KR20130028355A

KR20130028355A - Spindle motor

Info

Publication number: KR20130028355A
Application number: KR1020110091847A
Authority: KR
Inventors: 강승규
Original assignee: 삼성전기주식회사
Priority date: 2011-09-09
Filing date: 2011-09-09
Publication date: 2013-03-19

Abstract

PURPOSE: A spindle motor is provided to improve electrical stability by maintaining insulation between a coil and a base through structural change of a penetration hole formed on a bottom surface of a base. CONSTITUTION: A shaft(11) consists of the center of the rotor. A sleeve(22) accommodates the shaft and rotatably supports. A base(21) is combined with the outer surface of the sleeve to support the sleeve. The base installs a core having a coil wound in the inner surface. The base forms a penetration hole(60) in the axial direction lower surface in which a coil penetrates.

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.

A flexible printed circuit board (FPCB) for power supply of the spindle motor is attached to the back of the base, and a coil wound on the core is connected. In this case, a through hole is formed in the bottom surface of the base for connecting the coil to the flexible circuit board attached to the rear surface of the base. When the coil passes through the through hole, an insulating sheet is formed around the inlet of the through hole to prevent an electrical short with the base. Thereby, there existed a problem that productivity was reduced by generation | occurrence | production of outgas and the addition of another material of an insulation sheet. In addition, although there is an insulating sheet, there is a problem that an electrical short circuit between the coil and the base occurs due to separation of the insulating sheet over time.

The present invention was created to solve the problems of the prior art as described above, an object of the present invention is to change the structure of the through-hole formed in the base bottom surface to connect the coil drawn from the core to the flexible circuit board formed on the back of the base By maintaining the insulation between the coil and the base through to provide a spindle motor for improving the productivity of the spindle motor and the reliability of the electrical stability of the spindle motor.

Spindle motor according to an embodiment of the present invention is coupled to the shaft forming the center of the rotor, the sleeve for receiving the shaft, rotatably supporting and the outer side of the sleeve to support the sleeve, the coil wound on the inner side The base is mounted, and the base is formed in the through hole through which the coil penetrates the axial bottom surface, the through hole is the width of the inlet and outlet through which the coil penetrates between the inlet and the outlet of the through hole Characterized in that formed wider than the width of the through-hole formed.

The flexible printed circuit board may be electrically connected to the back surface of the base through the through hole.

In addition, the through hole is formed in the inlet portion, the passage portion, the outlet portion sequentially in the axial direction through which the coil passes, the portion connected to the passage portion from the inlet portion is formed so that the width of the through hole is gradually smaller, the passage portion In the through hole connected to the outlet portion is characterized in that it is formed to become wider.

In addition, the through-flow is characterized in that the insulating coating on the inner surface.

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, through the structure of the through-hole for preventing an electrical short between the coil and the base wound on the core of the spindle motor has an effect of fundamentally solving the electrical short circuit between the coil and the base.

In addition, through the structural change of the through hole formed in the base, the coil drawn out from the core is not in contact with the base portion, thereby improving the operation reliability of the spindle motor.

In addition, by maintaining the insulation between the coil and the base drawn out from the core through the structural change of the through-hole of the base can be omitted the insulation sheet attached to the conventional base has the effect of improving the productivity of the spindle motor.

In addition, there is an effect to improve the operation reliability and operating performance of the spindle motor by essentially blocking the generation of outgas that can be generated due to the attachment of the conventional insulating sheet.

1 is a cross-sectional view of a spindle motor according to an embodiment of the present invention;
2 is an enlarged partial view of FIG. 1;
3 is a partially enlarged cross-sectional view of a spindle motor according to another embodiment of the present invention;
4A and 4B are partially enlarged views of the through hole according to the present invention; And
5A and 5B are partially enlarged views of a through hole according to another 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. Also, the terms "one side,"" first, ""first,"" second, "and the like are used to distinguish one element from another, no. "Axial" in the present invention means the direction from top to bottom along the axis of the center of rotation of the spindle motor. 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 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 an embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is a partially enlarged cross-sectional view of a spindle motor according to another embodiment of the present invention, FIGS. Figure 4b is a partially enlarged view of the through hole according to the present invention.

5A and 5B are partially enlarged views of a through hole according to another embodiment of the present invention.

Spindle motor according to the present invention includes a shaft (11) forming a center of the rotor (10), a sleeve (22) for receiving and supporting the shaft (11) rotatably; And a through hole 60 coupled to an outer surface of the sleeve 22 to support the sleeve 22, and having a core 23 wound around a coil on an inner surface thereof, and penetrating the coil on an axial lower surface thereof. And a base 21 formed therein, wherein the through hole 60 has a width of an inlet and an outlet through which the coil penetrates between the inlet and the outlet of the through hole 60. Characterized in that formed wider than the width.

