mounting bracket so as to face the magnet. The stator includes a stator core, and the stator core is provided with a plurality of teeth by forming slots at intervals in a circumferential direction, and a coil wire is wound around each tooth as required.

In such a spindle motor, since a slot is formed in the stator core, a detent torque is generated by a mutual magnetic action between the stator core and the magnet of the rotor. The detent torque is periodically and repeatedly generated by the rotation of the rotor, and causes problems such as mechanical vibration, rotation speed fluctuation, and rotation noise due to the detent torque.

In order to solve such a problem, there has been proposed a motor in which the detent torque is reduced (Japanese Patent Laid-Open No. Hei 8 (1996)).
-37763). In this motor, the stator is improved, and the stator includes a cylindrical stator core and a cylindrical coil body, and the coil body is disposed on the surface of the stator core. The coil body has a helical coil. The coil has an axial line extending in the rotation axis direction of the rotor and a circumferential line extending in the rotation circumferential direction of the rotor. The rotor is rotationally driven in a predetermined direction by the magnetic force generated by the current. In this motor, since there are no irregularities such as grooves on the surface of the stator core, substantially no detent torque is generated, and it is possible to reduce mechanical vibrations, fluctuations in rotation speed, rotation noise, and the like.

[0005]

However, in this improved motor, since the axial line portion of the coil extends substantially parallel to the rotation axis of the rotor, a current having a rectangular waveform is supplied as the drive current. When the drive current rises or falls, the drive torque fluctuates rapidly,
Vibration occurs due to the sudden torque fluctuation.

Further, the coil has an axial line portion that contributes to the driving torque and a circumferential line portion that does not substantially contribute to the driving torque, and the axial line portion and the circumferential line portion are the same cylindrical shape. Because it is located on the surface, the ratio of the length of the axial line portion of the coil to the axial length of the coil body is reduced,
In order to obtain a desired length of the axial line portion, the coil body becomes large, and the motor becomes large.

An object of the present invention is to provide a motor capable of suppressing a sudden change in driving torque and thereby reducing vibration during rotation.

Another object of the present invention is to provide a motor capable of increasing the effective torque of the axial line portion of the coil to increase the driving torque.

[0009]

SUMMARY OF THE INVENTION The present invention comprises a stationary member,
A stator rotatable relative to the stationary member, a magnet mounted on the rotor, and a stator mounted on the stationary member facing the magnet, wherein the stator has a cylindrical stator core. And a motor having a cylindrical coil body disposed on the surface of the stator core on the magnet side, wherein the cylindrical coil body has a coil through which a drive current flows, and the coil is
An axial line portion extending in the rotational axis direction of the rotor, and a circumferential line portion extending in the rotational direction of the rotor, wherein the axial line portion is inclined in a circumferential direction with respect to the axial direction. It is characterized by having.

According to the present invention, since the axial line portion of the coil in the cylindrical coil body has an inclined portion inclined in the circumferential direction with respect to the axial direction, a drive current having, for example, a rectangular waveform is applied to the coil. Even if the drive current is fed, the drive torque generated when the drive current is switched does not have a step shape, and it is possible to suppress a sudden change in the drive torque.

The present invention is also directed to the first aspect, wherein the axial line portion of the coil has a first inclined portion extending in a circumferential direction from a central portion to one end portion, and a first inclined portion extending from the central portion to the other end portion. And a second inclined portion extending inclining in the circumferential direction.
The inclined portion and the second inclined portion are arranged symmetrically with respect to an axis passing through the central portion and orthogonal to the axial direction.

According to the present invention, the first inclined portion and the second inclined portion are arranged symmetrically with respect to an axis passing through the center of the axial line portion of the coil and orthogonal to the axial direction. Therefore, this axial line portion is formed in a substantially rectangular shape or a substantially inverted rectangular shape, and the central portion and both ends thereof are shifted in the circumferential direction of the rotor. Therefore, for example, even when a drive current having a rectangular waveform is supplied, the drive torque generated at the time of switching the drive current is reduced without being stepped.

Further, the present invention is characterized in that the inclined portion of the axial line portion of the coil extends in a circumferential direction from one end to the other end of the axial line portion.

According to the present invention, since the axial line portion of the coil extends from one end to the other end while being inclined in the circumferential direction, the one end and the other end of the axial line portion are different from each other. It is shifted in the circumferential direction. Therefore, for example, even when a drive current having a rectangular waveform is supplied, the drive torque generated at the time of switching the drive current is reduced without being stepped.

