WO2011159062A2

WO2011159062A2 - Spindle motor

Info

Publication number: WO2011159062A2
Application number: PCT/KR2011/004222
Authority: WO
Inventors: Changhyun Park
Original assignee: Lg Innotek Co., Ltd.
Priority date: 2010-06-16
Filing date: 2011-06-09
Publication date: 2011-12-22
Also published as: KR101135266B1; WO2011159062A3; KR20110137189A

Abstract

A spindle motor including: a bearing assembly including a first floor plate, a first and second lateral surface plate, a bearing housing, and a bearing accommodated in the bearing housing; a base plate inserted into the second lateral surface plate; a stator including a core coupled to the periphery of the first lateral surface plate and a coil wound on the core; and a rotor including a yoke coupled to a rotation shaft inserted into the bearing and a magnet arranged at the yoke to face the core, wherein the second floor plate is formed with a housing disengagement prevention unit that is extended from an edge of the second floor plate to a bottom surface of the base plate facing an upper surface of the base plate to prevent the bearing housing from being disengaged from the base plate.

Description

SPINDLE MOTOR

The teachings in accordance with the exemplary embodiments of this invention relate generally to a spindle motor.

A spindle motor is widely employed to perform the function of rotating a disk at a high speed in an optical disk drive (ODD) and a hard disk. The spindle motor for rotating a disk at a high speed generally includes a bearing housing that further include a bearing for supporting a rotation shaft that rotates at a high speed, and a base plate in which the bearing housing is secured.

The conventional bearing housing of the spindle motor is coupled to a burring unit formed at the base plate. However, there is a disadvantage in that the bearing housing is moved or disengaged from the base plate, if a floor surface of the bearing housing is applied with shocks.

If the bearing housing is moved or disengaged from the base plate, a distance between a disk rotated by the spindle motor and an optical pickup module is changed to generate a data read error or a data write error.

The present invention is directed to provide a spindle motor configured to improve a coupled structure between a bearing housing and a base plate, whereby the bearing housing is prevented from being moved or disengaged from the base plate.

Technical problems to be solved by the present invention are not restricted to the above-mentioned, and any other technical problems not mentioned so far will be clearly appreciated from the following description by skilled in the art.

An object of the invention is to solve at least one or more of the above problems and/or disadvantages in a whole or in part and to provide at least the advantages described hereinafter. In order to achieve at least the above objects, in whole or in part, and in accordance with the purposes of the invention, as embodied and broadly described, and in one general aspect of the present invention, there is provided a spindle motor, the spindle motor comprising:

a bearing assembly including a first floor plate, a first lateral surface plate extended from an edge of the first floor plate, a second lateral surface plate protrusively formed from an inner lateral center surface of the first floor plate toward a periphery of the first floor plate,

a bearing housing including the second floor plate connected to the second lateral surface plate, and a bearing accommodated in the bearing housing;

a base plate inserted into the second lateral surface plate;

a stator including a core coupled to the periphery of the first lateral surface plate and a coil wound on the core; and

a rotor including a yoke coupled to a rotation shaft inserted into the bearing and a magnet arranged at the yoke to face the core,

wherein the second floor plate is formed with a housing disengagement prevention unit that is extended from an edge of the second floor plate to a bottom surface of the base plate facing an upper surface of the base plate to prevent the bearing housing from being disengaged from the base plate.

Preferably, the housing disengagement prevention unit takes the shape of a circle when viewed from a top plan view.

Preferably, the housing disengagement prevention unit is plurally and intermittently formed when viewed from a top plan view.

Preferably, a height of the second lateral surface plate is same as thickness of the base plate when measured from the first floor plate.

