KR20120049028A

KR20120049028A - Spindle motor

Info

Publication number: KR20120049028A
Application number: KR1020100110583A
Authority: KR
Inventors: 장호경
Original assignee: 삼성전기주식회사
Priority date: 2010-11-08
Filing date: 2010-11-08
Publication date: 2012-05-16

Abstract

The present invention relates to a spindle motor, wherein the spindle motor according to the present invention is coupled to a shaft to rotate together with the shaft, and when coupled with the shaft, the inner diameter side of the axial lower surface is coupled to be caught by a step formed in the shaft. It may include a plate, and a shock absorbing coating material formed between the stepped portion and the inner diameter side of the axial lower surface of the thrust plate.

Description

Spindle Motor

The present invention relates to a spindle motor, and more particularly, to a spindle motor capable of absorbing external shock applied to the coupling portion of the shaft and the thrust plate and preventing breakage due to fine cracks.

In general, a compact spindle motor used in a recording disk drive uses a hydrodynamic bearing assembly, and a bearing clearance formed between the shaft and the sleeve of the hydrodynamic bearing assembly is filled with a lubricating fluid such as oil, During rotation, the oil filled in the bearing gap is compressed to create a fluid dynamic pressure to rotatably support the shaft.

In this case, a stopper member may be used in combination with the shaft to prevent the floating of the rotor or to prevent the rotor from being separated. The stopper member is fixedly coupled to the shaft, and may be in the form of an annular plate having a hole in which the shaft is inserted. The annular plate can function as a thrust plate by forming fluid dynamic pressure between the sleeve and the sleeve for rotatably supporting the shaft.

As a material of the thrust plate, a ceramic material is used, and ceramic material has an advantage of easy processing with a small surface roughness, and has an advantage of improving lubrication characteristics by solid friction due to a low friction coefficient.

However, there is a problem in that the impact resistance is weak due to the characteristics of the ceramic material. In particular, since an external impact is applied, the maximum stress is concentrated at the coupling portion of the shaft and the thrust plate, so that fracture occurs at the coupling portion. At this time, when minute cracks or the like exist on the surface of the thrust plate, such breakdown can be accelerated.

Accordingly, the present invention is to solve the problems of the prior art as described above, to provide a spindle motor that can absorb the external shock applied to the coupling portion of the shaft and the thrust plate and prevent destruction by minute cracks, etc. There is this.

Spindle motor according to an embodiment of the present invention for achieving the above technical problem is coupled to the shaft to rotate with the shaft and the inner diameter side of the axial lower surface when engaged with the shaft is caught on the step formed in the shaft A thrust plate to be coupled, and may include a shock-absorbing coating material formed between the stepped and the inner diameter side of the axial lower surface of the thrust plate.

In addition, in the spindle motor according to an embodiment of the present invention, the shock absorbing coating material may be applied on the step.

In addition, in the spindle motor according to an embodiment of the present invention, the shock absorbing coating material may be applied to the inner diameter side of the axial lower surface of the thrust plate facing the step.

In addition, in the spindle motor according to an embodiment of the present invention, the shock absorbing coating material may be formed in the circumferential direction.

In addition, in the spindle motor according to an embodiment of the present invention, the shock absorbing coating material may be made of a synthetic resin.

According to the spindle motor according to the present invention, it is possible to absorb the external impact applied to the coupling portion of the shaft and the thrust plate, and to prevent destruction by minute cracks or the like.

1 is an axial cross-sectional view of a spindle motor according to an embodiment of the present invention.
FIG. 2 is an enlarged view of portion A of FIG. 1.
3 is a perspective view of a thrust plate in a spindle motor according to an embodiment of the present invention.
4 is a perspective view of a shaft in a spindle motor according to another embodiment of the present invention.

Hereinafter, with reference to the drawings will be described in detail a specific embodiment of the present invention. However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention may further deteriorate other inventions or the present invention by adding, changing, or deleting other elements within the scope of the same idea. Other embodiments included within the scope of the invention can be easily proposed, but it will also be included within the scope of the invention.

