JPH0255557A - Head access vibrating motor - Google Patents

Abstract

PURPOSE:To increase an access speed of a motor by providing two flat coils adjoining one flat coil to another and, at the same time, by providing three magnets formed more widely by comparing a central magnet with other two magnets to the opposed surface. CONSTITUTION:A head access vibrating motor is equipped with a stator having a circular yoke 1 and with a rotor 4 which is provided by the stator so that it is capable of swiveling and in which an arm 9 is projected to an opposite side of the yoke 1. A head assembly 10 provided with a magnetic head 11 is provided to the tip of the arm 9. Three permanent magnets 6-8 are provided to the peripheral surface opposed to the yoke 1 of the above-mentioned rotor 4 at a specific interval, and the circumferential width of a central magnet 7 of the magnets 6-8 is wider than that of each of other two magnets. In addition, two coils 2-3 wound up so as to have parallel sections are provided to the internal circumferential surface of the yoke opposed to the magnets 6-8 so that the parallel sections are adjoined closely. Accordingly, each width of the flat coils 2-3 can be wider.

Description

[Detailed Description of the Invention] [Summary] Regarding the swing motor that accesses the read/write button f' of an external storage disk device, the access speed of the motor can be increased by increasing the number of poles of the swing motor and generating a large motor torque. The purpose of this invention is to realize a swing motor structure that can rotate the motor in the opposite direction, and includes a stator having an arc-shaped yoke, a stator that is rotatably supported within the stator, and an arm on the opposite side of the yoke. In a rocking motor having a protruding rotor, three permanent magnets are provided at predetermined intervals on the outer peripheral surface of the rotor facing the yoke, and the width of the center magnet in the circumferential direction is The width of the yoke is wider than the width of the two coils, and on the inner peripheral surface of the yoke facing the magnet, two coils are wound so as to have parallel portions along the inner peripheral surface and the parallel portions are in close contact with each other. The windings of these coils are connected so that current flows in opposite directions to each coil when energized.

[Industrial Application Field] The present invention relates to a swing motor for accessing a read/write head of a magnetic disk device, an optical disk device, etc. used as an external storage device of a computer or the like.

In recent years, the storage capacity of magnetic disk devices, optical disk devices, and the like used as external storage devices for computers has increased dramatically. For example, the recording density of a hard disk device that uses a magnetic disk as a storage medium is 1.
It has increased more than 10 times in the past year, and its storage capacity has reached 1 GB/spindle for large-capacity types.

FIGS. 8 and 9 show an example of the configuration of a hard disk device using such a magnetic disk. The hard disk drive has a spindle S that rotates at a high speed of about 360 rpm, and a plurality of magnetic disks D (for example, 10 disks) are attached to this spindle S at predetermined intervals. Data is recorded on both sides of the magnetic disk D, and magnetic heads H provided on both sides of the magnetic disk D write to and read data from the magnetic disk. Movement of the magnetic head H over the magnetic disk D is performed by an actuator via an arm A. There are two types of actuators for moving the magnetic head H: a linear type and an oscillating type, but the oscillating type shown in FIGS. 8 and 9 is more often used.

A swing type actuator generally uses a swing motor SM that can rotate (swing) only within a predetermined angle and can finely control the rotation angle. This swing motor SM is composed of a stator ST and a rotor R, and the rotor R has the same number of magnetic disks D attached to the spindle S, or one more or less than the number of magnetic disks D (9 in the figure). The arm A of the book) is installed protrudingly.

Then, the SSy is attached to a magnetic head assembly having two magnetic heads H attached to the tip of the arm so as to face each other so as to sandwich the magnetic disk D therebetween. The stator ST of the oscillating motor is installed near the magnetic disk D as shown in FIG. corresponds to the recording area of the magnetic disk D.

A swing motor S? used in the actuator of such a hard disk device? I preferably has a large torque in order to perform high-speed access by the magnetic head H, and it is desired to improve the torque constant of the swing motor.

[Conventional technology]

A swing motor, which is an actuator for driving and accessing the magnetic head of a hard disk drive, generally has a permanent magnet in the stator and a coil in the rotor.
Although so-called moving coil type motors are the mainstream, there are also attempts to adopt so-called moving magnet type motors, which have a coil on the stator side and a permanent magnet on the rotor side (Japanese Patent Publication No. 62, 3518). (see publication).

FIG. 6 (Al shows the configuration of a conventional movable magnet type swing motor 60. In the figure, 61 is a yoke of the stator, and 62 is a rotary shaft 63 provided on the stator, which is rotatable. The attached rotor.

A flat coil 64 as shown in FIG. Two permanent magnets 65 and 66 extending in the winding direction of the flat coil 64 are cut out on the outer peripheral surface of the rotor 62 facing the winding part. When it is a pole, the permanent magnet 66 is the outer or north pole, and the two permanent magnets 65
．． The outer magnetic poles of 66 are different from each other.

