JPH06233515A - Oscillating motor - Google Patents

Abstract

PURPOSE:To provide an oscillating motor with a high power without reducing the resiliency of a carriage and the waste of space, and to make it possible to realize a reduced access time, with respect to an oscillating motor in which a center yoke is provided inside a coil for linking an upper yoke and a lower yoke together. CONSTITUTION:An oscillating motor is provided with: an oscillating section 1 having a rotating shaft 6; a coil 10 attached to the oscillating section 1; a number of yokes 11 which are opposed to each other and provided on both sides of the coil 10 parallel thereto; magnets 12 provided adjacent to the coil 10 with a predetermined gap between them; and a center yoke 16 provided between the magnets 12 within the coil 10 for linking the yokes 11 on both sides together. Moreover, the coil 10 is alternately energized forwardly and reversely, which causes the oscillating section 1 to be oscillated around the rotating shaft 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillating motor for driving a carriage of a magnetic disk device, and more particularly to an oscillating motor provided with a center yoke connecting upper and lower yokes inside a coil.

Recently, a magnetic disk device for writing / reading information on / from a magnetic disk by a magnetic head is widely used as a peripheral device of a computer. Such a device has been developed in accordance with the progress of higher density, higher capacity and higher speed of the magnetic disk, and further downsizing and higher performance of the device.
There is a demand for miniaturization and high performance of each component, and in particular, miniaturization is demanded by increasing the power of a motor that drives a carriage that seeks a magnetic head on the magnetic disk surface.

[0003]

2. Description of the Related Art A conventional example will be described below with reference to FIGS. FIGS. 4A and 4B are a plan view and a side view of the magnetic disk device. As shown in the figure, spring arms 3a, 3b, ─ are fixed to the mounting arms 2a, 2b, ─ of the carriage 1a, and gimbal springs are attached to the tips of the spring arms 3a, 3b, ─.
Magnetic heads 5a, 5b, -are attached via 4a, 4b,-.

The carriage 1a is driven by a voice coil motor (VCM: hereinafter referred to as a swing motor) M1 provided on the opposite side of the mounting arms 2a, 2b, with respect to the pivot shaft 6a. Rotate back and forth.

Further, a plurality of magnetic disks 7a, 7b, -are mounted on the spindle 8 at an equal pitch, and each magnetic disk 7a, 7b,-
The magnetic heads 5a, 5b, -are arranged so as to face the surface. The magnetic disks 7a, 7b, ... Rotate horizontally by driving a motor M2 connected to the spindle 8.

Therefore, by reciprocating rotation of the carriage 1a,
Magnetic heads 5a, 5b, ─ at the tips of spring arms 3a, 3b, ─
, Reciprocally driven in the radial direction of the rotating magnetic disks 7a, 7b, ... As shown in the arrow to seek a target track, and data is recorded or reproduced.

Here, the structure of the swing motor M1 will be described in detail. As shown in the figure, the swing motor M1 includes a carriage 1a.
Coil 10a held by the coil holding portion 9 of the above, pivot shaft
6a is rotatably held at the upper and lower ends via a bearing B, and is opposed to the coil 10a at a distance from it. An upper yoke 11a, a lower yoke 11b, and an upper yoke 11a and a lower yoke.
It is composed of magnets 12a and 12b which are fixed to the facing surface of 11b and are arranged with a coil 10a and a predetermined gap, respectively, and are driven by forward and reverse control of the current flowing through the coil 10a.

At both ends of the moving area of the coil holding portion 9,
Assuming that the rocking motor M1 has runaway, the coil holding portion 9 collides with the stopper 13a for stopping the carriage 1a,
13b is provided. O-ring 1 for stoppers 13a and 13b
4a and 14b are fitted so as to cushion.

Further, as shown in FIGS. 5 (a) and 5 (b), a side yoke 15 is provided at the right end and an upper yoke 11a and a lower yoke 11 are provided.
There is also an oscillating motor M1 'in which b is connected to reduce the leakage of magnetic flux.

[0010]

According to the above-mentioned conventional method, the rocking motor has performed high power of the rocking motor and reduction of inertia of the driven carriage in order to achieve the required access time. However, as the swing motor becomes higher in power, the yoke becomes oversaturated, magnetic flux leaks out of the device, and the carriage inertia approaches the limit, and the rigidity of the carriage decreases.

Further, since the stoppers are provided at both ends of the moving area of the coil holding portion, it is necessary to secure this space, and it is not possible to increase the power of the swing motor. There is a problem.

An object of the present invention is to provide a swing motor capable of realizing high power without lowering the rigidity of the carriage and wasting space, and shortening the access time.

[0013]

FIG. 1 shows the principle of the present invention. In the figure, 6 is a rotating shaft, 1 is a swinging part having the rotating shaft 6, 10 is a coil attached to the swinging part 1, 11 is both ends of the rotating shaft 6 rotatably held, A plurality of magnets, which are parallel to the coil 10 and face each other on both sides of the coil 10, are fixedly provided on the coil 10 side of the plurality of yokes 11, respectively, and are arranged with a predetermined gap from the coil 10, 16 Is a center yoke that is provided between the magnets 12 inside the coil 10 and connects the yokes 11 on both sides.

