JP4330019B2 - Spindle motor and disk drive using the spindle motor - Google Patents

Description

  The present invention relates to a spindle motor for driving an optical disk, a magneto-optical disk, and the like, and a disk drive device using the spindle motor, and more particularly to a disk drive device having an improved spindle motor for rotationally driving a disk.

A disk drive device having a head mechanism for reading information recorded on a disk or writing information on a disk is known as an optical disk such as a CD, a DVD, or an MD, or a magneto-optical disk drive.
In this disk drive device, an abduction type brushless motor is used as a so-called spindle motor for rotationally driving the disk. A rotation table of the spindle motor is provided with a turntable on which a disk is mounted so as to rotate integrally. The rotation shaft is rotatably supported by a stator by a bearing.

In addition, sintered oil-impregnated metal bearings are used as the bearings because they are less expensive than roller bearings and can reduce the cost of motors and devices. However, unlike a roller bearing, a clearance is required between the sintered oil-impregnated metal bearing and the rotating shaft, and the rotational shaft runs out more than the roller bearing due to this clearance.
This run-out of the rotating shaft causes the disc surface to run out and the disc run-out when the disc is mounted on a turntable and rotated, and the head mechanism cannot read the information accurately from the disc. This causes inconveniences such as failure to write information accurately.

Various configurations and methods have been proposed so far as means for preventing the above-described rotation of the rotating shaft. In particular, a configuration in which a fixed force is applied to the rotor not only in the rotation axis direction (so-called thrust direction) but also in the radial direction (so-called radial direction), and the rotor is slightly tilted and is biased in a predetermined direction is disclosed in Patent Document As shown in FIG.
In this way, by applying a force to the rotor in a predetermined direction and rotating the spindle motor in a state in which the rotor is shifted in the predetermined direction, the runout of the rotating shaft can be suppressed and the surface runout and the center of the disk can be suppressed. Runout is improved.

On the other hand, in the relative movement of the head mechanism and the disk in the disk drive device, in the focus direction, the head mechanism can relatively easily follow the vibration of the disk, and signals can be read even if the disk swings to some extent. However, although tracking is possible in the tracking direction, the accuracy of surface shake and center shake is required compared with the focus direction.
Therefore, Patent Document 2 discloses a technique that relates the moving direction of the head mechanism and the rotor shifting direction of the spindle motor.
JP 2004-7905 A JP 09-74750 A

  As shown in Patent Document 1, when a magnetically unbalanced state is configured to shift the rotor, there is a concern that this unbalanced state affects the rotation accuracy such as jitter. That is, when a magnetic generator (suction magnet) or a magnetic suction body (magnetic cap) is provided on the stator side to create a magnetic imbalance, this magnetic generator or magnetic suction body is close to the core and particularly in contact with it. However, there is a problem that a magnetic influence is exerted on the coil wound around the core, and the magnetic imbalance state adversely affects the rotation accuracy such as jitter.

  Further, as shown in Patent Document 2, in a disk drive device using an optical reading head, a configuration in which the rotor is offset in the direction in which the head moves is effective. The magnetic core shape of the stator core in which a plurality of magnetic plates are laminated is cut out by a predetermined portion, thereby forming a magnetic imbalance with respect to the driving magnet provided on the rotor, thereby causing the rotor to be offset.

  In such a configuration, it is necessary not only to process each magnetic plate into a predetermined shape, but also to assemble the processed magnetic plates in a certain combination. Furthermore, since it is necessary to determine an assembly direction when the stator core is assembled as a drive device, the assembly is very troublesome. Further, a dedicated motor must be used as the disk drive device, and its application is limited.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spindle motor that can improve rotational accuracy such as jitter and the like, and a disk drive device using the motor, while the rotor is shifted in a simple configuration. .

In order to solve the above problems, the invention of claim 1 (hereinafter referred to as “the first invention of the present application”)
A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor has a rotating shaft, a rotor case that rotates integrally with the rotating shaft, and a driving magnet fixed to the rotor case,
The stator includes a plate-like base, a bearing fixed to the base and rotatably supporting the rotating shaft, and a coil 3n connected around the bearing and wound in three phases (n is an integer of 2 or more) ) Having a core with one salient pole,
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
On the stator side facing the magnetic upper surface portion of the rotor case, an arc magnetized body magnetized in an arc shape is attached so that the magnetized region is concentric with the rotating shaft,
Magnetized areas of the arcuate wear magnetized member is of the salient pole, to set free for three consecutive phases as one set Ri straddle the salient poles to form the (n-1) sets, and, to the set not consecutive (N-1) The spindle motor is characterized by being arranged with an opening angle that does not reach salient poles not included in the set .

In the invention of claim 4 (hereinafter referred to as “the second invention of the present application”),
A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor includes a rotating shaft, a rotor case that rotates integrally with the rotating shaft, a driving magnet fixed to the rotor case, and an annular magnet fixed to the inner peripheral side of the driving magnet. ,
The stator is disposed around the bearing, a plate-shaped base, a bearing fixed to the base and rotatably supporting the rotating shaft, a magnetic attracting body attached to an end of the bearing on the rotor side, and A core having 3n (n is an integer of 2 or more) salient poles around which a three-phase connected coil is wound;
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
The magnetic attraction member has a facing surface that faces the annular magnet, salient said facing surface of said salient poles, which forms a to set no continuous three-phase as one set (n-1) sets Ri extend over, and it is intended that the spindle motor, characterized in that arranged in the opening angle falls short of a set to not be included in (n-1) sets of salient pole said successive.

In the invention of claim 7 (hereinafter referred to as “the third invention of the present application”),
A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor has a rotating shaft, a rotor case that rotates integrally with the rotating shaft, and a driving magnet fixed to the rotor case,
The stator includes a plate-shaped base, a bearing fixed to the base and rotatably supporting the rotary shaft, and a core having a plurality of salient poles wound around a three-phase connection coil disposed around the bearing. Have
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
On the stator side facing the magnetic upper surface of the rotor case, within the opening angle of the annular portion located between two adjacent salient poles of the core, and between the two salient poles The spindle motor is characterized in that a magnetic generator is arranged so as not to reach the opening angle .

In the invention of claim 9 (hereinafter referred to as “the fourth invention of the present application”),
A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor includes a rotating shaft, a rotor case that rotates integrally with the rotating shaft, a driving magnet fixed to the rotor case, and an annular magnet fixed to the inner peripheral side of the driving magnet. ,
The stator is disposed around the bearing, a plate-shaped base, a bearing fixed to the base and rotatably supporting the rotating shaft, a magnetic attracting body attached to an end of the bearing on the rotor side, and A core having a plurality of salient poles wound with a three-phase connected coil;
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
The magnetic attraction body has a facing surface that faces the annular magnet, and the facing surface is within an opening angle of the annular portion located between two adjacent salient poles of the core , and the 2 The spindle motor is characterized in that it is arranged so as not to be within the opening angle of two salient poles .