In the movable magnet type swing motor 60 configured as described above, the swing of the rotor 62 can be controlled by controlling the amount and direction of the current flowing through the flat coil 64 attached to the yoke 61. Can be done.

However, in general, the above operation is possible with such a configuration, but in order to increase the access time of the magnetic head by performing higher-speed oscillation, the oscillation motor with the configuration shown in FIG. 1 ~ Luk is insufficient.

Therefore, as shown in FIG.
A multipolar swing motor like the brushless motor of -a is created by taking the set of flannel I coils 74 and installing four permanent magnets 75, 76 and 7778 with different polarities alternately on the rotor 72 side. 70 is considered.

In this way, by making the movable magnet type swing motor multipolar, the torque increases compared to the swing motor 60 shown in Fig. 6, and the magnetic flux flowing through each flat coil can be reduced, so the yoke The thickness of the motor 71 can also be made thinner than the two-pole swing motor 60.

[Problem to be solved by the invention]

However, when such a multi-pole swing motor is used for head access, an arm member, etc. that supports the head is arranged on the opposite side of the magnet mounting surface of the rotor of the swing motor. There is not enough space to construct such a multi-pole swing motor. Conversely, if we try to create a multi-pole swing motor with a constant stroke (rotation angle) in a limited space, we will inevitably have to narrow the circumferential width of the permanent magnets. In addition to not being able to obtain sufficient torque, there are problems such as not being able to obtain a sufficient gap magnetic flux density due to the narrow width of the permanent magnet.

Furthermore, in a movable magnet type swing motor, it is meaningful to reduce the weight of the magnet, but there is no harm in making the weight of the coil heavy. In this respect, a so-called long coil type, in which the width of the coil is wider than the width of the magnet, as shown in FIG. 7, is considered to be superior in principle to a movable magnet type swing motor. However, if an attempt is made to realize a multipolar swing motor using a long coil type, there is a problem in that the space becomes increasingly tight and it becomes almost impossible to manufacture the coils.

The present invention has been made to solve these conventional problems, and it is possible to increase the number of poles of the swing motor for head access within a limited space and generate a large motor torque, thereby improving motor access. The purpose of this invention is to realize a swing motor for head access that can change the speed.

[Means to solve the problem]

A swing motor for head access according to the present invention that achieves the above object includes a stator having an arc-shaped yoke 1, and an arm 9 that is rotatably supported within the stator, and an arm 9 protruding from the opposite surface of the yoke 1. In the head access swing motor equipped with a rotor 4, three permanent magnets 6, 7.8 are provided at predetermined intervals on the outer peripheral surface of the rotor 4 facing the yoke 1, and the center of the magnet The width of the magnet 7 in the circumferential direction is made wider than the width of the other two magnets, and the inner peripheral surface of the yoke 1 facing the magnets 6, 7.8 has two magnets wound so as to have parallel parts. Coils 2 and 3 are arranged adjacent to each other so that the parallel parts are in close contact with each other along the inner peripheral surface, and the windings of the coils 2 and 3 are connected so that current flows in opposite directions to each coil when energized. It is characterized by what it did.

Note that the present invention that achieves the above object can also be realized by providing the magnets 6, 7.8 provided on the rotor 4 in the stator and the flant coil 2.3 provided in the stator in the rotor 4 in the above-described configuration. .

[For production]

In the swing motor for head access of the present invention, there are three magnets on the opposite side of the swing arm mounting surface of the rotor, the center magnet having a circumferential width larger than the magnets on both sides, and facing these magnets. Two flat coils are attached to the inner circumferential surface of the yoke of the stator with their parallel parts in close contact with each other along the inner circumferential surface of the yoke, and the windings are connected so that currents flow in opposite directions in each coil. 2 in the center when the power is turned on.
Current flows in the same direction through the two coils, working as a three-pole head access swing motor.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an outline of the configuration of an embodiment of a swing motor for head access according to the present invention, and in this embodiment, the swing motor for head access is applied to the head access of a magnetic disk device. FIG. 1 shows only the essential parts of the head access swing motor.

In the figure, ■ is the stator yoke, 2 and 3 are the yoke 1
4 is a yoke that swings around the rotating shaft 5; 6 and 78 are permanent magnets that are attached to the surface of the rotor 4 facing the yoke; 9 is the opposite side of the yoke of the rotor 4; A protruding arm 10 is a magnetic head assembly, and a magnetic head 11 is fixed to the tip of the arm 10.

The yoke 1 is manufactured using, for example, low carbon steel, and is a curved body having at least a semicircular inner peripheral surface. flat coil 2.3
have almost the same shape, and as shown in Fig. 2, are composed of parallel parts (effective parts) 2a, 3a and coil return parts 2b, 3b above and below the parallel parts 2a, 3a.
The yoke 1 is bent along the inner circumferential surface of the yoke 1 with one side of the yoke 1 in close contact with each other, and then attached to the inner circumferential surface.