Further, in the invention, it is preferable that the circumferential line portion of the coil is disposed axially outside of a surface facing the stator core and the magnet.

According to the present invention, the circumferential line portion of the coil is disposed axially outward of the opposing surfaces of the stator core and the magnet. The circumferential line portion of the coil does not substantially contribute to the generation of the driving torque. By arranging the circumferential line portion in this manner, the stator core and the magnet can be used without waste and the efficiency of the magnetic circuit can be increased. . Usually, the circumferential line portions of the coil are provided at both ends of the axial line portion, and this also includes configuring at least one of these circumferential line portions as described above.

Further, the present invention is characterized in that the circumferential line portion of the coil is bent in the radial direction with respect to the axial line portion and is disposed on the stator core side.

According to the present invention, since the circumferential line portion of the coil is bent and disposed on the stator core side, the axial length of the entire stator can be reduced, thereby reducing the entire motor. The size can be reduced. Normally, the circumferential shaft portions of the coil are provided at both ends of the axial line portion, and this includes a configuration in which at least one of the circumferential line portions is bent.

The present invention further provides a stationary member, a rotor rotatable relative to the stationary member, a magnet mounted on the rotor, and a magnet mounted on the stationary member facing the magnet. A motor having a cylindrical stator core and a cylindrical coil body disposed on the magnet-side surface of the stator core, wherein the cylindrical coil body includes a coil through which a drive current flows. The coil has an axial line portion extending in the rotation axis direction of the rotor, and a circumferential line portion extending in the rotation direction of the rotor, wherein the circumferential line portion is
The stator core and the magnet are disposed axially outside of a facing surface of the magnet, and are bent toward the stator core in a radial direction with respect to the axial line portion.

According to the present invention, since the circumferential line portion of the coil is disposed axially outside the facing surface of the stator core and the magnet, the stator core and the magnet can be used without waste and the efficiency of the magnetic circuit can be increased. it can. Further, since the circumferential line portion of the coil is bent toward the stator core with respect to the axial line portion, the axial length of the entire stator can be reduced, and the size of the entire motor can be reduced. Can be. Normally, the circumferential line portions of the coil are provided at both ends of the axial line portion, and this includes configuring at least one of these circumferential line portions as described above.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a motor according to the present invention will be described with reference to the accompanying drawings. FIG.
It is a cross-sectional view showing one embodiment of a motor according to the present invention,
FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a view showing a relationship between the developed coil body, the stator core, and the magnet.

Referring to FIG. 1, the illustrated spindle motor as an example of a motor includes a mounting bracket 2 as a stationary member, and a rotor hub 4 as a rotor rotatable with respect to the mounting bracket 2. ing. The mounting bracket 2 has a circular bracket body 6, and the bracket body 6 is attached to, for example, a base plate (not shown) of a hard disk drive. A circular mounting hole 8 is provided in the center of the bracket body 6, and one end of the shaft member 10 is fixed to the mounting hole 8 by, for example, press-fitting. The bracket body 6 also includes an annular support wall 12.
Is provided. A stator 14 is attached to the annular support wall 12 as described later.

The rotor hub 4 is rotatably supported on the shaft member 10 via bearing means. In the illustrated embodiment, the bearing means comprises thrust hydrodynamic bearings 18, 20 and radial hydrodynamic bearings 22, 24, and the rotor hub 4 has a hub body 16 having a cylindrical outer shape. An annular member 25 is fixed to the inner peripheral portion of the other end by, for example, caulking. The shaft member 10 has an elongated shaft body 26 having a circular cross section, and an annular flange 28 integrally provided near the other end of the shaft body 26. The outer end surface of the annular flange 28 (in FIG. 1). One thrust hydrodynamic bearing 18 is interposed between the upper end surface) and the inner surface of the annular member 25, and the other thrust hydrodynamic bearing 18 is provided between the inner end surface (the lower end surface in FIG. 1) of the annular flange 28 and the hub body 16. A hydrodynamic bearing 20 is interposed. Also, the shaft body 26
A pair of radial hydrodynamic bearings 22 and 24 are interposed between the intermediate portion in the axial direction (vertical direction in FIG. 1) and the hub main body 16 and spaced apart in the axial direction. Therefore, the rotor hub 4 is provided with thrust hydrodynamic bearings 18 and 20.
And the shaft member 1 via the radial hydrodynamic bearings 22 and 24
0, which are rotatably mounted on the thrust hydrodynamic bearings 18 and 2
0 supports the thrust load acting on the rotor hub 4,
The radial hydrodynamic bearings 22 and 24 support a radial load acting on the rotor hub 4. The thrust hydrodynamic bearings 18 and 20 and the radial hydrodynamic bearings 22 and 24
May have a structure known per se.

