JP2001069738A - External circumference opposing type motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration of rotor by obtaining a sufficient bias force in an external circumference opposing type motor. SOLUTION: In an external circumference opposing type motor where the magnets 34 in the side of rotor 31 are provided oppositely at the end surface of the multi-pole core 21 fixed in the side of a chassis, distribution of the lines of magnetic force 42 at the gap 41 are unbalanced causing a magnet 34 to generate a downward bias force F in the shaft direction. With this bias force, the rotor is always placed in control even if an external vibration is applied. The bias force can also be generated by adding a magnet to any one of rotor, core, magnet and chassis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer peripheral facing motor.

[0002]

2. Description of the Related Art A conventional outer peripheral facing motor will be described with reference to the drawings. 1A and 1B show a configuration of a conventional outer peripheral facing motor, in which FIG. 1A is a plan view as viewed from the line AA in FIG. 1B, and FIG. 1B is a side view as viewed from the line BB in FIG. It is sectional drawing. The outer peripheral facing motor 11 is formed on a chassis 12.

[0003] A bearing 13 is mounted on the chassis 12. A bearing 13 is attached to the inner periphery of a cylindrical holder 14, and a thrust plate 15 is disposed on the bottom surface inside the holder 14. The holder 14 is fixed to the chassis 12 by caulking. A nine-pole core 21 is radially attached to the holder 14. A coil 22 is wound around each core 21. Each coil 22 is connected in three phases and connected to a drive circuit (not shown). Connection method of each coil 22,
The configuration of the driving circuit and the like are well known in the art, and thus description thereof will be omitted.

[0004] The rotor 31 is formed in a disk shape, and a shaft 32 provided at the center thereof is rotatably supported by the bearing 13 and the thrust plate 15. A flange-like yoke portion 33 is formed downward on the outer peripheral portion of the rotor 31, and an annular magnet (permanent magnet) 34 is attached inside the yoke portion 33. The magnet 34 is divided into twelve poles in the circumferential direction and magnetized to form magnetic poles 35 respectively. The state of magnetization of each magnetic pole 35 is as shown in FIG. 1A, and the N pole and the S pole are alternately arranged in the circumferential direction. In addition,
In this specification, the direction along the axis 32 is referred to as “axial direction”.
Say

The outer peripheral surface of the core 21 and the inner peripheral surface of the magnet 34 face each other with a gap 41 interposed therebetween. The center of the core 21 in the axial direction coincides with the center of the magnet 34, and the width of the magnet 34 in the axial direction is
Greater than one width. Therefore, the magnetic lines of force 42 in the gap 41 do not become parallel, and the magnetic field lines 42 are directed upward from the magnet 34 toward the core 21 on the chassis 12 side (lower side in the figure) and from the magnet 34 toward the core 2 on the opposite side (upper side in the figure).
It occurs downward toward 1.

A Hall sensor 43 for detecting the rotational position of the rotor 31 is arranged at a position facing the magnet 34. The drive circuit supplies an exciting current having a predetermined waveform and a predetermined phase to each coil 22 based on the detection signal of the Hall sensor 43 to rotate the rotor 31. Of the components described above, the chassis 12, the bearing 13, the core 21, the rotor 31, and the like are made of a material having high magnetic permeability, for example, a soft magnetic material.

[0007]

SUMMARY OF THE INVENTION An outer peripheral facing motor 11
Has an advantage that it is easy to design a large torque compared to a flat opposed motor. However, the outer peripheral facing motor 11 has a small bias force acting in the axial direction (thrust direction). As shown in FIG. 1B, in the outer peripheral opposed motor 11, the magnetic force line 42 generated in the gap 41 cancels the component in the axial direction (thrust direction), so that a bias force for pressing the rotor 31 toward the chassis 12 is generated. do not do. Therefore, when an external vibration is applied in the axial direction, the rotor 31 easily moves up and down.
Therefore, it is unsatisfactory as a spindle motor of an optical disk deck for a car that requires vibration resistance.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the vibration of a rotor by obtaining a sufficient bias force in an outer peripheral facing motor.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object. An outer peripheral facing motor according to the present invention is configured such that a coil is wound around each of the cores, and a multi-pole core is disposed around a bearing and disposed on a chassis, and a multi-pole is disposed on a peripheral end surface of the core via a gap. And a rotor whose shaft is supported by the bearing, wherein the magnetic field line in the gap has an unbalanced distribution in the axial direction. By forming a path, a bias force for attracting the rotor to the chassis is applied.

