JP2013132194A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle motor which can prevent flotation of a rotor and easily prevent decline in a rotational characteristic.SOLUTION: The spindle motor comprises: a shaft 11 comprising a groove 11a; a stator 20 comprising a bearing 21 so as to rotatably support the shaft 11; an armature 30 comprising a core 31 disposed on the stator 20; a rotor 10 which is disposed on an upper part of the shaft 11 and comprises a main magnet 13 opposed to the core 31 and generating electromagnetic force; and a stopper 21a, one end of which is inserted into the groove 11a to prevent flotation of the rotor 10. The stopper 21a is disposed inside the bearing 21.

Description

  The present invention relates to a spindle motor.

  Since the spindle motor rotates while maintaining a constant contact section with respect to the bearing, the rotation characteristics can be easily maintained. Therefore, a hard disk drive (HDD), an optical disk drive (Optical Disk Drive). : ODD) is widely used as a driving means for recording media that require high-speed rotation.

  Such a spindle motor usually includes an electric element, a rotor including a main magnet that forms an electromagnetic force with the electric element, and a stator that rotatably supports the rotor. Yes.

  The rotor may include a disk fixing device for fixing the disk of the recording medium, and the rotor rotates by an electromagnetic force generated between the electric element and the main magnet. The disc of the recording medium loaded in is recorded and reproduced.

  On the other hand, since the spindle motor requires high-speed rotation as described above, there is a problem that the rotor rises due to its characteristics. In order to solve this problem, the anti-floating structure is applied. In the case of a normal slim type spindle motor, the rotor is prevented from floating by a stopper structure.

  This is disclosed in detail in Patent Document 1. That is, a ring-shaped reduction part formed by the rotor sinking into the lower end of the shaft installed at the upper part is formed, and a stopper is provided inside the bearing holder, and the reduction part is applied to the stopper. By doing so, the rotor is prevented from rising.

  However, the anti-floating structure using the stopper disclosed in the prior art such as Patent Document 1 has a problem in that the length of the contact surface between the shaft and the bearing is shortened.

  In other words, the spindle motor forms a shaft system by the contact surface between the shaft and the bearing, and the longer the shaft system, the more stably the rotor can rotate, and in terms of characteristics with the external set. Although safety can be ensured, as described above, when the anti-floating structure is configured with a stopper, the length of the shaft system has to be shortened relatively, so that the rotor shakes (Wobble) during rotation. ) Phenomenon occurs and its life is shortened.

Korean Published Patent No. 2011-0010231

  Therefore, the present invention is to solve the problem of shortening the shaft system by preventing the rotor from rising using the stopper and the problem of the rotor swinging phenomenon and the shortening of the service life. It is.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spindle motor that can easily prevent a rotor from rising and prevent a decrease in rotational characteristics.

  To achieve the above object, the present invention provides a shaft in which a groove is formed; a stator including a bearing so as to rotatably support the shaft; an electric element including a core provided in the stator; A rotor that includes a main magnet that is disposed on the top and is disposed opposite to the core to generate electromagnetic force; and a stopper that is inserted into the groove to prevent the rotor from floating, the stopper including: Provided is a spindle motor which is disposed inside a bearing.

  In order to achieve the above object, the present invention provides a shaft having a groove portion; a bearing holder in which a bearing that rotatably supports the shaft is provided; A base plate provided; a core provided outside the bearing holder and wound with a coil; a rotor case provided with a main magnet so as to be disposed on the shaft and facing the core; and the groove portion And a stopper for preventing the rotor case from floating, and the stopper is disposed inside the bearing to provide a spindle motor.

  The stopper may be plate-shaped.

  It is preferable that a space portion is formed in the bearing in the horizontal direction, and a stopper is provided in the space portion.

  The space is preferably formed to correspond to the thickness of the stopper.

  It is preferable that the space portion is formed in a lower portion with reference to a center portion of the bearing.

  It is preferable that an annular space is formed around the shaft inside the bearing, and a stopper is disposed to face the space.

  The space is preferably formed to correspond to the thickness of the stopper.

  It is preferable that the space portion is formed in a lower portion with reference to a center portion of the bearing.

  A disk fixing device including a clamp is preferably installed on the upper part of the rotor case.

  According to the present invention, since the stopper is provided inside the bearing, the shaft system formed by surface contact between the bearing and the shaft is prevented from being shortened, thereby not only preventing the rotor from floating. The occurrence of wobbling due to unsafe rotation can be prevented, and the life can be extended by stable rotation.

