KR20130019137A - Spindle motor - Google Patents

Abstract

PURPOSE: A spindle motor is provided to prevent the separation of a cap member and a sleeve due to external shock by using a separation preventing projection. CONSTITUTION: A sleeve(120) rotatably supports a shaft(130). A separation preventing portion(126) is formed in the upper end of the sleeve. A separation preventing protrusion(156) is formed in a cap member(150). The cap member is fixed to the upper part of the sleeve.

Description

[0001] The present invention relates to a spindle motor,

The present invention relates to a spindle motor, and more particularly to a spindle motor having a cap member for preventing leakage of lubricating fluid.

In general, a compact spindle motor used in a hard disk drive (HDD) is provided with a fluid dynamic bearing assembly, and a bearing gap provided in the fluid dynamic bearing assembly is filled with lubricating fluid.

Then, when the shaft is rotated, the lubricating fluid filled in the bearing gap is pumped to form a fluid dynamic pressure to support the shaft rotatably.

On the other hand, the fluid dynamic bearing assembly may be provided with a cap member to form an interface between the lubricating fluid and the air to suppress the leakage of the filled lubricating fluid.

That is, the cap member serves to form an interface (ie, a gas-liquid interface) between the lubricating fluid and the air so that the lubricating fluid is not leaked by the capillary phenomenon in the normal driving state of the spindle motor.

As such, the cap member is generally disposed on top of the thrust plate, so that the gas-liquid interface is formed together with the thrust plate. To this end, the cap member may be fixed to the sleeve.

On the other hand, the cap member is joined to the sleeve by an adhesive and assembled. However, when a long time passes, the bonding force between the cap member and the sleeve becomes weak due to the cracking of the adhesive, and in this case, there is a problem that the cap member and the sleeve are separated when an impact is applied from the outside.

An object of the present invention is to provide a spindle motor capable of preventing separation of the sleeve and the cap member by an external impact.

Spindle motor according to an embodiment of the present invention rotatably supports the shaft, the sleeve is formed in the upper end of the separation prevention portion and the separation prevention jaw is fastened to the separation prevention portion is formed, the cap member fixed to the upper portion of the sleeve It includes.

The release prevention jaw is composed of a plurality of protrusions protruding toward the radially inward from the lower end of the cap member, the release prevention portion may be composed of a groove having a shape corresponding to the release prevention jaw.

The release preventing part may be connected to a cutout part that guides the release preventing jaw to be fastened to the release preventing part.

An end portion of the separation prevention portion may be formed smaller than the separation prevention jaw so that the separation prevention jaw is fitted.

The cap member may include a body having a lower end bonded to the sleeve and an extension part extending radially inward from the body, and the release preventing jaw may extend from an inner surface of the end portion of the body.

According to the present invention, even when an external impact is applied, there is an effect of preventing the separation of the sleeve and the cap member by the separation prevention jaw coupled to the separation prevention portion.

1 is a schematic sectional view showing a spindle motor according to an embodiment of the present invention.
Figure 2 is an exploded perspective view showing a sleeve and a cap member provided in the spindle motor according to an embodiment of the present invention.
Figure 3 is a partial cutaway perspective view showing a sleeve and a cap member provided in the spindle motor according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventive concept. Other embodiments which fall within the scope of the inventive concept may be easily suggested, but are also included within the scope of the present invention.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a schematic cross-sectional view showing a spindle motor according to an embodiment of the present invention, Figure 2 is an exploded perspective view showing a sleeve and a cap member provided in the spindle motor according to an embodiment of the present invention, Figure 3 is a present invention Partial cutaway perspective view showing a sleeve and a cap member provided in the spindle motor according to an embodiment of the.

1 to 3, the spindle motor 100 according to an embodiment of the present invention is, for example, a base member 110, a sleeve 120, a shaft 130, a thrust plate 140, and a cap member. 150, the rotor hub 160, and the cover member 170 may be configured.

On the other hand, the spindle motor 100 according to an embodiment of the present invention may be a motor applied to the recording disk drive device for rotating the recording disk.

Here, when defining the term for the direction first, the axial direction refers to the up, down direction, that is, the direction from the bottom of the shaft 130 to the top or the direction from the top of the shaft 130 to the lower side in FIG. The radial direction refers to the left and right directions in FIG. 1, that is, the direction from the outer circumferential surface of the rotor hub 160 to the shaft 130 or the direction from the shaft 130 toward the outer circumferential surface of the rotor hub 160. And, the circumferential direction means the direction of rotation along the outer circumferential surface of the rotor hub 160.