In order to unbalance the lines of magnetic force in the gap in the axial direction, the thickness of the magnet is changed in the axial direction, the yoke effect of the yoke on the back of the magnet is changed in the axial direction, Alternatively, the shape of the magnet may be changed in the axial direction, the center of the core and the magnet may be shifted in the axial direction, and the magnetization of the magnet may be changed in the axial direction.

The lines of magnetic force in the gap act as an attraction between the core and the rotor. Therefore, by making the magnetic lines of force in the gap unbalanced in the axial direction, the attraction force becomes a bias force for pressing the rotor against the chassis. This bias force suppresses the rotor from vibrating in the axial direction even when vibration is applied to the motor. In another aspect of the outer peripheral facing motor of the present invention, an axial bias force is applied by providing a magnet that applies a force to attract the rotor toward the chassis. This magnet can be provided on the core, rotor, or chassis.

In another aspect of the outer peripheral facing motor of the present invention, a rotor-side shaft and a chassis-side bearing form
A magnetic path for providing a force for attracting the shaft to the chassis is formed. This magnetic path is formed by magnetizing a bearing, its holder, a thrust plate, or a shaft. Further, in another aspect of the outer peripheral facing motor of the present invention, the magnet, the gap, and the core are sequentially arranged in the axial direction. Thus, the attractive force between the magnet and the core acts as an attractive force between the rotor and the chassis, and applies an axial bias force to the rotor.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a motor according to an embodiment of the present invention; Each embodiment of the present invention has basically the same configuration as that of the above-described conventional example shown in FIG. Hereinafter, only the characteristic portions of each embodiment are illustrated and described. The following embodiments can be implemented by combining a plurality of embodiments.

(Embodiment 1) In the present embodiment, the magnet 34 whose thickness changes in the axial direction (vertical direction in the drawing) is used to reduce the gap 4.
The bias force is generated in the magnet 34 by making the distribution of the magnetic force lines 42 in 1 unbalanced. FIG. 2 is a side view showing the structure of the magnet 34 according to the first embodiment.
(A) and (B) show different examples.

In the example shown in FIG. 1A, a step is formed on the back side of the magnet 34 so that the portion on the chassis 12 side is a thin portion 51 and the rest is a thick portion 52.
In the second example of (B), by forming an inclination on the back side, the portion on the chassis 12 side is made into a thin portion 51 and the rest is made into a thick portion 52. If the magnets 34 are formed of the same material and of the same shape, the magnetomotive force is large in a thick portion and small in a thin portion. Accordingly, in the gap 41, the lines of magnetic force 42 from the thick portion 52 of the magnet 34 toward the core 21 become stronger, and the thin portion 51
The magnetic force line 42 heading toward is weakened. As a result, the lines of magnetic force 42 directed downward from above the magnet 34 toward the core 21.
Is stronger in the line of magnetic force 42 directed from below the magnet 34 to the core 21.

Accordingly, the magnet 34 receives a force to be attracted downward in the axial direction from the core 21 fixed to the chassis 12. This force acts as a bias force F for pressing the rotor 31 against the chassis 12. Due to the addition of the bias force F, even if vibration is applied from outside the motor,
Since the movement of the rotor 31 in the axial direction is suppressed, the rotor 31 is not exposed.

Further, in the present embodiment, since only the shape of the magnet 34 is changed and other parts can be used, a rise in manufacturing cost can be minimized. (Embodiment 2) In this embodiment, the distribution of the magnetic force lines 42 in the gap 41 is unbalanced by reducing the yoke effect on the chassis side of the yoke portion 33 of the rotor 31 to generate a bias force on the magnet 34. .

FIG. 3 shows a yoke section 33 according to the second embodiment.
(A), (B) and (C) show different examples, respectively. In the example shown in (A), the yoke 33 is cut on the chassis 12 side (the lower part in the figure). As a result, the magnet 34 has the yoke 3
3, the lower half is a cut portion 53 without a yoke, and the lower half of the magnet 34 has a reduced yoke effect.

