JP2004120932A - Motor and disk unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor that can suppress the occurrence of cogging, is thin and can generate strong torque, and to provide a disk device. <P>SOLUTION: This motor is an outer rotor motor. The motor is characterized in that an armature having a cylindrically formed back yoke 3 and a coil 4 wound round a cylinder peripheral face is concentrically arranged at a motor base 8; an external peripheral magnet 6 that is formed into a cylindrical shape and has a plurality of magnetic poles magnetized to its cylindrical peripheral face is arranged at the peripheral part of the armature; an internal peripheral magnet 11 that is formed into a cylindrical shape and has a plurality of magnetic poles magnetized to its cylindrical peripheral face is arranged at the internal peripheral part of the armature; and the magnetic pole appearing on the internal peripheral face of the external peripheral magnet 6 and the magnetic pole appearing on the external peripheral face of the internal peripheral magnet 11 become one and the same magnetic pole at a cylinder peripheral face position where the magnetic poles oppose each other. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor used for rotationally driving a disk-shaped medium, and more particularly to a rotating field type motor, and more particularly, to a motor characterized by an armature structure and a field structure. The present invention also relates to a disk-shaped medium rotation drive device using these motors, for example, a disk device.
[0002]
The disc-shaped medium refers to a concentric disc-shaped medium having a center hole, and includes, for example, old record (LP, EP, etc.) discs, floppy (R) discs, MO, MD, PD, CD (ROM, R, RW), DVD (ROM, R, RW, RAM) and the like. As a general term including these, it is simply abbreviated as a disk hereinafter. In addition, the disk is intended to rotate the disk, and is generically referred to as a disk regardless of whether the disk is housed in a jacket or not.
[0003]
[Prior art]
As the motor used to drive the disk in rotation, a rotating field type outer rotor type motor is generally used because of its smooth rotation and simple structure. Further, in response to demand for rapid acceleration / deceleration performance, motors having high torque in addition to smooth rotation are also supplied. For example, it is common practice to use a new magnetic material as a field to increase the magnetic flux density. Alternatively, a motor having a feature in a field structure has been proposed (for example, see Patent Document 1).
[0004]
[Patent Document 1]
JP-A-54-156106 (Page 2, FIG. 1 (b) and FIG. 2)
[0005]
[Problems to be solved by the invention]
Electronic devices equipped with a disk device, particularly personal computers and AV playback devices, are required to be small, thin, and lightweight. In order to make the disk device thin, the thickness of the motor (the thickness in the direction of the disk rotation axis) is required. Therefore, it is required to reduce the thickness in the axial direction of the motor. Naturally, it is necessary to maintain high torque that satisfies smooth rotation and acceleration / deceleration performance. However, it has been difficult to realize a thin motor having smooth rotation and high torque.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a thin motor capable of generating strong torque by reducing the occurrence of cogging, and a disk device using the motor.
[0007]
[Means for Solving the Problems]
The present invention has been made in order to solve the above problems, and is a motor in which a rotating shaft of a rotating disk is axially mounted on a bearing member fixed to a base, wherein the base has an electric motor formed in a cylindrical shape. An armature having an armature yoke and an armature coil wound around a cylindrical peripheral surface of the armature yoke is arranged concentrically with the bearing member, and is formed in a cylindrical shape and a plurality of magnetic poles are attached to the cylindrical peripheral surface. A magnetized outer peripheral cylindrical field is arranged on the rotating disk concentrically with the bearing member on the outer peripheral portion of the armature, and is formed in a cylindrical shape and a plurality of magnetic poles are magnetized on a cylindrical peripheral surface. A field is arranged on the rotating disk concentrically with the bearing member on the inner peripheral portion of the armature, and the magnetic poles appearing on the inner peripheral surface of the outer cylindrical field and the outer peripheral surface of the inner cylindrical field are formed on the rotating disk. Arranged so that the magnetic poles appearing are the same at the position of the cylindrical surface facing each other Motor, characterized, and a disk apparatus using this motor.
