KR20130026781A - Spindle motor - Google Patents

Abstract

PURPOSE: A spindle motor is provided to improve durability by implementing a thrust plate integrated type rotary shaft. CONSTITUTION: A rotation unit includes a rotary shaft(110), a hub and a magnet. A sleeve(140) supports a rotary shaft. A static unit includes an armature(160) facing the sleeve and net. A fluid dynamic pressure bearing unit is filled with oil and is formed between the rotation unit and the static unit. An upper rotary shaft(111) forms a thrust plate unit. A lower rotary shaft(112) combines the upper rotary shaft.

Description

Spindle Motor

The present invention relates to a spindle motor.

In general, a spindle motor used as a driving device for a recording disk such as a hard disk has a lubricating fluid such as oil stored between a rotating part and a fixed part at the time of rotation of the motor. It is used in various ways.

More specifically, a spindle motor equipped with a fluid dynamic pressure bearing that maintains axial rigidity of the shaft only by the moving pressure of the lubricating oil by centrifugal force is based on the thrust force. Therefore, there is no metal friction, And it is mainly applied to high-end optical disc apparatuses and magnetic disc apparatuses, since the high-speed rotation of the rotating object is smoother than the motor having the ball bearing.

More specifically, the spindle motor according to the prior art is composed of a rotating part including a rotating shaft, a hub, a magnet, an armature consisting of a sleeve, a base, a core and a coil, and a fixing part including a cover and filled with oil, which is a working fluid. A hydrodynamic bearing portion is formed. In addition, a thrust plate for generating fluid dynamic pressure with the sleeve is mounted on the rotation shaft.

However, as the thrust plate is manufactured separately and mounted on the rotating shaft, it is difficult to maintain parallelism, and the performance of the motor may be degraded due to the twist of the thrust plate due to external impact. In addition, as the rotary shaft needs to be processed in order to couple the thrust plate to the rotary shaft, the strength of the rotary shaft is lowered and the design freedom is also reduced, and as the thrust plate is formed to have a predetermined thickness or more, the radial bearing part The problem is that the length of the rotating shaft, that is, the span length, is affected by the decrease and the dynamic characteristics are also reduced.

The present invention has been made in order to solve the above problems, and is implemented by a thrust plate integrated rotary shaft is more robust by external impact, excellent parallelism of the thrust plate, the thickness of the thrust plate of the prior art thrust By implementing a smaller than the plate, it is to provide a spindle motor in which the length of the rotating shaft affected by the radial bearing portion, that is, the span length is increased and thus the dynamic characteristics are also improved.

The present invention comprises a rotating part including a rotating shaft, a hub, and a magnet, and a fixing part including a sleeve for supporting the rotating shaft and an armature opposed to the magnet, and filled with oil to provide fluid dynamic pressure between the rotating part and the fixing part. A spindle motor having a bearing portion, wherein the rotating shaft includes an upper rotating shaft having a thrust plate portion and a lower rotating shaft to which the upper rotating shaft is coupled.

The upper rotating shaft may include an upper body on which the hub is mounted, a thrust plate portion positioned below the upper body and configured to generate fluid dynamic pressure with the sleeve, and a lower portion of the thrust plate portion to be inserted into the lower rotating shaft. It consists of a lower body located.

In addition, an upper portion of the lower rotary shaft is formed with a receiving groove into which the lower body of the upper rotary shaft is inserted.

In addition, the upper rotary shaft and the lower rotary shaft are bonded or bonded.

In addition, the hub may be a cylindrical portion fixed to the upper body of the upper rotary shaft, a disk portion extending radially outward from the cylindrical portion, and a side wall portion extending downward in the axial direction of the rotation shaft at the radially outer end of the disk portion. Is done.

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, by implementing a thrust plate integrated rotary shaft, it becomes more robust by impact, excellent parallelism of the thrust plate, and by implementing the thickness of the thrust plate smaller than the thrust plate of the prior art, by the radial bearing part It is possible to obtain a spindle motor in which the length of the affected rotating shaft, that is, the span length, is increased and thus the dynamic characteristics are also improved.

1 is a cross-sectional view schematically showing a rotating shaft in the spindle motor according to the present invention.
2 is a schematic exploded cross-sectional view of the rotating shaft shown in FIG.
3 is a cross-sectional view schematically showing a spindle motor according to an embodiment of 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, preferred embodiments of the spindle motor according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view schematically showing a rotating shaft in the spindle motor according to the present invention, Figure 2 is a schematic exploded cross-sectional view of the rotating shaft shown in FIG. As shown in the figure, the rotating shaft 110 includes an upper rotating shaft 111 and a lower rotating shaft 112.

More specifically, the upper rotating shaft 111 is composed of an upper body 111a, a thrust plate portion 111b and a lower body 111c, the upper body 111a is mounted with a hub of the spindle motor, the thrust The plate portion 111b is formed to generate a fluid dynamic pressure with the sleeve, and is located below the upper body 111a, and the lower body 111c is inserted into and coupled to the lower rotation shaft 112. It is located under the plate portion 111b. In addition, a fluid dynamic pressure generating groove (not shown) may be formed in the thrust plate part 111b.

The lower rotating shaft 112 is formed with a receiving groove 112a such that the lower body 111c of the upper rotating shaft 111 is inserted and coupled thereto.