In addition, the inner winding ends of the flat coils 2 and 3 are connected to each other so that current flows in the opposite direction to each of the flat coils 2 and 3, and from one of the outer winding ends of the flat coils 2 and 3. A current is passed through it, and the current flows out from the other end of the winding. As a result, when energized, current flows in the same direction through the two central parallel portions 2a and 3a of the flat coils 2 and 3.

The side of the rotor 4 that oscillates around the rotating shaft 5 that faces the yoke 1 is a circumferential surface, and this circumferential surface has three permanent magnets (for example, rare earth magnets such as neodymium iron magnets).
6. 7. 8 is attached. This rotating shaft 5
Although a bearing such as a bearing is actually provided around the , the bearing is not shown in this embodiment. Also, rotor 4
As shown in the conventional example shown in FIG. 8, on the opposite side of the yoke 1, nine arms 9 are provided protruding at predetermined intervals in the direction of the rotating shaft 5, for example, for ten magnetic disks. A head assembly 10 having two magnetic heads 11 is attached to the free end side of each arm 9 so as to be interposed between two magnetic disks. For this reason, the magnets 6, 7, .
8 is also extended in the rotation axis direction according to the protruding range of the arm 9.

In this way, by placing the flant coils 2.3 in close contact with each other without leaving any space between them, the width of the flat coils 2 and 3 can be increased by the space that is lost between them, and the width of the flant coils 2.3 can be increased by the space between them. Since the number of magnets facing each other is only three, the width of each magnet 6° 7.8 can be increased.

In the above embodiment, the flat coil 2.3 is shown as a single-layer coil, but the flat coil 2.3 is actually a laminated coil with several layers, and the flat coil 2.3 in FIG. The second and subsequent layers of coils are stacked on the inside.

FIG. 3 shows an implementation example of the embodiment described above. In this implementation example, the yoke 1 is divided into a yoke body 1a and ilb, and the lid 1b is attached to the yoke body 1 with a bolt 12.
It is designed to be fixed to a. Then, with the lid 1b removed, the yoke body 1a and the hole 1c provided in the lid ib are
, fit the rotating shafts 5c and 5d into the yoke body ld, attach the lid 1b to the yoke body 1a, and attach the rotor 4 to the body ld.
It is decorated inside. This figure shows the actual shape of the stacked flant coils 2 and 3 installed adjacently in the yoke body la, the shape of the three magnets 6.7.8 installed on the back of the L1-tor 4, and the shape of the arm 9. Installation condition is shown. Note that the head assembly attached to the tip of the arm 9 is not shown in this figure.

Next, the operating principle of the embodiment shown in FIG. 1 will be explained using FIG. 4. The head access swing motor of the present invention includes two magnets 76 inside the four-pole swing motor 50 shown in FIG.
77 can be considered as a single unit.The major difference is that in the case of the four-pole swing motor 70 shown in FIG. 7, the polarity of the adjacent magnetic poles is opposite, but the present invention In the case of the configuration, the outside and inside of the central wide magnet 7 have uniform polarity. As for the magnetic circuit, it may be considered that the short width magnets 6 and 8 on both sides receive the return of the magnetic field lines from the wide magnet 7 at the center. Therefore, the head access swing motor of the present invention can be considered as a three-pole motor, and the two flat coils 2 and 3 also have adjacent parallel portions 2a.

Since current flows in the same direction through 3a, they can be considered as having the same polarity.

From the above, in the case of the head access swing motor shown in FIG. 4, the generated 1-rook M of the head access swing motor is expressed by the following equation.

M=B72i-r where B is the gap magnetic flux density, l is the effective length of the coil i is the flowing current, and r is the radius of the magnet. From this formula, the fourth
Since the swing motor for head access shown in the figure has twice the coil length l compared to the conventional swing motor shown in Fig. 6, there is not much difference in the values of the gap magnetic flux density B, the current i, and the radius r of the magnet. Otherwise, the torque M generated by the swing motor would be approximately doubled.

In the case of a magnetic circuit configured as shown in FIG. 4, the gap magnetic flux density is generally not symmetrical between the wide center magnet 7 side and the narrow magnets 6.8 sides on both sides, but the torque M is This asymmetry is not a particular problem because it occurs as a sum of the

In addition, in the conventional configuration shown in FIG. 6(a), the magnet is 65°6
The suction force between the yoke 6 and the yoke 61 becomes an axial load, and this suction force becomes a large force of 20 to 50 kg.
This places a large burden on the bearings. On the other hand, in the configuration shown in FIG. 4, since the narrow magnets 6 and 8 are almost opposed to each other, their attractive forces almost cancel each other out, and only the attractive force of the wide magnet 17 becomes the bearing load. . Therefore, in the head access swing motor of the present invention, even if the applied l·lux increases, the suction force hardly increases compared to the conventional two-pole motor.