At one end (the lower end in FIG. 1) of the hub body 16, an annular space 17 is formed between an outer peripheral wall 32 and an inner peripheral wall 34 which are arranged concentrically. One end of the opening 17 is open at one end surface of the hub body 16 (the end surface facing the bracket body 6), and magnetic circuit means for rotating and driving the hub body 16 is accommodated in the annular space 17.

FIG. 2 (rotor hub 4 and mounting bracket 2)
, The magnetic circuit means is constituted by an annular magnet 30 and the stator 14 disposed opposite to the magnet 30,
The magnet 30 is mounted on the inner peripheral surface of the outer peripheral wall portion 32 of the hub body 16, and the stator 14 is disposed radially inside the magnet 30 and mounted on the outer peripheral surface of the annular support wall 12 of the mounting bracket 2. Instead of the configuration described above, the magnet 30 may be mounted on the outer peripheral surface of the inner peripheral wall portion 34 of the hub body 16 and the stator 14 may be mounted on the inner peripheral surface of the annular support wall 12 of the mounting bracket 2. This stator 14 will be described later in detail.

An annular flange 36 is provided at one end of the hub body 16 so as to protrude outward in the radial direction. The annular flange 36 functions as a disk mounting portion, and one magnetic disk for recording information, that is, one hard disk (not shown), or a plurality of magnetic disks via a spacer (not shown) is provided on the annular flange 36. Placed on

With this configuration, the rotor 4 is rotated by its magnetic axis by the magnetic action of the magnetic circuit means.
When the center axis of 0 constitutes this rotation axis), the hard disk is driven to rotate integrally with the rotor 4 in a predetermined direction.

Next, the stator 14 will be described mainly with reference to FIGS. 2 and 3.
Is a cylindrical stator core 42 and the stator core 4
2, that is, a cylindrical coil body 44 disposed on the peripheral surface facing the magnet 30. The stator core 42 is formed by stacking steel plates, for example, and is fixed to the outer peripheral surface of the annular support wall 12 of the mounting bracket 2 by, for example, press fitting. This stator core 42
May be constituted by a sleeve member formed of a magnetic material. The coil body 44 has a base member 46 formed of an insulating synthetic material. A coil 48 is provided on the surface of the base member 46, and the coil 48 is covered with an insulating layer (not shown). I have. Coil body 44
Is flexible and is wound in a cylindrical shape as shown in FIG. 2, and is attached to the outer peripheral surface of the stator core 42 by, for example, an adhesive. Therefore, the coil body 44 is located facing the magnet 30 of the rotor hub 4.

The illustrated coil 48 is, as shown in FIG.
In the unfolded state, the base member 46 has six winding portions 50a to 50f arranged in the lateral direction, and these winding portions 50a to 50f are electrically connected in series. In this embodiment, the odd-numbered winding part 50 from the left in FIG.
a, 50c, and 50e are formed in a substantially rectangular spiral that turns clockwise, while the even-numbered winding portions 50b, 50d, and 50f from the left in FIG. 3 are formed in a substantially rectangular spiral that turns counterclockwise. Have been. Such a coil 48 can be formed by plating, vapor deposition, etching, or the like.

Each of the winding portions 50a to 50f has substantially the same basic structure. Hereinafter, the winding portions 50a (50b to 50f) will be described.
Will be described. Winding part 50a (50b-50
f) is an axial line portion 52, 54 extending in the axial direction of the coil body 44 (vertical direction in FIGS. 1 and 3 and substantially parallel to the rotation axis of the rotor hub 4);
5 (FIG. 2), and circumferential line portions 56 and 58 extending in the rotation direction of the rotor hub 4. One axial line part 5
2 extends upward in the vertical direction, and the other axial line portion 54
Extends downward in the vertical direction, one circumferential line portion 56 connects one end (upper end portion) of the axial line portions 52 and 54, and the other circumferential line portion 58 connects to the axial line portions 52 and 54. Is connected to the other end (lower end).