[0008]
With the above-described motor configuration, it is possible to provide a thin motor that generates less cogging, is thin, and can generate a strong torque, and a disk device using the motor.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
According to a first aspect of the present invention, there is provided a motor in which a rotating shaft of a turntable is axially mounted on a bearing member fixed to a base, wherein the base comprises an armature yoke formed in a cylindrical shape and a cylindrical periphery of the armature yoke. An armature having an armature coil wound on the surface is arranged concentrically with the bearing member, and an outer peripheral cylindrical field formed by forming a cylindrical shape and magnetizing a plurality of magnetic poles on the cylindrical peripheral surface is used as the armature. An inner peripheral cylindrical field, which is arranged on the rotating disk concentrically with the bearing member on the outer peripheral portion and is formed in a cylindrical shape and magnetizes a plurality of magnetic poles on the cylindrical peripheral surface, is concentric with the bearing member on the inner peripheral portion of the armature. And arranged so that the magnetic poles appearing on the inner peripheral surface of the outer cylindrical field and the magnetic poles appearing on the outer peripheral surface of the inner cylindrical field have the same pole at the positions of the cylindrical peripheral surfaces facing each other. And a disk device using the motor.
[0010]
A motor that can generate strong torque on the outer and inner circumferential portions of the armature coil in the circumferential direction when current flows through the armature coil wound around the armature yoke cylindrical surface. A motor that can be configured and a disk device using the motor can be provided.
[0011]
In particular, by generating a suction force in the thrust direction, it is possible to prevent the rotor of the motor from being pulled out of the bearing of the motor, and to prevent the rotor from floating during rotation of the motor.
[0012]
Also, in the armature yoke, the magnetic force generated from the cylindrical field arranged on the outer periphery of the armature yoke does not interfere with the magnetic force generated from the cylindrical field arranged on the inner periphery of the armature yoke. By this, the flow of magnetic flux crossing the armature coil wound around the cylindrical surface of the armature yoke becomes lubricated, and when current flows through the armature coil wound around the armature yoke cylindrical surface, the A strong torque can be generated in the outer peripheral portion and the inner peripheral portion in the circumferential direction of the child coil.
[0013]
Further, the attraction force generated between the armature yoke and the cylindrical field disposed on the outer peripheral portion and the inner peripheral portion of the armature yoke is reduced, and the armature coil wound around the armature yoke cylindrical peripheral surface. The cylindrical field disposed on the outer and inner peripheral portions of the armature yoke so that the magnetic flux density generated by the cylindrical field disposed on the outer and inner peripheral portions of the armature yoke passing therethrough increases. By providing a predetermined gap between the armature and the armature yoke, the efficiency of the motor can be improved.
[0014]
Also, by increasing the circumferential thickness of the cylindrical field disposed on the outer peripheral portion of the armature yoke, the magnetic flux density passing through the outer peripheral portion of the armature coil wound on the cylindrical peripheral surface of the armature yoke is increased. Can be higher. Further, the more the position of the armature coil wound on the cylindrical peripheral surface of the armature yoke is moved outward in the circumferential direction, the more the rotation generated on the outer peripheral portion of the armature coil wound on the cylindrical peripheral surface Power can be increased.
[0015]
In addition, the armature coil is wound around the cylindrical peripheral surface of the armature yoke with respect to the armature yoke. Can suppress the generation of a force in the reverse direction.
[0016]
In addition, the armature coil wound around the upper surface of the armature yoke by applying a magnetic flux from the cylindrical field disposed on the outer and inner peripheral portions of the armature yoke from the upper surface direction of the armature yoke. When an electric current is applied to the armature coil, a rotational force is generated in the same direction as the rotational force generated by the outer peripheral portion and the inner peripheral portion of the armature coil wound on the armature yoke. it can.
[0017]
In particular, from the upper surface direction of the armature yoke, the magnetic flux is applied from the cylindrical field arranged on the outer peripheral portion and the inner peripheral portion of the armature yoke, so that the armature coil wound on the upper surface position of the armature yoke is formed. When the electric current flows, a rotational force is generated in the same direction as the rotational force generated by the outer and inner peripheral portions of the armature coil wound on the armature yoke, and the rotational force can be increased. .
[0018]
According to a second aspect of the present invention, there is provided a motor in which a rotating shaft of a rotating disk is axially mounted on a bearing member fixed to a base, wherein the base has an armature yoke formed in a cylindrical shape and an armature yoke. An armature having an armature coil wound around a cylindrical peripheral surface is arranged concentrically with a bearing member, and an outer peripheral cylindrical field formed by forming a cylindrical shape and magnetizing a plurality of magnetic poles on the cylindrical peripheral surface. An inner peripheral cylindrical field is disposed on the rotating disk concentrically with the bearing member on the outer peripheral portion of the armature, and is formed in a cylindrical shape and a plurality of magnetic poles are magnetized on the cylindrical peripheral surface. And concentrically arranged on the turntable so that the magnetic poles appearing on the inner peripheral surface of the outer cylindrical field and the magnetic poles appearing on the outer peripheral surface of the inner cylindrical field become the same pole at the position of the opposing cylindrical surface. The armature yoke is composed of a plurality of divided pieces formed of a laminated core, Motor, characterized in that it is formed, and a disk apparatus using this motor.