  The present invention also includes a disk drive device having the above-described spindle motor of the present invention and a read or write head that moves in a direction perpendicular to the rotation center axis of the spindle motor.

According to the spindle motor of the first invention of the present application and the second invention of the present application, the rotor can be effectively biased by the magnetic imbalance, and the coils wound around the core have a magnetic influence almost equally on each phase. Therefore, the rotation accuracy such as jitter can be improved.
In addition, according to the spindle motors of the third and fourth inventions of the present application, the magnetic influence on the coil wound around the core is minimized while making the ideal magnetic imbalance and causing the rotor to be offset. Therefore, the rotation accuracy such as jitter can be improved.
Further, according to the disk drive device of the present invention, the surface vibration and the center vibration of the disk are improved, and the drive device can stably read and write information.

  Embodiments of the present invention will be exemplarily described below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

(First embodiment)
This embodiment relates to an embodiment of the first invention of the present application.
A basic configuration of a disk drive device according to this embodiment will be described with reference to FIG. FIG. 1 is a plan view showing the disk drive device 101, in which the left half of the paper surface of the rotor R is a cross section taken along the line AA.

  The disk drive device 101 has a configuration in which a chassis 102 is provided with a spindle motor M and a pickup P as a read / write head. The pickup P is attached to the chassis 102 so that the optical axis of the laser beam moves on an axis Y passing through the rotation center C of the spindle motor M and parallel to the rotation plane of the disk D. Since a mechanism for moving the pickup P, signal processing, a motor drive circuit, and the like are not directly related to the present invention, description thereof is omitted.

  Here, for ease of explanation, a line passing through the rotation center C and parallel to the rotation plane of the disk D and intersecting the axis Y at right angles is defined as an axis X. An axis line passing through the rotation center C and orthogonal to the axis line X and the axis line Y (that is, the rotation center axis line of the spindle motor M) is defined as an axis line Z.

The spindle motor M includes a stator S and a rotor R, and the rotor R is provided with a disk guide 103 and a friction sheet 104 so as to function as a turntable. The turntable may be fixed to the rotating shaft separately from the rotor case.
A disk D is placed on a turntable provided in the rotor R. The disk D is centered by the disk guide 103 and rotated by the spindle motor M about the axis Z.
An arcuate magnet 113 having a magnetized portion (magnetized region) 114 magnetized in an arc on an annular magnetic body is attached to the stator S. This arc magnetized body 113 is attached so as to be concentric with the rotation axis, and the magnetized portion 114 is arranged symmetrically with respect to the axis Y and on the pickup P side as viewed from the axis X (in FIG. 1). The magnetized portion 114 is shown by cross-hatching).

The spindle motor M used in the disk drive device 101 of this example will be described with reference to FIGS. FIG. 2 is a side sectional view of the spindle motor M, and is a sectional view partially cut along the line AA in FIG. FIG. 3 is a plan view of the stator S. FIG.
In the stator S, a brass bearing holder 106 cut into a cylindrical shape is attached to a base 105 in which an iron plate is overlapped and attached to a so-called iron substrate or printed wiring board on which a printed circuit is formed. The bearing holder 106 is integrally formed in a cup shape, and a cylindrical guide portion 106a that houses a bearing 107 made of sintered oil-impregnated metal on the inner side and a laminated core 108 on the outer side, and the bearing holder 106 is fixed to the base 105 by caulking or the like. The fixing portion 106b and the holding portion 106d that supports the rotor R in the thrust direction and holds the laminated core 108 are configured.

  The bearing holder 106 is for configuring the bearing 107 as a part of the stator, and may be integrated with the same material as the bearing 107, or may be integrated with a base material (base 105 constituting the stator) with resin or the like. It may be configured. There are various such configurations, and the bearing holder can be integrated with the base material with an iron plate or the like. For example, the bearing holder 106 may be made of resin or metal plate in addition to brass, and in that case, may be integrated with the base 105.

  The bearing 107 is a cylindrical sintered metal impregnated with lubricating oil, and is generally used for a spindle motor. The bearing 107 is fixed to the inner peripheral side of the guide portion 106a by press fitting or the like. In this example, as shown in FIG. 2, the end portion 106e of the bearing holder 106 and the end portion 107e of the bearing 107 are attached so as to have the same height, and a cap 110 is attached to the end portion to prevent scattering of the lubricating oil. It has been.

The laminated core 108 is composed of a laminated plate having a plate-like core formed with a central annular portion 108b and a plurality of salient poles 108a magnetically connected to the outer periphery of the annular portion 108b. The laminated core 108 is fixed to the outer peripheral side of the guide portion 106a of the bearing holder 106 so as to be held with respect to the base 105 by a holding portion 106d. Coils 108d (U1, V1, W1,..., U4, V4, W4) are wound around the salient poles 108a with the insulating sheet 108c inserted.
An arc-shaped magnet 113 is attached to the plate-like core positioned at the uppermost part of the laminated core 108 concentrically with the rotation center C with an adhesive or the like. The arc-shaped magnet 113 is disposed in close proximity to the magnetic upper surface portion of the rotor R, and the magnetized portion 114 is magnetized in two directions of N and S in the axis Z direction.
The sensor 109 is a Hall sensor that is provided on the base 105 so as to face a driving magnet 115 described later and detects the rotation of the rotor R.

The rotor R has a cap-shaped rotor case 111 formed of a magnetic plate so that a magnetic path can be formed, a rotating shaft 112 fixed to the rotor case 111 and supported by the bearing 107 for rotation, and the rotor R functions as a turntable. For this purpose, a disk guide 103 and a friction sheet 104 are integrated on the upper surface of the rotor case 111.
The rotor case 111 is formed of a cylindrical portion 111 a formed in a cylindrical shape coaxially with the rotation shaft 112 and an upper surface portion 111 b having a surface perpendicular to the rotation shaft 112. A cylindrical driving magnet 115 facing the salient pole 108a is attached inside the cylindrical portion 111a. This drive magnet 115 is magnetized in a plurality of NS directions alternately in the circumferential direction.

Here, the stator S will be described in detail with reference to FIG. FIG. 4 is a connection diagram of a coil wound around the salient pole 108a.
In the laminated core 108, 12 salient poles 108a are formed at equal intervals on the outer periphery of the annular portion 108b, and the arrangement angle of each salient pole is 30 degrees. On the other hand, since the coil has three phases by star connection, U, V, and W phases are wound around four salient poles in order. 3 and 4, U1, V1, W1,... U4, V4, W4.

  In the first invention of the present application, the magnetized portion 114 of the arc-shaped magnet 113 is composed of 3n (n is an integer of 2 or more) salient poles around which three-phase connected coils are wound. It arrange | positions with the open angle which straddles the salient pole which forms 1 set thru | or a continuous (n-1) set. In other words, the magnetized portion 114 is an angle including one set to (n−1) sets of U, V, and W three-phase salient poles, and adjacent salient poles not included in the set are It is arranged at an angle that does not reach.

