JP2000004558A - Motor and disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize highly accurate rotation. SOLUTION: An intermediate seat 9, provided between outer rings 54a, 55a of a pair of bearings 54, 55, is inserted and placed in contact with the internal circumference of a bearing housing 4 and is then fixed. Moreover, a gap 10 is provided between both outer rings 54a, 55a of a pair of bearings 54, 55 and bearing housing 4. Thereby, the external circumference of the outer rings 54a, 55a of the bearings and the internal circumference of bearing housing 4 will not be placed in direct contact, and the deterioration of true circle by the housings 54, 55 and bonding agent can be avoided as in the conventional case and thereby the spindle motor 1 of high accuracy rotation can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor such as a spindle motor for rotating a recording disk such as an optical or magnetic disk, and a disk drive using the same.

[0002]

2. Description of the Related Art Conventionally, this kind of spindle motor is a disk storage device of a computer peripheral device such as a CD-ROM (Compact Disk Read Only Memory) or a DVD (Digital Video Disk) which requires high-precision rotation. In such a case, the shaft and the outer peripheral body are supported via a bearing so that a recording disk such as an optical disk or a magnetic disk mounted on the outer peripheral body is driven to rotate together with the outer peripheral body. Has become.
FIG. 2 shows a vertical sectional structure of such a spindle motor.

FIG. 2 is a longitudinal sectional view showing a schematic configuration of a conventional spindle motor. In FIG. 2, a fixed frame 51 of a disk drive (not shown) has an upper surface 51a.
The bracket 52 is mounted and fixed with the reference as the mounting reference plane. An upright hole is provided in the center of the bracket 52, and the fixed shaft 53 is fitted into the upright hole. A pair of annular ball bearings 54 and 55 are fitted into the fixed shaft 53, and the disk mounting spindle hub 56 rotates about the axis of the fixed shaft 53 as the rotation center CL via the ball bearings 54 and 55. It is freely supported.

[0004] On this spindle hub 56, a required number of recording disks DK are mounted. Also, at the lower end of the outer periphery of the spindle hub 56,
The rotor magnet 57 is provided in an annular shape, and an armature 58 is fixed to the bracket 52 so as to face the annular rotor magnet 57. When a current is supplied to the armature 58, the armature 58 and the rotor magnet 5
7, the spindle hub 56 is connected to the armature 5
8 so as to rotate relative thereto.

A housing 59 for supporting a bearing is formed at the center of the spindle hub 56, and a small-diameter projection 60 is formed at an intermediate height position. Ball bearings 54 and 55 are fitted into the housing 59 from above and below, respectively. The ball bearings 54 and 55 are fixed to the housing 59 by using a small gap between the outer peripheral portion of the outer ring and the inner peripheral portion of the housing 59 with an adhesive 61 or the like.

As described above, the spindle motor 62 is configured to rotate and drive the recording disk DK mounted on the spindle hub 56.

[0007]

However, in the above-mentioned conventional configuration, the ball bearings 54 and 55 fix their outer rings in the housing 59 via an adhesive layer. Effect and adhesive 6
1 and the stress caused by uneven application of the adhesive 61,
In a disk drive that requires high-precision rotation,
There has been a problem that it causes a malfunction when writing or reading data.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a motor capable of realizing high-precision rotation and a disk drive device using the same.

[0009]

According to the present invention, there is provided a motor in which a centrally rotating shaft and an outer peripheral body which are relatively rotated are supported via at least one set of bearings. A spacer is provided between the outer rings of a pair of bearings to abut against an inner peripheral portion of the housing for housing the bearing.
A pair of bearings is characterized by having a gap between the outer peripheral portion of the outer ring and the inner peripheral portion of the housing.