[0019]
According to the present invention, the winding of the coil can be facilitated by dividing the armature yoke.
[0020]
In particular, by combining the divided armature yokes such that the protrusions and recesses at both ends thereof coincide with each other, it is possible to prevent a reduction in magnetic flux flowing in the armature yoke.
[0021]
Further, by forming the armature coil in advance into the air-core coil, the winding operation can be managed as a component. Alternatively, by winding an armature coil around the split piece in advance, the split piece and the coil can be managed as an integral part.
[0022]
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention will be described below by taking a spindle motor for driving a disk as an example of a type of motor that can effectively utilize the features of the present invention. Needless to say, the examples used in the description do not limit the present invention to applications of the spindle motor.
[0023]
(Embodiment 1)
FIG. 1 is a perspective view of a motor according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a rotating shaft of a motor. 2 is a bearing for the rotating shaft 1. Reference numeral 3 denotes a back yoke made of a magnetic material, which is arranged concentrically with respect to the rotating shaft 1 and 4 is a coil wound around the back yoke 3. Reference numeral 5 denotes a yoke, and reference numeral 6 denotes an outer peripheral magnet arranged on the outer peripheral portion of the back yoke 3. The outer peripheral magnet 6 holds the outer peripheral magnet 6 by being closely attached to the yoke 5, and a radial plane is a turntable 13. It has the function of Reference numeral 11 denotes an inner peripheral magnet disposed on the inner peripheral portion of the back yoke 3, and reference numeral 12 denotes an inner peripheral yoke attached so as to be in close contact with the inner peripheral magnet.
[0024]
Since the chucking unit 15 and the chucking ball 16 provided on the turntable 13 are the same as those described in the related art, the same names and reference numerals are given and duplicate explanations are omitted.
[0025]
The outer peripheral magnet 6 and the inner peripheral magnet 11 are formed in a cylindrical shape, and a plurality of poles are alternately magnetized N / S in the circumferential direction of the cylindrical peripheral surface. The outer magnet 6 and the back yoke 3 around which the coil 4 is wound are arranged concentrically with respect to the rotating shaft 1 with a predetermined gap therebetween. Reference numeral 8 denotes a motor base to which the bearing 2 and the back yoke 3 are fixed.
[0026]
Next, the armature (stator) portion, which is a feature of the present invention, will be described in detail.
FIG. 2 is a plan view of a main part of FIG. In FIG. 2, the armature portion includes a back yoke 3 and a coil 4. First, the back yoke 3 is formed of a ferromagnetic material having a high magnetic permeability in a cylindrical shape using a magnetic material. It is a magnetic material that is easy to work with and easy to obtain, and generally uses carbon steel, electromagnetic steel, and silicon steel. Since an alternating magnetic flux flows through the back yoke 3, ferromagnetic bodies formed in a thin plate shape may be stacked and used for the purpose of reducing eddy current loss. In addition, it is also possible to use a sintered material that can be easily formed in consideration of economical efficiency at the time of mass production as a material of the back yoke. In this case, a ferrite-based sintered material or the like is preferably used.
[0027]
Next, a method of winding the coil 4 around the back yoke 3, which is a first feature of the present invention, will be described. FIG. 3 is a diagram for explaining the coil winding method of FIG. Here, for convenience of description, a motor constituted by 18 coils 4, a 12-pole outer magnet 6, and an inner magnet 11 will be described. In FIG. 3, the 18 coils 4 are all wound around the back yoke 3 in the same direction A to simplify the winding process (for all the coils, the direction is opposite to the direction A). It is also possible to roll.) Now, since the coil 4 is the smallest structural unit, it is abbreviated as a unit coil 41 for ease of description below.
[0028]
FIG. 4 is a connection diagram of all the coils of FIG. In FIG. 4, the unit coil 41 is formed into a three parallel circuit in which unit coils 41 are connected in series. That is, it becomes a three-phase armature coil. All winding end terminals of each series connection are connected to form a COM terminal (indicated by C in the figure), and are connected to a common power supply (for example, 0 V) of all circuits. The winding start terminal of each series connection is connected to a three-phase power supply (indicated as U, V, W in the figure). The circuit configuration shown in FIG. 4 is an example for explaining the basic configuration, and the present invention is not limited to the above description. For example, the number of unit coils 41 connected in series is one circuit. However, four or more circuits may be used. Also, the number of parallel circuits is not limited to three, and may be six.