In this example, 12 salient poles are formed to form four sets of three phases, and the magnetized portion 114 is formed with an opening angle of 90 degrees corresponding to three salient poles (that is, one set). (See FIG. 3). When the width of the salient pole is wide, there is not much room until it reaches the adjacent salient pole. In that case, considering the opening angle of the slot 108e between the salient poles, the magnetization portion 114 has a range of about several degrees. The opening angle may be narrowed (that is, for example, an opening angle of 80 to 85 degrees in the minimum magnetization range shown in FIG. 3).
In the first invention of the present application, when the number of salient poles spanned by the magnetized portion 114 is C, in order to avoid as much as possible the influence of magnetic force on the adjacent salient poles not included in the set, The opening angle D is preferably D = 360 degrees ÷ the number of salient poles × the number of phases × C.
That is, when the magnetized portion 114 is formed with an open angle that spans one set of salient poles as a set of three phases of 12 salient poles as in this example, the maximum open angle of the magnetized portion 114 is approximately It may be 90 degrees (that is, 360 degrees ÷ 12 × 3 × 1).

If the arc-shaped magnet 113 is directly disposed on the laminated core 108, the core can serve as a yoke and the rotor can be attracted efficiently. However, the coil wound around the core is likely to have a magnetic influence. If this magnetic influence is unevenly applied to the respective phases of the three-phase connected coils, the rotational accuracy such as jitter is adversely affected.
However, when the magnetized region 114 of the arc-shaped magnet 113 is arranged at an open angle across the salient poles forming one set or three (n-1) sets with three phases as one set as in the first invention of the present application, Magnetic influences are applied to each phase almost evenly, and the influence of magnetism can be reduced as a whole, and the rotational accuracy can be improved while the rotor is offset.

  That is, in the case of this example, as shown in FIG. 4, the range of the influence of the magnetism by the magnetized portion 114 of the arc-shaped magnet 113 on each coil is the first coil of U, V, and W. It becomes uniform. Therefore, for example, the phase of the current flowing through each phase is constant, and the rotor R is rotated with high accuracy.

  FIG. 5 compares the jitter of the spindle motor in which the magnetized portion 114 is arranged as in this example and the comparison spindle motor in which the magnetized portion is arranged only at one salient pole position. The bar graphs a1 to a5 are for the comparative spindle motor, and the bar graphs b1 to b5 are for the spindle motor of this example, and jitter measurement is performed with five samples each. Thus, it can be seen that according to the first invention of the present application, a clear improvement effect is seen, and the jitter is almost halved.

  Further, in this example, the magnetized portion 114 of the arc-shaped magnet 113 is arranged symmetrically with respect to the axis Y and on the pickup P side when viewed from the axis X. Therefore, the resultant force of the attractive force F in the Z direction acting on the rotor R due to the action of the arc-shaped magnet 113 and the magnetic upper surface portion 111b of the rotor case 111 opposed thereto acts on the axis Y. Further, a suction force F acts on the rotor R so as to be moved away from the pickup P, and the inclination direction thereof coincides with the axis Y direction. As described above, when the moving direction of the pickup P and the direction of the shifting are made coincident, information is read and written by the pickup P with high accuracy.

  In this example, the hall sensor 109 is arranged in the direction opposite to the magnetized portion 114 of the arc-shaped magnet 113 when viewed from the axis X. However, if these are arranged in the same direction, the hall sensor 109 passes over the hall sensor 109. The locus of the driving magnet 115 is stabilized and the hall output is stabilized.

  In the first invention of the present application, the moving direction (axis Y direction) of the pickup P substantially coincides with the symmetry axis direction of the magnetized region 114 of the arc-shaped magnetized body passing through the rotation center axis (axis Z) of the rotor. Although effective in characteristics, the direction of the symmetry axis of the magnetized region 114 is a direction perpendicular to the moving direction of the pickup (that is, the direction of the axis X), or a direction inclined by a predetermined angle with respect to the axis Y can be considered. It can be determined appropriately according to the situation in which the drive device is used.

(Second Embodiment)
The present embodiment relates to another embodiment of the first invention of the present application.
A spindle motor used in the disk drive apparatus according to this embodiment will be described with reference to FIGS. 6 is a side cross-sectional view of the spindle motor M, and is a cross-sectional view partially cut along the line AA on the axis Y as in FIG. FIG. 7 is a plan view of the stator S. FIG.
In the first embodiment, the arc-shaped magnet 113 is directly arranged on the core 108, but in this example, the arc-shaped magnet 113 is arranged on the step 106f formed at the upper end of the guide 106a of the bearing holder 106.
Here, the same reference numerals are assigned to the same components as those in the first embodiment, and the description thereof is omitted.

  The arc-shaped magnet 113 is attached so as to be concentric with the rotation axis, and the magnetized portion 114 is arranged symmetrically with respect to the axis Y and on the pickup P side when viewed from the axis X. The magnetized portion 114 is formed with an opening angle of 90 degrees corresponding to three salient poles (that is, one set), and an opening angle straddling one set of salient poles with three phases of 12 salient poles as one set. Is arranged in.

As a result of comparing the jitter of the spindle motor in which the magnetized portion 114 is disposed as in this example and the comparison spindle motor in which the magnetized portion is disposed only at one or two salient pole positions, the present example is clear. Improvement effect was seen.
That is, not only when the arc-shaped magnet 113 is directly disposed on the laminated core 108 as in the first embodiment, but also the arc-shaped magnet 113 is attached to the bearing holder 106 as in this example and is close to the laminated core 108. Even when arranged in the same manner, the magnetic effects are almost equally applied to the respective phases of the three-phase connected coils, and the influence of magnetism can be reduced as a whole. it can. In addition, when at least a part of the arc-shaped magnet is disposed on the core, the first invention of the present application provides a greater improvement effect.

  In the embodiment of the first invention of the present application described above, an arc-shaped magnetic body magnetized with a predetermined angle region is used as an arc-shaped magnetized body. However, in the first invention of the present application, all magnetic bodies having an arcuate outer shape are used. What was magnetized can also be used as an arc-shaped magnet. When an annular arc-shaped magnetized body is used, attachment to the laminated core is relatively easy, but the magnetization range is unclear and alignment is difficult. On the other hand, when an arc-shaped magnetized body in which all the magnetic bodies having an arc-shaped outer shape are magnetized is used, the magnetized range is clear and alignment is easy, but attachment to the laminated core is relatively difficult.

In the embodiment of the first invention of the present application described above, the magnetized portion 114 of the arc-shaped magnet 113 is set to an open angle corresponding to three salient poles (that is, one set). It may be magnetized. For example, when a laminated core is formed with 18 salient poles in three phases, the maximum magnetizing range is 60 degrees to fit one set of salient poles within the magnetizing range, and two sets of phases are magnetized. To fit within the range, the maximum magnetization range is 120 degrees.
However, since it is advantageous to attract the rotor in a narrow range as much as possible for rotational runout accuracy, it is preferable to attach the magnetized portion 114 of the arc-shaped magnetized body 113 so as to straddle only one set of phases. Even when magnetized with two or more pairs of opening angles, if the opening angle of the magnetized portion 114 is 180 degrees or less, the rotation loss due to the attractive force that does not contribute to the shifting is suppressed, The shifting can be performed effectively.

