JP2007202394A - Symmetrical voice coil motor structure, method for assembly thereof and hard disk microdrive information storage device equipped with the motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact, symmetrical voice coil motor structure which is useful as a microdrive. <P>SOLUTION: This symmetrical voice coil motor comprises a voice coil motor assembly with a central axis, a bearing assembly which rotates using the central axis as the center, a coil assembly provided radially outside of the bearing assembly with at least one pair of coils and an inside yoke, and a permanent magnet set provided radially outside of the coil assembly with at least one pair of magnets and an outside yoke. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention mainly relates to an information storage device. Specifically, the present invention relates to a hard disk drive including a voice coil motor assembly and a method for manufacturing the voice coil motor assembly. In particular, it relates to a symmetric voice coil motor assembly for disk drives.

  As an information storage device, there is a disk device including a magnetic disk for storing data and a movable recording / reproducing head that is positioned on the magnetic disk and records / reproduces data on / from the magnetic disk.

  The user expects not only a large storage capacity but also a faster and more accurate recording / reproducing operation for the disk device as described above. Therefore, disk device manufacturers have improved disk devices to increase capacity by increasing the density of data tracks, reducing track width, and / or reducing track spacing, for example. I keep doing it.

  However, in order to increase the track density and realize a recording / reproducing operation quickly and accurately using a disk with a high recording density, the disk device appropriately responds to the increase in the track density in the positioning control of the recording / reproducing head. Need to work. However, as the track density increases, it becomes more difficult to quickly and accurately control the recording / reproducing head positioning on the target data track on the storage medium. Therefore, disk device manufacturers are constantly searching for ways to improve the positioning control of the read / write head in order to take advantage of the ever-increasing track density.

  One technique that has been used effectively by disk drive manufacturers to improve the positioning control of the read / write head for high-density disks is known as a microactuator that operates in conjunction with the main actuator. The auxiliary actuator is used. Thereby, quick and accurate positioning control of the recording / reproducing head can be realized. A disk device incorporating such a microactuator is known as a two-stage actuator system.

  In order to increase the speed of the recording / reproducing head or to finely adjust the recording / reproducing head on the target track on the high-density recording medium, various two-stage actuator systems have been developed. Such a two-stage actuator system generally includes a voice coil motor (VCM) serving as a main actuator and an auxiliary microactuator such as a PZT microactuator.

  The above-described boil coil motor (VCM actuator) serving as the main actuator is controlled by a servo control system that rotates an actuator arm that supports a recording / reproducing head on a target data track on a recording medium. Yes. The PZT microactuator, which is an auxiliary actuator, is used in cooperation with the VCM actuator so as to increase the positioning speed and to finely adjust the recording / reproducing head on the target track. Accordingly, the VCM actuator greatly adjusts the position of the recording / reproducing head, and then the PZT microactuator finely adjusts the position of the recording / reproducing head relative to the recording medium. As described above, by connecting and cooperating the VCM actuator and the PZT microactuator, it is possible to effectively and accurately realize information recording / reproduction on a high-density recording medium.

  As a well-known configuration of the microactuator, there is one in which a PZT element for performing minute positioning adjustment of the recording / reproducing head is incorporated. Such a PZT microactuator has an electrical configuration that can be excited to selectively expand and contract the PZT element. The PZT microactuator is configured to cause the microactuator to move the recording / reproducing head when the PZT element expands and contracts. Such an operation is used to adjust the position of the recording / reproducing head at high speed and with high accuracy as compared with a disk device using only a VCM actuator.

  In general disk devices, a magnetic disk is mounted on a spindle motor that rotates the disk. A voice coil motor arm supports a head gimbal assembly (HGA) having a microactuator on which a magnetic head slider in which a recording / reproducing head is incorporated is mounted. This voice coil motor (VCM) is provided for controlling the operation of the voice coil motor arm, in other words, provided for controlling the magnetic head slider to move between tracks on the surface of the disk. ing. As a result, data can be recorded / reproduced on / from the disc by the recording / reproducing head. During operation, a flying force is generated by an aerodynamic interaction between the magnetic head slider in which the recording / reproducing head is incorporated and the rotating magnetic disk. This levitation force is generated in the direction opposite to the spring force applied by the suspension of the HGA, whereby the magnetic head slider is levitated above the surface of the rotating magnetic disk to a predetermined height, and the motor arm However, the flying height of the magnetic head slider is maintained while operating in the entire radial direction.