In another general aspect of the present invention, there is provided a spindle motor, the spindle motor comprising: a bearing assembly including a bearing housing and a bearing; a base plate inserted and coupled to the bearing housing; a stator including a core and a coil, and coupled to the bearing housing; a rotation shaft rotatably inserted into the bearing assembly where a bottom distal end of the rotation shaft faces the bearing housing; a rotor coupled to the rotation shaft to rotate with the rotation shaft; and a housing disengagement prevention unit integrally formed with the bearing housing, and extended from a bottom surface to prevent the bearing housing from being disengaged from the base plate.

Preferably, the housing disengagement prevention unit is formed by caulking press process of a lug of the bearing housing that has passed the bottom surface of the base plate.

Preferably, the housing disengagement prevention unit takes the shape of a disk when viewed from a top plan view.

Preferably, the housing disengagement prevention unit is tightly coupled to the bottom surface of the base plate.

Preferably, the base plate includes a printed circuit board (PCB).

Preferably, the base plate is formed with a through hole in which the bearing house is accommodated.

Preferably, the bearing house includes a doughnut-shaped first floor plate, a first lateral surface plate extended upward from the first floor plate, a second lateral surface plate extended downward from an inner edge of the first floor plate, and a second floor plate formed at the second lateral surface plate.

Preferably, the second lateral surface plate and the second floor plate are formed by allowing a center of the first floor plate to protrude from an inner lateral surface of the first floor plate toward a periphery of the first floor plate.

Preferably, the first and second floor plates are formed in parallel.

In still another general aspect of the present invention, there is provided a spindle motor, the spindle motor comprising: a bearing assembly including a bearing housing and a bearing; a base plate inserted and coupled to the bearing housing; a stator including a core and a coil, and coupled to the bearing housing; a rotation shaft rotatably inserted into the bearing assembly where a bottom distal end of the rotation shaft faces the bearing housing; a rotor coupled to the rotation shaft to rotate with the rotation shaft; and a housing disengagement prevention unit integrally formed with the bearing housing, and extended from a bottom surface to prevent the bearing housing from being disengaged from the base plate, wherein the housing disengagement prevention unit is formed by caulking press process of a portion of the bearing housing so coupled to allow passing a through hole formed at the base plate and to be tightly adhered to the base plate.

The spindle motor according to the present invention has an advantageous effect in that a bearing housing is prevented from being moved or disengaged from a base plate even if a shock is applied to the bearing housing, whereby generation of data read error and data write error of an optical disk can be avoided.

The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view illustrating a spindle motor according to an exemplary embodiment of the present invention;

FIG. 2 is an enlarged view of 'A' of FIG. 1;

FIG. 3 is a rear surface view of a bearing housing illustrated in FIG. 1; and

FIG. 4 is a rear surface view of bearing housing in a spindle motor according to another exemplary embodiment of the present invention.

The following description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the following teachings, and skill and knowledge of the relevant art are within the scope of the present invention. The embodiments described herein are further intended to explain modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention.

The disclosed embodiments and advantages thereof are best understood by referring to FIGS. 1-4 of the drawings, like numerals being used for like and corresponding parts of the various drawings. Other features and advantages of the disclosed embodiments will be or will become apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional features and advantages be included within the scope of the disclosed embodiments, and protected by the accompanying drawings. Further, the illustrated figures are only exemplary and not intended to assert or imply any limitation with regard to the environment, architecture, or process in which different embodiments may be implemented. Accordingly, the described aspect is intended to embrace all such alterations, modifications, and variations that fall within the scope and novel idea of the present invention.

Furthermore, "exemplary" is merely meant to mean an example, rather than the best. It is also to be appreciated that features, layers and/or elements depicted herein are illustrated with particular dimensions and/or orientations relative to one another for purposes of simplicity and ease of understanding, and that the actual dimensions and/or orientations may differ substantially from that illustrated. That is, in the drawings, the size and relative sizes of layers, regions and/or other elements may be exaggerated or reduced for clarity. Like numbers refer to like elements throughout and explanations that duplicate one another will be omitted. Now, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view illustrating a spindle motor according to an exemplary embodiment of the present invention, FIG. 2 is an enlarged view of 'A' of FIG. 1, FIG. 3 is a rear surface view of a bearing housing illustrated in FIG. 1, and FIG .4 is a rear surface view of bearing housing in a spindle motor according to another exemplary embodiment of the present invention.