(Third embodiment)
The present embodiment relates to an embodiment of the second invention of the present application.
A disk drive apparatus according to this embodiment will be described with reference to FIGS. FIG. 8 is a plan view showing the disk drive device 201, in which the left half of the paper surface of the rotor R is a cross section taken along the line AA. FIG. 9 is a side sectional view of the spindle motor M, and is a sectional view partially cut along a line AA in FIG. FIG. 10 is a plan view of the stator S. FIG.
Here, the same reference numerals are assigned to the same components as those in the first embodiment, and the description thereof is omitted.

  A magnetic attraction body 202, which is a feature of the second invention of the present application, is attached to the stator S. The magnetic attracting body 202 will be described in detail later.

  In addition to brass, the bearing holder 106 may be made of resin or metal plate. In this case, the bearing holder 106 may be integrated with the base 105. In particular, when the bearing holder 106 is formed of a magnetic plate material, the bearing holder 106 and the magnetic attracting body 202 can be integrally formed by pressing.

  The rotor case 111 is formed of a cylindrical portion 111 a formed in a cylindrical shape coaxially with the rotation shaft 112 and an upper surface portion 111 b having a surface perpendicular to the rotation shaft 112. A cylindrical driving magnet 115 facing the salient pole 108a is attached inside the cylindrical portion 111a. This drive magnet 115 is magnetized in a plurality of NS directions alternately in the circumferential direction. A disk guide 103 and a friction sheet 104 are provided on the upper surface portion 111 b of the rotor case 111.

An annular magnet 203 having a surface 203a that is substantially rectangular in cross section and orthogonal to the rotation shaft 112 is attached to the inner surface on the inner peripheral side of the upper surface portion 111b with the rotation shaft 112 as a center at a position facing the magnetic attracting body 202. . The annular magnet 203 is magnetized with NS2 poles in the axis Z direction.
The annular magnet 203 is attached to the upper surface portion 111b of the rotor case 111. However, the present invention is not limited to this. For example, the center of the upper surface portion 111b is a circular opening and the disk guide 103 is integrated by resin molding. In this case, the disk guide 103 may be attached at a position facing the magnetic attracting body 202.

The inner diameter of the annular magnet 203 is the same as or slightly smaller than an opening 202c (described later) of the magnetic attraction body 202 through which the rotary shaft 112 is inserted, and the outer diameter is slightly larger than the outer diameter of the magnetic attraction body 202. When the magnetic attraction body 202 is attached to the end portion 106e of the bearing holder 106, the diameter thereof is relatively large and the attraction force F by the annular magnet 203 is large.
When the end 107 e of the bearing 107 protrudes from the end 106 e of the bearing holder 106, the magnetic attraction body 202 may be directly attached to the bearing 107. In such a case, the outer diameter of the magnetic attraction body 202 is smaller than that of this example, but the outer diameter of the annular magnet 203 is also the same as or slightly larger than the outer diameter of the magnetic attraction body 202. That is, even if the outer diameter of the annular magnet 203 is increased more than necessary, the attractive force F does not increase.
That is, the efficiency of the surface 203a of the annular magnet 203 and the ceiling portion 202f (details will be described later) of the magnetic attracting body 202 is substantially the same as the inner and outer diameters, or the surface 203a is slightly larger in the radial direction than the ceiling portion 202f. Good.

  11A is a plan view of the magnetic attracting body 202, and FIG. 11B is a side cross-sectional view along the axis Y. FIG.

  The magnetic attraction body 202 is formed of a thin iron plate having ferromagnetism, for example, a silver top having a thickness of 0.25 mm or a SECE material. The shape is a cap, and has a step surface 202a (a portion shown by cross-hatching in FIG. 11A) which is a flat surface perpendicular to the axis Z and a step with respect to the surface 202a which is also a plane perpendicular to the axis Z. It is formed of a lid 202g and a mounting portion 202b having a cylindrical shape concentric with the axis Z. The facing surface 202a faces the surface 203a of the annular magnet 203 in parallel.

The facing surface 202a and the lid 202g are connected by stepped portions 202d and 202e, are formed in a continuous annular shape, and form a ceiling portion 202f as an annular magnetic material. The step is preferably about 0.1 to 0.2 mm. This step is formed so that the facing surface 202a is always convex toward the annular magnet 203 of the rotor with respect to the lid 202g. That is, the ceiling portion 202f is positioned between the end surface 107f of the bearing 107 and the surface 203a of the annular magnet 203, and the facing surface 202a is closer to the surface 203a of the annular magnet 203 than the lid 202g.
Further, the ceiling portion 202f is continuous with the mounting portion 202b at the outer peripheral portion thereof, and the circular opening 202c is formed so that the shaft 112 does not contact the center side and the ceiling portion 202f covers the end surface 107f of the bearing 107. Is formed.

The inner diameter of the mounting portion 202b is substantially the same as the outer diameter of the guide portion 106a of the bearing holder 106. After the mounting portion 202b is attached to the end portion 106e of the guide portion 106a, it is fixed to the guide portion 106a by adhesion, caulking, or the like. When the inner diameter of the mounting portion 202b is slightly smaller than the outer diameter of the guide portion 106a, it can be fixed by press-fitting.
Although the attachment portion 202b is used to attach the magnetic attracting body 202 in this way, the ceiling portion 202f can be directly attached to the end portion 106e of the bearing holder 106 by welding or the like. Moreover, if the bearing holder 106 is formed of a magnetic metal plate as described above, the ceiling portion 202f can be formed continuously with the bearing holder.

  Since the magnetic attracting body 202 is formed of a thin magnetic metal plate, such a shape can be formed by press working. In the shape shown in FIG. 11, the facing surface 202a is formed by the ceiling portion having the same thickness. Similarly, the facing surface 202a is thickened by pressing and the portion of the lid 202g is thinned so that the facing surface 202a protrudes. It is also possible.

If the ceiling portion 202f is configured as described above, it does not protrude greatly in the radial direction with respect to the end portions 107e and 106e of the bearing 107 and the bearing holder 106. For this reason, the annular magnet 203 can be made smaller and the surrounding shape is not affected, so that it is not necessary to enlarge the motor and the degree of freedom in design is increased.
Further, when the magnetic attraction body 202 is formed in a cap shape having an opening 202c through which the shaft passes through the ceiling portion 202f, the magnetic attraction body 202 can be easily attached by the cylindrical attachment portion 202b without enlarging the ceiling portion 202f. be able to.
Further, since the magnetic attracting body 202 is formed in an annular shape in which the facing surface 202a and the lid 202g are continuous and covers the end surface 107f of the bearing 107, the oil impregnated in the bearing 107 can be prevented from scattering. .