  On the other hand, the accuracy error inherent in the VCM and the asymmetry of the driving force adversely affect the performance of the recording / reproducing head for accurately recording / reproducing data on / from the disk. Positioning control cannot be realized. Therefore, as described above, the PZT microactuator is provided to improve the position control between the magnetic head slider and the recording / reproducing head. In particular, the PZT microactuator corrects the positional deviation of the magnetic head slider more minutely than the VCM in order to supplement the resonance resistance of the VCM and / or the head suspension assembly. For example, the microactuator can be used for a disk having a narrower data track interval, thereby increasing the value of track per inch (track / inch (TPI)) in the disk device by 50%. At the same time, the seek time and settling time of the head can be reduced. In this way, the PZT microactuator can dramatically increase the surface recording density of the disk device and the disk used therefor.

  However, the above-described PZT type microactuator has a problem that it is not economical in cost and usually requires high driving power during operation.

  Here, recent hard disk drives, in particular, microdrives of the type described below, are generally not only stable actuators but also have the advantage of miniaturization. However, many hard disk drives have only one coil sufficient to drive a voice coil motor (VCM) system. Therefore, it is difficult for a single coil to have a beneficial relationship between the center of gravity and the center of force. Furthermore, since the asymmetric system is used for the driving force, the apparatus becomes unstable, and is not suitable for applications that rotate periodically at high speed, for example, in a magnetic disk apparatus or an optical disk apparatus.

  And in the field of information storage devices, the mass of the coil is generally used to correct the mass of the head arm that helps keep the actuator balanced. Therefore, the driving force by the coil is generally asymmetrical. Therefore, in high-end products, in order to minimize the frequency of off-track errors, auxiliary actuators such as the PZT microactuator described above are used in hard disk drives. It is not uncommon to add

  Here, the hard disk drive (HDD) in the prior art generally includes an actuator for positioning the magnetic head on the upper and lower surfaces of the disk and moving the rotating arm block. (This makes it easy to record and reproduce data on the magnetic disk.) In general, the design of a voice coil motor is classified into two types: moving coil (MC) and moving magnet (MM). The Of these two types, the movable magnet type is used in hard disk drives that are generally popular and used in today's market.

  FIG. 8 shows a typical conventional microdrive having a moving coil (MC) type voice coil motor (VCM) as a main actuator. The disk drive shown in FIG. 8 includes three basic components of a voice coil motor (VCM), that is, a magnet 1, a yoke 2, and a movable coil 3. The movable coil 3 is excited by a drive current, and when the movable coil 3 is excited, the arm 7 and the head gimbal assembly 6 are rotated around the shaft 8 fixed to the base portion 10. At this time, as a result of the potential dynamic balance and the possible eccentricity of the spindle motor 9, the magnetic head 4 can reproduce and record data accurately from the disk 5 that vibrates or moves up and down, for example. The position needs to be adjusted.

  FIG. 9 shows a conventional hard disk drive, in particular, a movable magnet (MM) type microdrive. In the apparatus shown in FIG. 9, the magnet 1 ′ and the yoke 2 ′ are movable, and the coil assembly 3 ′ is fixed to the base portion 10. In such an apparatus, the assembly process can be simplified by changing the coil type from a winding configuration to an integrated loop 3 '. Then, based on Faraday's law, Lorentz force is generated by the excited coil and the permanent magnet. Then, when the coil is pressed and fixed on the base portion 10, the bidirectional force can move the magnet and rotate the arm 7 and the head gimbal assembly 6 around the shaft 8 together. Therefore, the magnetic head 4 is operated by servo control in order to adjust the relative position on the disk 5. As a result, the symmetrical VCM structure is similar to the structure of the spindle motor 9.

  The above-mentioned MM type VCM has advantages in terms of reduced size and low cost, but on the other hand, there is a risk of magnetic contamination, which is undesirable for disk drive manufacturers.

  Here, in the conventional system, the MM type VCM generally requires a smaller installation area in the hard disk drive (HDD) than the MC type. As a general rule, both the MM type VCM and the MC type VCM use a pair of driving forces to generate relative rotation. Also, as hard disk drive sizes shrink, it becomes more difficult to adopt a symmetric design for VCM. Thus, although symmetrical designs have been improved, they cannot be widely adopted in industry and various problems are discussed at least in part.

