JP3185517B2 - Optical disk spindle motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for suppressing scattering of oil mist of an optical disk spindle motor.

[0002]

2. Description of the Related Art In recent years, with the spread of personal computers, large-capacity and small external storage devices have become indispensable. Optical disk devices are expected to be large-capacity, low-bit-cost, random-access, and disk-exchangeable external storage devices, and are being rapidly developed with the aim of downsizing for personal use. Accordingly, there is a demand for a smaller and thinner disk drive spindle motor. In an optical disk device, data writing / reading is performed by laser light. Therefore, adhesion of dust that causes attenuation and confusion of laser light to an optical system such as a lens or a disk surface is one factor that lowers the reliability of the apparatus. On the other hand, generally, in an optical disk spindle motor, a shaft of a rotor having a chucking mechanism for transmitting a driving force to a disk is rotatably supported by a ball bearing. Oil such as grease is sealed in the ball bearing in order to maintain smooth rotation for a long period of time, and it is inevitable that minute oil mist is generated during high-speed rotation. The adhesion of the oil mist promotes the adsorption of other dust and increases the effect on the optical system. For this reason, conventional optical
In the disk apparatus, it was essential to periodically clean the optical system or the disk surface. However, there is a demand for a device that can prevent dust from entering the optical system and make maintenance unnecessary or reduce the frequency, with the aim of using the optical system in a wider range. Therefore, also in the optical disk spindle motor, it is an important issue to suppress the scattering of oil mist, which has not been a problem in the past.

[0003] A motor structure of a conventional optical disk spindle motor will be described below.

FIG. 2 shows the structure of a conventional optical disk spindle motor. In the respective drawings, the same components are denoted by the same reference numerals, and the optical disk is indicated by 101 in each drawing. In FIG. 2, 201 is engaged while positioning the center of rotation of the optical disc 101, and
A shaft 202, which rotates at a predetermined number of rotations integrally with the optical disk 101, is mounted on the disk mounting portion A by the optical disk.
Placing the click 101 and the positioning in the height direction, the spindle hub that is secured by press-fitting or bonding to the shaft 201, 203 magnetically chucking plate 102 made of a soft magnetic material in the central portion of the optical disc 101 A chucking magnet for attracting and fixing the optical disc 101 to the upper end portion A of the spindle hub 202; a chucking yoke 204 made of a soft magnetic material and forming a magnetic path of the chucking magnet 203; The magnet 203 is fixed to the chucking yoke 204, and the chucking yoke 204 is fixed to the spindle hub 202 by bonding or press fitting. A field magnet 205 and a magnetic path yoke 206 for forming a magnetic path of the field magnet 205 are fixed to the spindle hub 202 by caulking or bonding. Further, 301 and 302 are drive coils, 303 is a stator core,
A stator is constituted by 301, 302 and 303. Reference numeral 401 denotes a circuit board on which elements such as an IC for driving a motor or a printed pattern are mounted, 501 denotes a chassis (not shown) of the apparatus main body, and the circuit board 401.
And a housing for fixing the stator by bonding or press fitting. A ball bearing 601 is fitted into the center cylindrical hole of the housing 501 on the spindle hub 202 side, and another ball bearing 602 is fitted on the opposite side of the spindle hub 202 in the axial direction. Is rotatably supported by inserting it into the inner ring. The ball bearing 6
01 and 602 are formed on the surface of the head of the screw 701 fastened to the female screw portion formed on the end surface of the shaft 201 on the side opposite to the spindle hub 202 in the axial direction, on the surface facing the ball bearing 602. , And an appropriate preload is applied by a dish-shaped preload spring 801 disposed so as to contact the other surface with the end surface of the inner ring of the ball bearing 602.

[0005]

However, in the above-described conventional configuration, the ball bearing 601 on the spindle hub 202 side which communicates with the outside air of the motor through a narrow gap between the stator core 303 and the field magnet 206 is provided. On the other hand, the ball bearing 602 located on the opposite side in the axial direction has a problem that oil mist is easily scattered because the distance from the outside air of the motor is short and there is almost no labyrinth.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a means for inexpensively suppressing scattering of oil mist generated from a ball bearing of an optical disk spindle motor.