[0029]
Next, the field portion will be described. FIG. 5 is a magnet layout diagram of FIG. The outer peripheral magnet 6 is formed of a ferromagnetic material in a cylindrical shape. The cylindrical peripheral surface facing the back yoke 3 is precisely machined with high accuracy in outer diameter dimensional accuracy and roundness. Therefore, the cylindrical peripheral surface is formed on a smooth and continuous peripheral surface. The cylindrical peripheral surface of the outer peripheral magnet 6 is magnetized with a plurality of poles in the circumferential direction of N, S, N, S,..., And the yoke 5 is fixed and held on the outer peripheral surface of the outer periphery magnet 6. ing. The yoke 5 functions as a yoke for increasing the gap magnetic flux density between the outer magnet 6 and the back yoke 3.
[0030]
Similarly, the inner peripheral magnet 11 is formed of a ferromagnetic material in a cylindrical shape, and the cylindrical peripheral surface portion facing the back yoke 3 is precisely machined with high accuracy in outer diameter dimension accuracy and roundness. Therefore, the cylindrical peripheral surface is formed on a smooth and continuous peripheral surface. The cylindrical peripheral surface of the inner peripheral magnet 11 is magnetized with a plurality of poles in the circumferential direction of N, S, N, S,. Fixed on the surface. The inner yoke 12 functions as a yoke for increasing the gap magnetic flux density between the outer magnet 6 and the back yoke 3.
[0031]
As shown in FIG. 5, the 12-pole outer magnet 6 and the 12-pole inner magnet 11 are attached to the yoke 5 such that the same poles face each other. As a result, as shown in FIG. 6, the outer peripheral magnet 6 forms a magnetic circuit that passes through the back yoke 3 and returns to a different pole next to the outer peripheral magnet 6. FIG. 6 is a diagram for explaining the magnetic flux emitted from the magnet of FIG. Similarly, the inner circumferential magnet 11 forms a magnetic circuit that passes through the back yoke 3 and returns to a different polarity next to the inner circumferential magnet 11.
[0032]
At this time, in the back yoke 3, the magnetic flux generated from the outer magnet 6 and the magnetic flux generated from the inner magnet 11 must prevent interference of the magnetic flux in the back yoke 3. 7 is an enlarged view of a main part of FIG. 6, and as shown in FIG. 7, the yoke thickness t1 secures a sufficient magnetic flux density, prevents eddy current loss, and reduces the resistance loss of the coil 4. Set to be less. To satisfy the former two, it is necessary to increase t1, and to satisfy the latter, it is necessary to reduce t. In the spindle motor of the disk drive to which the present invention is applied, by setting the yoke thickness t1 to 1.2 ≧ t1 ≧ 2.0 (mm), a motor having a suitable low loss performance can be obtained. .
[0033]
Next, the height relationship between the outer magnet 6, the inner magnet 11, and the back yoke 3, which are field portions, will be described. FIG. 8 is a sectional view of a main part of FIG. 1, and FIG. 9 is a partially enlarged view of FIG. 8, the upper surface of the outer magnet 6 and the upper surface of the inner magnet 11 are provided at a position higher than the height of the back yoke 3 with respect to the motor base 8. Thereby, as shown in FIG. 9, an attractive force including a downward component is generated in the outer magnet 6, the inner magnet 11, and the back yoke 3. Therefore, the attraction force generated between the outer peripheral magnet 6 and the inner peripheral magnet 11 causes the yoke 5 to be prevented from being removed from the bearing 2 by the buoyancy generated when the yoke 5 rotates. Things. Therefore, the retaining mechanism can be omitted, and the cost can be reduced and the weight of the rotor unit can be reduced.
[0034]
Next, in order to control the rotation of the motor, a means for sensing the rotation state (change in the magnetic flux during rotation, the number of rotations, etc.) is required. As a sensing means therefor, for example, magnetic sensors 7 such as Hall elements are attached at several places, and the rotational state of the motor is sensed to perform feedback control. FIG. 10 is a perspective view of a motor using a magnetic sensor. Reference numeral 7 denotes a magnetic sensor serving as a sensing means, which represents a state in which the magnetic sensor 7 is disposed in a gap between the inner peripheral magnet 11 which is a field portion and a lower portion of the motor base 8.