In this embodiment, the winding portion 5 of the coil 48
0a (50b to 50f) in the axial line portions 52 and 54
Inclined portions 52a and 54a and second inclined portions 52b and 54b are provided. The first inclined portions 52a and 54a extend from the central portions of the axial line portions 52 and 54 upward in the axial direction to the right in FIG. 52b, 54b are axial line portions 5
2, and extends downward from the center of the coil body 44 in the circumferential direction of the coil body 44 to the right in FIG. Therefore, the first inclined portions 52a and 54a and the second inclined portion 5
2b and 54b are arranged symmetrically with respect to an axis passing through the center of the axial lines 52 and 54 and orthogonal to the axial direction (an axis extending in the horizontal direction in FIG. 3). Most of 52 and 54 (excluding both ends)
In FIG. 3, it extends in a substantially rectangular shape in the left direction, that is, in the direction opposite to the rotation direction of the magnet 30.

Further, the coil body 44, the stator core 42 and the magnet 30 are configured to have the following positional relationship. As shown in FIG. 3, the axial lengths of the stator core 42 and the magnet 30 are set substantially equal. With this configuration, the magnet 30
The magnetic lines of force from the N pole of the above flow toward the stator core 42,
Magnetic lines of force from the stator core 42 flow to the S pole of the magnet 30, and leakage of the magnetic lines of force to the outside can be reduced. The circumferential line portions 56 and 58 of the coil 48
The opposing surface of the stator core 42 and the magnet 30 (a region of the opposing surface is indicated by reference numeral 60 in FIG. 3) is disposed axially outside. The circumferential line portion 56 of the coil 48,
58 does not substantially contribute to the generation of the driving torque for rotationally driving the rotor hub 4, and therefore, the circumferential line portions 56,
By arranging the 58 in this way, the stator core 42 and the magnet 30 do not become unnecessarily large, and these can be effectively used to increase the efficiency of the magnetic circuit. In this embodiment, both circumferential direction line portions 5 are used.
6 and 58 are arranged outside the area 60 of the facing surface, and at least one of these circumferential line portions 56 (or 5
By arranging 8) outside the region 60, a desired effect is achieved. In the motor having such a configuration, when a drive current flows through the coil 48 of the coil body 44,
Since the drive current flows in the axial lines 52 and 54 of the coil 48 in the axial direction, a drive torque in a predetermined direction is generated by the action of the current flowing through the drive axial lines 52 and 54 and the magnetic field of the magnet 30. Then, the rotor hub 4 is rotationally driven in a predetermined direction indicated by an arrow 55 (FIG. 2) by the driving torque. The circumferential line portion 5 of the coil 48
In Nos. 6, 58, the driving current flows in the circumferential direction, so that the driving current flowing in the circumferential direction does not substantially generate the driving torque in the rotational direction.

In this motor, since the stator core 30 is cylindrical and has substantially no irregularities on its outer peripheral surface, substantially no detent torque is generated, and mechanical vibrations, fluctuations in the number of revolutions, and the like can be suppressed. it can. In addition, coil 4
8 are the first and second inclined portions 52, 54.
a, 52b, 54a, and 54b, a part of the axial line portions 52 and 54 of the coil 48 precedes the rotation direction of the rotor hub 4 and is generated even when a rectangular waveform drive current is supplied to the coil 48. The driving torque does not have a step-like shape, and the rise and fall of the driving torque at the time of current switching are mitigated, whereby the mechanical vibration, the fluctuation of the rotation speed, and the like can be further reduced. The degree of easing of the rise and fall of the driving torque depends on the inclinations 52a, 52b, 54a, and 54.
b, the inclination angles of these inclined portions 52a, 52b, 54a,
It can be adjusted by appropriately setting the length in the axial direction of 54b.

In the above-described embodiment, the coil 48
3 are formed in a substantially rectangular shape in FIG. 3, the inclination directions of the first and second inclined portions 52a, 52b 54a, 54b of the axial line portions 52, 54 are as described above. Alternatively, the axial line portions 52 and 54 may be formed in a reversed letter shape in FIG. 3, and the same effect as described above is achieved with this configuration.

In such a motor, when the circumferential line portions 56 and 58 of the coil 48 are arranged outside the region 60, it is desirable to configure the motor as shown in FIG. Referring to FIG. 4 showing a part of a modified form of the motor,
In the motor of this modified embodiment, both ends of the coil body 44, that is, portions where the circumferential lines 56 and 58 of the coil 48 are provided (these portions protrude outward from the stator core 42 in the axial direction) are arranged in the radial direction. It is bent inward and arranged on the stator core 42 side. By bending both ends of the coil body 44 toward the stator core 42 in this manner,
The axial length of the coil body 44 can be reduced, so that relatively long axial lines 52 and 54 can be ensured with the limited annular space 17. Therefore, the magnetic circuit means can be made compact, and downsizing of the motor is achieved. In addition, the coil body 4
A desired effect can also be achieved by bending at least one end of 4 (the end where the circumferential line portion 56 or the circumferential line portion 58 is formed).