[0007]

In order to achieve the above object, the present invention provides, as a first means, a structure for closing an opening of a housing, and a second means, comprising a screw for fixing an axial position of a ball bearing. A structure for forming a labyrinth between housings is provided.

[0008]

With this configuration, the ball bearing 6 located on the opposite side in the axial direction from the spindle hub 202 of the above-described conventional configuration.
02 is sealed by the first means, and
According to the means, the scattering of oil mist generated from the ball bearing of the optical disk spindle motor can be suppressed by the labyrinth.

[0009]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1A, reference numeral 201 designates the position of the center of rotation of the optical disc 101 and engages with it.
Shaft rotating at a predetermined rotational speed so that the optical disk 101 and integral, 202 positioning in the height direction by placing the optical disc 101, spindle hub which is fixed by press-fitting or bonding to the shaft 201, 501 A motor chassis with a reference surface, 60
Reference numeral 1602 denotes a bearing. A spacer 901 and a preload spring 801 functioning to apply a preload to the bearings 601 and 602.
The housing 501 includes the bearings 601 and 60.
2. The spacer 901 and the preload spring 801 are housed in a hole provided in one direction, and the other one blocks the convection between the bearing and the outside air.

Reference numeral 203 denotes a chucking magnet;
Is a chucking yoke, 303 is a stator core, 205
Denotes a field magnet, 206 denotes a magnetic path yoke, and 401 denotes a circuit board.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

In FIG. 1B, reference numeral 201 denotes the optical disk.
Engage with the positioning of the center of rotation of the disk 101, and the shaft for rotating the optical disc 101 and together at a predetermined rotation speed, the optical de the disk loading portion A is 202
The positioning in the height direction by placing the disc 101, spindle hub which is fixed by press-fitting or bonding to the shaft 201, 203 magnetically chucking plate 102 made of a soft magnetic material in the central portion of the optical disc 101 The optical disc 101 is attracted to the upper end portion A of the spindle hub 202.
Is a chucking yoke that is formed of a soft magnetic material and forms a magnetic path of the chucking magnet 203. The chucking magnet 203 is attached to the chucking yoke 204, and the chucking yoke 204 is attached to the chucking yoke 204. Each is fixed to the spindle hub 202 by bonding or press fitting. A field magnet 205 and a magnetic path yoke 206 for forming a magnetic path of the field magnet 205 are fixed to the spindle hub 202 by caulking or bonding. Also, 3
01 and 302 are drive coils, 303 is a stator core, and 301, 302 and 303 constitute a stator. Reference numeral 401 denotes a circuit board on which an element such as an IC for driving a motor or a printed pattern is mounted.
Reference numeral 01 denotes a housing for engaging the chassis (not shown) of the apparatus main body and the circuit board 401 and fixing the stator by bonding or press fitting. A ball bearing 6 is provided on the side of the spindle hub 202 of the cylindrical hole at the center of the housing 501.
01 is inserted, and another ball bearing 602 is inserted on the opposite side of the spindle hub 202 in the axial direction, and the shaft 201 is inserted into the inner ring to rotatably support the shaft 201. The ball bearings 601 and 602 are provided on the side of the head of a screw 701 that is fastened to a female screw portion formed on an end surface of the shaft 201 on the side opposite to the spindle hub 202 in the axial direction. An appropriate preload is applied by a disc-shaped preload spring 801 arranged such that one surface is in contact with the surface and the other surface is in contact with the end surface of the inner ring of the ball bearing 602.
A stepped side surface portion 702 is formed on a side surface of the head of the screw 701 facing the housing 501, and a stepped side surface portion 702 is formed on the inner peripheral surface of the housing 501 facing the stepped side surface portion 702 formed on the screw 701. Also the step-shaped inner peripheral part 502
Are formed. The stepped side surface portion 702 and the stepped inner peripheral portion 502 are opposed to each other with a slight distance of, for example, about 0.1 mm to 0.2 mm to form a labyrinth, so that an oil mist generated from the ball bearing 602 is formed. Can be suppressed from scattering to the outside of the spindle motor.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