[0035]
Using the magnetic flux leaking from the inner peripheral magnet 11, the magnetic sensor 7 detects a change in the field. The drive current of the unit coil 41 is controlled based on the detection result. Since the magnetic sensor 7 is disposed in the gap between the inner peripheral magnet 11 and the lower part of the motor base 8, it is not necessary to widen the magnetic gap or change the magnetic gap length. Therefore, the air gap between the field portion and the unit coil 41 can be accurately maintained within a narrow range.
[0036]
Next, the arrangement of the back yoke 3 around which the outer magnet 6, the inner magnet 11 and the unit coil 41 are wound will be described. FIG. 11 is a diagram illustrating the attraction force between the magnet and the back yoke. An attractive force is generated between the outer magnet 6, the inner magnet 11 and the back yoke 3 by the outer magnet 6 and the inner magnet 11.
When the distance between the outer magnet 6 and the back yoke 3 or the distance between the inner magnet 11 and the back yoke 3 is reduced, the motor is driven to overcome the attractive force between the outer magnet 6, the inner magnet 11 and the back yoke 3. More torque must be generated to rotate it.
[0037]
Conversely, if the distance between the outer magnet 6 and the back yoke 3 or the distance between the inner magnet 11 and the back yoke 3 is increased to reduce the attractive force between the outer magnet 6 and the back yoke 3, the magnetic flux crossing the coil 4 And the generated torque also decreases. Therefore, the gap (gap length g) between the outer magnet 6 and the back yoke 3 minimizes the attraction force acting between the outer magnet 6 and the back yoke 3 or between the inner magnet 11 and the back yoke 3 and makes the coil 4 smaller. The number of magnetic fluxes traversing is made as large as possible to provide an optimal positional relationship that maximizes the generation of torque.
[0038]
In FIG. 7 again, g represents the gap length. When the back yoke 3 and the outer magnet 6 were made of the materials described at the beginning, a motor having the required high torque and low cogging performance could be obtained when 1.0 ≧ g ≧ 1.5 (mm).
[0039]
Next, the circumferential thickness t2 of the outer magnet 6 in FIG. 7 will be described. When the outer diameter shape of the yoke 5 is determined, the outer diameter shape of the outer peripheral magnet 6 is also determined. When it is desired to increase the rotational force of the motor, it is desirable to increase the circumferential thickness t2 of the outer magnet 6 and increase the magnetic flux generated from the outer magnet 6. However, by increasing the thickness t2 of the outer magnet 6 in the circumferential direction, the position of the coil 4 wound around the back yoke 3 becomes the inner circumferential direction, and the rotational torque decreases.
[0040]
Therefore, it is necessary to secure the circumferential thickness t2 of the outer magnet 6 so as to maximize the generation of the rotational torque, and to position the coil 4 wound around the back yoke 3 in the outer circumferential direction. In the spindle motor of the disk drive to which the present invention is applied, by setting the yoke thickness t2 to 1.5 ≧ t2 ≧ 2.0 (mm), it is possible to obtain a motor having a suitable rotation torque. Was.
[0041]
Next, FIG. 12 is a diagram illustrating the winding angle of the coil, and the winding angle of the coil 4 wound around the back yoke 3 will be described. θ represents an angle occupied by the unit coil 41 in the front periphery of the back yoke 3. As described above, the coil 4 is aligned and wound around the cylindrical portion of the back yoke 3. Here, in the present embodiment, since the 18 unit coils 41 are wound, the unit coil 41 can be wound by 20 degrees with respect to one unit coil 41. When the unit coil 41 is wound around the unit 3, a reverse rotational force may be partially generated in an arbitrary positional relationship between the outer magnet 6, the inner magnet 11 and the unit coil 41. In a spindle motor of a disk drive to which the present invention is applied, when the winding angle θ is 12 ≧ θ (°), no reverse rotational force is generated, or when θ approaches 12 (°), the reverse rotational force A motor whose generation was suppressed was obtained.
[0042]
Subsequently, the rotation operation of the motor of the present invention will be described. As shown in FIG. 6, a magnetic circuit is formed in which the magnetic flux generated from the outer magnet 6 and the inner magnet 11 enters the back yoke 3 so as to go straight through the coil 4 wound around the back yoke 3. Have been. When a current flows through the coil 4, an electromagnetic force is applied to the coil 4 according to Fleming's left-hand rule. That is, FIG. 13 is a diagram for explaining the generation of the rotational force. In FIG. 13, the magnetic flux passing from the outer magnet 6 and the inner magnet 11 toward the back yoke 3 (in the radial direction) corresponds to the current flowing through the copper wire of the coil 4. Since the component in the axial direction (the same direction as the motor shaft) crosses the magnetic flux, the direction of the electromagnetic force is generated in the normal direction of the coil 4, that is, in the rotation direction.