  In addition, according to the present invention, the spindle motor can be easily reduced in thickness, and it is possible to ensure improved quality and improve reliability.

1 is a cross-sectional view illustrating a spindle motor including a stopper according to an embodiment of the present invention. It is sectional drawing which expands and shows the principal part of FIG. It is a perspective view which shows the Example of the stopper by this invention. FIG. 6 is a cross-sectional view illustrating a spindle motor including a stopper according to another embodiment of the present invention.

  Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and examples based on the accompanying drawings. On the other hand, in the description of the present invention, detailed descriptions of related known techniques that unnecessarily obscure the subject matter of the present invention are omitted.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the spindle motor according to the present invention includes a shaft 11, a stator 20 including a bearing 21 that rotatably supports the shaft 11, and a core ( The core 30, the rotor 30 including the main magnet 13 installed on the shaft 11 and facing the core 31, and the rotor. 10 includes a stopper 21a as an anti-floating structure.

  That is, as is well known, the stopper 21a prevents the rotor 10 from floating due to interference with the shaft 11. For this reason, the groove part 11a is formed in the shaft 11, and the end of the stopper 21a is inserted in the groove part 11a. Therefore, when the rotor 10 is lifted, the groove 11a is applied to the stopper 21a in the process of lifting the shaft 11 together with the rotor 11, thereby preventing the lift.

  At this time, unlike the stopper of the prior art, the stopper 21a according to the present invention is arranged inside the bearing 21, unlike the one arranged at the lower end of the bearing and the groove formed at the lower end of the shaft. It is possible to prevent the length of the shaft system H formed by surface contact with the shaft 11 from being shortened (see FIG. 2).

  As described above, the shaft system H is configured by surface contact between the bearing 21 and the shaft 11. However, as in the prior art, a stopper is disposed at the lower portion of the bearing to shorten the overall length of the bearing 21. As a result, the shaft system is shortened, the rotation characteristics of the spindle motor become unstable, a rotor wobbling phenomenon occurs, and the life of the spindle motor is also shortened.

  Accordingly, the spindle motor 1 according to the present invention has a stopper 21 a disposed inside the bearing 21 so that the shaft system H can be secured to the maximum by extending the bearing 21, and is formed on the shaft 11. It is preferable that the groove portion 11a is moved upward corresponding to the stopper 21a.

  Here, the embodiment of the spindle motor 1 including the stopper 21a will be specifically described as follows.

  That is, as shown in FIG. 1 or FIG. 4, the stator 20 including the bearing 21 that rotatably supports the shaft 11 in which the groove portion 11 a is formed is provided with the bearing 21 inside a bearing holder 22. A holder 22 is installed on an upper portion of a base plate 24 having a circuit board 23 for supplying external power to the electric element 30.

  The electric element 30 is embodied with a core 31 provided outside the bearing holder 22. For this reason, the stepped portion 22 a is formed in a step shape outside the bearing holder 22. A coil 32 is wound around the core 31 by a pole, thereby generating an electromagnetic force with the main magnet 13 to rotate the rotor 10.

  The rotor 10 is provided with a rotor case 12 on an upper portion of a shaft 11 and a main magnet 13 on the inner side so as to face the core 31. That is, the rotor case 12 is formed by horizontally bending the disc portion 12b on which the disc is mounted from the lower end of the fixing portion 12a fixed to the shaft 11, and then bending the coupling portion 12c downward from the disc portion 12b. The main magnet 13 is provided inside the coupling portion 12c.

  Since the rotor case 12 having such a configuration can easily secure a space with the core 31, the spindle motor 1 can be easily thinned. Since the disk fixing device 14 including the clamp 14a for elastically mounting the disk can be easily installed on the disk portion 12b, the error rate in the process of recording and reproducing the disk Decreases.

  Therefore, the spindle motor 1 including the rotor 10, the electric element 30, and the stator 20 supplies external power to the electric element 30 through the circuit board 23, so that the main motor 13 and the core 31 are connected. The rotor 10 is rotationally driven by the generated electromagnetic force, and the disk of the recording medium attached to the disk fixing device 14 by the clamp 14a can be easily recorded and reproduced.

  Further, in this process, it is possible to easily prevent the rotor 10 from floating upward due to the rotational force by the stopper 21 a disposed inside the bearing 21, and the shaft sufficiently secured by the extension of the bearing 21. A stable rotation of the rotor 10 can be induced by the system H.

