JPH0614496A - Spindle motor - Google Patents

Abstract

PURPOSE:To make manufacturing and assembly easy and to provide an effective sealing mechanism in a motor by installing a first ring member on either inner ring or outer ring of a bearing member and installing a second ring member on the other ring and by forming the first and the second ring member by press-working. CONSTITUTION:This motor is provided with a fixed member 2 and a rotary member 1 which is so supported as to rotate relatively to the fixed member 2. Between the fixed member 2 and the rotary member 1, bearing members 100, 200 are provided. Each of the bearing members 100, 200 has an inner ring 101, an outer ring 102 and a ball-like member 103 located between the inner ring 101 and the outer ring 102. A first ring member 211 is installed on either the inner ring 101 or the outer ring 102 through a washer 210 and a second ring member 212 is installed on the other. These ring members 211, 212 are formed by press-working. In such a structure, a desired labyrinth space can be formed by adjusting the thickness of the washer 210.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor mounted on, for example, an optical / magnetic disk device or the like and used for rotationally driving a recording disk.

[0002]

2. Description of the Related Art A spindle motor is provided with a bracket as a stationary member and a shaft member mounted on the bracket. A stator having a coil wire wound around a stator core is mounted on a bracket or a part of the shaft member. Has been done.

A hub member 1 is provided as a rotating member,
It is rotatably supported by a stationary member via a bearing. A rotor magnet is provided on the hub member 1 so as to face the stator. Then, it is rotationally driven by electromagnetic interaction between the stator and the rotor magnet.

The recording disk is mounted at a required position on the hub member 1 and rotates together with the hub member 1.

Further, a seal structure is provided outside the bearing member to prevent impurities such as grease from the bearing member from scattering into the disk chamber and adhering to the recording disk.

A magnetic fluid seal or a labyrinth seal is generally used for the seal structure. The magnetic fluid seal is a seal structure in which pole pieces made of a magnetic material are mounted on both surfaces of a permanent magnet, and the magnetic fluid is magnetically held between the pole piece and the shaft member to shut off the inside and the outside of the motor. .

The labyrinth seal is a seal structure that forms a narrow gap between a stationary member and a rotating member, and makes ventilation inside and outside the motor extremely difficult.

In general, the bearings provided on the upper portion of the hub member 1 are provided with a magnetic fluid seal, and the bearings provided on the lower portion are provided with a labyrinth seal.

[0009]

By the way, although the magnetic fluid seal has a high sealing effect, it is expensive and requires a mounting process.

On the other hand, the labyrinth seal is possible if a certain length can be secured between the stationary member and the rotating member, but it is required that the facing surfaces of both members be machined with high precision.

The reason why the upper bearing of the hub member 1 is often provided with a magnetic fluid seal is that it is difficult to obtain a sufficient length to form a labyrinth seal between the hub member 1 and the shaft member, and the hub member is also difficult. Since the end face of 1 and the recording disk are close to each other, it is necessary to ensure the seal, and an expensive magnetic fluid seal is used.

The labyrinth seal is often provided on the lower bearing of the hub member 1 because the bearing and the recording disk are considerably separated from each other and the labyrinth can be easily constructed.

There is also a labyrinth seal formed by combining an annular bearing member with the upper bearing of the hub member 1. However, the members used are resin molded products or machined products, which is troublesome to manufacture the parts. It took a while.

In view of the above problems, the present invention is to provide a spindle motor having a seal structure which is easy to manufacture and assemble and which is effective.

[0015]

A first annular member is provided on one of an inner ring and an outer ring of a bearing member via a washer, and a second annular member for holding a narrow gap with respect to the first annular member is attached to the other. Then, the first annular member and the second annular member were formed by press working.

[0016]

In this spindle motor, the annular member can be manufactured at low cost by press working, and furthermore, an arbitrary labyrinth space can be constructed by adjusting the thickness of the washer.

[0017]

FIG. 1 shows an embodiment of a spindle motor according to the present invention. Reference numeral 1 is a hub member 1 as a rotating member.

The hub member 1 is made of a metal material and has a substantially cylindrical shape with one end expanded in a fan shape. The cylindrical portion 11 on the upper portion of the hub member 1 is thick and is provided with a plurality of screw holes 12 for clamping the disc.