  FIG. 10 shows a conventional MC type VCM. In addition to the magnet 1 and the bottom yoke 2a, the VCM includes a top yoke 2b that assists in increasing the magnetic flux density. Normally, two space portions are formed in the MC type VCM. One exists between the magnet 1 and the coil 3, and the other exists between the coil 3 and the top yoke 2b. On the other hand, in the MM type VCM, one space portion is generally formed. It is necessary to minimize such a space.

  The MM type VCM is compact and thin and inexpensive, but generally it is heavy. With this heavy weight, a moment greater than the moment of inertia of the conventional MC type VCM can be generated. In addition, if a permanent magnet is positioned under the integrated loop coil described above to increase the magnetic flux density, the bidirectional force supplied to the magnet results in a large amount of friction (resistance). In other words, such friction causes the MM type VCM to operate slower than the MC type VCM.

  Moreover, it is rather undesirable to use a symmetric drive scheme. For example, some designers may prefer a symmetrical arrangement for the VCM assembly, but current common designers find it difficult to introduce additional coils into the VCM assembly. Some symmetric designs have also been proposed, but they are not compact and do not have sufficient advantages for wide implementation.

JP-A-5-101558

  For this reason, the present invention aims to solve the above-mentioned problems of the VCM structure in the conventional example, and particularly to provide a symmetrical and more compact VCM structure that is useful as a microdrive. It is said.

  The present invention includes an improved voice coil motor (VCM) configuration. The present invention includes an improved VCM configuration that exhibits good dynamic performance as compared to the prior art.

  In addition, the present invention is provided with a symmetrical VCM configuration that can be downsized and effective, and that can improve the disadvantages of the conventional symmetrically designed VCM. Furthermore, the present invention has a unique symmetrical structure such as a moving coil (MC) type VCM configuration for microdrive.

  In addition, the present invention includes a symmetrical VCM structure in which the space is minimized and the magnetic flux density is increased. The present invention also includes an improved VCM structure that minimizes coil deflection and twisting and, as a result, reduces vibration.

  In addition, the present invention includes a VCM structure having a structure that is relatively compact despite having many coils as compared with the prior art. Furthermore, the present invention provides a disk drive capable of achieving high performance, downsizing, and cost reduction.

  Specifically, a voice coil motor assembly according to the present invention has a central axis, and a bearing assembly for rotation around the central axis, and at least a pair of them are positioned radially outward from the bearing assembly. And a permanent magnet set including at least a pair of magnets and an outer yoke. The coil assembly includes a coil assembly including the first coil and the inner yoke.

  The voice coil assembly includes a head suspension assembly that is connected to the coil assembly and includes a head gimbal assembly and an arm that is connected to the head gimbal assembly.

  Each magnet has an N-pole or an S-pole on the inner surface in the radial direction, and is different from other magnets adjacent to each other in polarity on the inner surface in the radial direction. Further, the magnetic flux is configured to pass through the coil assembly when the coil is excited by current. Further, the number of coils and the number of magnets are the same. In addition, a nut for connecting the head suspension assembly to the coil assembly is provided. Furthermore, it is characterized by comprising at least two pairs of coils and two pairs of magnets.

  Each coil has a center line orthogonal to the central axis and is formed in an arc shape with respect to the central axis. Further, the coil and the magnet are characterized by being formed symmetrically with respect to the central axis, and further, the coil and the magnet are characterized by being arranged symmetrically around the central axis. .

  A hard disk drive, which is a microdrive according to another embodiment of the present invention, includes a base portion to which components of the hard disk drive are attached, a hard disk for storing data, a spindle motor that rotationally drives the hard disk, and a central axis. A voice coil motor assembly, wherein the voice coil motor assembly is a bearing assembly for rotation about a central axis, and is positioned radially outward from the bearing assembly, and includes at least a pair of coils and an inner yoke. A permanent magnet set having at least a pair of magnets and an outer yoke, coupled to the coil assembly, and connected to the head gimbal assembly and the head gimbal assembly. Communicating A head suspension assembly having an arm that is, with a, is characterized in that.