With this configuration, the spacer provided between the outer races of the pair of bearings is inserted together with the spacer into the inner peripheral portion of the housing, and the outer peripheral portion of the spacer is brought into contact with the inner peripheral portion of the housing for fixing. Let it. At this time, there is a gap between the outer peripheral portion of the outer ring of one set of bearings and the inner peripheral portion of the housing. As described above, in a state where the outer peripheral portion of the outer ring of one set of bearings does not directly contact the inner peripheral portion of the housing, the outer peripheral portion of the spacer is sandwiched by the outer ring of one set of bearings. And the inner peripheral portion of the housing are abutted and fixed, so that the influence of the roundness of the inner peripheral portion of the housing, the influence of the stress due to the curing shrinkage of the adhesive, and the application of the adhesive as in the past. A motor having a higher rotational accuracy is less likely to be affected by stress due to unevenness in the amount.

Preferably, the spacer in the motor of the present invention is pressed between outer rings of a set of bearings.

With this configuration, when a spacer provided between the outer races of a set of bearings is inserted into the inner peripheral portion of the housing together with the bearing, even if a strong deformation force acts on the outer peripheral portion of the spacer, the spacer and the spacer are removed. By sliding between the outer rings, deformation of the spacer is not easily transmitted to the bearing, and the bearing does not deform, so that higher rotational accuracy can be maintained. Also, at the time of rotation, from the outer periphery of the spacer abutting the inner periphery of the housing,
The rotational force is transmitted to the outer ring of the pair of bearings pressed against the spacer, and smooth rotation is performed between the inner ring of the pair of fixed bearings and the outer ring of the rotating side via the bearing balls.

Preferably, the outer periphery of the spacer in the motor according to the present invention is in pressure contact with the inner periphery of the housing.

According to this configuration, if the outer peripheral portion of the spacer provided between the outer races of the pair of bearings is pressed into the inner peripheral portion of the housing and fixed, the spacer is combined with the pair of bearings. As compared with the case where the spacer is inserted into the housing and the spacer is bonded into the housing, the work efficiency is improved by the amount of the bonding process. Even if a strong deformation force is applied during the press-fitting, deformation of the spacer is hardly transmitted to the bearing, and the bearing does not deform, so that higher rotational accuracy can be maintained.

Further, preferably, the spacer of the motor according to the present invention has an outer peripheral portion projecting more than the outer peripheral portion of the pair of bearings.

With this configuration, in order to provide a gap between the outer peripheral portion of the outer ring of one set of bearings and the inner peripheral portion of the housing, the contact position with the spacer is protruded at the inner peripheral portion of the housing. Compared with the case, when the inner peripheral portion of the housing is flush, the processing of the inner peripheral portion of the housing and the insertion into the inner peripheral portion of the housing are easier. In other words, the outer circumference of the spacer is 1
If the inner peripheral portion of the housing is flush with the outer peripheral portion of the set of bearings, a gap is obtained between the outer peripheral portion of the outer ring of one set of bearings and the inner peripheral portion of the housing.

Further, preferably, the gap in the motor of the present invention is filled with an adhesive having a small curing shrinkage.

With this configuration, if the gap is filled with an adhesive, the outer peripheral portion of the outer ring of one set of bearings and the inner peripheral portion of the housing are more reliably fixed. Thus, 1
Even if the outer peripheral portion of the outer ring of the set of bearings and the inner peripheral portion of the housing are fixed with an adhesive, the outer peripheral portion of the spacer and the outer peripheral portion of the housing are sandwiched by the outer ring of the set of bearings. Since the inner peripheral portion is fixed after being in contact with the inner peripheral portion, it is less susceptible to the influence of stress due to the curing shrinkage of the adhesive as in the past and the influence of the stress due to the uneven application amount of the adhesive. A motor having rotational accuracy is obtained.

A disk drive according to the present invention is characterized by using the motor according to any one of the first to fifth aspects.

With this configuration, the displacement of the axis of the motor is suppressed, so that a disk drive which requires high-precision rotation can prevent malfunctions that occur when data is written or read.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a disk drive device according to an embodiment of the present invention.