The upper rotation shaft 111 and the lower rotation shaft are coupled to each other by inserting and coupling the lower body 111c of the upper rotation shaft 111 to the receiving groove 112a of the lower rotation shaft 112. The integrated rotary shaft 110 is completed.

In addition, the upper rotating shaft and the lower rotating shaft may be more firmly coupled by secondary bonding by bonding or welding.

3 is a cross-sectional view schematically showing a spindle motor according to an embodiment of 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, a base 150, an armature 160, and a cover 170. It is made of a fixed portion including a), the working fluid is filled with oil to form a hydrodynamic bearing portion.

The hub 120 is coupled to the upper body 111a of the upper rotation shaft 111 in the rotation shaft 110.

In addition, the hub 120 is a cylindrical portion 121 fixed to the upper body 111a of the rotating shaft 110, a disc portion 122 extending radially outward from the cylindrical portion 121, the disc portion It consists of a side wall portion 123 extending downward in the axial direction of the rotation axis at the radially outer end of (122).

In addition, the magnet 130 made of an annular ring shape is mounted on the inner circumferential surface of the side wall portion 123 so as to face the armature 160.

Next, the sleeve 140 supports the rotating shaft 110 to be rotatable. To this end, the lower rotating shaft 112 of the rotating shaft 110 is inserted and rotatably coupled to the sleeve. In addition, the sleeve 140 is fixed to the base 1500. In addition, the sleeve 140 has an oil circulation hole 141 is formed in the axial direction of the rotary shaft 110 to connect the upper and lower surfaces of the sleeve 140 so that the oil circulates through the rotary shaft system.

The cover 170 is for sealing oil injected to form a hydrodynamic bearing, and is fixed to the inner circumferential surface of the lower end of the sleeve 140.

A radial hydrodynamic bearing portion RB, which is a hydrodynamic bearing portion, is formed between the sleeve 140 and the lower rotary shaft 112 of the rotary shaft 110. More specifically, the radial dynamic pressure bearing portion (RB) is a minute gap is formed between the outer diameter of the lower rotary shaft 112 and the inner diameter of the sleeve 140, the oil is filled in the minute interval radial radial bearing part ( RB) is formed.

To this end, the radial dynamic pressure bearing portion (RB) is made of a dynamic pressure generating groove (not shown) selectively formed on the inner circumferential surface of the sleeve 140 and the outer circumferential surface of the lower rotating shaft 112 opposite thereto. In addition, two dynamic pressure generating grooves may be selectively formed at the upper and lower portions of the inner circumferential surface of the sleeve or at the upper and lower portions of the outer circumferential surface of the rotating shaft.

In addition, an armature 160 composed of a core 162 and a coil 161 is fixed to the outer circumferential portion of the base 150 by pressing or bonding, so as to face the magnet 130, and the base 150 as described above. The sleeve 140 is fixed to the inner circumferential portion of) by pressing or bonding.

In addition, the spindle motor 100 further includes a suction plate 151 which is positioned to be opposed to the magnet 130 in the axial direction and fixed to the base 150 to prevent injury of the hub 120. It can be done by.

As described above, the spindle motor according to the present invention includes a thrust plate-integrated rotary shaft, which is more robust by external impact as compared to a structure in which a separate thrust plate according to the prior art is coupled to the rotary shaft, and the parallelism of the thrust plate is increased. In addition to being excellent, the design of the thrust plate can be made smaller than that of the conventional thrust plate. This is because, when separately manufactured and combined, a certain minimum thickness is required for the minimum strength and bonding process. In addition, as can be implemented in a small thickness as described above, the length of the rotating shaft affected by the radial bearing portion, that is, the span length is increased and thus the dynamic characteristics are improved.

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
111: upper rotating shaft 111a: upper body
111b: thrust plate portion 111c: lower body
112: lower rotary shaft 112a: receiving groove
120: hub 130: magnet
140: sleeve 150: base
160: armature 170: cover

Claims (5)

A rotating part including a rotating shaft, a hub and a magnet, and a fixing part including a sleeve for supporting the rotating shaft and an armature opposed to the magnet, and filled with oil to form a hydrodynamic bearing part between the rotating part and the fixing part. As spindle motor,
The rotary shaft is an upper rotary shaft formed with a thrust plate portion; And
Spindle motor comprising a lower rotating shaft coupled to the upper rotating shaft.
The method according to claim 1,
The upper rotation axis
An upper body to which the hub is mounted;
A thrust plate portion positioned below the upper body to generate fluid dynamic pressure with the sleeve; And
Spindle motor, characterized in that consisting of a lower body located below the thrust plate portion to be coupled to the lower rotary shaft.
The method according to claim 2,
Spindle motor, characterized in that the receiving groove is formed in the upper portion of the lower rotary shaft is coupled to the lower body of the upper rotary shaft.
The method according to claim 1 or 3,
And said upper rotating shaft and said lower rotating shaft are bonded by welding or welding.
The method according to claim 2,
The hub
A cylindrical portion fixed to the upper body of the upper rotating shaft;
A disc portion extending radially outward from the cylinder portion; And
And a side wall portion extending downward in the axial direction of the rotation shaft at the radially outer end of the disc portion.

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