Therefore, the coil 10 is alternately energized in the forward and reverse directions to swing the swing portion 1 about the swing shaft 6.

[0015]

By providing the center yoke 16 that connects the upper and lower yokes 11 inside the coil 10, the cross-sectional area of the magnetic path can be increased, so that the thickness of the plurality of yokes 11 can be reduced. Since the thickness of the magnet 12 can be increased, it is possible to increase the power of the swing motor.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the carriage of the magnetic disk drive described in the conventional example will be described with reference to FIGS. FIG. 2 is a configuration diagram of a carriage showing an embodiment,
(a) is a plan view, (b) is a plan view without the upper yoke and magnet of the swing motor, and FIG. 3 is an explanatory view of the embodiment. The same reference numerals denote the same objects throughout the drawings.

The carriage 1b and the pivot shaft 6a shown in FIG.
The upper yoke 11a and the lower yoke 11b in FIG. 2 correspond to the yoke 11 in FIG. 1, respectively.

As shown in FIG. 2, the swing motor M1 "of the carriage 1b is constructed as follows: Along the center line of the pivot shaft 6a and the upper and lower yokes 11a and 11b inside the coil 10a. Center yoke 16a is provided.
The center yoke 16a connects the upper yoke 11a and the lower yoke 11b, and magnets 12A to 12D are arranged on both sides of the upper and lower ends of the center yoke 16a.

Further, a stopper 13A formed in a rivet shape with a material having elasticity, for example, rubber, is formed at the center position of both side surfaces of the center yoke 16a facing the inner surface of the coil 10a (corresponding to the stopper of claim 2). Is provided. Therefore, the stoppers 13a and 13b described in the conventional example are omitted.

With this structure, the center yoke 16a increases the cross-sectional area of the magnetic path, reduces the leakage of magnetic flux when the coil 10a is energized, and increases the magnetic flux density. The thickness of the lower yoke 11b can be reduced, and the thicknesses of the magnets 12A to 12D can be increased accordingly, and the swing motor M1 ″ can be made to have high power.

Further, since the stopper 13A is provided on the center yoke 16a, as shown in FIG.
When the carriage 1b rotates in the direction of the arrow more than during normal operation due to the runaway of 1 ″, the inside of the coil 10a is the stopper 13A.
Can be stopped by colliding with. The same applies when the carriage 1b rotates in the opposite direction.

Therefore, as compared with the case where the stoppers 13a and 13b are provided outside the coil holding portion 9 as in the conventional example, a free space is secured on both sides of the coil holding portion 9, and the magnets 12A to The area of 12D can be expanded,
Higher power of swing motor M1 ″ is possible.

Therefore, it is possible to obtain the rocking motor M1 ″ having high power and improved flatness. In the above example, the rocking motor M1 ″ used for the carriage of the magnetic disk device is obtained.
However, it is needless to say that the present invention can be applied to a device that records and reproduces information with respect to another recording medium, for example, a swinging motor of a carriage of an optical disk device, and is generally used for swinging. The same effect can be obtained by applying it to a motor.

[0024]

As described above, according to the present invention, in claim 1, by providing the center yoke connecting the yokes on both sides inside the coil, the cross-sectional area of the magnetic path increases,
Since the leakage of the magnetic flux is reduced and the magnetic flux density is increased, the thickness of the yoke can be reduced, and the thickness of the magnet can be increased accordingly, so that the swing motor can have a high power and flatness can be improved.

According to the second aspect of the present invention, elastic stoppers are provided on the surfaces of the center yoke which the inside of the coil approaches as the swing part swings, so that a free space is secured around the outside of the coil. As a result, the area of the magnet can be increased by that amount, and the power of the swing motor can be increased. There is an effect.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram of an example.

FIG. 4 is a configuration diagram showing a conventional example of a magnetic disk device.

FIG. 5 is a configuration diagram showing a different conventional example.

[Explanation of symbols]

1 is a swinging part, 1a and 1b are carriages, 6 is a rotating shaft, 6a is a pivot shaft, 10 and 10a are coils,
11 is a yoke, 11a is an upper yoke, 11b is a lower yoke, 12, 12a to 12d, 12A to 12D are magnets,
13a, 13b and 13A are stoppers, 16 and 16a are center yokes, M1 and M
1 ′, M1 ″ is a swing motor,

Claims (2)

[Claims] 1. A swing part (1) having a swing shaft (6), a coil (10) attached to the swing part (1), and swinging both ends of the swing shaft (6). A plurality of yokes (11), which are held freely and are opposed to both sides of the coil (10) in parallel with the coil (10), and fixed to the coil (10) side of the yoke (11). And a plurality of magnets (12) arranged with a predetermined gap from the coil (10) and the magnets (12) inside the coil (10). 11) and a center yoke (16) for connecting the coil (10), and the coil (10) is alternately energized in the forward and reverse directions to swing the swinging portion (1).
An oscillating motor which oscillates around the oscillating shaft (6). 2. A stopper having elasticity is provided on each of the surfaces of the center yoke (16) to which the inside of the coil (10) approaches as the swing part (1) swings. The swing motor according to claim 1.