The base member 110 constitutes a stator as a fixing member. In addition, the base member 110 may include an installation part 112 on which the sleeve 120 is installed. The installation part 112 is formed to protrude toward the upper side in the axial direction, and may have a hollow cylindrical shape. In addition, the sleeve 120 may be inserted into the installation unit 112 and installed.

Meanwhile, a stator core 102 around which the coil 101 is wound may be installed on the outer circumferential surface of the installation unit 112. That is, the stator core 102 may be installed in the mounting portion 112 so that the bottom surface is supported by the mounting surface 112a formed on the outer circumferential surface of the mounting portion 112.

The sleeve 120 rotatably supports the shaft 130. As described above, the sleeve 120 may be bonded to the inner surface of the installation unit 112.

In addition, the through hole 122 may be formed in the sleeve 120 so that the shaft 130 may be inserted into the sleeve 120. That is, the sleeve 120 may have a hollow cylindrical shape.

Meanwhile, when the shaft 130 is inserted into the sleeve 120, the inner surface of the sleeve 120 and the outer circumferential surface of the shaft 130 are spaced apart from each other by a predetermined gap to form a bearing gap B1. Lubricating fluid can be filled in this bearing gap B1.

In addition, a dynamic pressure groove (not shown) may be formed on the inner surface of the sleeve 120 to generate fluid dynamic pressure by pumping the lubricating fluid filled in the bearing gap B1 when the shaft 130 rotates.

In addition, a stepped portion 124 for installing the cap member 150 may be formed at the upper edge of the sleeve 120. The stepped portion 124 is formed to have an outer diameter smaller than the outer diameter of the lower end of the sleeve 120 so that the cap member 150 may be seated and installed.

In addition, an adhesive may be applied to the stepped portion 124 when the cap member 150 is installed.

On the other hand, the separation prevention portion 126 may be formed on the upper end of the sleeve 120. The departure prevention part 126 may be configured as a groove indented toward the radially inward from the step portion 124, and serves to prevent the separation of the cap member 150 during an external impact.

In addition, the departure prevention part 126 is connected to the cutout 128, the details of the cutout 128 and the departure prevention part 126 will be described later.

In addition, an indentation groove 129 for installing the cover member 170 may be formed at the lower end of the sleeve 120, and the indentation groove 129 may be indented toward the upper side in the axial direction.

The shaft 130 is rotatably installed in the sleeve 120. That is, the shaft 130 may be inserted into the through hole 122 of the sleeve 120.

In addition, the shaft 130 may include a mounting part 132 on which the thrust plate 140 and the rotor hub 160 are installed. That is, the thrust plate 140 and the rotor hub 160 are installed at the upper end of the shaft 130, and a mounting part 132 may be provided to have a smaller diameter than the lower end.

The thrust plate 140 is fixedly installed on the shaft 130, and thus, when the shaft 130 is rotated, the thrust plate 140 may be rotated in association with the shaft 130.

Meanwhile, when the shaft 130 is installed in the sleeve 120, the thrust plate 140 may be disposed on the upper portion of the sleeve 120.

The thrust plate 140 may have a circular ring shape in which an installation hole 142 is formed to allow the shaft 130 to pass therethrough.

In addition, the bottom surface of the thrust plate 140 and the top surface of the sleeve 120 may be spaced apart by a predetermined interval to form a bearing gap. A thrust dynamic pressure groove (not shown) may be formed on at least one of the bottom surface of the thrust plate 140 and the top surface of the sleeve 120 to generate thrust fluid dynamic pressure when the shaft 130 rotates.

That is, when the thrust plate 140 is rotated together with the shaft 130, a force toward the upper side in the axial direction is generated by the lubricating fluid pumped by the thrust dynamic pressure groove, and thus the rotor hub 160 may be lifted to a predetermined height. Can be.

The cap member 150 is fixedly installed on the upper portion of the sleeve 120. In addition, the cap member 150 may be provided with a separation prevention jaw 156 that is fastened to the separation prevention part 126.

The cap member 150 may include a body 152 having a lower end joined to the sleeve 120 and an extension 154 extending from the body 152 to form a radially inner side.