Since the magnets 34 are formed of the same material and of the same shape, the magnetomotive force is reduced in portions where the yoke effect is low. Therefore, in the gap 41, the magnetic line of force 42 in the upper part of the figure becomes stronger, and the magnetic line of force 42 in the lower part of the figure becomes weaker. Line of magnetic force 4 in this gap 41
2 is the same as that in FIG. 2 of the first embodiment,
In the second embodiment, the same operation and effect as those of the first embodiment can be obtained.

The example shown in FIG. 2B is an example in which a hole 54 is provided in the lower part of the figure to reduce the yoke effect. The example shown in (C) is an example in which a step is formed in the middle of the yoke section 33 and the step section 55 is separated from the magnet 34 to reduce the yoke effect. In the examples shown in FIGS. 7A and 7B, the Hall sensor 43 is connected to the cut portion 53 of the yoke portion 33 or the hole 54.
Can be arranged on the outer peripheral side. This eliminates the need to dispose the Hall sensor 43 below the magnet 34, thereby reducing the overall height of the motor.

(Embodiment 3) In the present embodiment, the distribution of the lines of magnetic force 42 in the gap 41 is made unbalanced by changing the shape of the teeth at the tip of the core 21. FIG. 4 is a side view showing the structure of the core 21 according to the third embodiment, and (A), (B), and (C) show different examples.

In the example shown in FIG. 2A, the width of the core 21 in the horizontal direction is different between the upper and lower parts. (B) lowers the core 21
It is assumed that the upper half 61 is wider than the lower half 62 as viewed from the line B. Therefore, the distribution of the magnetic field lines 42 in the gap 41 is strong in the upper part of the figure and weaker in the lower part, as shown in FIG. Since the distribution of the magnetic field lines 42 in the gap 41 is the same as that in FIG. 2 of the first embodiment, the same operation and effect as in the first embodiment can be obtained in the second embodiment.

In the example shown in FIG.
4 is projected from the upper half 63. The width of the core 21 is the same in the upper part 63 and the lower part 64. As a result, the magnetic resistance in the lower half 64 is smaller than that in the upper half 63, so that the lines of magnetic force 42 in the gap 41 are stronger on the lower half side of the core 21 and the magnet 34 than on the upper half side.

In the example shown in FIG. 2C, the magnetic permeability of the lower half 66 of the core 21 is made larger than the magnetic permeability of the upper half 65. Thereby, the magnetic field lines 42 in the gap 41 are
The lower half side of the core 21 and the magnet 34 is stronger than the upper half side. (B) In the example shown in FIG.
Is attracted to the lower half of the core 21, so that a downward bias force is generated.

(Embodiment 4) In this embodiment, the distribution of the magnetic force lines 42 in the gap 41 is made unbalanced by shifting the centers of the core 21 and the magnet 34 in the axial direction. FIG. 5 is a side view showing the structure of the core 21 and the magnet 34 in the fourth embodiment, and FIGS. 5A and 5B show different examples.

In the example shown in (A), the center of the magnet 34 in the axial direction is disposed above the center of the core 21 in the axial direction in the figure. Accordingly, an axial component is generated in the attraction force between the magnet 34 and the core 21, and a bias force F for pressing the rotor 31 against the chassis 12 is generated. (B)
In the example shown in FIG. 19A, a part 67 below the tip of the core 21 in the example of FIG. As a result, the lines of magnetic force 42 going downward from the magnet 34 increase.

(Embodiment 5) In this embodiment, the distribution of the magnetic force lines 42 in the gap 41 is made unbalanced by changing the shape of the magnet 34 on the gap 41 side in the axial direction. FIG. 6 is a side view showing the structure of the magnet 34 according to the fifth embodiment, and FIG.
(B) shows different examples.

In the example shown in (A), a step is formed on the gap 41 side of the magnet 34, and in the example shown in (B), the portion of the magnet 34 on the chassis 12 side is far from the core 21 by forming an inclination. A portion 72 is set, and the rest is set as a near portion 71. As a result, the gap 41 becomes shorter in the upper part of the drawing and longer in the lower part, so that the core 21 and the magnet 34
The lower half is stronger than the upper half.