FIG. 1 is a longitudinal sectional view showing a schematic structure of a spindle motor according to one embodiment of the present invention. Members having the same functions and effects as those of the conventional example of FIG. Is omitted.

In FIG. 1, a spindle motor 1 used in a rotary drive unit of a disk drive device has a pair of a center shaft 2 and an outer body 3 which rotate relative to each other with an axis as a rotation center CL (this embodiment). 2) ball bearings 5
And a bearing housing 4 which is provided inside the outer peripheral body 3 and accommodates ball bearings 54, 55.
And (independently). Here, the outer peripheral body 3 is a rotating body, and an annular back iron 6 and a magnet 57 are provided on the lower outer peripheral part of the spindle hub 5 on which the recording disk DK is mounted.

A fixed shaft 53 that supports ball bearings 54 and 55 is fixed to the bracket 52 (or base plate) as the fixed-side shaft 2 by standing upright on the bracket 52 (or base plate). An armature 58 is fixed to the bracket 52 so as to face the magnet 57. The armature 58 is provided with the stacked stator laminations 7.
And a winding 8 wound therearound.

Further, the spacer 9 which is an annular spacer member abutting on the inner peripheral portion of the bearing housing 4 is attached to the outer races 54a, 5 of a pair of upper and lower ball bearings 54, 55.
It is provided sandwiched between 5a. The outer diameter of the annular spacer 9 is determined by the outer rings 54a, 55 of the ball bearings 54, 55.
A diameter slightly larger than the outer diameter of a (for example, about 0.001 mm)
Is set to In other words, the spacer 9 has outer peripheral portions 54 a, 5 of the pair of ball bearings 54, 55.
5a protrudes from the outer peripheral portion. As a result, the outer rings 54a, 55 of the pair of upper and lower ball bearings 54, 55
Only the spacers 9a are fixed to the inner peripheral portion of the bearing housing 4 by, for example, pressure contact.
A gap 10 is provided between the outer peripheral portions of the outer rings 54 a and 55 a of 55 and the inner peripheral portion of the bearing housing 4. The clearance 10 is at least 0.001 mm, and prevents direct contact between the outer races 54a, 55a of the bearings 54, 55 and the inner peripheral portion of the bearing housing 4 on the rotor side.

When manufacturing the bearing portion of the spindle motor 1 having the above configuration, first, a bearing unit including the bearings 54 and 55, the spacer 9, and the fixed shaft 53 is manufactured. That is, the spacer 9 is positioned between the outer rings 54a, 55a of the upper and lower two bearings 54, 55 so that all members are concentric using an assembly jig or the like.
By applying hydraulic pressure or the like, the fixed shaft 53 at the axial center position is inserted (or press-fitted) into the inner ring 54b of the bearing 54, the spacer 9 and the inner ring 55b of the bearing 55 to penetrate.

At this time, the two bearings 54, 55
Are assembled on the basis of the fixed shaft 53 side, so that they are concentric. Further, in order to assemble the spacer 9 concentrically with the fixed shaft 53, it is necessary to position the spacer 9 with an assembling jig or the like so that the spacer 9 does not shift in the radial direction with respect to the fixed shaft 53.

Further, the outer races 54a, 55 are
a is maintained at a predetermined size, and two upper and lower bearings 54,
Preload is applied by a dead weight or a spring so that the two inner rings 54b and 55b of the 55 are close to each other, and in this state, the fixed shaft 53 and the two inner rings 54b and 55b of the two bearings 54 and 55 are bonded with an adhesive. And fix it.

Thus, a bearing unit including the spacer 9, the bearings 54 and 55, and the fixed shaft 53 is manufactured. At this time, the outer diameter of the spacer 9 is the bearing 5
Because it is set slightly larger than the outer diameter of 4,55,
The outer peripheral portion of the spacer 9 is formed by the outer races 54 of the bearings 54 and 55.
a, 55a projecting over the entire periphery from the outer periphery.