In addition, the component with the same function within the range of the same idea shown by the figure of each embodiment is demonstrated using the same or similar reference numeral.

1 is an axial cross-sectional view of a spindle motor according to an embodiment of the present invention, FIG. 2 is an enlarged view of a portion A of FIG. 1, and FIG. 3 is a perspective view of a thrust plate in the spindle motor according to an embodiment of the present invention. to be.

1 to 3, the spindle motor 100 according to an embodiment of the present invention includes a fluid dynamic bearing assembly 10 forming a fluid dynamic pressure between the shaft 11 and the fluid dynamic bearing assembly ( 10 may include a stator 40 coupled to the outer circumferential side and a rotor 20 coupled to the shaft 11 to rotate in conjunction with the shaft 11.

On the other hand, when defining the term for the direction, as shown in Figure 1, the axial direction means the up and down direction relative to the shaft 11, the radial direction of the outer end direction of the rotor 20 relative to the shaft 11 Or it means the direction of the center of the shaft 11 with respect to the outer end of the rotor (20).

The hydrodynamic bearing assembly 10 may include a shaft 11, a sleeve 12, a thrust plate 13, a sealing cap 14, and a cover plate 16. Here, the sleeve 12, thrust plate 13, sealing member 15, and cover plate 17 may be provided as bearing members.

The shaft 11 is inserted into the hollow portion formed in the central portion of the sleeve 12, the thrust plate 13 is disposed in the axial upper portion of the sleeve 12, the sealing member 15 of the thrust plate 13 It is arranged in the axial upper part, the cover plate 17 is disposed in the axial lower part of the thrust plate 13 and the sleeve 12.

Here, the oil is filled as a lubricating fluid in the minute gap between the outer circumferential surface of the shaft 11 and the inner circumferential surface of the sleeve 12, and a spiral or herringbone formed on at least one of the outer circumferential surface of the shaft 11 and the inner circumferential surface of the sleeve 12. The dynamic pressure generated by the radial radial pressure groove of the die can more smoothly support the rotation of the rotating member including the shaft 11 and the rotor 20.

In this case, a bypass passage 16 may be formed in the sleeve 12 so as to communicate with the upper and lower portions of the sleeve 12 in an axial direction, and may distribute the pressure of the oil in the fluid dynamic bearing assembly.

The thrust plate 13 may include an insertion hole 131 into which the shaft 11 is inserted, and the shaft 11 is pressed into and inserted into the insertion hole 131.

The thrust plate 13 may serve as a stopper that is coupled to the shaft 11 so that the inner diameter side end portion of the axial lower surface is caught by the stepped portion 112 of the shaft 11 to prevent the injuries of the shaft 11.

At this time, the shock absorbing coating material 14 may be formed on the inner diameter side of the lower surface of the thrust plate 13 in the axial direction. The shock absorbing coating material 14 may be continuously formed in the circumferential direction, and the material may be a synthetic resin. In the present embodiment, as a material of the shock absorbing coating material 134, any material capable of absorbing shock in addition to the synthetic resin may be used.

Formation of the shock-absorbing coating material 14 is, for example, by applying a thermosetting resin to cure at a temperature at which the ceramic thrust plate 13 does not melt, bonding a polymer resin such as a polymer by bonding, or a polymer film Or a silicon oxide film is formed by vapor deposition or the like.

The oil is filled as a lubricating fluid in the minute gap between the axial lower surface of the thrust plate 13 and the axial upper surface of the sleeve 12, and among the axial lower surfaces of the thrust plate 13 and the axial upper surface of the sleeve 12. The rotation of the thrust plate 13 can be more smoothly supported by dynamic pressure generated by the helical or herringbone type thrust dynamic pressure grooves formed in at least one.

The sealing member 15 may be attached to the top of the sleeve 12. The sealing member 15 is disposed above the axial direction of the thrust plate 13, and can fix the thrust plate 13 in the axial direction.

The sealing member 15 may have a protrusion formed on an axial lower surface to seal the oil passage, and a meniscus of oil may be formed on the outer side of the protrusion to taper seal.