Since the distribution of the lines of magnetic force 42 in the gap 41 is the same as that in FIG. 2 of the first embodiment, the same operation and effect as in the first embodiment can be obtained in the second embodiment. (Embodiment 6) In this embodiment, the magnet 34
By changing the intensity of magnetization in the axial direction, the distribution of the magnetic lines of force 42 in the gap 41 is unbalanced.

FIG. 7 shows a magnet 3 according to the sixth embodiment.
4 is a side view showing the structure of FIG. The magnet 34 makes the magnetization of the upper half 73 stronger than the magnetization of the lower half 74. As a result, the distribution of the magnetic force lines 42 in the gap 41 becomes weaker in the lower part. Since the distribution of the lines of magnetic force 42 in the gap 41 is the same as that in FIG. 2 of the first embodiment, the same operation and effect as in the first embodiment can be obtained in the sixth embodiment.

(Embodiment 7) In the present embodiment, an additional magnet is attached to the rotor 31, the core 21, or the chassis 12, and an attractive force to the core 21 is generated by the magnet. 8 to 11 are side views illustrating the structure of the additional magnet according to the seventh embodiment.

FIG. 8 shows an example in which an additional magnet is provided on the rotor 31 side. (A) and (B) show different examples. In the example shown in (A), the magnet 34 is extended upward, and further extended along the lower part of the rotor 31 to a position reaching the upper part of the core 21, and this extended part is used as an additional magnet 81. Since the additional magnet 81 faces the core 21, it generates an attraction force to the core 21. Therefore, a bias force F acting downward in the axial direction is generated in the rotor 31.

In the example shown in (B), an additional magnet 82 facing the core 21 is attached to the ceiling surface of the rotor 31 separately from the magnet 34. This additional magnet 82
An attraction force to the core 21 is generated. Therefore, a bias force F acting downward in the axial direction is generated in the rotor 31. The additional magnet 62 can be provided at a portion closer to the bearing 13 than the coil 22 as shown in FIG.

FIG. 9 shows an example in which an additional magnet is provided on the core 21 side. (A) and (B) show different examples.
In the example of (A), the additional magnet 82 is provided on the distal end side of the core 21 so as to face the rotor 31. In the example of (B),
The additional magnet 82 is opposed to the rotor 31 and the core 21.
Is provided on the bearing 13 side. Accordingly, a force for attracting the rotor 31 to the core 21 side is generated, and a bias force F acting on the rotor 31 in the axial direction downward is generated.

FIG. 10 shows an example in which an additional magnet is provided on the rotor 31 so as to face the chassis 12. (A) (B)
Indicates another example. In the example shown in (A), the lower portion of the magnet 34 is extended to the outside of the rotor 31, and this extended portion is used as an additional magnet 83. In the example shown in (B), the additional magnet 82 is attached to the outside of the yoke 32 of the rotor 31. The additional magnets 82 and 83 generate an attractive force with respect to the chassis 12 formed of a soft magnetic material. Therefore, a bias force F acting downward in the axial direction is generated on the rotor 31.

In the examples shown in FIGS. 3A and 3B, the Hall sensor 43 can be arranged on the outer peripheral side of the yoke section 33. Thus, FIG. 3A of the second embodiment described above.
As in the example shown in (B), the height of the entire motor can be reduced. FIG. 11 shows the additional magnet
1 shows an example in which the device is provided on the chassis 12 side opposite to the device 1. (A)
(B) shows another example. The example shown in (A) is a portion 9 extending outward at the lower end of the yoke portion 32 of the rotor 31.
1 and an additional magnet 82 is mounted on the chassis 12 so as to face the portion 91. 3B, an additional magnet 84 is attached between the cores 21 on the chassis 12 so as to face the rotor 31. In these examples (A) and (B), the rotor 31 itself is
And a bias force F is generated.

(Embodiment 8) In this embodiment, the shaft 32 of the rotor 31 and the bearing 13 on the chassis 12
A biasing force is generated on the rotor 31 by forming a magnetic path that generates a force for attracting the shaft 32 to the chassis 12.
FIG. 12 is a side cross-sectional view illustrating a structure of a bearing unit according to the eighth embodiment. (A), (B) and (C) show different examples.