[0043]
Since the actual armature part is on the fixed side, the field part, that is, the outer magnet 6, the inner magnet 11, and the yoke 5 rotate by the reaction. Therefore, it becomes a rotating field type. By controlling the direction and timing of the current flowing through the coil 4 in order based on the positional relationship between the coil 4 and the inner peripheral magnet 11 using the signal of the magnetic sensor 7, a rotating force is generated in sequence, The motor keeps rotating.
[0044]
Further, FIG. 14 is a diagram for explaining generation of rotational force, FIG. 15 is a sectional view of a motor having the structure of FIG. 14, and FIG. 16 is a diagram for explaining magnetic flux in FIG. At this time, as shown in FIG. 5, the 12-pole outer magnet 6 and the 12-pole inner magnet 11 are attached to the yoke 5 such that the same poles face each other. As shown in FIGS. 14 and 15, the upper magnet 17 is added to the outer yoke 6 so that the outer magnet 6 and the inner magnet 11 have the same magnetic force direction as the poles facing each other. Rotational force is also generated in the coil on the upper surface of the coil 4, and a motor with higher torque can be obtained.
[0045]
Further, even when the upper magnet 17 is not used, the height of the back yoke 3 is reduced as shown in FIG. 16 so that the coil wound around the back yoke 3 from the outer magnet 6 and the inner magnet 11. By passing the magnetic flux to the upper surface of the coil 4, a high torque motor can be obtained using the upper surface of the coil 4.
[0046]
Next, the winding process of the coil 4 will be described. First, FIG. 17 is an assembly explanatory diagram in the case where a coil is wound directly around a divided back yoke. For example, as shown in FIG. 17A, the entire circumference of the ring-shaped back yoke 3 is divided into a plurality of parts in order to facilitate the winding of the coil 4.
[0047]
The entire circumference is divided into three in the circumferential direction, and the coil 4 is wound around the divided back yoke 3 according to a guide such as a projection for dividing the coil provided on the back yoke 3 with a material such as resin. The plurality of back yokes 3 around which the coils 4 are wound are joined by means such as welding to form a ring-shaped back yoke 3. That is, as shown in FIG. 17B, the coil 4 can be rotated and wound while the back yoke 3 is being fed.
[0048]
The wound back yoke around which the coil 4 is wound and integrally joined is attached to the back yoke mounting base 18 which holds both ends of the unit coil 41 as shown in FIG. 17C. It is fixed to the motor base 8 by fastening means such as screws.
[0049]
FIG. 18 is a diagram for explaining wiring connection of the motor. As shown in FIG. 18, both ends of the unit coil 41 are connected to a wiring member such as an FPC attached to the upper surface of the motor base 8.
[0050]
Alternatively, FIG. 19 is an explanatory view for assembling when a unit coil is connected to the back yoke. In FIG. 19A, the unit coil 41 may be wound in advance, and the coil 4 may be mounted on the divided back yoke 3. At this time, if the unit coil 41 is wound in advance on a bobbin, handling becomes easier.
[0051]
After attaching the coil 4 to the back yoke 3, the unit coil 41 is distributed at a predetermined angle as shown in FIG. 19 (b), and the unit coil 41 is attached to the back yoke mounting base 18 holding both ends of the coil. It is fixed to the base 8.
[0052]
FIG. 20 is a diagram for explaining wiring connection of the motor. As shown in FIG. 20, both ends of the unit coil 41 are connected to a wiring member such as an FPC attached to the upper surface of the motor base 8. As described above, the winding step can be facilitated.
[0053]
Next, as described above, when the entire circumference of the ring-shaped back yoke 3 is divided into a plurality of parts in order to facilitate the winding process of the coil 4, the outer circumference magnet 6, the inner circumference magnet 11, and the back yoke 3 are formed. The divided magnetic circuit weakens the magnetic flux due to the division of the back yoke 3, causing deterioration of the motor performance. FIG. 21 is a diagram illustrating a method of laminating the yoke plates. Therefore, as shown in FIG. 21, the divided back yokes 3 are laminated with iron plates so that both ends alternately have irregularities, and are combined so that the irregularities at both ends of the adjacent divided back yokes 3 are matched to form a ring. By assembling, deterioration of the magnetic circuit can be prevented, and a circuit having the same performance as the magnetic circuit in the undivided back yoke 3 can be formed.