  In this example, the opposing surface 202a of the magnetic attracting body 202 is arranged symmetrically with respect to the axis Y and on the side opposite to the pickup P when viewed from the axis X (see FIG. 8). The width of the facing surface 202a (the difference between the radius of the cylindrical mounting portion 202b and the radius of the opening 202c) is determined as appropriate by the required attractive force F in combination with the facing annular magnet 203. In this case, it is desirable that the width of the annular surface formed by the surface 203a of the annular magnet 203 is the same as or larger. Further, it is efficient if the surface 203a and the facing surface 202a face each other in parallel, and the lid 202g portion may not be flatter than the facing surface 202a as long as a step with the facing surface 202a is secured.

  In the second invention of the present application, the opposing surface 202a of the magnetic attracting body 202 is a continuous set of three phases among 3n (n is an integer of 2 or more) salient poles wound with a three-phase connected coil. It arrange | positions with the open angle which straddles the salient pole which forms 1 set thru | or (n-1) set to do. That is, the opposing surface 202a of the magnetic attracting body 202 is an angle that always includes one set to (n-1) sets of U, V, and W three-phase salient poles, and is not included in the set. It is arranged at an angle that does not reach the salient pole.

In this example, 12 salient poles are formed to form four sets of three phases, and the facing surface 202a is formed with an opening angle of 90 degrees corresponding to three salient poles (that is, one set) ( (See FIG. 10). When the salient poles are wide, there is not much room to reach the adjacent salient poles. In that case, considering the opening angle of the slot 108e between the salient poles, the opening of the opposing surface 202a is within a range of several degrees. The angle may be narrowed (that is, the minimum opening angle shown in FIG. 10 is, for example, an opening angle of 80 to 85 degrees).
In the second invention of the present application, when the number of salient poles straddling the opposing surface 202a is C, the maximum opening angle D of the opposing surface 202a is avoided in order to avoid the influence of magnetic force on the adjacent salient poles not included in the set. Is preferably D = 360 ° ÷ the number of salient poles × the number of phases × C.
That is, when the opposing surface 202a is formed with an opening angle that spans one set of salient poles as a set of three phases of 12 salient poles as in this example, the maximum opening angle of the opposing surface 202a is approximately 90 degrees. (That is, 360 degrees ÷ 12 × 3 × 1).

When an annular magnet 203 is provided on the rotor side and a magnetic attraction body 202 is provided on the stator side to create a magnetic imbalance, when this magnetic attraction body 202 is close to and particularly in contact with the laminated core 108, it is wound around the core. Magnetic effects are likely to occur in the coil. If this magnetic influence is unevenly applied to the respective phases of the three-phase connected coils, the rotational accuracy such as jitter is adversely affected.
However, as in the second invention of the present application, the facing surface 202a of the magnetic attracting body 202 adjacent to the annular magnet 203 is opened across the salient poles that form one set or three (n-1) sets of three phases as one set. When arranged at the corners, the magnetic influence is almost equally applied to the respective phases, and the influence of magnetism can be reduced as a whole, and the rotation accuracy can be improved while the rotor is shifted.

  That is, also in the case of this example, the magnetic influence by the annular magnet 203 and the magnetic attracting body 202 acts uniformly on each of the U, V, and W phases. Therefore, for example, the phase of the current flowing through each phase is constant, and the rotor R is rotated with high accuracy.

  The jitter of the spindle motor in which the opposing surface 202a of the magnetic attraction body 202 is arranged as in this example and the comparison spindle motor attached so that the opposing surface of the magnetic attraction body is located only at one or two salient pole positions. As a result of comparison, the present example showed a clear improvement effect.

  Further, since the facing surface 202a of the magnetic attracting body 202 has a step of 0.1 to 0.2 mm with respect to the lid 202g, the action of the annular magnet 203 also acts on the portion of the lid 202g. That is, the action of causing the rotor R to be displaced by the suction force F works, and the suction force in the rotation center axis Z direction also acts on the rotor by the annular facing surface 202a and the lid 202g, so that the rotation of the rotor R is stable. Become.

  Further, in this example, the facing surface 202a of the magnetic attracting body 202 is arranged symmetrically with respect to the axis Y and on the side opposite to the pickup P when viewed from the axis X. Therefore, the resultant force of the attractive force F in the Z direction acting on the rotor R by the action of the annular magnet 203 and the facing surface 202a acts on the axis Y. In addition, a suction force F acts on the rotor R so as to be moved closer to the pickup P, and the inclination direction thereof coincides with the axis Y direction. As described above, when the moving direction of the pickup P and the direction of the shifting are made coincident, information is read and written by the pickup P with high accuracy.

  In the second invention of the present application, the characteristic is that the moving direction (axis Y direction) of the pickup P substantially coincides with the symmetry axis direction of the opposing surface 202a of the magnetic attraction body passing through the rotation center axis (axis Z) of the rotor. Although effective, the axis of symmetry of the opposing surface 202a is a direction perpendicular to the moving direction of the pickup (that is, the direction of the axis X), or a direction inclined by a predetermined angle with respect to the axis Y can be considered. It can be determined appropriately according to the situation of use.

(Fourth embodiment)
The present embodiment relates to another embodiment of the second invention of the present application.
A spindle motor used in the disk drive apparatus according to this embodiment will be described with reference to FIGS. FIG. 12 is a side cross-sectional view of the spindle motor M, and is a cross-sectional view partially cut along the line AA on the axis Y as in FIG. FIG. 13 is a plan view of the stator S. FIG. FIG. 14 is a diagram showing details of the magnetic attraction body, (a) is a plan view thereof, and (b) is a side cross-sectional view along the line AA on the axis Y.
Here, the same components as those in the third embodiment having the same functions are denoted by the same reference numerals, and the description thereof is omitted.

  The magnetic attraction body 202 of this example is formed by a facing surface 202a (a portion indicated by cross-hatching in FIG. 14A) which is a flat surface perpendicular to the axis Z, and a mounting portion 202b having a cylindrical shape concentric with the axis Z. Has been. The facing surface 202a faces the surface 203a of the annular magnet 203 in parallel.

The magnetic attracting body 202 is attached so as to be concentric with the rotation axis, and the opposing surface 202a is arranged symmetrically with respect to the axis Y and disposed on the opposite side of the pickup P as viewed from the axis X. The opposing surface 202a is formed with an opening angle of 90 degrees corresponding to three salient poles (that is, one set), and an opening angle straddling one set of salient poles with three phases of 12 salient poles as one set. Is arranged (see FIG. 13).
Also in this example, the effect of improving the rotation accuracy was seen as in the third embodiment.

  In the second invention of the present application, as in the third and fourth embodiments, a part of the magnetic attraction body 202 is in contact with the core, such as the mounting portion 202b of the magnetic attraction body 202 being directly placed on the core. However, if the magnetic attraction body 202 is close to the core, a predetermined improvement effect can be obtained.