Next, this bearing unit is press-fitted into the inner peripheral portion of the bearing housing 4 by a press-fitting machine or the like and fixed. At this time, the outer peripheral portion of the spacer 9 is pressed against the inner peripheral portion of the bearing housing 4 and stopped, so that the bearing unit can be fixed in the inner peripheral portion of the bearing housing 4.

The deformation caused by the press-fitting is absorbed by the spacer 9 so that the transfer to the bearings 54 and 55 is reduced. Conversely, deformation caused by press-fitting is received by the spacer 9, so that the bearings 54, 55 are not deformed. The outer races 54a, 55a of the bearings 54, 55 and the upper and lower surfaces of the spacer 9 are only sandwiched and fixed, but not securely fixed, so that they are strongly deformed during press-fitting. Even if force acts, both outer rings 54 of bearings 54 and 55
a, 55a and the upper and lower surfaces of the spacer 9 slip, and the deformation of the spacer 9 is not transmitted to the outer rings 54a, 55a of the bearings 54, 55.
Will be avoided.

Further, after assembling the spindle motor 1,
When a current is supplied to the armature 58, the shaft body 2 and the outer peripheral body 3 rotate relative to each other by the electromagnetic action of the armature 58 and the rotor magnet 57 facing the armature 58. At this time, the outer body 3
Bearing integrated with the spindle hub 5
The rotational force is transmitted to the housing 4, the spacer 9 pressed against the inner peripheral portion of the bearing housing 4, and the outer rings 54a, 55a of the bearings 54, 55 sandwiching the spacer 9 up and down. Fixed shaft 53 via
And the fixed-side shaft body 2 composed of the inner rings 54b and 55b of the bearings 54 and 55 relatively rotates about the rotation center.

As described above, the pair of bearings 54, 5
The outer peripheral portion of the spacer 9 provided between the outer races 54a, 55a of the fifth bearing 5 is fixed by inserting and contacting the inner peripheral portion of the bearing housing 4 and the outer races 54a, 55a of the pair of bearings 54, 55. With a structure having a gap 10 between the bearing housing 4 and the outer peripheral portions of the bearing outer races 54a, 55a and the bearing housing 4
The inner peripheral portion of the spindle motor does not come into direct contact with the housing, and the roundness deterioration caused by the housings 54 and 55 and the adhesive as in the related art can be avoided, and the spindle motor 1 with high precision rotation can be obtained.

In this embodiment, the gap 10 is provided between the outer peripheral portions of the outer rings 54a, 55a of the pair of bearings 54, 55 and the inner peripheral portion of the bearing housing 4. Both outer rings 54 of bearings 54 and 55
The spacer 9 sandwiched between the bearing housings 4a and 55a
After being fixed to the inner peripheral portion, the gap 10 is filled with an adhesive having a small curing shrinkage so that a pair of bearings 54 and
The two outer rings 54a, 55a of 55 and the bearing housing 4 may be bonded and fixed. in this case,
Both outer rings 54a, 55a of the pair of bearings 54, 55 and the bearing housing 4 are securely fixed. As described above, the outer rings 54a,
Even if the outer peripheral portion of the bearing 55a and the inner peripheral portion of the bearing housing 4 are fixed, the outer peripheral portion of the spacer 9 and the bearing housing are sandwiched between the outer rings 54a, 55a of the pair of bearings 54, 55. 4 is fixed by being pressed against the inner peripheral portion, so that even if the curing shrinkage ratio is small and the curing time is long, the adhesive can be used without affecting the productivity, and a higher A motor having rotation accuracy can be obtained.