Even if the coil body is configured as shown in FIG. 5, mechanical vibrations and fluctuations in the number of revolutions can be further reduced as described above. In this modification, the shape of the axial line portion of the coil of the coil body is modified. Referring to FIG. 5, coil 104 of coil body 102 has a plurality of winding portions 106a, 106b, 106c,. In this embodiment, the odd-numbered winding portions 106a, 106c... From the left in FIG. 5 are formed in a substantially rectangular spiral shape in the clockwise direction, while the even-numbered winding portions 106b. Are formed in a substantially rectangular spiral shape in the counterclockwise direction.

The winding portion 106a (106b, 106c
.) Indicate the axial line portions 108 and 110 extending in the axial direction of the coil body 102, similarly to the embodiment shown in FIGS.
And a circumferential line portion 11 extending in the rotation direction of the rotor hub 4.
2,114. In this embodiment, substantially all of the axial line portions 108 and 110 are inclined portions, and are inclined in the circumferential direction with respect to the axial direction (vertical direction in FIG. 5) from one end to the other end thereof. Extending. Other configurations of the coil body 102 are substantially the same as those described above.

In the coil body 102, the coil 1
Since the axial line portions 108, 110 of 04 are inclined in the circumferential direction, one end of the axial line portions 108, 110 of the coil 104 precedes the other end in the rotation direction of the rotor hub 4, Even if a drive current having a rectangular waveform is applied to the coil 104, the generated drive torque does not have a step shape, and the rise and fall of the drive torque at the time of current switching are alleviated, and the same effects as described above are achieved. The axial line portion 10
The same effect can be achieved by inclining 8, 110 in the direction opposite to the direction shown in FIG.

Also in this coil body 102, the winding portion 1
06a (106b, 106c...) Circumferential line portion 11
2 and 114 are arranged outside the region 60 of the opposing surface of the stator core 42 and the magnet 30, and both ends of the coil body 102, that is, the portions where the circumferential line portions 112 and 114 of the coil 104 are provided are radially inserted into the stator core 42. Fold it towards the side.

Further, the configuration for bending the end of the coil body is as follows.
For example, the present invention can be applied to the coil body shown in FIG.
Referring to FIG. 6, coil 124 of coil body 122
Has a plurality of winding portions 126a to 126f, and odd-numbered winding portions 126a, 126c, and 12 from the left in FIG.
Reference numeral 6e denotes an approximately rectangular spiral formed in a clockwise direction, and the even-numbered winding portions 126b, 126d, and 12 from the left in FIG.
.. Are formed in a substantially rectangular spiral shape in the counterclockwise direction.

Winding part 126a (126b to 126f)
Is the axial line portion 12 extending in the axial direction of the coil body 122.
8, 130, and circumferential lines 132, 144 extending in the rotation direction of the rotor hub 4, and axial lines 128, 13
0 extends substantially parallel to the axial direction without inclination. In addition, the winding part 126a (126b to 126f)
Are arranged outside the region 60 of the facing surface of the stator core 42 and the magnet 30.

In such a coil body 122 as well, both ends of the coil body 122 (ends at which the circumferential lines 132 and 134 are provided) protrude from the stator core 42 on both sides. Similarly, by bending the coil body 122 toward the stator core 42, the axial length of the coil body 122 can be reduced.

Although the embodiment of the motor according to the present invention has been described above, the present invention is not limited to such an embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

For example, in the illustrated embodiment, one coil body 44 (102, 122) is used for a single-phase motor, but when applied to, for example, a three-phase motor, three substantially identical three-phase motors are used. The coil body 44 (102, 104) may be wound in a cylindrical shape with the phase shifted, and can be similarly applied to a three-phase motor or the like.

In the illustrated motor, for example, the rotor hub 44 is rotatably supported via the hydrodynamic bearings 18, 20, 22, and 24, but is not limited thereto. The present invention can be similarly applied to those which are rotatably supported via other bearings.

In the illustrated embodiment, the present invention is applied to a spindle motor for a hard disk as an example of a motor. However, the present invention is applicable to other spindle motors for a CD-ROM and the like, and further includes a DC brushless motor. The same can be applied to a general motor.

[0047]

According to the motor of the first aspect of the present invention, the rise and fall of the drive torque at the time of switching the drive current are alleviated, and the mechanical vibration, the fluctuation of the rotation speed, and the like can be suppressed.