Referring to FIGS. 1 to 3, a slim spindle motor (200) includes a bearing assembly (210), a base plate (220), a stator (230), a rotation shaft (240) and a rotor (250). The slim spindle motor (200) may further include a disk centering member (270) for centering of an optical disk in addition to the above configuration.

The bearing assembly (210) includes a bearing housing (215) and a bearing (218). The bearing housing (215) includes a first floor plate (211), a first lateral surface plate (212), a second floor plate (213), a second lateral surface plate (214) and a housing disengagement prevention unit (214a).

The first floor plate (211) takes the shape of a doughnut. The first lateral surface plate (212) is extended upwards from an outer edge of the first floor plate (211), and the bearing housing (215) is formed with an accommodation space for accommodating the bearing (218) by the first floor plate (211) and the first lateral surface plate (212).

The second lateral surface plate (214) is extended downward from an inner edge of the first floor plate (211), and is formed with the second floor plate (213).

The first lateral surface plate (212) takes the shape of a cylinder having a first diameter, and the second lateral surface plate (214) takes the shape of a cylinder having a second diameter.

The second lateral surface plate (214) and the second floor plate (213) are formed by protruding a center of the first floor plate (211) from an inner lateral surface of the first floor plate (211) to a periphery of the first floor plate (211), where the second lateral surface plate (214) and the second floor plate (213) are formed in parallel.

In the present exemplary embodiment of the present invention, the first floor plate (211), the first lateral surface plate (212), the second floor plate (213) and the second lateral surface plate (214) may be formed by press work, for example.

The second floor plate (213) may take various shapes, for example, a disk shape, an oval shape, a rectangular shape and a polygonal shape, when viewed from a top plan view. In the present exemplary embodiment of the present invention, the second floor plate (213) may take the shape of a disk, for example.

The bearing (218) is accommodated into an accommodation space formed by the first floor plate (211) and the first lateral surface plate (212) of the bearing housing (215). In the present exemplary embodiment of the present invention, the bearing housing (218) may take the shape of a cylinder formed with a rotation shaft hole (216) and inserted into an inner lateral surface of the first lateral surface plate (212). The bearing (218) press-fitted into the bearing housing (215) may include an oil impregnation sintered bearing, for example.

The base plate (220) may take the shape of a plate, and include a printed circuit board (PCB). The base plate (220) may be formed with a through hole (220a) and have a diameter and a shape adequate for being inserted into the second lateral surface plate (214) of the bearing housing (215). For example, in a case the second lateral surface plate (214) of the bearing housing (215) takes the shape of a cylinder, the through hole (220a) has a round shape for being inserted into a periphery of the second lateral surface plate (214), and has a diameter to be inserted into the second lateral surface plate (214).

In the present exemplary embodiment of the present invention, thickness of the base plate (220) is substantially same as a height between the periphery of the first floor plate (211) and an inner lateral surface of the second floor plate (213). Thus, the periphery of the second floor plate (213) of the bearing housing (215) is protruded from the periphery of the base plate (220) as high as the thickness of the second floor plate (213).

An edge of the second floor plate (213) of the bearing housing (215) protruded from the periphery of the base plate (220) is processed by press work in order to prevent the bearing housing (215) from being disengaged from the base plate (220) by shock and/or vibration from outside, whereby a housing disengagement prevention unit (214a) is formed at the edge of the second floor plate (213) of the bearing housing (215) by being extended to the periphery of the base plate (220) inserted into the second lateral surface plate (214) of the bearing housing (215).