In the example shown in FIG. 7A, the holder 14 made of a magnetizable magnetic material is magnetized. Also,
The example shown in (B) is for the bearing 13 and the example shown in (C) is for the shaft 3.
2 is magnetized. The example shown in (D) inserts a permanent magnet 82 between the thrust plate 15 and the holder 14. Due to these magnetizations, the magnetic path 92 indicated by an arrow
Is formed. Since the magnetic path 92 generates an attraction force between the tip of the shaft 32 and the thrust plate 15, the magnetic path 92 gives the rotor 31 a bias force F acting downward in the axial direction.

When the motor is used in an optical disk deck or the like, a mechanism for detaching the optical disk can be provided by providing a solenoid coil 93 surrounding the shaft 32 in the example shown in FIG. When a current flows through the solenoid coil 93, a magnetic field having a polarity corresponding to the direction of the current is generated.
An axial driving force is generated on the magnetized shaft 32. Therefore, when the motor is driven, a current having a polarity for applying the bias force F to the rotor 31 flows through the solenoid coil 73. In addition, when the optical disk is attached or detached, a current of the opposite polarity is supplied to raise the rotor 31.

(Embodiment 9) In the present embodiment, the magnet 34 is used so that the attraction force between the magnet 34 and the core 21 can be directly used as a bias force to the rotor.
And the core 21 are arranged. FIG. 13 is a side view showing the structure of the magnet 34 and the core 21 according to the ninth embodiment.

A magnet 34 is disposed on the ceiling surface of the rotor 31 so as to face the tip of the core 21 in the axial direction. At this time, the magnet 34, the gap 41, and the core 21
It is arranged in the axial direction. As a result, most of the attraction force of the magnetic field lines 42 of the gap 41 is
It can be used as an adsorbing power. Therefore, the rotor 31
, A bias force F is generated downward in the axial direction.

The motor according to the present embodiment has a configuration similar to a flat opposed motor, but the flat opposed motor uses an air-core coil, whereas the motor according to the present embodiment uses a core 21 is different. In the present embodiment, the gap 41 can be reduced by inserting the core 21 into the coil 23, and the magnetic resistance of the magnetic circuit of the motor can be reduced, so that the efficiency can be improved.

[0043]

According to the present invention, a sufficient biasing force can be obtained in the outer peripheral facing motor, and the vibration of the rotor can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a conventional outer peripheral facing motor.

FIG. 2 is a side view showing the first embodiment of the outer peripheral facing motor of the present invention.

FIG. 3 is a side view showing a second embodiment of the outer peripheral facing motor according to the present invention.

FIG. 4 is a side view showing a third embodiment of the outer peripheral facing motor according to the present invention.

FIG. 5 is a side view showing a fourth embodiment of the outer peripheral facing motor of the present invention.

FIG. 6 is a side view showing a fifth embodiment of the outer peripheral facing motor of the present invention.

FIG. 7 is a side view showing a sixth embodiment of the outer peripheral facing motor of the present invention.

FIG. 8 is a side view (part 1) showing a seventh embodiment of the outer peripheral facing motor of the present invention.

FIG. 9 is a side view showing a seventh embodiment of the outer peripheral facing motor according to the present invention (part 2).

FIG. 10 is a side view showing a seventh embodiment of the outer peripheral facing motor according to the present invention (part 3).

FIG. 11 is a side view showing a seventh embodiment of the outer peripheral facing motor according to the present invention (part 4).

FIG. 12 is a side sectional view showing an eighth embodiment of the outer peripheral facing motor according to the present invention;

FIG. 13 is a side sectional view showing a ninth embodiment of the outer peripheral facing motor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Peripheral facing motor 12 ... Chassis 13 ... Bearing 14 ... Holder 15 ... Thrust plate 21 ... Core 22 ... Coil 31 ... Rotor 32 ... Shaft 33 ... Yoke part 34 ... Magnet 35 ... Magnetic pole 41 ... Gap 42 ... Magnetic force line 43 ... Hole Sensor 51 Thin part 52 Thick part 53 Cut part 54 Hole 55 Step 61 Upper half 62 Lower half 64 Lower half 65 Lower half 66 Upper half 66 Lower half 67 Lower part 71 ... Near portion 72. Far portion 73. Upper half 74. Lower half 81, 82, 83, 84. Additional magnet 91. Extended portion 92. Magnetic path 93. Solenoid coil F.