As in the spindle motor according to one embodiment of the invention shown in FIG. 1, the spindle motor of the invention comprises a rotor 10 and a stator 20. The rotor 10 includes a shaft 11 and a hub 12, and the stator 20 may include a base 21, a sleeve 22, a core 23, and a pulling plate. Accordingly, each configuration and embodiments of the present invention will be described below.

As shown in FIG. 1, the shaft 11 forms a central axis in which the spindle motor rotates, and generally has a cylindrical shape. In the embodiment of FIG. 1, a thrust dynamic pressure bearing part 40 is formed between one end surface of the sleeve 22 accommodating the shaft 11 and the bottom surface of the hub 12 facing the shaft 11. Here, the dynamic pressure generating groove for forming the thrust dynamic pressure bearing part 40 may be formed at one end surface of the sleeve 22 facing each other or at the bottom surface of the hub 12.

However, unlike illustrated in FIG. 1, a separate thrust plate (not shown) may be inserted into the shaft 11 and formed. That is, a thrust plate for forming a thrust dynamic bearing by a hydrodynamic bearing may be inserted to be orthogonal to the upper portion of the shaft 11. Here, the thrust plate is formed in the upper portion of the shaft 11, of course, can be inserted into the lower end of the shaft 11 to be installed orthogonally. The thrust plate may be separate laser welding or the like for fixing to the shaft 11, but it is apparent to those skilled in the art that the thrust plate may be press-fitted by applying a predetermined pressure to the thrust plate. In order to form the thrust dynamic bearing part 40 by the hydrodynamic bearing, a dynamic pressure generating groove (not shown) may be formed in the thrust plate.

The sleeve 22 accommodates the shaft 11 therein and has a hollow cylindrical shape to rotatably support the shaft 11, and has an outer circumferential surface 11a of the coupled shaft 11 and an inner circumferential surface 22a of the sleeve 22. The radial dynamic pressure bearing part 50 may be formed by an oil that is a working fluid. In addition, a dynamic pressure generating groove (not shown) for generating dynamic pressure of the radial dynamic bearing part 50 is formed on the outer circumferential surface 11a of the shaft 11 forming the radial dynamic bearing part 50 or the sleeve 22. Of course it can be formed on the inner peripheral surface (22a) of.

The hub 12 is for mounting and rotating an optical disk or a magnetic disk, which is not shown, and the shaft 11 is integrally coupled to the center and is disposed on the shaft 11 so as to correspond to the axial upper surface of the sleeve 22. Combined. The rotor magnet 13 is formed to face the core 23 of the base 21 to be described later in the radial direction. The core 23 generates magnetic flux as a magnetic field is formed when current flows. The rotor magnet 13 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 rotor magnet 13 are generated by the repulsive force between the magnetic force due to the linkage of the magnetic flux, thereby rotating the hub 12 and the shaft 11 coupled thereto.

As already seen, it is of course possible to form a thrust dynamic pressure bearing portion 40 between the axially distal top surface of the sleeve 12 facing the hub 12.

The base 21 is coupled to the outer circumferential surface of the sleeve 22 so that the sleeve 22 including the shaft 11 is coupled to the inside. On the other side opposite to one side of the base 21, a core 23 wound around the winding coil 23a is coupled to a position corresponding to the rotor magnet 13 formed on the hub 12. The base 21 serves to support the overall structure at the bottom of the spindle motor, and the manufacturing method may be manufactured by a press working or die-casting method. The material by press working may be a metal of various materials such as aluminum and steel, but is preferably formed to have rigidity. An adhesive may be applied to the inner surface of the base 21 or the outer surface of the sleeve 22 to be assembled with the sleeve 22. A conductive adhesive (not shown) for conduction of the base 21 and the sleeve 22 may be connected to the bottom surface at which the base 21 and the sleeve 22 are bonded. By forming the conductive adhesive, it is possible to improve the reliability of the motor operation by allowing the overcharge generated during operation of the motor to flow through the base 21.

The core 23 is generally formed by stacking a plurality of thin metal plates, and is fixedly disposed on an upper portion of the base 21 on which the flexible printed circuit board 70 is provided. A plurality of holes (not shown) are formed to correspond to the coils 23a drawn out from the winding coils 23a, and the coils 23a drawn out through the holes are soldered to the flexible printed circuit board 70 to be electrically connected to each other. Can be.

The through hole 60 is formed on the bottom surface of the base 21 so that the coil 23a drawn out from the core 23 is connected to the flexible printed circuit board 70. In the present invention, the through hole 60 is structurally changed such that the coil 23a drawn out through the through hole 60 does not contact the base 21. Conventionally, the insulating sheet is attached to the inlet side of the through hole 60 to insulate the base 21 and the coil 23a. However, as time passes, the insulating sheet may be detached. There was a problem that caused outgassing.