[0054]
FIG. 22 is a diagram illustrating evaluation of temperature characteristics. FIG. 22 shows the motor current consumption when a standard 12 cm disc is mounted on the motor and rotated. The motor to be compared is an outer rotor motor having a conventional salient pole type armature. Of course, the drive device for driving the motor has the same conditions. As shown in the figure, the motor having the structure of the present invention has almost constant current consumption (240 mA) in the range of 0 ° C. to 70 ° C. and shows no change. On the other hand, the conventional motor showed an increase of 14.2% from 360 (mA) to (411 mA).
[0055]
Such an excellent temperature characteristic is that the motor having the structure of the present invention has a much smaller gap length than the conventional motor and is constant over the entire circumference of the motor rotor. This is because the permeance to be formed does not change due to temperature (in other words, the magnetic circuit of the motor does not include an element affected by temperature).
[0056]
Since a motor having the structure of the present invention is used in a disk drive because of having such excellent temperature characteristics, stable long-term operation can be performed even when the battery capacity of the disk drive (for example, a laptop computer) decreases at low temperatures. Secured. Alternatively, stable long-term operation is ensured even when the disk device is used for a long time and the internal temperature rises.
[0057]
The motor of the present invention configured as described above can generate a large torque. This is because the gap between the magnet and the back yoke can be narrowed from the structural point of view, and a high gap magnetic flux density can be secured. Further, similarly, due to the structure, an electromagnetic force for rotating the motor is generated near the outermost periphery of the rotor (field portion), so that a large moment (radius) can be obtained, so that the motor torque can be increased. Furthermore, it is possible to form a large number of coils by configuring the coil. In addition, since the cylindrical magnet is arranged on the outer periphery and the number of magnetized poles can be increased, the torque constant can be improved and the motor torque can be increased. Therefore, if the loads are the same, a motor with lower power consumption can be realized.
[0058]
Further, in the motor according to the configuration of the present invention, since the coil is mechanically fixed to the back yoke, it can be made to be a rigid body, so that the coil is hardly vibrated. Further, since the magnetic flux generated in the back yoke acts directly on the coil, it is possible to increase the torque generated in the motor and at the same time to perform a quick acceleration / deceleration operation. If a motor having such features is used in a disk drive, access time and power consumption can be reduced, and the thickness of the disk drive can be reduced.
[0059]
The examples used in the description do not limit the present invention to the use of the spindle motor. For example, the rotation field and the armature of the motor according to the configuration of the present invention can be extended in the direction of the rotation axis, so that the motor having a small motor diameter, high torque, small inertia and low power consumption can be obtained. It is also possible to realize.
[0060]
As described above in detail, according to the present invention, it is possible to provide a motor that has a low power consumption, a high efficiency, a small change in current consumption with respect to a temperature change, and that can be configured to be thin. Can be.
[0061]
【The invention's effect】
As described in detail above, according to the present invention, a motor having high efficiency with respect to power consumption and a small change in current consumption with respect to a temperature change can be configured to be thin, and furthermore, occurrence of cogging can be reduced. It is possible to provide a motor and a disk device that can generate a large torque while reducing the number of motors.
[Brief description of the drawings]
FIG. 1 is a perspective view of a motor according to an embodiment of the present invention.
FIG. 2 is a plan view of a main part of FIG. 1;
FIG. 3 is a view for explaining the coil winding method of FIG. 1;
FIG. 4 is a connection diagram of all coils of FIG. 1;
FIG. 5 is a magnet layout diagram of FIG. 1;
FIG. 6 is a view for explaining magnetic flux emitted from the magnet of FIG. 1;
FIG. 7 is an enlarged view of a main part of FIG. 6;
FIG. 8 is a sectional view of a main part of FIG. 1;
9 is a partially enlarged view of FIG. 8;
FIG. 10 is a perspective view of a motor using a magnetic sensor.
FIG. 11 is a view for explaining an attractive force between a magnet and a back yoke.
FIG. 12 is a diagram illustrating a winding angle of a coil.
FIG. 13 is a diagram illustrating generation of a rotational force.
FIG. 14 is a diagram illustrating generation of a rotational force.
FIG. 15 is a sectional view of a motor having the structure of FIG. 14;
16 is a view for explaining the magnetic flux in FIG.
FIG. 17 is an explanatory view of assembling when a coil is directly wound around a divided back yoke.
FIG. 18 is a diagram illustrating wiring connection of a motor.
FIG. 19 is an explanatory view of an assembly in a case where a unit coil is connected to a back yoke.
FIG. 20 is a diagram illustrating wiring connection of a motor.
