KR20130019666A

KR20130019666A - Sindle motor

Info

Publication number: KR20130019666A
Application number: KR1020110081761A
Authority: KR
Inventors: 임동오
Original assignee: 삼성전기주식회사
Priority date: 2011-08-17
Filing date: 2011-08-17
Publication date: 2013-02-27

Abstract

The spindle motor according to the present invention includes a shaft, a sleeve for receiving the shaft and rotatably supporting the hub, a hub integrally coupled to the central portion and corresponding to one end of the sleeve, and vertically perpendicular to the axial direction. Is formed, formed between the sleeve and the spaced space of the hub facing one end of the sleeve, and corresponds to the thrust plate formed of a material including pores and the outer peripheral surface of the sleeve, is formed spaced apart to form a working fluid sealing It includes a sealing member. According to the present invention, the thrust plate of the spindle motor by the hydrodynamic bearing is formed of a material including pores to impregnate the working fluid to continuously supply the working fluid when the motor is operated, thereby improving the operating performance of the spindle motor and thereby This has the effect of extending the life of the motor.

Description

Spindle Motor

The present invention relates to a spindle motor.

In general, a spindle motor belongs to a brushless DC motor (BLDC). In addition to a motor for a hard disk drive, a spindle motor includes a laser beam scanner motor for a laser printer, a motor for a floppy disk drive (FDD) And a motor for an optical disk drive such as a DVD (Digital Versatile Disk).

In order to minimize the occurrence of non-repeatable run out (NRRO), which is a vibration generated when noise and ball bearings are employed, in devices requiring high capacity and high driving force such as a hard disk drive in recent years, Spindle motors with hydrodynamic bearings are widely used. Hydrodynamic bearings basically form a thin oil film between the rotating body and the fixed body to support the rotating body and the fixed body with the pressure generated during rotation, so that the friction load is reduced because the rotating body and the fixed body do not contact each other. Therefore, in the spindle motor to which the fluid dynamic bearing is applied, the shaft of the motor for rotating the disk is maintained by the lubricating oil (hereinafter referred to as 'working fluid') only by the dynamic pressure (pressure returned to the oil pressure center by the centrifugal force of the rotating shaft). It is distinguished from a ball bearing spindle motor supported by a shaft ball steel ball.

When the hydrodynamic bearing is applied to a spindle motor, since the rotating body is supported by the fluid, the amount of noise generated by the motor is small, power consumption is low, and the impact resistance is excellent.

However, in the spindle motor to which the conventional hydrodynamic bearing is applied, there is a problem in that the operating life of the hydrodynamic bearing is shortened due to leakage due to external impact of the oil used as the working fluid in the hydrodynamic bearing, evaporation of the oil, and the like. In addition, there are various problems such as a decrease in operating performance due to the inability to maintain a smooth working fluid during initial operation due to repetition of operation and stop of the motor, and inferior motor operation reliability.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to form a thrust plate for forming a thrust dynamic pressure portion by a hydrodynamic bearing formed of a material containing pores working fluid of the hydrodynamic bearing It is to provide a spindle motor for improving the operation performance and reliability of the motor by enabling efficient management of the motor.

Spindle motor according to the present invention is a shaft that forms the center of rotation of the motor, a sleeve for receiving the shaft, rotatably supporting the hub, the shaft is integrally coupled to the central portion and formed to correspond to one end surface of the sleeve, shaft It is formed in the axial direction perpendicular to the upper direction, and formed between the spaced space with the hub facing the one end surface of the sleeve, and is spaced apart from the outer peripheral surface of the thrust plate and the sleeve formed of a material including pores, It includes a sealing member for forming a sealing portion of the hydraulic fluid bearing working fluid.

Here, the thrust plate is characterized in that the porous body made of a sintered metal.

In addition, the thrust plate is characterized in that coupled to one end surface of the sleeve facing the hub.

In addition, the thrust plate is characterized in that formed in the axial direction perpendicular to the lower portion.