A dynamic groove may be formed in at least one of the axial lower surface of the sealing member 15 and the axial upper surface of the thrust plate 13, and may pump oil toward the fluid dynamic bearing assembly with the dynamic pressure generated by the dynamic groove. have.

The cover plate 17 is made of an elastic material, which is elastically deformed when engaged to the axial lower portion of the sleeve 12, and covers the lower portion of the sleeve 12 to support the sleeve 12 and the shaft 11. .

The cover plate 17 can be engaged by its outer circumferential surface in contact with the radially outer inner surface of the sleeve 12, the oil being received in the gap between the cover plate 17 and the sleeve 12, and as such a shaft 11. It can serve as a bearing for supporting the lower surface of the.

The rotor 20 is a rotating structure rotatably coupled to the shaft 11 with respect to the stator 40 together with the shaft 11, and may include a rotor case and a magnet 26 mounted inside the rotor case. Can be.

The rotor case has a cylindrical portion 22 coupled to the outer circumferential surface of the shaft 11, a disk portion 23 extending radially outward from the cylindrical portion 22, and a radially outer side of the disk portion 23 from the radially outer side to the lower portion. A magnet support 24 that is bent to support the magnet 26, and a flange 25 extending radially outwardly from the bottom of the magnet support 24 and on which the disk is mounted.

The magnet 26 is provided as a permanent magnet in which the N pole and the S pole are alternately magnetized in the circumferential direction to generate a magnetic force of a predetermined intensity. The rotor 20 is rotated by the electromagnetic interaction between the winding coil 46 and the magnet 26.

The stator 40 is a fixed structure including a winding coil 46 generating a predetermined magnitude of electromagnetic force when power is applied and a plurality of cores 44 on which the winding coil 46 is wound.

The core 44 is fixedly disposed on an upper portion of the base 42 on which the printed circuit board 43 on which the pattern circuit is printed is provided, and the winding coil 46 is formed on one surface of the base 42 corresponding to the winding coil 46. A plurality of coil holes having a predetermined size may be formed to expose the lower portion thereof, and the winding coil 46 may be electrically connected to the printed circuit board 43 to supply external power.

4 is a perspective view of a shaft in a spindle motor according to another embodiment of the present invention.

Spindle motor according to another embodiment of the present invention shown in Figure 4 shows a modification of the shock absorbing coating material, the configuration other than the spindle motor according to an embodiment of the present invention shown in Figures 1 to 3 Since they are substantially the same, detailed descriptions of these configurations will be omitted, and the following description will focus on differences.

Referring to FIG. 4, in the spindle motor according to another exemplary embodiment of the present invention, a shock absorbing coating material 14 formed at a portion where the shaft 11 and the thrust plate are coupled to each other may be formed on the stepped portion of the shaft 11. have.

The shock absorbing coating material 14 may be continuously formed in the circumferential direction of the step 112, and the material may be a synthetic resin.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. For example, the components of the spindle motor in the present invention are merely illustrated and may have various configurations, and in particular, various configurations may be employed as components of the bearing member in the fluid dynamic bearing assembly. Accordingly, the true scope of the present invention should be determined by the appended claims.

10: fluid dynamic bearing assembly 11: shaft
12: sleeve 13: thrust plate
14: coating material for shock absorption 15: sealing member
17: cover plate 20: rotor
26: magnet 40: stator
42: base 44: core
46: winding coil

Claims

A thrust plate coupled to the shaft and rotating together with the shaft, the thrust plate engaging the inner diameter side of the lower surface in the axial direction when engaged with the shaft to be caught by a step formed in the shaft; And
And a shock absorbing coating material formed between the stepped portion and the inner diameter side of the axial lower surface of the thrust plate.

The method of claim 1,
The impact absorbing coating material is a spindle motor, characterized in that applied to the step.

The method of claim 1,
The shock absorbing coating material is a spindle motor, characterized in that applied to the inner diameter side of the axial lower surface of the thrust plate facing the step.

The method of claim 1,
The shock absorbing coating material is a spindle motor, characterized in that formed in the circumferential direction.

The method of claim 1,
The shock absorbing coating material is a spindle motor, characterized in that made of a synthetic resin.