Patent Application
20130100794
This application is based on Japanese Patent Application No. 2011-229486 filed with the Japan Patent Office on Oct. 19, 2011, the entire content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a disk rotating motor and a disk drive device provided with the same and, more particularly, to a disk rotating motor that can be fabricated in a simple method and a disk drive device provided with the same.
2. Description of the Related Art
When information is written in or read from a recording medium having information recorded therein such as an optical disk or a magneto-optical disk, a disk drive device is used to rotate a disk. The disk drive device includes a disk rotating motor for rotating the disk. The techniques relevant to the disk rotating motor in the prior art are disclosed in, for example, Documents 1 and 2.
Document 1 discloses a brushless motor including a burring unit constituting a bearing housing and a fixing base unit for fixing the motor, the units being formed integrally with each other.
Document 2 discloses a spindle motor including a bracket having an annular recess and a cylindrical opening, the bracket being integrally molded by pressing. The annular recess is formed in an axial direction, and contains a stator and a rotor magnet therein. A shaft is fitted to the inner circumference of the cylindrical opening.
Document 1: Japanese Patent Laying-Open No. 2002-262540
Document 2: Japanese Patent Laying-Open No. 2001-314058
Cost reduction has been strongly required for the disk rotating motor in recent years. In order to reduce the cost of the disk rotating motor, the disk rotating motor needs be fabricated in a simple method. For example, the number of component parts for the disk rotating motor is reduced; or not a relatively complicated (i.e., expensive) processing method such as cutting but a relatively simple (i.e., inexpensive) method such as pressing needs be used to process component parts constituting the disk rotating motor. Moreover, not a complicated tightening method but a relatively easy (i.e., inexpensive) tightening method typified by press-fitting need be adopted with high assembling precision in assembling the component parts. The prior art has been susceptible to improvement from the viewpoint of simplification of the fabricating method.
The present invention has been accomplished to solve the above-described problems to be solved. Therefore, an object of the present invention is to provide a disk rotating motor that can be fabricated by a simple method and a disk drive device provided with the same.
A disk rotating motor according to one aspect of the present invention is provided with: a stator including a stator core and a bracket for fixing the stator core; a rotor that can be rotated with respect to the stator and includes a rotary shaft; and a bearing that rotatably supports the rotary shaft on the outer diameter side of the rotary shaft; the bracket including a cylindrical portion extending along the rotary shaft and a folded portion formed by folding the end of the cylindrical portion onto the outer diameter side, and the bearing being fixed to the inner circumferential surface of the cylindrical portion whereas the stator core being fixed to the outer peripheral surface of the folded portion.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
Hereinafter, embodiments according to the present invention will be described with reference to the attached drawings.
In the following description, “an outer diameter side” signifies an outer diameter side when the rotary shaft of a disk rotating motor is referred to as the center whereas “an inner diameter side” signifies an inner diameter side when the rotary shaft of the disk rotating motor is referred to as the center. Moreover, “an outer peripheral surface” signifies an outer peripheral surface when the rotary shaft of the disk rotating motor is referred to as the center whereas “an inner circumferential surface” signifies an inner circumferential surface when the rotary shaft of the disk rotating motor is referred to as the center.
Referring to
Referring to
Rotor 10 includes a rotor frame 11, a magnet 12, a shaft 13, and a stopper washer 14. Rotor frame 11 is adapted to prevent a magnetic field from leaking from the inside of rotor frame 11, and is typified by a magnetic member. Rotor frame 11 includes a turn table 11a and a side wall 11b. Turn table 11a extends in, for example, a direction perpendicular to the extension direction of shaft 13 (laterally in
Magnet 12 is fixed to the inner circumferential surface of side wall 11b. Magnet 12 is formed into an annular shape, and includes regions magnetized to an N pole and regions magnetized to an S pole alternately at constant intervals in a circumferential direction. Magnet 12 is fixed to rotor frame 11 in such a manner as to face stator 20.
Shaft 13 extends in a vertical direction in
Stopper washer 14 is fitted to a groove 13a formed at shaft 13 near the lower end of shaft 13 in
Stator 20 includes a stator core 21 (i.e., a core), a stator coil 22, bracket 23, a bottom plate 24, and a thrust plate 25. Stator core 21 is fixed to bracket 23. Stator core 21 includes a plurality of teeth 21a radially extending from its inner diameter side toward its outer diameter side. Stator coil 22 is wound around each of teeth 21a. Bracket 23 is adapted to fix stator core 21. Bottom plate 24 is made of, for example, a magnetic material, and is fixed onto a rotor 10 side in bracket 23.
Referring to
Bearing 30 is fixed at the inner circumferential surface of cylindrical portion 23d. Bearing 30 is formed into a cylindrical shape, and extends along shaft 13. The outer peripheral surface of bearing 30 is brought into contact with the inner circumferential surface of cylindrical portion 23d.
Stator core 21 is fixed at the outer peripheral surface of folded portion 23e. Stator core 21 has a bore 61 formed at the inner-diameter end thereof. The inner circumferential surface of bore 61 is brought into contact with the outer peripheral surface of folded portion 23e.
Thrust plate 25 is formed into, for example, a circular shape, and has a contact surface in contact with the lower end of shaft 13 in
Motor 100 further includes a centering member 41 and a cushion rubber 42. Turn table 11a has an inner-diameter end 11c bent upward in
Next, a description will be given of one example of a fabricating method for the disk rotating motor in the present embodiment with reference to
Referring to
Referring to
Returning to
The present embodiment can provide the disk rotating motor that can be fabricated in a simple method and a disk drive device provided with the same.
In the present embodiment, bracket 23 including cylindrical portion 23d for fixing bearing 30 and folded portion 23e for fixing the stator core is fabricated by bending one plate, thus reducing the number of component parts and reducing the number of assembling processes. As a consequence, it is possible to fabricate motor 100 in a simple method, so as to reduce the cost of the motor.
Moreover, first to third bottoms 23a to 23c supporting the lower end of shaft 13 in
Additionally, bracket 23 includes first bottom 23a in contact with thrust plate 25 and second bottom 23b that is formed by bending first bottom 23a and surrounds the outer periphery of thrust plate 25, thus restricting the position of thrust plate 25.
Referring to
Incidentally, the configuration of motor 100 except the above-described matter is identical to that of the motor in the first embodiment, and therefore, its description is not repeated here.
In the present embodiment, the position of suction magnet 44 can be restricted on the boundary between cylindrical portion 23d and folded portion 23e. As a consequence, suction magnet 44 can suck rotor 10 by uniform suction force.
Referring to
Incidentally, the configuration of a motor 100 except the above-described matter is identical to that of the motor in the second embodiment, and therefore, its description is not repeated here.
In the present embodiment, the position of suction magnet 44 can be restricted by stator core 21. As a consequence, suction magnet 44 can suck rotor 10 by uniform suction force.
Referring to
Incidentally, the configuration of a motor 100 except the above-described matter is identical to that of the motor in the second embodiment, and therefore, its description is not repeated here.
In the present embodiment, the radial length of separating portion 23g can adjust the radial position of folded portion 23e. As a consequence, stator cores 21 having various sizes can be disposed in bracket 23.
The disk rotating motor according to the present invention may be exemplified by an axially fixed motor, a planar opposite motor, and the like in addition to the above-described axially rotational motor.
The above-described embodiments may be appropriately combined with each other. In the case where bracket 23 includes separating portion 23g in combination of the configuration shown in
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the present invention being interpreted by the terms of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-229486 | Oct 2011 | JP | national |