At the bottom of the cylindrical portion 11, there is provided a disk mounting portion 13 which is expanded outward in the radial direction.

A disk (not shown) for reading and writing information magnetically is placed on the disk placing portion 13, the upper surface of the disk is held by a clamp member (not shown), and further the screw hole 12 is provided. The disc is held on the outer surface of the cylindrical portion 11 by fixing the clamp member with a screw (not shown) screwed to the.

At the lower portion of the disk mounting portion 13, a rotor portion 18 which is expanded outward in the radial direction is provided. A drive magnet 19 is disposed at the tip of the rotor portion 18 in the axial direction, and the rotor end portion 15 covers the outer periphery of the drive magnet 19 so that the magnetism of the drive magnet 19 does not affect the disk. Like, it has a magnetic shield.

The bearing 1 is provided on the inner peripheral side of the disk mounting portion 13.
A bearing holding projection 14 for holding 00 and 200 is projected inward in the radial direction.

The lower end of the inner circumference located below the bearing holding protrusion 14 projects to the height of the rotor portion, is the lower bearing mounting portion 16 on which the lower bearing 100 is mounted, and the upper portion of the bearing holding protrusion 14. The inner peripheral surface of the cylindrical portion located at is the upper bearing mounting portion 17 on which the upper bearing 200 is mounted.

The screw hole 12 for clamping the disk penetrates from the cylindrical portion 11 to the rotor portion 18, and the screw hole 12 is formed in the opening surface of the hub member 1 connecting the lower bearing mounting portion 16 and the rotor portion 18. A seal 26 for sealing is provided.

Reference numeral 3 is a shaft member. The shaft member 3 is composed of a columnar portion 31 located on the inner circumference of the hub member 1 and a stator holding portion 32 that extends outward in the radial direction at the lower end of the columnar portion 31.

A mounting screw hole 35 for fixing the spindle motor to the frame or frame of the disk drive is provided through the axial center of the columnar portion 31.

A pair of bearings 10 are provided on the outer peripheral side of the cylindrical portion 31.
0 and 200 are mounted, and the hub member 1 is rotatably held via the bearings 100 and 200.

There is a stator holding portion 32 extending radially outward from the lower end of the shaft member 3, and a stator holding protrusion 33 for fixing the stator is provided upright at the end.

A stator 37 is pressure-bonded to the outer circumference of the stator holding protrusion 33. The stator 37 is formed by winding a coil wire 35 around a stator core 36.

The stator 37 is arranged at a position facing the rotor magnet 19, and substantially the stator 37 and the stator holding portion 33 of the shaft member 3 are arranged so that the lower bearing mounting portion 16 of the hub member 1, the rotor portion 18, and the rotor. 19 on the magnet
The shape is more covered.

A labyrinth is formed by forming a narrow gap between the outer peripheral surface of the lower bearing mounting portion 16 of the hub member 1 and the inner peripheral surface of the stator holding projection 33.

At the intermediate portion of the stator holding portion 32,
The bracket 2 integrally formed by pressing is attached to the hook portion 34 protruding downward by crimping.

The bracket 2 extends outward in the radial direction from the caulking fixing portion 23 to the rotor end portion 15, is bent upward outside the rotor end portion 15, and has the same height as the stator holding protrusion 33. , It is bent outward again and extends.

The extension end 21 of the bracket 2 is provided with a hole 24 for fixing a spindle motor.

By the way, the bearings mounted on the bearing holding portion 14 of the hub member 1 and the columnar portion 31 of the shaft member 3 have the structure shown in FIG. 2A is a sectional view of the lower bearing 100, and FIG. 2B is a sectional view of the upper bearing 200. Both structures are the same, and the mounting directions are opposite.

Reference numeral 101 is an inner ring of the bearing, 102 is an outer ring, and 103 is a spherical member arranged in a plurality of spaces between the inner ring and the outer ring. The plurality of spherical members 103 are held by a retainer 104 so as not to collide with each other. A seal member 105 is attached to one end of the outer ring so as to cover the retainer 104, and prevents grease inside the bearing from penetrating the peripheral wall of the retainer 104 and scattering outside the bearing.

However, the seal member 105 alone cannot completely prevent the scattering of the grease.