In the third and fourth embodiments, the opposing surface 202a of the magnetic attracting body 202 is set to an open angle corresponding to three salient poles (that is, one set). . For example, when a laminated core is formed of 18 salient poles in three phases, the opening angle is 60 degrees at the maximum to fit one set of salient poles within the opening angle of the opposing surface 202a. Is set to an opening angle of 120 degrees at the maximum to fit within the opening angle of the facing surface 202a, and an opening angle of up to 180 degrees to store the three sets of salient poles within the opening angle of the facing surface 202a.
However, since it is advantageous to suck the rotor in a narrow range as much as possible for rotational runout accuracy, it is preferable that the facing surface 202a is mounted so as to straddle only one set of phases. Even when two or more sets are straddled, if the opening angle of the facing surface 202a is 180 degrees or less, it is effective to perform the misalignment while suppressing the rotation loss due to the suction force that does not contribute to the misalignment. Can be done.

(Fifth embodiment)
The present embodiment relates to an embodiment of the third invention of the present application.
A disk drive apparatus according to this embodiment will be described with reference to FIGS. FIG. 15 is a plan view showing the disk drive device 301, in which half of the rotor R is a cross section taken along the line AA. 16 is a side sectional view of the spindle motor M, and is a sectional view partially cut along a line BB in FIG. FIG. 17 is a plan view of the stator S. FIG.
Here, the same reference numerals are assigned to the same components as those in the first embodiment, and the description thereof is omitted.

  An arc-shaped magnetic generator 302, which is a feature of the third invention of the present application, is attached to the plate-like core positioned at the top of the laminated core 108 with an adhesive or the like concentrically with the rotation center C. The magnetism generator 302 is disposed in close proximity to the magnetism upper surface portion 111b of the rotor R, and is magnetized into two poles of N and S in the axis Z direction.

  In the third invention of this application, the magnetic generator 302 is disposed within the opening angle of the annular portion 108b located between two adjacent salient poles of the stator core. That is, the magnetic generator 302 is disposed so as not to reach the opening angle of the salient pole 108a. In the case of this example, twelve salient poles are formed, the opening angle of the annular portion 108b located between the two salient poles is about 18 degrees, and the opening angle of the magnetic generator 302 is 12 degrees. (See FIG. 17).

When the magnetism generator 302 is directly disposed on the laminated core 108, the core becomes a yoke and the rotor can be attracted efficiently. However, the coil wound around the core is likely to have a magnetic influence. If this magnetic influence is unevenly applied to the respective phases of the three-phase connected coils, the rotational accuracy such as jitter is adversely affected.
However, as in the third invention of the present application, when the magnetic generator 302 is disposed within the opening angle of the annular portion 108b located between two adjacent salient poles of the stator core, an ideal magnetic imbalance is created. However, the magnetic influence on the coil wound around the salient poles can be minimized, and the rotational accuracy can be improved while the rotor is moved to the center.

  As a result of comparing the jitter of the spindle motor in which the magnetic generator 302 is disposed as in this example and the comparison spindle motor in which the magnetic generator having the same opening angle is mounted at an arrangement angle overlapping the salient pole, A clear improvement effect was observed.

  In the third invention of the present application, it is effective in terms of characteristics that the moving direction (axis Y direction) of the pickup P substantially coincides with the symmetry axis direction of the magnetic generator 302 passing through the rotation center axis (axis Z) of the rotor. However, the symmetry axis direction of the magnetic generator 302 can be a direction perpendicular to the moving direction of the pickup (that is, the direction of the axis line X), or a direction inclined by a predetermined angle with respect to the axis line Y. It can be decided appropriately according to the situation.

  Further, it is advantageous to attract the rotor in a narrow range as much as possible for rotational runout accuracy. However, if the opening angle of the magnetic generator 302 is too small, it is difficult to obtain a sufficient attractive force F. The opening angle of 302 is preferably close to the opening angle of the annular portion 108b located between the two salient poles.

In this embodiment, the magnetic generator 302 has an arc shape, but a circular or rectangular shape can also be used.
Further, in the present embodiment, an arc-shaped magnetic generator that is fully magnetized is used. However, in the third invention of the present application, an annular magnetic material that is magnetized at a predetermined angle region may be used as the magnetic generator. it can. When an arc-shaped magnetic generator is used, the magnetization range is clear and positioning is easy, but attachment to the laminated core is relatively difficult. On the other hand, when an annular magnetic generator is used, attachment to the laminated core is relatively easy, but the magnetization range is unclear and alignment is difficult.

(Sixth embodiment)
The present embodiment relates to an embodiment of the fourth invention of the present application.
A disk drive apparatus according to this embodiment will be described with reference to FIGS. FIG. 18 is a plan view showing the disk drive device 401, in which half of the rotor is a cross section taken along the line AA. FIG. 19 is a side cross-sectional view of the spindle motor M, which is a cross-sectional view taken along line BB in FIG. FIG. 20 is a plan view of the stator S. FIG.
Here, the same reference numerals are assigned to the same components as those in the first embodiment, and the description thereof is omitted.

  A magnetic attraction body 402, which is a feature of the fourth invention of the present application, is attached to the stator S. The magnetic attracting body 402 will be described in detail later.

  In addition to brass, the bearing holder 106 may be made of resin or metal plate. In this case, the bearing holder 106 may be integrated with the base 105. In particular, when the bearing holder 106 is formed of a magnetic plate material, the bearing holder 106 and the magnetic attracting body 402 can be integrally formed by pressing.

  The rotor case 111 is formed of a cylindrical portion 111 a formed in a cylindrical shape coaxially with the rotation shaft 112 and an upper surface portion 111 b having a surface perpendicular to the rotation shaft 112. A cylindrical driving magnet 115 facing the salient pole 108a is attached inside the cylindrical portion 111a. This drive magnet 115 is magnetized in a plurality of NS directions alternately in the circumferential direction. A disk guide 103 and a friction sheet 104 are provided on the upper surface portion 111b.

An annular magnet 403 having a substantially rectangular cross section and a surface 403a perpendicular to the rotation shaft 112 centered on the rotation shaft 112 at a position facing the magnetic attracting body 402 is attached to the inner surface of the upper surface portion 111b. . The annular magnet 403 is magnetized with NS2 poles in the axis Z direction.
The annular magnet 403 is attached to the upper surface portion 111b of the rotor case 111. However, the present invention is not limited to this. For example, the center of the upper surface portion 111b is a circular opening and the disk guide 103 is integrated by resin molding. At this time, the disk guide 103 may be attached at a position facing the magnetic attracting body 402.