In addition, the thrust plate is characterized in that the dynamic pressure generating groove is formed on one surface in contact with the oil.

In addition, the sleeve and the thrust plate is characterized in that formed of a dissimilar material.

In addition, the thrust plate is characterized in that coupled to the coupling groove corresponding to one end surface of the sleeve.

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 thrust plate is formed of a material including pores for managing the working fluid of the spindle motor operated by the hydrodynamic bearing, thereby improving the operation reliability of the motor.

In addition, by forming the thrust plate of the spindle motor by the hydrodynamic bearing with a material including pores, the thrust plate is impregnated with a working fluid to continuously supply the working fluid when the motor is operated, thereby improving the operating performance of the spindle motor and thereby This has the effect of extending the life of the motor.

In addition, the thrust plate is formed between the hub and the sleeve to effectively prevent leakage or evaporation of the working fluid impregnated into the pores in the thrust plate to the outside, while at the same time supplying the working fluid to the thrust dynamic pressure during operation of the spindle motor It has the effect of increasing the operating reliability and extending the service life.

In addition, the thrust plate formed of a material containing pores is formed in a structure that couples to one surface of the sleeve, thereby preventing leakage or evaporation of oil impregnated by the sleeve of the material not containing pores.

1 is a cross-sectional view of a spindle motor according to the present invention;
2 is a partially enlarged view of a thrust dynamic pressure part in which the thrust plate of FIG. 1 is formed; And
3 is a perspective view of a thrust plate 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. Also, the terms "one side,"" first, ""first,"" second, "and the like are used to distinguish one element from another, no. In addition, "top", "upper", "lower", "lower" of the present invention shall mean the upper and lower parts based on the axial direction. 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 present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a spindle motor according to the present invention, FIG. 2 is a partially enlarged view of a thrust dynamic pressure part in which the thrust plate of FIG. 1 is formed, and FIG. 3 is a perspective view of a thrust plate according to the present invention.

The spindle motor according to the present invention includes a shaft 11 forming the rotation center of the motor, a sleeve 22 accommodating the shaft 11 and rotatably supporting the shaft 11, and the shaft 11 is integrally coupled to a central portion of the shaft 11. Hub 12 is formed to correspond to one end surface of the sleeve 22, the axial direction is formed perpendicular to the axial direction, the space between the space between the hub 12 facing one end surface of the sleeve 22 And a thrust plate 30 formed of a material including pores and spaced apart from an outer circumferential surface of the sleeve 22 to form a working fluid sealing part of the hydrodynamic bearing.

As shown in FIG. 1, the shaft 11 forms a central axis in which the spindle motor rotates, and a central portion of the hub 12 to which the magnet 14 is attached is coupled to the shaft 11 in the upper axial direction. The shaft 11 is generally formed in a cylindrical shape.

The sleeve 22 is for rotatably supporting the shaft 11 and has a hollow cylindrical shape as a whole, and has a fluid on the bearing surface facing the outer circumferential surface 11a and the thrust plate 30 of the coupled shaft 11. Dynamic pressure bearings are formed. On the inner circumferential surface 22a of the sleeve 22, a radial dynamic pressure generating groove (not shown) is formed between the outer circumferential surface 11a of the shaft 11 to form a radial dynamic pressure portion by the fluid dynamic bearing. A working fluid (for example, oil or the like may be used) is stored between the inner circumferential surface 22a and the shaft 11. The radial dynamic pressure generating groove maintains a non-contact state between the shaft 11 and the sleeve 22 by generating fluid dynamic pressure using a fluid stored between the sleeve 22 and the shaft 11 when the shaft 11 rotates. . Of course, the radial dynamic pressure generating groove may be formed on the outer circumferential surface 11a of the shaft 11.

The thrust plate 30 is formed between the sleeve 22 and the spaced space of the hub 12 facing the one end surface of the sleeve 22 and is formed of a material including pores.