Therefore, in the lower bearing 100, as described above, a narrow gap is provided between the outer peripheral surface of the lower bearing mounting portion 16 and the inner peripheral surface of the stator holding projection 33 to form a labyrinth structure.

On the upper surface of the inner ring 201 of the upper bearing 200,
An inner cap member 212 having a substantially L-shaped cross section is attached.

A ring-shaped washer 210 is mounted on the upper surface of the outer ring 202, and an outer cap 211 is provided on the upper surface of the washer 210.

The outer periphery of the outer cap 211 and the inner peripheral surface of the upper bearing mounting portion 17 of the hub member 1 are fixed to each other with an adhesive.

The end of the inner cap 212 is horizontally adjacent to the washer 210, and the end of the inner cap 212 is attached to the outer peripheral surface of the cylindrical portion 31 of the shaft member 3.

The space between the inner cap and the outer cap is a narrow space to form a labyrinth structure.

Moreover, since the inner cap and the outer cap are formed by press working, and the distance between both caps can be defined by the thickness of the washer, an arbitrary labyrinth can be constructed by selecting the thickness of the washer.

FIG. 3 shows a modified example of the cap member provided on the upper bearing 200. Reference numeral 312 is a disk-shaped first inner cap mounted on the upper surface of the inner ring side, and 310 is a first outer washer mounted on the upper surface of the outer ring.

One end of the first inner cap 312 is mounted on the outer ring of the columnar portion 31 of the shaft member 3 and the inner ring 201 of the upper bearing 200, and the other end of the first inner cap 312 projects toward the outer ring and is close to the first outer washer 310. is doing.

The upper surface of the first outer washer 310 has a first
The outer cap 311 is attached to the first inner cap 31.
A first inner washer 314 is attached to the upper surface of 2.

The upper surface of the first inner washer 314 has a second
The inner cap 316 is attached.

The second inner cap 316 is a cylindrical member having a substantially L-shaped cross section, and the cylindrical portion is attached to the outer peripheral surface of the shaft member 3.

A second outer washer 313 is mounted on the upper surface of the first outer cap 311, and a second outer cap 315 is provided on the upper surface of the second outer washer 313.

The second outer cap 315 is fixed by an adhesive 317.

The space between the first inner cap 312 and the first outer cap 311, the space between the first outer cap 311 and the second inner cap 316, and the space between the second inner cap 316 and the second outer cap 315 are narrowed. It constitutes a triple labyrinth.

The first inner cap 312, the second inner cap 314, the first outer cap 311, and the second outer cap 315 are formed by pressing.

Although one embodiment of the spindle motor according to the present invention has been described above, the present invention is not limited to this embodiment, and various variations and modifications can be made without departing from the scope of the present invention. is there.

For example, in this embodiment, the outer ring is capped via the washer and the inner ring is directly capped. However, the inner ring is capped via the washer and the outer ring is capped directly. Is also good.

Although the inner cap is not attached with an adhesive, it may be fixed with an adhesive like the outer ring.

The laminated structure may have any structure, and the labyrinth structure may be used for the lower bearing.

[0058]

Since the present invention has the above-mentioned structure, it has the following effects. That is, since the labyrinth is formed by the pressed parts, the seal can be easily manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a spindle motor according to the present invention.

2 is an enlarged cross-sectional view of a bearing portion of the spindle motor of FIG.

FIG. 3 shows another embodiment of the present invention.

[Explanation of symbols]

 1 Hub Member 2 Bracket 3 Shaft Member 100 Lower Bearing 200 Upper Bearing 210 Washer 211 First Annular Member 212 Second Annular Member

Claims (2)

[Claims] 1. A spindle motor comprising a stationary member, a rotating member rotatably supported relative to the stationary member, and a bearing member interposed between the stationary member and the rotating member. In the above, the bearing member includes an inner ring, an outer ring, and a spherical member arranged between the inner ring and the outer ring, and one of the inner ring and the outer ring has a first member through a washer. A spindle motor, wherein an annular member is provided, a second annular member is attached to the other, and the first annular member and the second annular member are formed by press working. 2. In the spindle motor, the first
The spindle motor according to claim 1, wherein the annular member is laminated on the upper surfaces of the annular member and the second annular member via a washer.