KR20120132156A

KR20120132156A - Spindle Motor

Info

Publication number: KR20120132156A
Application number: KR1020110050810A
Authority: KR
Inventors: 김영태
Original assignee: 삼성전기주식회사
Priority date: 2011-05-27
Filing date: 2011-05-27
Publication date: 2012-12-05

Abstract

The present invention consists of a rotating part including a rotating shaft, a hub and a magnet, and a fixing part including a sleeve supporting the rotating shaft and an armature opposed to the magnet, and working to form a fluid dynamic bearing part between the rotating shaft and the sleeve. A fluid-filled spindle motor, wherein the sleeve is a sintered sleeve formed by sintering, and the sintered sleeve is connected to the axial pores of the rotating shaft to form a fluid circulation hole, and the inner and outer diameters of the sleeve are surface-filled.

Description

Spindle Motor

The present invention relates to a spindle motor.

In general, a spindle motor used as a drive device for a recording disk such as a hard disk has a lubricating fluid such as oil stored in a gap between a rotating shaft and a sleeve when the motor rotates, and uses a dynamic pressure generated by the lubricating fluid. Dynamic pressure bearings are used in various ways.

More specifically, since a spindle motor equipped with a fluid dynamic bearing which maintains the shaft stiffness only by the dynamic pressure of the lubricating oil by centrifugal force is based on the winsim force, there is no metal friction and the stability is increased at high speeds, resulting in noise and vibration. It has the advantages of low noise, low noise, long impact resistance and long life, and is mainly applied to high-end optical disk devices and magnetic disk devices.

In addition, the fluid dynamic bearing has a gap formed between the shaft and the sleeve, and the dynamic pressure groove is formed in the sleeve or the shaft to move the fluid by relative rotational movement and act as a bearing by the pressure of the fluid movement. In addition, a bubble formed in the shaft system by the hydrodynamic bearing is discharged and a circulation hole is formed for pressure balancing. However, the spindle motor according to the prior art forms a fluid circulation hole in the axial direction in the sleeve or the axis of rotation to achieve this.

However, there is a problem in that the production cost is increased to form the fluid circulation hole.

The present invention has been made to solve the above problems, an object of the present invention comprises a sintered sleeve in the spindle motor, by using the axial pores of the sintered sleeve as a fluid circulation hole, a separate fluid circulation hole It is possible to maintain the equilibrium by dispersing the internal pressure of the fluid dynamic bearing part as the fluid forming the dynamic pressure is circulated without processing, and by performing coating for surface refilling in the inner and outer diameters of the sintered sleeve, It is to provide a spindle motor that can reduce the manufacturing cost, improve productivity, increase design freedom by not having a housing.

The sintered sleeve is formed by sintering Cu—Fe alloy powder or SUS powder.

In addition, the inner and outer diameters of the sleeve are formed by coating the surface with a carbon coating or nickel plating.

In addition, a dynamic pressure generating groove is selectively formed on an inner circumferential surface of the sleeve and an outer circumferential surface of the rotating shaft opposite thereto, and a radial dynamic bearing part is formed by the dynamic pressure generating groove.

And a dynamic pressure generating groove is formed in the upper portion of the sleeve facing the hub, the thrust bearing is formed by the dynamic pressure generating groove.

The fixing part is fixed to the inner circumference of the sleeve by press-fitting or adhesive, and the base is fixed to the outer periphery of the base by press-fitting or adhesive so as to face the magnet, and coupled to the lower end of the base to support the rotating shaft. It further comprises a cover for sealing the fluid.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

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 present invention, the spindle motor includes a sintered sleeve, and by using the axial pores of the sintered sleeve as a fluid circulation hole, there is no need to process a separate fluid circulation hole. By balancing the internal pressure of the bearing part to maintain the equilibrium, and by coating the surface in the inner and outer diameters of the sintered sleeve, there is no separate sleeve housing to reduce manufacturing costs, improve productivity, design freedom It has the effect of obtaining the effect of increase.

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

BRIEF DESCRIPTION OF THE DRAWINGS The objectives, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. It will be further understood that terms such as " first, "" second," " one side, "" other," and the like are used to distinguish one element from another, no. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of related arts which may unnecessarily obscure the gist of the present invention will be omitted.

Hereinafter, exemplary embodiments of the spindle motor according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a spindle motor according to the present invention. As shown in the drawing, the spindle motor 100 includes a rotating part including a rotating shaft 110, a hub 120, and a magnet 130, a sleeve 140, an armature 150, a base 160, and a coating layer 170. ), A cover 180, and a fixing part including the suction magnet 190, and a working fluid is filled to form a gap between the rotating shaft 110 and the sleeve 140 and the sleeve 140 and the hub 120. The hydrodynamic bearing part is formed in the gap between the).