The inner lateral surface of the base plate (220) is tightly adhered to the periphery of the first floor plate (211) of the bearing housing (215), and the periphery of the base plate (220) is secured by the housing disengagement prevention unit (214a) extended from the edge of the second floor plate (213) of the bearing housing (215), whereby the bearing housing (215) is prevented from being moved or disengaged from the base plate (220).

In the present exemplary embodiment of the present invention, as illustrated in FIG.3, the housing disengagement prevention unit (214a) may be continuously formed in a round shape along an opening (220a) of the base plate (220).

Meanwhile, the housing disengagement prevention unit (214a) may be plurally and continuously formed along the opening (220a) of the base plate (220), as illustrated in FIG. 4, and each of the plurality of housing disengagement prevention units (214a) may be formed at an equidistant gap therebetween.

Referring to FIG. 1 again, a washer may be interposed between the bearing (218) accommodated into the bearing housing (215) and the first floor plate (211) for preventing the rotation shaft (240, described later) from being separated or floated from the bearing (218). The stator (230) includes a core (232) and a coil (234).

The core (232) includes a plurality of iron pieces each stacked on the other. A center of the stacked plurality of iron pieces is formed with a through hole coupled to the bearing housing (215). The coil (234) is wound on the core (232).

The core (232) is tightly fixed at the first lateral surface plate (212) of the bearing housing (215) by using the through hole of the core (232).

The core (232) including a plurality of stacked iron pieces is generally fixed by a burring unit of the base plate (220). However, the base plate (220) is not formed with the burring unit in the present exemplary embodiment of the present invention, such that the core (232) may be moved from the first lateral surface plate (212) of the bearing housing (215), and in a case the core (232) is moved from the first lateral surface plate (212) of the bearing housing (215), the rotation shaft (240) of the spindle motor cannot accurately rotate.

In order to prevent the core (232) from moving from the first lateral surface plate (212) of the bearing housing (215), a core disengagement prevention unit (227) is interposed between the core (232) and the base plate (220) to apply pressure to the core (232). The core disengagement prevention unit (227) may take the shape of a cylinder, for example. It should be apparent that the core disengagement prevention unit (227) may alternatively take the shape of a ring that is situated at a position to apply pressure to the core (232) in the first lateral surface plate (212) of the bearing housing (215).

The rotation shaft (240) is rotatably inserted into the rotation shaft hole (216) of bearing at the bearing assembly (210). A bottom distal end of the rotation shaft (240) faces the second floor plate (213) of the bearing housing (215), and a thrust bearing (245) is arranged between the second floor plate (213) of the bearing housing (215) and the bottom distal end of the rotation shaft (240) to allow the rotation shaft (240) to rotate at a high speed.

The rotor (250) is coupled to the rotation shaft (250) to rotate with the rotation shaft (240). The rotor (250) includes a yoke (252) and a magnet (254).

The yoke (252) takes the shape of a disk. A rotation center of the yoke (252) is formed with a yoke burring portion (253) coupled to the rotation shaft (240). An edge of the yoke (252) is formed with a skirt unit (252a) bent to face the core (232) of the stator (230).

The magnet (254) is coupled to an inner lateral surface of the skirt unit (252a) of the yoke (252), and faces the core (232) of the stator (230).

The rotation shaft (240) is rotated by rotational force generated by a magnetic field from the magnet (254) and a magnetic field from the coil (234) wound on the core (232).

The disk centering member (270) is press-fitted into the burring portion (253) and the optical disk is coupled to the disk centering member (270).

As apparent from the foregoing, the spindle motor according to the present invention is advantageous in that the a bearing housing is prevented from being moved or disengaged from a base plate even if a shock is applied to the bearing housing, whereby generation of data read error and data write error of an optical disk can be avoided.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this invention. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawing and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

The present invention has an industrial applicability in that a coupled structure between a bearing housing and a base plate is improved and a bearing housing is prevented from being moved or disengaged from a base plate even if a shock is applied to the bearing housing, whereby generation of data read error and data write error of an optical disk can be avoided.