Claims (19)

[Claims] A coil is wound around each of the cores, and has a multi-pole core disposed on a chassis around a bearing, and a multi-pole magnet disposed on a peripheral end surface of the core with a gap therebetween. A rotor whose shaft is supported by the bearing; and an outer peripheral facing motor having: a magnetic path formed by the core and the magnet such that the magnetic lines of force in the gap have an unbalanced distribution in the axial direction. A biasing force for attracting the rotor toward the chassis by applying a bias force. 2. A thickness of the magnet changes in an axial direction, and a thickness on the chassis side is formed smaller than a thickness of another portion, thereby generating an unbalanced distribution of the magnetic force lines in the axial direction. The outer peripheral facing motor according to claim 1. 3. The yoke effect of the yoke arranged on the back side of the magnet changes in the axial direction, and the yoke effect on the chassis side is formed to be smaller than the yoke effect on other parts. The outer peripheral facing motor according to claim 1, wherein an unbalanced distribution of the lines of magnetic force is generated in the axial direction. 4. The outer peripheral facing motor according to claim 1, wherein the shape of the core on the gap side changes in the axial direction, thereby generating an unbalanced distribution of the magnetic force lines in the axial direction. 5. The outer peripheral opposed motor according to claim 1, wherein an axially unbalanced distribution of the lines of magnetic force is generated by displacing the center of the magnet and the center of the core in the axial direction. 6. The outer peripheral facing motor according to claim 1, wherein the shape of the magnet on the gap side changes in the axial direction to generate an unbalanced distribution of the lines of magnetic force in the axial direction. 7. The motor according to claim 1, wherein an unbalanced distribution of the lines of magnetic force in the axial direction is generated by changing the intensity of magnetization of the magnet in the axial direction. 8. A multi-pole core which is wound around a coil and is arranged on a chassis around a bearing, and a multi-pole magnet which is arranged via a gap on an outer peripheral end face of the core. And a rotor whose shaft is supported by the bearing; and an outer peripheral facing motor having an additional magnet for applying a force to attract the rotor toward the chassis. 9. The outer peripheral facing motor according to claim 8, wherein the additional magnet is a magnet that is disposed on the rotor and generates an attraction force to the core. 10. The outer peripheral facing motor according to claim 8, wherein the additional magnet is a magnet that is arranged on the core and generates an attraction force to the rotor. 11. The outer peripheral facing motor according to claim 8, wherein the additional magnet is a magnet arranged on the rotor to generate an attraction force to the chassis. 12. The outer peripheral facing motor according to claim 8, wherein the additional magnet is a magnet that is disposed on the chassis and generates an attraction force to the rotor. 13. A multi-pole core which is wound around a coil and is arranged on a chassis around a bearing, and a multi-pole magnet which is arranged on a peripheral end surface of the core with a gap therebetween. And a rotor whose shaft is supported by the bearing, wherein the shaft and the bearing form a magnetic path for applying a force to attract the shaft to the chassis. Outer peripheral facing type motor. 14. The outer peripheral facing motor according to claim 13, wherein the magnetic path is formed by magnetizing the holder of the bearing. 15. The outer peripheral facing motor according to claim 13, wherein the magnetic path is formed by magnetizing the bearing. 16. The magnetic path is formed by adding a permanent magnet to a thrust plate of the bearing.
An outer peripheral facing type motor according to the above item. 17. The motor according to claim 13, wherein the magnetic path is formed by magnetizing the shaft. 18. A solenoid coil, wherein the magnetic path is formed by magnetizing the shaft, and the solenoid is arranged to surround the shaft, and includes a solenoid coil that moves the shaft in the axial direction when excited. 9. The outer peripheral facing motor according to 8. 19. A multi-pole core which is wound around a coil and is arranged on a chassis around a bearing, and a multi-pole magnet which is arranged on the core with a gap therebetween, wherein the shaft is A rotor supported by the bearing, wherein the magnet, the gap, and the core are sequentially arranged in the axial direction to provide a force for attracting the rotor in the chassis direction. An outer peripheral facing type motor.