Accordingly, an object of the present invention is to provide a through hole 60 having a structure as shown in FIGS. 4A and 4B. Specifically, the through hole 60 of the present invention may be divided into an inlet portion (a), a passage portion (b), an outlet portion (c) sequentially in the axial direction. In particular, in consideration of the fact that the coils 23a drawn out through the inlet portion a and the outlet portion c of the through hole 60 are likely to contact the surface of the base 21, both edges of the through hole 60 are provided. By forming the portion wider than the passage portion b, insulation between the coil 23a and the base 21 can be maintained. Figure 4a is formed so that the width of the inlet portion (a) of the through-hole 60 toward the passage portion (b) gradually narrower, the width becomes gradually wider from the passage portion (b) toward the outlet portion (c) One embodiment is shown. FIG. 4B illustrates that the inlet portion a has a wider width, the passage portion b has a relatively narrower width, and the outlet portion c has a wider width. An example is shown. Since the passage part b is a portion in which the coil 23a is connected to the flexible circuit board 70 and finally sealed, the passage part b does not need to be formed unnecessarily wide, and the inlet part a and the outlet part c are relatively formed. By processing with a wide width, the ease of processing and unnecessary material loss at the time of sealing the last through-hole 60 can be prevented. In addition, the shape of the through hole 60 of the present invention is not limited thereto, and the coil drawn out from the core by expanding the widths of the edge portions of the inlet part a and the outlet part c of the through hole 60 ( It will be apparent to those skilled in the art that various structures can be selected and applied as long as the structure 23a) is not in contact with the base 21.

5a and 5b are related to another embodiment of the through hole 60 according to the present invention, the base 21 and the coil (s) more stably through the additional insulating coating layer (60a) inside the through hole (60) The insulation between 23a) can be maintained. The insulating coating layer 60a is not necessarily required, and may be selectively applied according to various structures of the spindle motor. The insulating coating layer 60a may reduce outgassing by using an epoxy-based thermosetting resin. However, the insulating coating layer 60a is not limited to these materials, and various insulating materials having insulating properties may be selected and applied.

Pulling plate 24 is preferably formed of a metal material for the attraction force with the rotor magnet (13). Specifically, it may be formed of a material such as SUS material, nickel, gold, etc., if the metal material of such a property is not limited to the illustrated material.

The cover member 30 is coupled to cover the axially opposite bottom surface of the sleeve 22 including the shaft 11. The cover member 30 may form a thrust dynamic bearing by forming a dynamic pressure generating groove in the inner surface 30a facing the lower surface 11b of the shaft 11. Cover member 30 is coupled to the end of the sleeve 22 is formed in a structure capable of storing the oil which is a working fluid therein.

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 stator 20 is composed of a base 21, a sleeve 22, a core 22, and a core 24. The stator 20 includes a base 21, a sleeve 22, (23) and a pulling plate (24). The core 23 and the rotor magnet 13 are attached to the outer side of the base 21 and the inner side of the hub 12, respectively, where the core 23 forms a magnetic field when current flows, do. The rotor magnet 13 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 rotor magnet 13 generate a repulsive force due to the electromagnetic force due to the linkage between the magnetic fluxes and thus the hub 12 and the shaft 11 coupled thereto rotate to drive the spindle motor of the present invention . Further, a pulling plate 24 is formed on the base 21 so as to correspond to the rotor magnet 13 in the axial direction in order to prevent floating of the motor when the motor is driven. The pulling plate 24 makes the rotary magnet 13 act gravitationally to enable stable rotation driving.

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: outer peripheral surface of the shaft 11b: lower surface of the shaft
12: hub 13: rotor magnet
20: stator 21: base
22: Sleeve 22a: Sleeve inner peripheral surface
23: core 24: pulling plate
30: cover member 40: thrust dynamic pressure bearing part
50: radial dynamic bearing part 60: through hole
60a: Insulation coating layer 70: Flexible Printed Circuit Board
a: entrance part b: passage part
c: outlet

Claims

A shaft forming the center of the rotor;
A sleeve for receiving the shaft and supporting the shaft rotatably; And
And a base coupled to an outer surface of the sleeve to support the sleeve, the core having a coil wound on the inner surface thereof, and a through hole through which the coil penetrates on an axial lower surface thereof.
The through-hole is a spindle motor, characterized in that the width of the inlet and outlet through which the coil penetrates wider than the width of the through-hole formed between the inlet and the outlet of the through-hole.

The method according to claim 1,
And a flexible printed circuit board on which the coil is electrically connected to the rear surface of the base through the through hole.

The method according to claim 1,
The through hole has an inlet portion, a passage portion, and an outlet portion sequentially formed in an axial direction through which the coil penetrates.
The portion of the inlet portion connected to the passage portion is formed such that the width of the through-hole becomes smaller and smaller, and the width of the through-hole connected to the outlet portion in the passage portion is formed so as to become wider.

The method according to claim 1,
The through-flow spindle motor, characterized in that the insulating coating on the inner surface.