In FIG. 1C, reference numeral 201 denotes the optical disk.
Engage with the positioning of the center of rotation of the disk 101, and the shaft for rotating the optical disc 101 and together at a predetermined rotation speed, the optical de the disk loading portion A is 202
The positioning in the height direction by placing the disc 101, spindle hub which is fixed by press-fitting or bonding to the shaft 201, 203 magnetically chucking plate 102 made of a soft magnetic material in the central portion of the optical disc 101 The optical disc 101 is attracted to the upper end portion A of the spindle hub 202.
Is a chucking yoke that is formed of a soft magnetic material and forms a magnetic path of the chucking magnet 203. The chucking magnet 203 is attached to the chucking yoke 204, and the chucking yoke 204 is attached to the chucking yoke 204. Each is fixed to the spindle hub 202 by bonding or press fitting. A field magnet 205 and a magnetic path yoke 206 for forming a magnetic path of the field magnet 205 are fixed to the spindle hub 202 by caulking or bonding. Also, 3
01 and 302 are drive coils, 303 is a stator core, and 301, 302 and 303 constitute a stator. Reference numeral 401 denotes a circuit board on which an element such as an IC for driving a motor or a printed pattern is mounted.
Reference numeral 01 denotes a housing for engaging the chassis (not shown) of the apparatus main body and the circuit board 401 and fixing the stator by bonding or press fitting. A ball bearing 6 is provided on the side of the spindle hub 202 of the cylindrical hole at the center of the housing 501.
01 is inserted, and another ball bearing 602 is inserted on the opposite side of the spindle hub 202 in the axial direction, and the shaft 201 is inserted into the inner ring to rotatably support the shaft 201. The ball bearings 601 and 602 are provided on the side of the head of a screw 701 that is fastened to a female screw portion formed on an end surface of the shaft 201 on the side opposite to the spindle hub 202 in the axial direction. An appropriate preload is applied by a disc-shaped preload spring 801 arranged such that one surface is in contact with the surface and the other surface is in contact with the end surface of the inner ring of the ball bearing 602.
A plurality of grooves 703 are formed concentrically on a surface of the head of the screw 701 facing the ball bearing 602, and a concentric circle facing the groove 703 is formed on a surface of the housing 501 facing the groove 703. Plural projections 503
The groove 703 and the projection 503 are opposed to each other with a slight distance of, for example, about 0.1 mm to 0.2 mm to form a labyrinth, whereby the ball bearing 6 is formed.
It is possible to suppress the oil mist generated from the oil mist 02 from scattering outside the spindle motor.

[0016]

In the optical disc spin <br/> Ndorumota bearing unit constructed as described above according to the present invention, low cost without adding a new component to suppress scattering of the oil mist generated from the ball bearing of the optical disk spindle motor It can be realized.

Although the first and second embodiments are directed to the circumferentially opposed spindle motor, it is needless to say that the same effects can be obtained in a flat opposed spindle motor.

[Brief description of the drawings]

FIG. 1A is a diagram illustrating an optical disk according to a first embodiment of the present invention.
Sectional view of the disk spindle motor (b) is a sectional view of an optical disc spin <br/> Ndorumota in the second embodiment of the present invention (c) is an optical disc spin <br/> Ndorumota in the third embodiment of the present invention Sectional view

FIG. 2 is a sectional view of a conventional optical disk spindle motor.

[Explanation of symbols]

101 Optical disk 102 Attraction plate 201 Shaft 202 Spindle hub 203 Chucking magnet 204 Chucking yoke 205 Field magnet 206 Magnetic path yoke 301, 302 Drive coil 303 Stator core 401 Circuit board 501 Housing 502 Stepped inner peripheral portion 503 Projecting portion 601 and 602 Bearing 701 Screw 702 Stepped side surface part 703 Groove part 801 Preload spring 901 Spacer A Disk mounting part

Continuation of front page (56) References JP-A-4-244756 (JP, A) JP-A-5-146128 (JP, A) JP-A-4-244760 (JP, A) JP-A-5-49199 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 5/10 H02K 5/173 H02K 21/22

Claims (1)

(57) [Claims] 1. A shaft, which is a rotating shaft, a spindle hub for mounting a disk on an upper end thereof for positioning in a height direction, a bearing, a housing, and a screw for fixing an axial position of the bearing. In an optical disk spindle motor, the bearing and outside air are placed between the screw and the opposite surface of the housing.
A magneto-optical disk spindle motor characterized in that a labyrinth is formed to communicate with the oil mist and prevent scattering of oil mist .