More specifically, the hub 120 is mounted on the outer circumferential surface of the upper end of the rotating shaft 110.

The hub 120 is fixedly coupled to the upper portion of the rotation shaft 110 and rotates in conjunction with the rotation shaft 110.

More specifically, the hub 120 is a cylindrical portion fixed to the upper end of the rotary shaft 110, a disk portion extending radially outward from the cylindrical portion, extending downward in the axial direction at the radially outer end of the disk It consists of a side wall part.

In addition, the magnet 130 having a circular ring shape is mounted on the inner circumferential surface of the side wall of the hub 120 so as to face the armature 150.

The sleeve 140 supports the rotatable shaft 110 to be rotatable and includes a sintered sleeve 140 formed by sintering. To this end, the sintered sleeve 140 is formed by sintering Cu-Fe-based alloy powder or SUS-based powder.

In addition, the sintered sleeve 140 has pores in the axial direction of the rotating shaft 110 connected to form a fluid circulation hole (not shown), and the inner and outer diameters of the sintered sleeve 140 are surface-filled.

In addition, the inner and outer diameters of the sintered sleeve 140 may be coated with the surface of the sintered sleeve 140 by carbon coating or nickel plating.

In addition, the sleeve 140 has a dynamic pressure generating groove 142 is formed on the inner circumferential surface opposite to the rotating shaft 110 to form a radial dynamic bearing portion by the working fluid.

The dynamic pressure generating groove 142 may be made by selecting one of a herringbone shape, a spiral shape, and a spiral shape, and the shape and number of the dynamic pressure generating grooves 142 are not limited. In addition, the dynamic pressure generating groove for forming the radial dynamic bearing portion may be formed on a rotating shaft opposite to the sleeve.

In addition, a dynamic pressure generating groove 141 is formed in the upper portion of the sleeve 140 opposite to the hub 120 to form a thrust dynamic bearing.

The base 160 has an armature 150 formed of a core 151 and a coil 152 such that the sleeve 140 is fixed to the inner circumferential part by press-fitting or adhesive, or the outer circumferential part to face the magnet 130. Or by an adhesive or the like.

The cover 180 supports the rotating shaft 110 at the lower end of the base 160 and seals the fluid.

The suction magnet 190 is opposed to the hub 120 and the magnet 130 and is mounted on the base 160 to prevent injuries of the rotating part.

As such, the spindle motor 100 according to the present invention implements the sleeve as a sintered sleeve, and by using the axial pores of the sintered sleeve as a fluid circulation hole, there is no need to process a separate fluid circulation hole, dynamic pressure As the fluid forming the water is circulated, the internal pressure of the fluid dynamic bearing part can be dispersed to maintain an equilibrium, and by performing coating for surface filling in the inner and outer diameters of the sintered sleeve, a separate sleeve housing is not provided. As a result, manufacturing cost reduction, productivity improvement, and design freedom can be obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be apparent that modifications and improvements can be made by those skilled in the art.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: spindle motor 110: rotation axis
120: hub 130: magnet
140: sleeve 150: armature
160: base 170: magnetic bearing part
180: cover 190: suction magnet

Claims

A rotating part including a rotating shaft, a hub and a magnet, and a fixing part including a sleeve supporting the rotating shaft and an armature opposed to the magnet, and filled with a working fluid to form a fluid dynamic bearing part between the rotating shaft and the sleeve. Spindle motor,
The sleeve is a sintered sleeve formed by sintering, the sintered sleeve is a spindle motor, characterized in that the axial pores of the rotating shaft is connected to form a fluid circulation hole, the inner and outer diameters of the sleeve are surface-filled.

The method according to claim 1,
The sintered sleeve is a spindle motor, characterized in that formed by sintering Cu-Fe-based alloy powder or SUS-based powder.

The method according to claim 1,
The inner diameter and the outer diameter of the sleeve is a spindle motor, characterized in that the coating layer formed by the surface coating by carbon coating or nickel plating.

The method according to claim 1,
And a dynamic pressure generating groove selectively formed on an inner circumferential surface of the sleeve and an outer circumferential surface of the rotating shaft opposite thereto, and a radial dynamic pressure bearing part is formed by the dynamic pressure generating groove.

The method according to claim 1,
Spindle motor, characterized in that the dynamic pressure generating groove is formed in the upper portion of the sleeve opposite to the hub, the thrust bearing is formed by the dynamic pressure generating groove.

The method according to claim 1,
The fixed portion
The sleeve is fixed to the inner circumference by press fitting or adhesive,
A base to which the armature is fixed by an indentation or an adhesive on an outer circumference thereof so as to face the magnet; And
And a cover coupled to the lower end of the base to support the rotating shaft and seal the fluid.