FIG. 21 is a diagram illustrating a method of laminating yoke plates.
FIG. 22 is a diagram showing evaluation of temperature characteristics.
[Explanation of symbols]
1 Rotary axis
2,21,22 bearing
3 Back yoke
4, 46, 47 coils
5, 51 yoke
6, 61, 62 Peripheral magnet
7 Magnetic sensor
8 Motor base
9 Coil hook
10 poles
11 Inner circumference magnet
12 Inner circumference yoke
13, 34 turntable
15 Chucking unit
16 Chucking Ball
17 Upper magnet
18 Back yoke mounting base
41 unit coil

Claims (13)

A motor in which a rotating shaft of a rotating disk is mounted on a bearing member fixed to a base,
On the base, an armature having an armature yoke formed in a cylindrical shape and an armature coil wound on a cylindrical peripheral surface of the armature yoke is arranged concentrically with the bearing member,
An outer peripheral cylindrical field formed in a cylindrical shape and magnetized with a plurality of magnetic poles on a cylindrical peripheral surface is arranged on the rotating disk concentrically with the bearing member on the outer peripheral portion of the armature,
An inner peripheral cylindrical field formed in a cylindrical shape and magnetized with a plurality of magnetic poles on a cylindrical peripheral surface is arranged on the turntable concentrically with the bearing member on an inner peripheral portion of the armature,
The magnetic poles appearing on the inner peripheral surface of the outer peripheral cylindrical field and the magnetic poles appearing on the outer peripheral surface of the inner peripheral cylindrical field are arranged so as to have the same polarity at the positions of the cylindrical peripheral surfaces facing each other. motor. 2. The motor according to claim 1, wherein at least one of the outer peripheral cylindrical field and the inner peripheral cylindrical field is arranged closer to the turntable than a position of the armature yoke. 3. . 2. The motor according to claim 1, wherein a thickness of the armature yoke in a radial direction is set in a range of 1.8 mm to 2.0 mm. 2. The motor according to claim 1, wherein a radial gap between an outer peripheral surface of the armature yoke and an inner peripheral surface of the outer cylindrical field is set in a range of 1.2 mm to 1.5 mm. 2. The motor according to claim 1, wherein a radial thickness of the outer peripheral cylindrical field is set in a range of 1.5 mm to 1.8 mm. 2. The motor according to claim 1, wherein when the armature is configured with three phases and six poles, a winding area of the armature coil is wound in a range of 12 degrees to 20 degrees. 3. The position of the end surface of the armature yoke measured from the base is arranged so as to be located on at least one of the inner peripheral surface of the outer peripheral cylindrical field and the outer peripheral surface of the inner peripheral cylindrical field. The motor according to claim 1, wherein: 8. The motor according to claim 7, wherein an annular field magnetized in the direction of the rotation axis is arranged between the outer peripheral cylindrical field and the inner peripheral cylindrical field. A motor in which a rotating shaft of a rotating disk is mounted on a bearing member fixed to a base,
On the base, an armature having an armature yoke formed in a cylindrical shape and an armature coil wound on a cylindrical peripheral surface of the armature yoke is arranged concentrically with the bearing member,
An outer peripheral cylindrical field formed in a cylindrical shape and magnetized with a plurality of magnetic poles on a cylindrical peripheral surface is arranged on the rotating disk concentrically with the bearing member on the outer peripheral portion of the armature,
An inner peripheral cylindrical field formed in a cylindrical shape and magnetized with a plurality of magnetic poles on a cylindrical peripheral surface is arranged on the turntable concentrically with the bearing member on an inner peripheral portion of the armature,
The magnetic poles appearing on the inner peripheral surface of the outer peripheral cylindrical field and the magnetic poles appearing on the outer peripheral surface of the inner peripheral cylindrical field are arranged so as to have the same pole at the position of the cylindrical peripheral surface facing each other,
The motor according to claim 1, wherein the armature yoke is composed of a plurality of divided pieces formed of a laminated core, and is formed in combination with each other. 10. The motor according to claim 9, wherein both ends of the split piece are formed by alternately stacking laminated cores in an uneven manner. The armature is characterized in that a plurality of unit coils wound in advance on an air core are arranged at predetermined positions of the divided pieces, and the divided pieces on which the unit coils are arranged are combined in an annular shape. The motor according to claim 9. The motor according to claim 9, wherein the armature is formed by winding a coil at a predetermined position of the split piece, and combining the split pieces wound with the coil in an annular shape. A disk drive for rotating a disk, wherein the motor according to claim 1 or 9 is used.

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