Furthermore, an assembling method of a cylindrical voice coil motor having a central axis, which is another embodiment of the present invention,
Configuring a head suspension assembly comprising a head gimbal assembly and an arm coupled to the head gimbal assembly;
A first outer peripheral portion including at least a pair of coils and an inner yoke, a first outer peripheral portion formed by at least the pair of coils, a radius from the central axis to the first outer peripheral portion, and a first inner peripheral portion formed by the inner yoke A coil assembly having a portion and a radius from the central axis to the first inner periphery, and
A second inner peripheral portion including at least a pair of magnets and an outer yoke, and a radius from the central axis to the second inner peripheral portion; Forming a permanent magnet set in which the radius to the inner periphery of the coil assembly is larger than the radius from the central axis to the first outer periphery of the coil assembly;
A third outer peripheral portion and a radius from the central axis to the third outer peripheral portion, and a radius from the central axis to the third outer peripheral portion is greater than a radius from the central axis to the first inner peripheral portion of the coil assembly. Forming a small bearing assembly;
Coupling the head suspension assembly to the coil assembly;
Inserting the coil assembly into a region surrounded by a second inner periphery formed by at least a pair of magnets of the permanent magnet set;
Inserting the bearing assembly into a region surrounded by a first inner periphery formed by the inner yoke of the coil assembly;
It is characterized by having.

  Further features and advantages of the present invention will be described with reference to the drawings and the like, which explain a part of the essence of the present invention in the embodiments described later.

  Since the present invention is configured and functions as described above, according to the present invention, it is possible to provide a voice coil motor assembly that is small and low-cost and that can obtain good dynamic performance. Another object of the present invention is to provide a high-performance disk drive by mounting the voice coil motor assembly on the disk drive.

  A preferred embodiment of the present invention will be described with reference to FIGS. In the various figures, like reference numerals represent like parts.

  As mentioned above, the present invention is designed to provide an improved voice coil motor (VCM) assembly as a microdrive having a symmetrical structure. The boil coil motor of the present invention is mounted on any disk drive that requires an actuator that desires to improve head control and resonance characteristics, for example, regardless of the specific structure of the disk drive, such as an HGA or other configurations. May be. The present invention is not limited to a special structure as illustrated and described below, and may be used for any microdrive in the industry.

  The present invention is characterized in that it can be incorporated into a disk drive without significant changes to, for example, the HGA and other main components mounted on the apparatus used in the prior art shown in FIG. Have

  FIG. 1 shows a hard disk drive according to a first embodiment of the present invention. In this embodiment, the hard disk drive, specifically, the microdrive, includes an MC type VCM. This disk drive design is generally similar to the conventional disk dry design except that the VCM has been modified to have a symmetrical structure to improve its operation. That is, the arrangement of specific components, such as the head gimbal assembly 106, the arm 107, and the base 110, is similar to the conventional disk drive design in this embodiment. Further, the disk drive shown in FIG. 1 further includes a magnetic head 104, a disk 105, and a spindle motor 109 as in the conventional disk drive. In addition, the VCM design shown in FIG. 1 is not only symmetric, but also has a smaller footprint compared to conventional devices.

  For example, in a small hard disk drive such as a microdrive, usually a very small space for just one additional coil is formed. However, the present invention incorporates several additional coils in a manner that is useful and effective in improving its operation. Specifically, as shown in FIG. 2, four coils 103a, 103b, 103c, and 103d are provided so as to surround the VCM bearing 111 (bearing) in an annular shape. Specifically, the individual coils 103 a to 103 d are formed in an arc shape so as to surround the periphery of the central axis of the bearing 111. The bearing 111 can rotate around its central axis.

  FIG. 2 shows two pairs of magnets 101a to 101d arranged inside the outer yoke 102a. First, each of the pair of ring magnets 101a and 101b has a north pole in the radial direction, and each of the other pair of ring magnets 101c and 101d has a south pole in the radial direction. Yes. In the present embodiment, the case where two pairs of ring magnets 101a to 101d and coils 103a to 103d are provided is illustrated. For example, one pair, three pairs, and more pairs of ring magnets and A coil may be used. The diameter of the inner peripheral portion (second inner peripheral portion) formed by the two pairs of ring magnets 101a to 101d is equal to the outer peripheral portion (first outer peripheral portion) formed by the coils 103a to 103d. It is formed larger than the diameter.