As shown in FIGS. 1 and 2, the thrust plate 30 is inserted and installed in a space spaced from one end surface of the sleeve 22 facing the hub 12. The thrust plate 30 may be formed in a structure coupled to one end surface of the sleeve 22 facing the hub 12. Therefore, a working fluid (hereinafter described as an embodiment using 'oil') is injected between one side of the thrust plate 30 and the hub 12 to form a thrust dynamic pressure part. The thrust plate 30 according to the present invention may be formed by impregnating the oil 42 by being formed of a material including pores. The impregnation of the oil 42 prevents evaporation of the oil 42 which may occur during the operation of the spindle motor, scattering of the oil 42 due to external impacts, and the like, and continuously supplies the oil 42 during operation of the motor. As a result, the reliability of motor operation can be improved. In addition, by doing so, the operating life of the spindle motor can be extended.

Since the thrust plate 30 may be formed of a material including pores, the thrust plate 30 may be formed of a porous body made of a sintered metal. If the oil 42 is impregnated with the oil 42 and the oil 42 impregnated during the operation of the spindle motor is leaked to the outside to supply the oil 42 to the thrust dynamic pressure unit properly, the oil 42 may be formed of various materials that may be composed of porous materials. Of course. Impregnating the oil 42 in the thrust plate 30 may be manufactured by a method of impregnating the oil 42 by high temperature pressurization in the thrust plate 30, and according to the material of the thrust plate 30. Appropriate methods for impregnation may be adopted.

Since the thrust plate 30 is formed of a material including pores, and the oil 42 is impregnated therein, there is a problem of evaporation of the oil 42 to the outside of the thrust plate 30, so that the thrust plate 30 is formed perpendicular to the axial direction. The thrust plate 30 is formed between one end surface of the sleeve 22 facing one side of the hub 12, and the coupling groove 22b or the like corresponding to the one end surface of the sleeve 22 is formed to bond the pores. Evaporation of the oil can be reduced by the sleeve 22 or the hub 12 that does not include. By doing so, the oil 42 impregnated in the thrust plate 30 can be prevented from evaporating or leaking out of the bearing surface which produces the thrust dynamic pressure part.

In particular, the thrust plate 30 is formed adjacent to the oil sealing portion 43 by the sealing member 40, as shown in Figs. 1 and 2, thereby the proper management of the oil interface 41 and the oil 42 To provide effective management of the oil 42 forming the hydrodynamic bearing. As shown in FIG. 2, the oil sealing part 43 is tapered to have a narrower width toward the inner side of the oil interface 41. This is to prevent the oil from scattering outside the oil interface 41 by using a capillary phenomenon. The oil sealing part 43 has a structure in which any one of the sleeve 22 and the sealing member 40 is formed to be relatively tapered so that the space between the sleeve 22 and the sealing member 40 is tapered. It may be formed so that the width of the separation space becomes narrower toward the inner side with respect to the oil interface 41. By doing so, it is possible to manage the oil interface 41 by capillary action.

Specifically, as shown in FIG. 2, the normal oil 42 is present between the thrust plate 30 and the hub 12 to maintain rotational performance, but when the amount of oil 42 decreases over time, FIG. 2. The oil 42 is moved from the A portion of the B to the B portion, the pressure does not generate the pressure to push the hub 12 upwards, the motor will run out. Since the thrust plate 30 in which the oil 42 is impregnated is present, when the oil 42 is present at the point A, the thrust plate 30 is maintained in the state in which the oil 42 is impregnated. When 42 is reduced, the oil 42 comes out to the contact surface closest to the bottom of the hub 12 so that the oil 42 is maintained between the A and B points, so that the oil 42 impregnated in the thrust plate 30 is reduced. ) Can extend the life of the motor until it is exhausted and consumed.

