KR20130069015A - Stator core of spindle motor - Google Patents

Abstract

The present invention relates to a stator core for a spindle motor, comprising: a core bag having a through hole at the center thereof and having an annular shape; It consists of a plurality of teeth protruding radially outward from the core back, providing a space for winding the coil.
In particular, the tees of the stator core according to the present invention are characterized by having a circular or regular polygonal cross section. The coil is wound around a tooth with a circular or regular polygonal cross section so that it is wound close to the circle.

Description

Stator core of spindle motor

The present invention relates to a stator core for a spindle motor.

Typically, a spindle motor is mounted inside a hard disk drive (HDD) to rotate a disk of an HDD that is recording and storing information.

Spindle motors generally consist of a rotor and a stator, which have a shaft in the center of the rotor case and arrange magnets along the rotor case edge. The stator seats the stator core on the base, with the stator core having a through hole in the center winding the coil around a tooth projecting radially. When a current is applied to the coil, a magnetic field is generated around the tip of the stator core. The magnetic field provides a magnetic force to the magnet provided in the rotor, which then rotates the rotor to drive the spindle motor.

As described above, an example of a spindle motor according to the prior art is disclosed in Patent Document 1.

The stator core according to the prior art has twelve radially extending stator poles and teeth at the tip of the stator poles protruding circumferentially, as is already well known to those skilled in the art.

In the stator core of this structure, a coil is wound around the stator pole. In particular, the stator pole consists of a plate-shaped member having a rectangular cross section. The spindle motor forms a stator core by loading a plurality of plate-shaped members as necessary. The spindle motor has a rectangular or rectangular cross section as it is loaded.

Stator poles arranged in a rectangular cross section will wind the coils around them. Coils wound over stator poles with a rectangular cross section will have to be wound in a generally rectangular shape.

Therefore, a coil wound in a rectangular shape may not guarantee a uniform magnetic flux flow for a coil arranged in a rectangular shape when an electric current is applied from the outside, causing an imbalance of magnetic flux density.

Patent Document 1: Republic of Korea Patent No. 10-0137920

The present invention has been made to solve the above-mentioned disadvantages, and aims to improve the magnetic flux density to be generated in the stator core of a motor for a hard disk drive.

The present invention allows the coil to be wound round or close to a circle around the tooth to produce a uniform flux density.

To this end, the present invention,

A core bag having a through hole at the center thereof and having an annular shape;

A plurality of teeth projecting radially outwardly from the coreback to provide space for winding the coil; And

Opposite portion is disposed opposite the magnet of the rotor at the end of the tooth; in particular, the tooth according to the invention is characterized in that it has an n-shaped cross section. Here, the n-square has n as the number of sides, and the larger the number of n, the closer to the circle.

In addition, the outer peripheral surface of the opposing part is formed in an arc shape so that the stator core of the present invention opposes close to the magnet of the rotor arranged in a ring shape.

That is, the present invention consists of a tooth consisting of a regular polygonal cross section. Since the regular polygonal teeth have the same side lengths and the same angles, the coils to be wound can be stably seated on the teeth as well as wound close to the circle.

The present invention is designed to have the number of sides larger than 4 so as to wind the coil close to a circle unlike a stator coil having a rectangular cross section.

Preferably, the teeth of the stator nose according to the invention are to have a circular cross section.

Prior to that, terms and words used in the present specification and claims should not be construed in a conventional and dictionary sense, and the inventor may properly define the concept of the term in order to best explain its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

According to the description of the present invention, the present invention is provided so that the coil can be wound around the tooth of the stator core in a circle or a regular polygon close to the circle.

The present invention is to ensure a uniform magnetic flux density by generating a magnetic flux flow radially by winding the coil in a regular polygonal shape close to the circular or circular.

Through this, the present invention can improve the electromagnetic properties of the motor by improving the focusing speed of the magnetic flux. The electromagnetic characteristics of the motor improve the noise as well as the vibration of the motor and provide more stable operation performance.