Claims

A spindle motor, the spindle motor comprising:

a bearing assembly including a first floor plate, a first lateral surface plate extended from an edge of the first floor plate, a second lateral surface plate protrusively formed from an inner lateral center surface of the first floor plate toward a periphery of the first floor plate, a bearing housing including the second floor plate connected to the second lateral surface plate, and a bearing accommodated in the bearing housing;

a base plate inserted into the second lateral surface plate; a stator including a core coupled to the periphery of the first lateral surface plate and a coil wound on the core; and

a rotor including a yoke coupled to a rotation shaft inserted into the bearing and a magnet arranged at the yoke to face the core, wherein the second floor plate is formed with a housing disengagement prevention unit that is extended from an edge of the second floor plate to a bottom surface of the base plate facing an upper surface of the base plate to prevent the bearing housing from being disengaged from the base plate.
The spindle motor of claim 1, wherein the housing disengagement prevention unit takes the shape of a circle when viewed from a top plan view.
The spindle motor of claim 1, wherein the housing disengagement prevention unit is plurally and intermittently formed when viewed from a top plan view.
The spindle motor of claim 1, wherein a height of the second lateral surface plate is same as thickness of the base plate when measured from the first floor plate.
A spindle motor, the spindle motor comprising:

a bearing assembly including a bearing housing and a bearing;

a base plate inserted and coupled to the bearing housing;

a stator including a core and a coil, and coupled to the bearing housing;

a rotation shaft rotatably inserted into the bearing assembly where a bottom distal end of the rotation shaft faces the bearing housing; a rotor coupled to the rotation shaft to rotate with the rotation shaft; and

a housing disengagement prevention unit integrally formed with the bearing housing, and extended from a bottom surface to prevent the bearing housing from being disengaged from the base plate.
The spindle motor of claim 5, wherein the housing disengagement prevention unit is formed by caulking press process of a lug of the bearing housing that has passed the bottom surface of the base plate.
The spindle motor of claim 6, wherein the housing disengagement prevention unit takes the shape of a disk when viewed from a top plan view.
The spindle motor of claim 6, wherein the housing disengagement prevention unit is plurally and intermittently formed when viewed from a top plan view.
The spindle motor of claim 6, wherein the housing disengagement prevention unit is tightly coupled to the bottom surface of the base plate.
The spindle motor of claim 5, wherein the base plate includes a printed circuit board (PCB).
The spindle motor of claim 10, wherein the base plate is formed with a through hole in which the bearing house is accommodated.
The spindle motor of claim 11, wherein the bearing house includes a doughnut-shaped first floor plate, a first lateral surface plate extended upward from the first floor plate, a second lateral surface plate extended downward from an inner edge of the first floor plate, and a second floor plate formed at the second lateral surface plate.
The spindle motor of claim 11, wherein the second lateral surface plate and the second floor plate are formed by allowing a center of the first floor plate to protrude from an inner lateral surface of the first floor plate toward a periphery of the first floor plate.
The spindle motor of claim 13, wherein the first and second floor plates are formed in parallel.
A spindle motor, the spindle motor comprising:

a bearing assembly including a bearing housing and a bearing;

a base plate inserted and coupled to the bearing housing; a stator including a core and a coil, and coupled to the bearing housing;

a rotation shaft rotatably inserted into the bearing assembly where a bottom distal end of the rotation shaft faces the bearing housing;

a rotor coupled to the rotation shaft to rotate with the rotation shaft; and

a housing disengagement prevention unit integrally formed with the bearing housing, and extended from a bottom surface to prevent the bearing housing from being disengaged from the base plate,

wherein the housing disengagement prevention unit is formed by caulking press process of a portion of the bearing housing so coupled to allow passing a through hole formed at the base plate and to be tightly adhered to the base plate.