The thrust plate 30 may be coupled to one end of the sleeve 22 as shown in FIGS. 1 and 2, but is not necessarily limited thereto. When the thrust plate 30 is coupled to one end of the sleeve 22, since the thrust dynamic pressure portion is formed between one surface of the thrust plate 30 and the corresponding hub 12, one side of the thrust plate 30 or the corresponding hub 12 It is possible to form a dynamic pressure generating groove on one surface. The thrust plate 30 may be formed at the lower side in the axial direction perpendicular to the axial direction, and may be coupled to the lower end of the sleeve 22. Since the thrust plate 30 is formed of a material including pores capable of impregnating the oil 42, the one surface is preferably coupled to a member such as the sleeve 22 to prevent evaporation or leakage of the oil 42. something to do. Therefore, the sleeve 22 may be formed of a material such as metal that does not contain pores so that the oil 42 does not leak, and is preferably formed of a different material from the thrust plate 30. That is, the sleeve 22 may be formed of a metal material containing no pores, and the thrust plate 30 may be formed of a porous body including pores. However, the material of the sleeve 22 is not necessarily limited thereto, and of course, the sleeve 22 may be integrally formed of a material having pores such as the thrust plate 30.

The thrust plate 30 may be separate laser welding or the like for fixing to one end surface of the sleeve 22, but it is obvious to those skilled in the art that the thrust plate 30 may be press-fitted by applying a predetermined pressure to the thrust plate 30. .

The configuration and operation relationship of the spindle motor according to an embodiment of the present invention will be described briefly with reference to FIG. 1 as follows.

The rotor 10 is composed of a shaft 11 and a hub 12 to which a magnet 14 is attached, which is a rotating shaft and is rotatable. The stator 20 includes a base 21, a sleeve 22, and a core ( 23 and the pulling plate 24 may be included. The core 23 and the magnet 14 are attached to the outer side of the base 21 and the inner side of the hub 12, respectively, where the magnetic flux is generated while a magnetic field is formed when current flows. . The magnet 14 facing the magnet is repeatedly magnetized with the N pole and the S pole to form an electrode corresponding to the variable electrode generated in the core 23. The core 23 and the magnet 14 are generated by the repulsive force by the electromagnetic force due to the linkage of the magnetic flux, thereby driving the spindle motor of the present invention by rotating the hub 12 and the shaft 11 coupled thereto. . In addition, a pulling plate 24 is formed on the base 21 so as to correspond to the magnet 14 in the axial direction so as to prevent the motor from floating when the motor is driven. The pulling plate 24 allows a stable rotational drive by allowing the magnet 14 and the attraction force to be applied.

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.

10: rotor 11: shaft
11a: shaft outer surface 12: hub
14: magnet 20: stator
21: base 22: sleeve
22a: inner sleeve surface 22b: coupling groove
30: thrust plate 40: sealing member
41: oil interface 42: oil
43: oil sealing part

Claims

A shaft forming a rotation center of the motor;
A sleeve for receiving the shaft and supporting the shaft rotatably;
A hub integrally coupled to the central portion and formed to correspond to one end surface of the sleeve;
A thrust plate formed vertically on an axial direction and formed between a space between the hub facing one end surface of the sleeve and formed of a material including pores; And
And a sealing member positioned to be spaced apart from an outer circumferential surface of the sleeve and forming a sealing portion of a fluid hydraulic bearing working fluid.

The method according to claim 1,
The thrust plate is a spindle motor, characterized in that the porous body made of a sintered metal.

The method according to claim 1,
And the thrust plate is coupled to one end of the sleeve facing the hub.

The method according to claim 1,
The thrust plate is a spindle motor, characterized in that formed in the axial direction perpendicular to the lower portion.

The method according to claim 1,
The thrust plate is a spindle motor, characterized in that the dynamic pressure generating groove is formed on one surface in contact with the oil.

The method according to claim 1,
Spindle motor, characterized in that the sleeve and the thrust plate is formed of a dissimilar material.

The method according to claim 3,
The thrust plate is coupled to the coupling groove corresponding to one end surface of the sleeve spindle motor.