All of the embodiments described above have a flannel I on the stator side.
This is a movable magnet type head access rocking motor that is equipped with a coil and a magnet on the rotor side. It can also be applied to a moving coil type head access swing motor whose mounting is reversed. This embodiment is shown in FIG.

The movable coil type head access swing motor shown in FIG. 5 has a wide magnet 57 in the center of the yoke 1, and two narrow magnets 56 and 58 on both sides with a predetermined distance apart.
It is best to attach flannel I coils 52, 53 similar to those shown in FIG. It is exactly the same as a swing motor.

As described above, in the present invention, the flannel coils installed in the central part are placed in close contact with each other without any spacing, and one magnet facing the flat coil in the central part is used to form a three-pole swing motor for head access. By doing so, it is possible to widen the width of the Flammie coil by the gap between the coils or the gap between the magnets, which is necessary for a swing motor for head access for four songs, and also to make the width of the Flammie coil wider by the gap between the coils and the gap between the magnets. Since only three magnets are required to face each other, the width of each magnet can be increased.

In addition, in the following examples, either a long coil type where the coil width is wider than the magnet width is explained, or a short coil type where the coil width is narrower than the magnet width and the magnetic flux of the coil is used completely. It goes without saying that the head access swing motor of the present invention may be constructed using the following.

〔Effect of the invention〕

As explained above, according to the head access swing motor of the present invention, two flat coils are provided adjacent to each other, and the central magnet is wider than the other two on the opposing surface of the flat coil. By providing three magnets formed in the same direction, the width of the flat coil or magnet can be increased in a limited space, and a large motor torque can be generated, which improves the motor access speed. This has the effect of allowing high-speed access to the 7th floor.

In addition, the head access swing motor of the present invention has three poles, and two of the three magnetic poles are located at substantially opposite positions, so that their attractive forces can be canceled out, so the load on the bearing can be reduced. , which has the advantage of increasing credibility.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the swing motor for head access of the present invention, and FIG. 2 is a front view showing the configuration of the furan 1-coil used in the swing motor for head access of the present invention. , FIG. 3 is a perspective view showing the assembly of an implementation example of the swing motor for head access shown in FIG. 1, FIG. 4 is a diagram illustrating the magnetic circuit of the swing motor for head access shown in FIG. 1, and FIG.
The figure is a partial configuration diagram showing an embodiment in which the swing motor for head access of the present invention is configured with a moving coil type, and FIG.
al is a schematic diagram showing the configuration of a conventional two-pole swing motor for head access, FIG. 6 is a perspective view showing the configuration of a flat coil, and FIG. 7 is a configuration of a four-pole swing motor for head access. 8 is a perspective view showing the configuration of the hard disk device, and FIG. 9 is a plan view showing the configuration of an example of the hard disk device. ■... Yoke, 2, 3... Flat coil, 2a, 3a ... Parallel part of the coil, 2b, '3b... Return part of the coil, 4... Rotor, 5... Rotating shaft, 6.7.8... Magnet, 9... Arm, 10 ...Head assembly, 11...Magnetic--Sodo.

Claims (1)

[Scope of Claims] 1. A stator having an arc-shaped yoke (1), and an arm (9) that is pivotally supported within the stator so as to be able to swing freely, and that protrudes from the opposite surface of the yoke (1). In the head access swing motor equipped with a rotor (4), three permanent magnets (6), (7), and (8) are provided on the outer peripheral surface of the rotor (4) facing the yoke (1). In addition to providing them at predetermined intervals,
The width of the center magnet (7) in the circumferential direction is wider than the width of the other two magnets, and the inner peripheral surface of the yoke (1) facing the magnets (6), (7), and (8) Two coils (2) and (3) wound so as to have parallel portions are provided adjacent to each other along the inner peripheral surface so that the parallel portions are in close contact with each other. ), (3) The windings are connected so that current flows in opposite directions to each coil when energized. 2. A stator having an arc-shaped yoke (1), and a rotor (4) that is swingably supported within the stator and has an arm (9) protruding from the opposite surface of the yoke (1). In the head access swing motor, two coils (52) and (53) are wound around the outer peripheral surface of the rotor (4) facing the yoke (1) so as to have parallel portions.
) are provided adjacently along the outer circumferential surface so that the parallel parts are in close contact with each other, and the coils (52), (53)
The windings are connected so that current flows in opposite directions to each coil when energized, and three permanent magnets (56 ),
(57) and (58) are provided at a predetermined interval, and the width of the center magnet (57) in the circumferential direction is wider than the width of the other two magnets.