1 is a schematic cross-sectional view of a spindle motor.
2 is a plan view of a stator core according to the present invention.
3A is a cross-sectional view showing an example of the stator core shown in FIG. 2.
3B is a cross-sectional view showing another example of the stator core shown in FIG. 2.
3C is a cross-sectional view illustrating still another example of the stator core shown in FIG. 2.
4 is a cross-sectional view of a coil wound on the stator core and its outer circumferential surface of the present invention shown in FIG. 3A.

Now, a stator core of a motor for a hard disk drive, preferably a spindle motor, according to the present invention will be described in detail with reference to the accompanying drawings.

Advantages, features, and methods of achieving the present invention will be apparent from the embodiments described below in conjunction with the accompanying drawings. In the present specification, in adding the reference numerals to the components of each drawing, the same reference numerals refer to the same or similar components throughout the specification. In addition, when the detailed description of the related art related to the present specification makes the gist of the present invention unclear, the detailed description is omitted.

1 is a schematic cross-sectional view of a spindle motor according to an embodiment of the present invention.

Referring to FIG. 1, the spindle motor 100 according to the present invention includes a base 110, a sleeve 120, a shaft 130, a rotor 140, and a stator 150.

The base 110 is installed in a device such as a hard disk drive (not shown), and provides a space for accommodating members constituting the motor therein. As shown, the base 110 forms a cylindrical support 111 in the center thereof, the sleeve 120 to be described later is inserted into the hollow formed in the center of the support 111 is coupled.

In addition, the base 110 attaches a pulling plate 112 made of a magnetic material to an upper surface thereof. Preferably, the pulling plate 112 is disposed at a portion adjacent to the magnet 145 to be described later, and a pulling plate. The attraction force due to the magnetic force acts between the 112 and the magnet 145.

The sleeve 120 may be inserted into the support 111 of the base 110 and assembled as described above. In addition, the sleeve 120 is formed in a generally cylindrical shape so that the shaft 130 can be rotatably supported therein.

The sleeve 120 forms a hydrodynamic bearing on an inner circumferential surface spaced by a predetermined gap from the shaft 130 and a bearing surface which is in contact with the thrust plate (not indicated).

The shaft 130 axially supports the hub 141 and is inserted into the sleeve 120 and rotatably supported by the sleeve 120, while its upper portion has a thrust plate.

In other words, the shaft 130 is preferably spaced apart at predetermined intervals in order to reduce the contact friction with the inner peripheral surface of the sleeve 120 to maintain a non-contact state. The clearance between the sleeve 120 and the shaft 130 may be filled with a fluid, for example, oil, and friction between the sleeve 120 and the sleeve 120 during rotation of the shaft 130 through oil may be reduced.

In addition, the rotor 140 includes a skirt portion 142 for mounting the cup-shaped hub 141 and the magnet 145 and arranges the shaft 130 on a vertical axis line that matches the center of rotation of the hub 141. do.

The rotor 140 is a rotating structure that is formed rotatably with respect to the stator 150 by forming an electric field for rotating the hub 141. The rotor 140 includes a ring- (145) is provided on the inner circumferential surface of the skirt portion (142), and the magnet (145) forming the magnetic field generates an electromagnetic force with the electric field formed by the coil (152). Through this electromagnetic force, the rotor 140 of the spindle motor is rotated. The hub 141 makes it possible to rotate a disk (not shown) for the purpose of signal recording and reproducing.

The stator 150 is a fixed structure having a ring-shaped core 151 fixedly disposed on the base 110 and a coil 152 wound on the core 151 to generate an electric field.

2 is a plan view of a stator core according to the present invention.

The present invention relates to a stator core 151 to be used in a motor for a hard disk drive, preferably a spindle motor.

As shown, the stator core 151 according to the present invention consists of an annular core bag 151a, a tooth 151b, and an opposing portion 151c.

The core bag 151a is formed in an annular shape. For example, the core bag 151a has a through hole that can be pressed into a mounting member, such as a support of the base, at the center thereof.

The annular core bag 151a is not limited to a circular shape and can be changed into various shapes such as a square ring shape, a hexagonal ring shape, an octagonal ring shape and the like according to the cross-sectional shape of the mounting member.