  On the other hand, the stopper 21a according to the present invention is provided in the form of a panel (see FIG. 3) as an embodiment (see FIG. 3). The stopper 21a is provided inside the bearing 21 on which the shaft 11 is rotatably installed. 11, the rotor 10 is prevented from rising, and the length of the bearing 21 is ensured to the maximum to constitute a stable shaft system H (see FIG. 2).

  Further, as an example, a space portion 21b is formed in the bearing 21 in the horizontal direction, and a plate-like stopper 21a is provided in the space portion 21b. Here, the space portion 21b is formed to correspond to the thickness of the stopper 21a, thereby preventing excessive movement or separation of the stopper 21a.

  Since such a space portion 21b is formed in the lower portion with reference to the center portion C of the bearing 21 (see FIG. 2), when the spindle motor is viewed as a whole, the space portion 21b is formed with the groove portion 11a formed in the shaft 11 in the lower portion. The floating of the rotor 10 is prevented by the interference action.

  As another embodiment, as shown in FIG. 4, the stopper 210 a is provided so as to be opposed to a space portion 210 b formed in an annular shape around the shaft 11, so that it interferes with the shaft 11. The effect can be doubled.

  That is, an annular space 210b is machined inside the bearing 21, and a large number of plate-like stoppers 210a are inserted into the annular space 210b so as to be opposed to each other, or the stopper 210a is arranged in a ring. By inserting after forming in the shape, the interference of the left and right sides with respect to the cross section of the shaft 11 can be caused to stably prevent the rotor 10 from floating.

  Such an annular space 210b is formed to correspond to the thickness of the stopper 210a, as in the above-described embodiment, and prevents the stopper 210a from being excessively moved or detached. The annular space 210b is formed in the lower portion with respect to the center portion C of the bearing 21, and the rotor 10 floats due to the interference with the groove 11a formed in the shaft 11 at the lower portion of the spindle motor 1. To prevent.

  As described above, the present invention has been described in detail based on the specific embodiments. However, this is for specifically explaining the present invention, and the spindle motor according to the present invention is not limited thereto. Various modifications and improvements may be made by those having ordinary knowledge in the field within the technical idea of the present invention. All simple variations and modifications of the present invention shall fall within the scope of the present invention, and the specific scope of protection of the present invention will be clearly determined by the claims.

  The present invention can be applied to a spindle motor that can prevent the rotor from rising and easily prevent the rotation characteristics from being deteriorated.

DESCRIPTION OF SYMBOLS 1 Spindle motor 10 Rotor 11 Shaft 11a Groove part 12 Rotor case 12a Fixing part 12b Disk part 12c Coupling part 13 Main magnet 14 Disc fixing device 14a Clamp 20 Stator 21 Bearing 21a, 210a Stopper 21b, 210b Space part 22 Bearing holder 22a Step part 23 Circuit board 24 Base plate 30 Electron 31 Core 32 Coil H-axis system C Center part

Claims (10)

Shaft with grooves;
A stator including a bearing to rotatably support the shaft;
An electric element including a core provided in the stator;
A rotor including a main magnet installed on an upper portion of the shaft and facing the core to generate an electromagnetic force; and a stopper having one end inserted into the groove to prevent the rotor from floating;
Including
A spindle motor, wherein the stopper is disposed inside a bearing. Shaft with grooves;
A bearing holder in which a bearing for rotatably supporting the shaft is provided;
A base plate on which the bearing holder is installed and provided with a circuit board;
A core provided outside the bearing holder and wound with a coil;
A rotor case provided at the upper part of the shaft and provided with a main magnet so as to be opposed to the core; and a stopper having one end inserted into the groove to prevent the rotor case from floating;
Including
A spindle motor, wherein the stopper is disposed inside a bearing.   The spindle motor as set forth in claim 2, wherein the stopper has a plate shape.   4. The spindle motor according to claim 3, wherein a space portion is formed in the bearing in the horizontal direction, and a stopper is provided in the space portion.   The spindle motor according to claim 4, wherein the space portion is formed to correspond to a thickness of the stopper.   The spindle motor as set forth in claim 5, wherein the space portion is formed at a lower portion with reference to a center portion of the bearing.   The spindle motor as set forth in claim 3, wherein an annular space portion is formed inside the bearing around a shaft, and a stopper is disposed to face the space portion.   The spindle motor according to claim 7, wherein the space portion is formed to correspond to a thickness of the stopper.   The spindle motor as set forth in claim 8, wherein the space portion is formed in a lower portion with reference to a center portion of the bearing.   The spindle motor as set forth in claim 2, wherein a disk fixing device including a clamp is installed on an upper portion of the rotor case.

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