  In this embodiment, each of the coils 103a to 103d has, as described above, two adjacent ones, one having the N pole on the radially inner surface and the other having the S pole on the radially inner surface. Affected by the ring magnet. Then, the VCM generates Lorentz force from the excited excited coil and the fixed permanent magnet. All these coils and magnets are arranged symmetrically around the rotating shaft 8 (the central axis of the bearing 111), so that the reaction force can be minimized and the rotation around the center of gravity can be realized. As a result, the operation performance of the apparatus can be further enhanced.

  In addition to the outer yoke 102a, an inner yoke 102b is provided to increase the magnetic flux density for the coils 103a to 103d. And since it has a symmetrical design and, as a result, the bidirectional force is balanced between the inner yoke 102b and the magnets 101a to 101d, the bearing mechanism operates smoothly and efficiently. To do. Furthermore, since the coils 103a to 103d are assembled together with the inner yoke 102b, the space that can be formed between the coils 103a to 103d and the inner yoke 102b can be minimized. Thus, by minimizing the space between the coils 103a to 103d and the inner yoke 102b, the actuator can be further miniaturized and the space can be used efficiently. Furthermore, by arranging the coils 103a to 103d close to the inner yoke 102b, the rigidity of the coils 103a to 103d can be increased, whereby the deflection and twisting of the coil during operation can be suppressed to a minimum. The vibration of the apparatus can be minimized. The diameter of the inner peripheral portion (first inner peripheral portion) surrounded by the inner yoke 102b is formed larger than the diameter of the outer peripheral portion (third outer peripheral portion) of the bearing assembly 115 to be inserted. .

  FIG. 3 shows an exploded view of the actuator in this embodiment shown in FIG. Therefore, various parts before the actuator is assembled and general assembly methods are also shown.

  The actuator in the present embodiment includes two head gimbals assemblies 106 and two magnetic heads 104 disposed on the upper surface and the lower surface of the hard disk, respectively. The actuator arm is generally machined from a block of metal, such as aluminum or magnesium, and formed in a so-called “E block” type. However, the product may be manufactured by any manufacturing method. Then, a head gimbal assembly (HGA) is connected to each arm in order to form a head stack assembly (HSA) 113 by stacking all of the HGAs on each arm.

  The cylindrical object as the coil assembly 112 has a central shaft hole for receiving the top-bottom bearing assembly 115, that is, a shaft hole located inside the inner yoke 102b. The four symmetrical coils 103a-103d are then integrated into the coil assembly 112 to form an assembly. And HSA113 connects the coil assembly 112 with the nut 114 or another connection tool. However, the coil assembly 112 does not need to be in direct contact with and connected to the HSA 113. Actually, it is not important to connect as described above, and the connection method may be changed according to the application in which the invention is used.

  After the coil assembly 112 is connected to the HSA 113 by the nut 114, the bearing assembly 115 or the center member is attached. At this time, the movable part of the actuator is assembled, but in order to minimize the risk of magnetic contamination, the stationary permanent magnet set 116 (with the ring magnets 101a to 101d and the outer yoke 102a) is assembled separately. It is done.

  As shown in FIGS. 2 and 3, the voice coil motor (including the coil assembly 112, the bearing assembly 115, and the magnet set 116) is assembled to the central axis set by the bearing assembly 115 when assembled. It is symmetrically configured. This actuator is then assembled to the drive unit and is operable to control the movement of the magnetic head to scan the surface of the disk 105 rotated by the spindle motor 109 to record and reproduce data on the disk. It is connected to a servo control system (not shown).

  FIG. 4 shows a vector diagram of magnetic flux density in the VCM system shown in FIG. Based on the current density shown in FIG. 5, the total driving force can be predicted by computer simulation. FIG. 6 shows a contour diagram of the coil and yoke. A diagram such as FIG. 6 is useful for designing a VCM within the scope of the present invention. In addition, commercial software such as ANSOFT is useful for designing VCM and hard disk drives with the symmetric VCM shown here. In addition, when designing a symmetric VCM in the present invention, the Lorentz force can be predicted by a finite element method based on Faraday's law in a magnet.

  FIG. 7 is a table showing numerical differences between the conventional VCM design as shown in FIG. 8 and the VCM design in the present embodiment described above, for example. From this table it can be seen that, for example, an increase of about 20% in the magnetic flux density can be achieved by the narrower space (0.2 mm) formed by the present invention. This table also shows that the total driving force in the present invention is about 114 mN, which is larger than the conventional design value of 87 mN. Therefore, better and more effective operation can be achieved by using the symmetrical VCM actuator of the present invention in the existing basic configuration.