Further, the inner diameter of the annular magnet 403 is the same as or slightly smaller than the opening 402c (described later) of the magnetic attracting body 402 through which the rotary shaft 112 is inserted, and the outer diameter is slightly larger than the outer diameter of the magnetic attracting body 402. When the magnetic attraction body 402 is attached to the end portion 106e of the bearing holder 106, the diameter thereof is relatively large and the attraction force F by the annular magnet 403 is large.
When the end 107 e of the bearing 107 protrudes from the end 106 e of the bearing holder 106, the magnetic attraction body 402 may be directly attached to the bearing 107. In such a case, the outer diameter of the magnetic attracting body 402 is smaller than that of this example, but the outer diameter of the annular magnet 403 is also the same as or slightly larger than the outer diameter of the magnetic attracting body 402. That is, even if the outer diameter of the annular magnet 403 is increased more than necessary, the attractive force F does not increase.
That is, the efficiency of the surface 403a of the annular magnet 403 and the ceiling portion 402f (details will be described later) of the magnetic attracting body 402 is substantially the same as the inner and outer diameters or the surface 403a is slightly larger in the radial direction than the ceiling portion 402f. Good.

  FIG. 21A is a plan view of the magnetic attracting body 402, and FIG. 21B is a side cross-sectional view along the axis Y.

  The magnetic attraction body 402 is formed of a thin iron plate having ferromagnetism, for example, a silver top having a thickness of 0.25 mm or a SECE material. The shape is a cap, and has a step surface 402a (a portion indicated by cross-hatching in FIG. 21A) which is a flat surface perpendicular to the axis Z, and a step with respect to the surface 402a which is also a plane perpendicular to the axis Z. It is formed by a lid 402g and a mounting portion 402b having a cylindrical shape concentric with the axis Z. The facing surface 402a faces the surface 403a of the annular magnet 403 in parallel.

The facing surface 402a and the lid 402g are connected by stepped portions 402d and 402e, are formed in a continuous annular shape, and form a ceiling portion 402f as an annular magnetic material. The step is preferably about 0.1 to 0.2 mm. The step is formed so that the facing surface 402a is always convex toward the annular magnet 403 of the rotor with respect to the lid 402g. That is, the ceiling portion 402f is located between the end surface 107f of the bearing 107 and the surface 403a of the annular magnet 403, and the facing surface 402a is closer to the surface 403a of the annular magnet 403 than the lid 402g.
Further, the ceiling portion 402f is continuous with the mounting portion 402b at the outer peripheral portion thereof, and a circular opening 402c is formed so that the shaft 112 does not contact the center side and the ceiling portion 402f covers the end surface 107f of the bearing 107. Is formed.

The inner diameter of the mounting portion 402b is substantially the same as the outer diameter of the guide portion 106a of the bearing holder 106. After the mounting portion 402b is attached to the end portion 106e of the guide portion 106a, it is fixed to the guide portion 106a by adhesion, caulking, or the like. When the inner diameter of the mounting portion 402b is slightly smaller than the outer diameter of the guide portion 106a, it can be fixed by press-fitting.
The attachment portion 402b is used to attach the magnetic attracting body 402 in this way, but the ceiling portion 402f can also be attached directly to the end portion 106e of the bearing holder 106 by welding or the like. Moreover, if the bearing holder 106 is formed of a magnetic metal plate as described above, the ceiling portion 402f can be formed continuously with the bearing holder.

  The width of the facing surface 402a of the magnetic attracting body 402 (difference between the radius of the cylindrical mounting portion 402b and the radius of the opening 402c) is determined appropriately according to the required attracting force F in combination with the facing annular magnet 403. In this case, it is desirable that the width of the annular surface formed by the surface 403a of the annular magnet 403 is the same as or larger. Further, the surface 403a and the facing surface 402a are efficient if they face each other in parallel, and the lid 402g may not be flatter than the facing surface 402a as long as a step with the facing surface 402a is secured.

  In the fourth invention of the present application, the facing surface 402a of the magnetic attracting body 402 is disposed within the opening angle of the annular portion 108b located between two adjacent salient poles of the stator core. That is, the facing surface 402a of the magnetic attracting body 402 is disposed so as not to reach the opening angle of the salient pole 108a. In the case of this example, 12 salient poles are formed, the opening angle of the annular portion 108b located between the two salient poles is about 18 degrees, and the opening angle of the facing surface 402a is 12 degrees. Yes.

When an annular magnet 403 is provided on the rotor side and a magnetic attraction body 402 is provided on the stator side to create a magnetic imbalance, when the magnetic attraction body 402 is close to and particularly in contact with the laminated core 108, the core is wound around the core. Magnetic effects are produced on the coil. If this magnetic influence is unevenly applied to the respective phases of the three-phase connected coils, the rotational accuracy such as jitter is adversely affected.
However, when the opposing surface 402a of the magnetic attraction body 402 adjacent to the annular magnet 403 is disposed within the opening angle of the annular portion 108b located between two adjacent salient poles of the stator core as in the fourth invention of the present application, While creating an ideal magnetic imbalance, the magnetic influence on the coil wound around the core can be minimized, and the rotational accuracy can be improved while the rotor is shifted.

  As a result of comparing the jitter of the spindle motor in which the opposing surface 402a of the magnetic attraction body 402 is arranged as in this example and the comparison spindle motor in which the opposing surface 402a is attached at an arrangement angle overlapping the salient pole, the thing in this example is clear. The improvement effect was seen.

  Further, since the facing surface 402a of the magnetic attracting body 402 has a step of 0.1 to 0.2 mm with respect to the lid 402g, the action of the annular magnet 403 also acts on the portion of the lid 402g. That is, the action of causing the rotor R to be biased by the suction force F works, and the suction force in the direction of the rotation center axis Z also acts on the rotor by the annular facing surface 402a and the lid 402g, so that the rotation of the rotor R is stable. Become.

  In the fourth invention of the present application, the characteristic is that the moving direction (axis Y direction) of the pickup P substantially coincides with the axis of symmetry of the opposing surface 402a of the magnetic attracting body passing through the rotation center axis (axis Z) of the rotor. Although effective, the direction of the symmetry axis of the facing surface 402a is a direction perpendicular to the moving direction of the pickup (that is, the direction of the axis X), or a direction inclined by a predetermined angle with respect to the axis Y can be considered. It can be determined appropriately according to the situation of use.

  In addition, it is advantageous to attract the rotor in a narrow range as much as possible for rotational runout accuracy. However, if the opening angle of the facing surface 402a of the magnetic attractant is too small, it is difficult to obtain a sufficient attracting force F. The opening angle of the facing surface 402a is preferably close to the opening angle of the annular portion 108b located between the two salient poles.