[0035]

As described above, according to the first aspect, the outer peripheral portion of the spacer provided between the outer races of the one set of bearings is inserted into contact with the inner peripheral portion of the housing to be fixed. A gap is provided between the outer peripheral portion of the outer ring of the bearing and the inner peripheral portion of the housing so that the outer peripheral portion of the outer ring of one set of bearings directly contacts the inner peripheral portion of the housing upon insertion. It is unlikely to be affected by the roundness of the inner peripheral part of the housing, the stress caused by the curing shrinkage of the adhesive, and the stress caused by the uneven amount of the adhesive applied. The displacement can be suppressed, and a motor having higher rotation accuracy can be obtained.

Further, according to the second aspect, since the spacer is not pressed and fixed to the outer ring, the spacer provided between the outer rings of one set of bearings is inserted together with them into the inner peripheral portion of the housing. Sometimes, even if a strong deformation force is applied to the outer periphery of the spacer, slippage between the spacer and the outer ring makes it difficult for the deformation of the spacer to be transmitted to the bearings, and the bearings do not deform. Obtainable. Further, during rotation, a rotational force can be transmitted from the outer peripheral portion of the spacer which comes into contact with the inner peripheral portion of the housing to the outer ring of a set of bearings pressed against the spacer.

Furthermore, in order to fix the outer peripheral portion of the spacer provided between the outer races of the one set of bearings to the inner peripheral portion of the housing, the one set of bearings is used. The number of working steps can be reduced as compared with the case of inserting into the housing and bonding. Further, even if a strong deformation force is applied at the time of press-fitting, the deformation of the spacer is not transmitted to the bearing, and the bearing is not deformed, so that higher rotational accuracy can be maintained.

Further, according to the fourth aspect, if the outer peripheral portion of the spacer is made to protrude beyond the outer peripheral portion of the one set of bearings, the outer race of the one set of bearings can be formed even if the inner peripheral portion of the housing is flush. A gap can be obtained between the outer peripheral portion and the inner peripheral portion of the housing. As described above, making the inner peripheral portion of the housing flush with the inner peripheral portion of the housing can facilitate the processing as compared with a case where the contact position with the spacer is protruded at the inner peripheral portion of the housing. .

Further, according to the fifth aspect, even if the gap is filled with an adhesive and the outer peripheral portion of the outer ring of one set of bearings and the inner peripheral portion of the housing are fixed with the adhesive, one set of the bearings is formed. Since the outer periphery of the spacer and the inner periphery of the housing are fixed by abutting the outer ring of the bearing with the outer ring of the bearing, the adhesive has a low curing shrinkage and a long curing time. Can be used without affecting productivity, and a motor having higher rotational accuracy can be obtained.

Further, according to the present invention, since the displacement of the axis of the motor is suppressed, it is possible to prevent erroneous operations occurring when writing or reading data in the disk drive.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view showing a schematic configuration of a conventional spindle motor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 spindle motor 2 shaft body 3 outer peripheral body 4 bearing housing 5 spindle hub 9, 11 spacer 10 gap 11 a projection 53 fixed shaft 54, 55 ball bearing 54 a, 55 a outer ring 54 b, 55 b inner ring

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference)

Claims (6)

[Claims] 1. A motor in which a relatively rotating central shaft body and an outer peripheral body are supported via at least one set of bearings, wherein an inner peripheral part of a housing for housing a bearing provided inside the outer peripheral body. Wherein a spacer is provided between the outer rings of the pair of bearings, and a gap is provided between an outer peripheral portion of the outer ring of the pair of bearings and an inner peripheral portion of the housing. . 2. The motor according to claim 1, wherein the spacer is pressed between outer rings of the pair of bearings. 3. The motor according to claim 1, wherein an outer peripheral portion of the spacer is pressed against an inner peripheral portion of the housing. 4. The motor according to claim 1, wherein an outer peripheral portion of the spacer protrudes from an outer peripheral portion of the one set of bearings. 5. The motor according to claim 1, wherein the gap is filled with an adhesive having a small curing shrinkage. 6. A disk drive device using the motor according to claim 1.