  As shown in the preferred embodiment described above, the present invention requires particularly less volume than a conventional microdrive. For example, the VCM mentioned above is as small as 30%. The present invention is formed as a more stable actuator by using a symmetric VCM. Further, the present invention has a high magnetic flux density because the gap of the magnetic field is minimized. In addition, vibrations due to coil deflection and torsion are minimized. As a result, all these advantages are provided in an improved VCM device compared to the prior art.

  Here, the physical size of a hard disk drive, such as a microdrive, is generally reduced over time. And as the physical size gets smaller, the dynamic performance is improved and the actuator must become more useful. In the present invention, the symmetrical VCM described above is configured to provide a convenient and economical solution so that it can be effectively used in the microdrive. Although there are MM type VCMs with symmetrical structures from before, they have different structures and operating characteristics and do not have the advantages achieved by the present invention as described above. . Furthermore, unlike the embodiments described above, many current hard disk drives (HDDs) on the market use asymmetric MC type VCMs. On the other hand, the preferred embodiment described above provides an improved MC type VCM having a symmetrical structure that can be used in a variety of drive devices such as, for example, a conventional rotary DVD pickup head or the like. .

  In addition, the VCM assembly of the present invention is not only symmetrical, but also has a narrow space compared to conventional VCM assemblies. Furthermore, the VCM of the present invention includes an additional coil as compared with the conventional example, but the overall spatial structure is more compact than a hard disk drive including a conventional microdrive. Therefore, in the present invention, it is possible to solve problems such as high performance, small size, and low cost disk devices. Furthermore, in the present invention, dynamic performance can be improved by symmetric VCM.

  Here, in general, the sensitivity of the actuator is expressed as a function of the weight of the movable part of the driving force of the VCM. And inside the microdrive, the VCM design is mainly limited by the disk size. For this reason, it is challenging to arrange a symmetric VCM in a narrow space, and indeed it is extremely difficult to equip a relatively simple and single actuator control system. However, the present invention can help overcome the challenges of such space saving arrangements.

  In general, one coil is required to perform uniaxial control with an actuator. However, if the center of gravity does not coincide with the center of force, it can have a significant effect depending on the particular application, such as vibration. If the servo system for the actuator cannot control the resulting vibration, an auxiliary actuator is required. However, the auxiliary actuator increases costs and has uneconomic problems. For this reason, the present invention provides a more effective and capable actuator by using a symmetrical design with multiple coils. Further, the auxiliary actuator in the disk drive is not required, and it is economically superior.

  Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to such contents, and includes various improvements and equivalent modifications that are included in the scope of the idea of the present invention.

  The boil coil motor in the present invention can be used for a disk drive to move the head gimbal assembly, and has industrial applicability.

It is a figure which shows the symmetrical movable coil (MC) type microdrive in this invention. It is a figure which shows the structure of the voice coil motor in the microdrive disclosed in FIG. It is a figure which shows the mode at the time of the assembly | attachment of the voice coil motor disclosed in FIG. It is a figure which shows the magnetic flux density of the voice coil motor disclosed in FIG. It is a figure which shows the current density of the voice coil motor disclosed in FIG. The contour figure in the coil and yoke of the voice coil motor disclosed in FIG. 2 is shown. It is a table | surface which shows the various characteristics of a conventional example and the voice coil motor in this invention. It is a figure which shows the structure of the movable coil (MC) type microdrive in a prior art example. It is a figure which shows the structure of the movable magnet (MM) type microdrive in a prior art example. It is a figure which shows the structure of the voice coil motor used with the conventional apparatus disclosed in FIG.