According to the motor of the second aspect of the present invention, the axial line portion of the coil is formed in a substantially rectangular shape or a substantially inverted rectangular shape, and the center portion and both end portions thereof are connected to the rotor. Since the driving current is shifted in the circumferential direction, for example, even if a driving current having a rectangular waveform is supplied, the driving torque generated at the time of switching the driving current is reduced without being stepped.

According to the motor of the third aspect of the present invention, the axial line portion of the coil extends in a circumferential direction from one end portion to the other end portion, and extends along one end of the axial line portion. Since it is displaced from the other end in the circumferential direction, for example, even if a drive current having a rectangular waveform is supplied, the drive torque generated at the time of switching the drive current is reduced without being stepped.

According to the motor of the fourth aspect of the present invention, since the circumferential portion of the coil is disposed axially outside the facing surface of the stator core and the magnet, the stator core and the magnet can be used without waste. The efficiency of the magnetic circuit can be increased.

According to the motor of the fifth aspect of the present invention, since the circumferential line portion of the coil is bent toward the stator core, the length of the stator in the axial direction is reduced, and the size of the entire motor is reduced. Can be achieved.

Further, according to the motor of the sixth aspect of the present invention, the efficiency of the magnetic circuit can be increased by using the stator core and the magnet without waste, and the length of the stator in the axial direction can be reduced. The overall size can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a spindle motor as an example of a motor according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram illustrating a relationship between a developed coil body, a stator core, and a magnet.

FIG. 4 is a sectional view showing a part of another embodiment of the motor according to the present invention.

FIG. 5 is a diagram showing a relationship between a coil body according to a modified embodiment, a stator core, and a magnet.

FIG. 6 is a diagram showing a relationship between a coil body according to another modification, a stator core, and a magnet.

[Explanation of symbols]

2 Mounting bracket (stationary member) 4 Rotor hub (rotor) 10 Shaft member 14 Stator 16 Hub main body 18, 20 Thrust dynamic pressure fluid bearing 22, 24 Radial dynamic pressure fluid bearing 30 Magnet 42 Stator core 44, 102, 122 Coil body 48, 104 , 124 Coil 52, 54, 108, 110, 128, 130 Axial line portion 52a, 54a First inclined portion 52b, 54b Second inclined portion 56, 58, 112, 114, 132, 134 Circumferential line portion

Claims (6)

[Claims] 1. A stationary member, a rotor rotatable relative to the stationary member, a magnet mounted on the rotor, and a stator mounted on the stationary member facing the magnet. Wherein the stator has a cylindrical stator core, and a motor having a cylindrical coil body disposed on a surface of the stator core on the magnet side, wherein the cylindrical coil body has a coil through which a drive current flows,
The coil has an axial line portion extending in the rotation axis direction of the rotor and a circumferential line portion extending in the rotation direction of the rotor, and the axial line portion extends in a circumferential direction with respect to the axial direction. A motor having an inclined portion that inclines. 2. The axial line portion of the coil has a first inclined portion extending inclining in a circumferential direction from a center portion to one end portion, and a first inclined portion extending in a circumferential direction from the center portion to the other end portion. A second inclined portion extending in an inclined manner, wherein the first inclined portion and the second inclined portion are disposed symmetrically with respect to an axis passing through the central portion and orthogonal to the axial direction. The motor according to claim 1, wherein: 3. The motor according to claim 1, wherein the inclined portion of the axial line portion of the coil extends in a circumferential direction from one end to the other end of the axial line portion. . 4. The motor according to claim 1, wherein the circumferential line portion of the coil is disposed axially outside a surface facing the stator core and the magnet. 5. The motor according to claim 4, wherein a circumferential line portion of the coil is bent in a radial direction with respect to the axial line portion and is disposed on the stator core side. 6. A stationary member, a rotor rotatable relative to the stationary member, a magnet mounted on the rotor, and a stator mounted on the stationary member facing the magnet. Wherein the stator has a cylindrical stator core, and a motor having a cylindrical coil body disposed on a surface of the stator core on the magnet side, wherein the cylindrical coil body has a coil through which a drive current flows,
The coil has an axial line portion extending in the rotation axis direction of the rotor, and a circumferential line portion extending in the rotation direction of the rotor, and the circumferential line portion is a portion of the facing surface of the stator core and the magnet. A motor arranged outside in the axial direction and bent toward the stator core in a radial direction with respect to the axial line portion.