The teeth 151b protrude radially outward from the annular core bag 151a to provide a space for winding the coil. It is preferable that a plurality of teeth 151b protrude from the core bag 151a at equal intervals.

The opposed portion 151c is formed at the end of the tooth 151b as illustrated, and the opposed portion 151c is a portion opposed to the magnet 145 of the rotor (see FIG. 1).

When a current is applied to the coil 152 (refer to FIG. 4) wound around the tooth 151b of the stator core 151, the stator is magnetized while the opposing portion 151c uses the magnet and the electromagnetic action as a means. Rotated.

The outer circumferential surface of the opposing portion 151c has an arc shape, and can be opposed to each other at a predetermined gap without being in direct contact with the magnets of the rotor arranged in a circular shape.

FIG. 3 shows a cross-sectional view of various examples of a stator core according to the present invention cut along the III-III line shown in FIG. 2.

The stator core according to one embodiment of the present invention has a tooth 151b (see FIG. 3A) having a circular cross section.

The stator core according to another embodiment of the present invention includes a tooth 151b (see FIG. 3B) having a regular hexagonal cross section.

The stator core according to another example of the present invention includes a tooth 151b (see FIG. 3C) having a square octagonal cross section.

The stator core according to the present invention is not limited to the teeth 151b having a circular cross section, a regular hexagonal cross section, and a regular octagonal cross section shown in FIG. 3, and coils 152 to be wound on the teeth 151b of the stator core; 1) can be arranged to be close to a circle.

In particular, the present invention consists of a tooth 151b having a regular polygonal cross section so that the coiled state of the coil to be wound can be formed almost close to a circle.

Here, the term regular polygon refers to a polygon in which all sides have the same length and all angles have the same size, and a regular polygon having a number of sides n is called a regular n polygon.

Since the present invention has to wind the wound state of the coil around the teeth 151b almost close to the circle, the teeth have a square n-shaped cross section as described, so that the number of sides should be n> 4. .

4 is a cross-sectional view of the stator core of the present invention wound with a coil.

As shown in Figs. 3a to 3c, the stator core according to the invention consists of a tooth 151b having a circular or regular polygonal cross section, while Fig. 4 is on a tooth 151b consisting of a circular cross section illustrated in Fig. 3a. An example of winding the coil 152 is briefly shown.

Referring to FIG. 4, the tooth 151b having a circular cross section of the stator core according to the present invention winds the coil 152 on the circumferential surface thereof, as illustrated, the coil wound on the tooth 151b. 152 is wound in a circle corresponding to the cross-sectional shape of the tooth.

Since the coil 152 wound in a circular shape generates a magnetic flux flow radially, it guarantees a uniform magnetic flux density, so that the imbalance of magnetic flux density occurring at the corner of the coil wound on the core of Patent Document 1 can be eliminated. Will be.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, this is for describing the present invention in detail, and the stator core according to the present invention is not limited thereto and is within the scope and / or scope of the appended claims. In the above, it will be apparent that modifications or changes are possible by those skilled in the art.

100: spindle motor, 110: base,
120: sleeve, 130: shaft,
140: rotor, 150: stator,
151: core, 152: coil.

Claims (6)

A core bag having a through hole at the center thereof and having an annular shape;
In the stator core consisting of a plurality of teeth protruding radially outward from the core back to provide a space for winding the coil,
The tees have an n-shaped cross section, where n represents the number of sides,
The coil of the stator core, characterized in that the coil is wound around the tooth round.
The method according to claim 1,
The tooth is a stator core for a spindle motor, characterized in that the length of the sides and the size of the angle is made of the same regular polygon.
The method according to claim 1,
The stator core is a stator core for a spindle motor, characterized in that consisting of a regular polygon having a number n of more than four.
The method according to claim 1,
And said tooth has a circular cross section.
The method according to claim 1,
And an opposite portion disposed opposite the magnet of the rotor at the end of the tooth.
The method according to claim 5,
The outer circumferential surface of the opposing portion of the opposing portion is formed in an arc shape, the stator core for the spindle motor.

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