FIG. 2 is a plan view showing a disk drive device according to an embodiment of the first invention of the present application, in which half of the rotor is a cross-section taken along line AA. FIG. 2 is a side cross-sectional view of a spindle motor used in the disk drive device of FIG. 1, and is a cross-sectional view partially cut along line AA in FIG. 1. It is a top view which shows the stator of the spindle motor used for the disk drive device of FIG. FIG. 2 is a coil connection diagram of a spindle motor used in the disk drive device of FIG. 1. It is a figure for demonstrating the rotation precision (jitter) of the spindle motor of this-application 1st invention. It is a side view of the spindle motor used for the disk drive device concerning another example of an embodiment of the 1st invention of this application, and is a sectional view cut partially along line AA. It is a top view which shows the stator of the spindle motor of FIG. It is a top view which shows the disk drive device based on one Example of this-application 2nd invention, and is the figure which made the half of the rotor the cross section along the AA line. FIG. 9 is a side cross-sectional view of a spindle motor used in the disk drive device of FIG. 8, and is a cross-sectional view partially cut along line AA in FIG. 8. It is a top view which shows the stator of the spindle motor used for the disk drive device of FIG. It is a figure which shows the detail of the magnetic attraction body used for the disk drive device of FIG. 8, (a) shows the top view, (b) shows side surface sectional drawing along the axis line Y. It is a side view of the spindle motor which concerns on another example of embodiment of this-application 2nd invention, and shows the cross section along line AA of FIG. It is a top view which shows the stator of the spindle motor of FIG. It is a figure which shows the detail of the magnetic attraction body of the spindle motor of FIG. 12, (a) shows the top view, (b) shows side surface sectional drawing along the axis line Y. It is a top view which shows the disk drive device based on one Example of this-application 3rd invention, and is the figure which made the half of the rotor the cross section along the AA line. FIG. 16 is a side sectional view of a spindle motor used in the disk drive device of FIG. 15, which is a sectional view partially cut along a line BB in FIG. 15. It is a top view which shows the stator of the spindle motor used for the disk drive device of FIG. It is a top view which shows the disk drive device which concerns on one Example of this-application 4th invention, and is the figure which made the half of the rotor the cross section along the AA line. FIG. 19 is a side cross-sectional view of a spindle motor used in the disk drive device of FIG. 18, and is a cross-sectional view partially cut along line BB in FIG. It is a top view which shows the stator of the spindle motor used for the disk drive device of FIG. It is a figure which shows the detail of the magnetic attraction body used for the disk drive device of FIG. 18, (a) shows the top view, (b) shows side surface sectional drawing along the axis line Y.

Explanation of symbols

101, 201, 301, 401 Disc drive device 102 Chassis 103 Disc guide 104 Friction sheet 105 Base 106 Bearing holder 106a Guide portion 106b Fixing portion 106d Holding portion 106e End portion of bearing holder 106f Stepped portion 107 Sintered oil-impregnated bearing 107e End of bearing Part 107f End face of bearing 108 Laminated core 108a Salient pole 108b Annular part 108c Insulating sheet 108d Coil 108e Slot 109 Sensor 110 Cap 111 Rotor case 111a Cylindrical part 111b Upper surface part 112 Rotating shaft 113 Arc-shaped magnet body 114 Magnetized part 115 Driving magnet 202, 402 Magnetic attracting body 202a, 402a Opposing surface 202b, 402b Mounting portion 202c, 402c Opening 202d, 202e, 402d, 402e Stepped portion 202 , 402 g lid 202f, 402f ceiling 203,403 annular magnet 302 a magnetic generator U1, V1, W1 ··· coil M spindle motor P pickup C center of rotation X, Y, Z-direction

Claims (11)

A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor has a rotating shaft, a rotor case that rotates integrally with the rotating shaft, and a driving magnet fixed to the rotor case,
The stator includes a plate-like base, a bearing fixed to the base and rotatably supporting the rotating shaft, and a coil 3n connected around the bearing and wound in three phases (n is an integer of 2 or more) ) Having a core with one salient pole,
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
On the stator side facing the magnetic upper surface portion of the rotor case, an arc magnetized body magnetized in an arc shape is attached so that the magnetized region is concentric with the rotating shaft,
Magnetized areas of the arcuate wear magnetized member is of the salient pole, to set free for three consecutive phases as one set Ri straddle the salient poles to form the (n-1) sets, and, to the set not consecutive (N-1) A spindle motor characterized by being arranged with an open angle that does not reach salient poles not included in the set .   The spindle motor according to claim 1, wherein an opening angle of a magnetized region of the arc-shaped magnet is 180 ° or less.   The spindle motor according to claim 1, wherein at least a part of the arc-shaped magnetized body is disposed on the core. A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor includes a rotating shaft, a rotor case that rotates integrally with the rotating shaft, a driving magnet fixed to the rotor case, and an annular magnet fixed to the inner peripheral side of the driving magnet. ,
The stator is disposed around the bearing, a plate-shaped base, a bearing fixed to the base and rotatably supporting the rotating shaft, a magnetic attracting body attached to an end of the bearing on the rotor side, and A core having 3n (n is an integer of 2 or more) salient poles around which a three-phase connected coil is wound;
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
The magnetic attraction member has a facing surface that faces the annular magnet, salient said facing surface of said salient poles, which forms a to set no continuous three-phase as one set (n-1) sets straddling Ri, and a spindle motor, characterized in that it is arranged in an opening angle falls short of a set to (n-1) are not included in the set saliency said contiguous to.   The spindle motor according to claim 4, wherein an opening angle of the facing surface is 180 degrees or less.   The spindle motor according to claim 4, wherein a part of the magnetic attraction body is disposed on the core. A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor has a rotating shaft, a rotor case that rotates integrally with the rotating shaft, and a driving magnet fixed to the rotor case,
The stator includes a plate-shaped base, a bearing fixed to the base and rotatably supporting the rotary shaft, and a core having a plurality of salient poles wound around a three-phase connection coil disposed around the bearing. Have
The core is composed of at least one plate-like core formed with a central annular portion and a plurality of salient poles that are magnetically connected to the annular portion,
On the stator side facing the magnetic upper surface of the rotor case, within the opening angle of the annular portion located between two adjacent salient poles of the core, and between the two salient poles A spindle motor characterized in that a magnetic generator is arranged so as not to reach the opening angle .   The spindle motor according to claim 7, wherein the magnetic generator is disposed on the core. A spindle motor having a rotor provided with a turntable on which a disk is placed, and a stator that rotatably supports the rotor,
The rotor includes a rotating shaft, a rotor case that rotates integrally with the rotating shaft, a driving magnet fixed to the rotor case, and an annular magnet fixed to the inner peripheral side of the driving magnet. ,
The stator is disposed around the bearing, a plate-shaped base, a bearing fixed to the base and rotatably supporting the rotating shaft, a magnetic attracting body attached to an end of the bearing on the rotor side, and A core having a plurality of salient poles wound with a three-phase connected coil;
The core is composed of an annular portion on the center side and at least one plate-like core in which a plurality of the salient poles connected to the annular portion and magnetically connected are formed.
The magnetic attraction body has a facing surface that faces the annular magnet, and the facing surface is within an opening angle of the annular portion located between two adjacent salient poles of the core , and the 2 A spindle motor characterized in that it is arranged so as not to extend within the opening angle of two salient poles .   The spindle motor according to claim 9, wherein a part of the magnetic attraction body is disposed on the core.   11. A disk drive device comprising: the spindle motor according to claim 1; and a read or write head that moves in a direction perpendicular to a rotation center axis of the spindle motor.

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