In addition, the detachment prevention jaw 156 may be formed of a plurality of protrusions protruding radially inward from the inner surface of the end portion of the body 152.

Here, the assembly method of the cap member 150 and the sleeve 120 will be described. First, an adhesive is applied to the stepped portion 124 of the sleeve 120. Thereafter, the cap member 150 is assembled to the sleeve 120 such that the separation preventing jaw 156 of the cap member 150 is inserted into the cutout 128.

Then, when the separation prevention jaw 156 of the cap member 150 reaches the end of the cutout 128, the cap member 150 is rotated so that the separation prevention jaw 156 is inserted into the separation prevention part 126.

On the other hand, as shown in Figure 3, the end of the departure prevention portion 126 may be formed smaller than the departure prevention jaw 156 so that the departure prevention jaw 156 is fitted. Accordingly, when the cap member 150 is rotated, the separation prevention jaw 156 may be fixedly coupled to the end of the separation prevention part 126.

In this case, the inner surface of the body 152 and the stepped portion 124 of the sleeve 120 may be bonded through an adhesive.

As such, the separation preventing jaw 156 formed on the cap member 150 is inserted into and fastened to the separation preventing part 126 of the sleeve 120, and thus, when the impact is applied from the outside, the cap member 150 and the sleeve ( 120 can be prevented from being separated.

On the other hand, the bottom surface of the extension portion 154 may be provided with an inclined surface to form a gas-liquid interface (that is, the interface between the lubricating fluid and air) together with the top surface of the thrust plate 140.

The rotor hub 160 may be installed in the mounting portion 132 to be disposed above the thrust plate 140. On the other hand, the rotor hub 160 is axially downward from the edge of the rotor hub body 162 and the rotor hub body 162 in which the mounting hole 162a into which the mounting portion 132 of the shaft 130 is inserted is formed. It may be provided with a magnet mounting portion 164 extending.

The magnet 105 may be installed on the inner surface of the magnet mounting unit 164, and the magnet 105 may be disposed opposite to the tip of the stator core 102 on which the coil 101 is wound.

On the other hand, the magnet 105 may have a ring shape, and may be a permanent magnet in which the N pole and the S pole are alternately magnetized along the circumferential direction to generate a magnetic force of a predetermined intensity.

Here, the rotation drive of the rotor hub 160 will be briefly described. The power is supplied to the coil 101 wound on the stator core 102, and the magnet 105 and the stator core 102 on which the coil 101 is wound. Electromagnetic interaction with) generates a driving force for the rotor hub 160 to rotate.

Accordingly, the rotor hub 160 is rotated, and the shaft 130 to which the rotor hub 160 is fixed may be rotated in association with the rotor hub 160.

The cover member 170 is installed in the indentation groove 129 formed at the lower end of the sleeve 120 to prevent the lubricating fluid from leaking to the lower side. The cover member 170 may be fixedly installed in the indentation groove 129 by adhesive or / and welding.

As described above, since the separation prevention jaw 156 formed on the cap member 150 is inserted into and fastened to the separation prevention part 126 of the sleeve 120, even when an impact is applied from the outside, the cap member 150 and The sleeve 120 may be prevented from being separated.

100: spindle motor 110: base member
120: sleeve 130: shaft
140: thrust plate 150: cap member
160: rotor hub 170: cover member

Claims (5)

A sleeve rotatably supporting the shaft and having a release preventing portion formed at an upper end thereof; And
A capping member formed to be coupled to the detachment preventing part and fixed to an upper portion of the sleeve;
Spindle motor comprising a. The method of claim 1,
The release prevention jaw is composed of a plurality of protrusions protruding toward the radially inward from the lower end of the cap member,
The separation prevention part is a spindle motor consisting of a groove having a shape corresponding to the separation prevention jaw. The method of claim 2,
The release prevention unit is a spindle motor connected to the incision to guide the separation prevention jaw to be coupled to the separation prevention portion. The method of claim 2,
The end of the separation prevention portion is a spindle motor that is formed smaller than the separation prevention jaw so that the separation prevention jaw. The method of claim 1, wherein the cap member is
A lower end portion is provided with a body bonded to the sleeve, and an extension portion extending radially inwardly from the body,
The release prevention jaw is a spindle motor extending from the inner surface of the end of the body.

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