Explanation of symbols

101a to 101d Ring magnet 102a Outer yoke 102b Inner yoke 103a to 103d Coil 104 Magnetic head 105 Disk 106 Head gimbal assembly 107 Arm 109 Spindle motor 110 Base portion 111 Bearing 112 Coil assembly 113 Head stack assembly 114 Nut 115 Bearing assembly 116 Magnet set

Claims (19)

A voice coil motor assembly having a central axis comprising:
A bearing assembly for rotation about the central axis;
A coil assembly located radially outward from the bearing assembly and comprising at least a pair of coils and an inner yoke;
A permanent magnet set that is located radially outside the coil assembly and includes at least a pair of magnets and an outer yoke;
A voice coil motor assembly comprising: A head suspension assembly coupled to the coil assembly and comprising a head gimbal assembly and an arm coupled to the head gimbal assembly;
The voice coil motor assembly according to claim 1. Each of the magnets has an N-pole or an S-pole on the radially inner surface, and the polarity on the radially inner surface is different from other adjacent magnets
The voice coil motor assembly according to claim 1 or 2, When the coil is excited by current, magnetic flux passes through the coil assembly.
4. The voice coil motor assembly according to claim 1, 2, or 3. The number of coils and the number of magnets are the same.
5. The voice coil motor assembly according to claim 1, 2, 3 or 4. A nut for connecting the head suspension assembly to the coil assembly;
6. The voice coil motor assembly according to claim 2, 3, 4 or 5. Comprising at least two pairs of the coils and two pairs of the magnets;
The voice coil motor assembly according to claim 1, 2, 3, 4, 5, or 6. Each of the coils has a center line orthogonal to the central axis and is formed in an arc shape with respect to the central axis.
8. The voice coil motor assembly according to claim 1, 2, 3, 4, 5, 6 or 7. The coil is formed symmetrically with respect to the central axis.
9. The voice coil motor assembly according to claim 1, 2, 3, 4, 5, 6, 7 or 8. The magnet is formed symmetrically with respect to the central axis.
10. The voice coil motor assembly according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9. The coil and the magnet are arranged symmetrically around the central axis.
11. The voice coil motor assembly according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. A base for mounting the components of the hard disk drive;
A hard disk for storing data;
A spindle motor that rotates the hard disk,
A hard disk comprising a voice coil motor assembly having a central axis,
The voice coil motor assembly includes:
A bearing assembly for rotation about the central axis;
A coil assembly located radially outward from the bearing assembly and comprising at least a pair of coils and an inner yoke;
A permanent magnet set that is located radially outside the coil assembly and includes at least a pair of magnets and an outer yoke;
A head suspension assembly coupled to the coil assembly and comprising a head gimbal assembly and an arm coupled to the head gimbal assembly.
A hard disk drive characterized by that. The hard disk drive is a microdrive;
13. The hard disk drive according to claim 12, wherein The coil motor assembly comprises at least two pairs of the coils and two pairs of the magnets.
The hard disk drive according to claim 12 or 13, characterized in that Each of the coils has a center line orthogonal to the central axis and is formed in an arc shape with respect to the central axis.
The hard disk drive according to claim 12, 13 or 14. The coil is formed symmetrically with respect to the central axis.
16. The hard disk drive according to claim 12, 13, 14, or 15. The magnet is formed symmetrically with respect to the central axis.
The hard disk drive according to claim 12, 13, 14, 15, or 16. The coil and the magnet are arranged symmetrically around the central axis,
18. The hard disk drive according to claim 12, 13, 14, 15, 16, or 17. A method of assembling a cylindrical voice coil motor having a central axis,
Configuring a head suspension assembly comprising a head gimbal assembly and an arm coupled to the head gimbal assembly;
A first outer peripheral portion formed by the at least one pair of coils, a radius from the central axis to the first outer peripheral portion, and a first outer portion formed by the inner yoke. Configuring a coil assembly having one inner circumference and a radius from the central axis to the first inner circumference;
At least a pair of magnets and an outer yoke; and a second inner periphery formed by the at least a pair of magnets; and a radius from the central axis to the second inner periphery, and the center Configuring a permanent magnet set in which a radius from a shaft to the second inner peripheral portion is larger than a radius from the central axis to the first outer peripheral portion of the coil assembly;
A third outer peripheral portion and a radius from the central axis to the third outer peripheral portion, and a radius from the central axis to the third outer peripheral portion is from the central axis to the first of the coil assembly. Forming a bearing assembly formed smaller than the radius to the inner periphery;
Coupling the head suspension assembly to the coil assembly;
Inserting the coil assembly into a region surrounded by the second inner periphery formed by the at least one pair of magnets of the permanent magnet set;
Inserting the bearing assembly into a region surrounded by the first inner periphery formed by the inner yoke of the coil assembly;
A method for assembling a cylindrical voice coil motor.