JP2000130449A - Bearing device, magnetic head device having it and recording disk driving motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device provided with a constitution easily and accurately assembleable without requiring skill, and a magnetic head device having this bearing device and a recording disk driving motor. SOLUTION: This bearing device is provided with a support shaft 1, pair of ball bearings 12, 13 fixed with each inner ring 18 to this support shaft 1, and a cylindrical spacer 14 concentrically arranged relating to the support shaft 1 to be interposed in an abutting condition to an end face of each outer or inner ring 19, 18 in both the ball bearings 12, 13 to set a mutual positional relation. A pair of the ball bearings 12, 13 are coated with a lubricating film in at least one of a rolling surface thereof or a surface of a rolling element 17, also at least one opening part of each opening part opposed to each other is formed as a gap without providing a seal 11, and an engaging stepped part 20 engaged with the spacer 14 by fitting to an opening end part of the outer or inner ring 19, 18 in concentric arrangement relating to the support shaft 1 is formed at an end part of opposed side to the outer or inner ring 19, 18 of the ball bearings 12, 13 provided with the gap.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bearing device used for a recording disk device such as a hard disk (HD), a magnetic head device using the bearing device, and a recording disk driving motor.

[0002]

2. Description of the Related Art Conventionally, in a magnetic head device for positioning a spindle motor or a magnetic head as a rotary drive source in a recording disk device, a rotating body is generally rotatably supported by using a bearing device as shown in FIG. . In this bearing device, a pair of upper and lower ball bearings 2 and 3 are disposed on the outer peripheral surface of a cylindrical fixed shaft 1 in the axial direction (vertical direction in the drawing) with a cylindrical spacer 4 interposed therebetween. It is externally fitted and fixed while maintaining the relationship. As the ball bearings 2 and 3, seals 11 are respectively provided on step portions 10 formed on the outer ring 8 side in the respective upper and lower openings, and the seals 11 are provided.
In this case, a structure is used in which the lubricating oil does not leak to the outside. The reason for using the ball bearings 2 and 3 having the seal 11 in this manner is as follows. That is, in the recording disk drive motor constituted by the ball bearing using the lubricating oil or the magnetic head device used therein, when the lubricating oil leaks from the ball bearings 2 and 3, the lubricating oil is gasified. A serious problem that data cannot be read or written because the magnetic head slider adheres to the surface of the magnetic disk medium or the magnetic head slider, or the magnetic disk medium sticks to the magnetic head slider and the magnetic head slider does not float. That's why.

In the above bearing device, a lower ball bearing 3, a spacer 4 and an upper ball bearing 2 are fitted into the fixed shaft 1 in this order from above, and the inner rings 7 of the ball bearings 2 and 3 are fixed to the fixed shaft 1. It is assembled by bonding to the outer peripheral surface and bonding the upper and lower contact surfaces of the spacer 4 to the outer rings 8 of the ball bearings 2 and 3 with an adhesive. At this time, a preload is applied in a direction to bring the inner rings closer to each other, and the inner rings are fixed. Here, the spacer 4 has a cylindrical shape having substantially the same outer diameter as the outer ring 8 of the ball bearings 2 and 3 and having an inner diameter sufficiently larger than the outer peripheral surface of the fixed shaft 1. Using a cylindrical assembly jig having an inner diameter substantially the same as the outer diameter of the ball bearings 2 and 3, the ball bearings are positioned so as to be concentric with the fixed shaft 1.

[0004]

However, the bearing device having the above-described structure requires the spacer
However, there is a problem that it is extremely difficult to apply an adhesive to a contact surface of each of the ball bearings 2 and 3 with respect to the outer ring 8 in the above. That is, the adhesive must be applied in a predetermined amount with great care so that it does not adhere to the seal 11 or enter the interior of the ball bearings 2 and 3. Requires skill. Further, the spacers having the adhesive applied to the contact surfaces on both sides need to be positioned by using the above-mentioned assembling jig while paying attention so that the adhesive does not adhere to the other. Therefore, the above-mentioned bearing device has poor assembly workability.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a bearing device having a structure which can be easily and accurately assembled without requiring skill. It is an object of the present invention to provide a magnetic head device and a recording disk drive motor having the same.

[0006]

In order to achieve the above-mentioned object, the present invention provides a support shaft, a pair of ball bearings each having an inner ring fixed to the support shaft, and a concentric shaft with respect to the support shaft. A bearing device comprising: a cylindrical spacer interposed in an abutting state on an end face of each outer ring or inner ring in the two-ball bearing in the arrangement of the two-ball bearing to set a mutual positional relationship between the two ball bearings.
In the pair of ball bearings, at least one of the rolling surface and the surface of the rolling element is coated with a lubricating film, and at least one of the openings facing each other does not have a seal. At the end on the side facing the outer ring or inner ring of the ball bearing provided with the gap, the opening end of the outer ring or inner ring in a concentric arrangement with the support shaft. An engagement step portion that fits into and engages with the portion is formed. The spacer is brought into contact with the outer ring side when preload is applied to the inner ring side, and the spacer is brought into contact with the inner ring side when preload is applied to the outer ring side.

In this bearing device, the engagement step of the spacer is engaged with the end on the side of the gap without the seal without engaging the seal at the mutual engagement depth without increasing the size by the absence of the seal. This is because the depth can be sufficiently secured. When assembling,
When the engaging step portion of the spacer is fitted and engaged with the end of the outer ring or the inner ring of the opposing ball bearing, the spacer is automatically positioned in an accurate concentric arrangement with respect to the support shaft, and in the radial direction. Is reliably prevented by the outer ring or the inner ring. Therefore, the spacer is prevented from moving in the radial direction by the outer ring or the inner ring of the ball bearing, and is prevented from moving in the axial direction of the support shaft by being sandwiched between the pair of ball bearings.
It can be fixed without using an adhesive. At this time, if the spacer is engaged with at least one of the pair of ball bearings, the spacer can be prevented from moving in the radial direction, so that the adhesive is unnecessary even if the other is not engaged. As described above, at least one of the rolling surface and the surface of the rolling element is coated with a lubricating film to eliminate the need for lubricating oil while using a bearing device having a pair of ball bearings having lubricity and low dust generation. Because the spacers can be accurately and easily positioned concentrically with respect to the support shaft without using an assembly jig, etc.
Since there is no need to apply an adhesive, the assembling workability is remarkably improved, and even an unskilled worker can assemble with a high yield. In addition, the problem of outgas generated from the adhesive is eliminated, so that the quality is improved.

Further, at least one of the openings of the ball bearings facing each other is not provided with a seal because it is necessary to provide a gap for engaging the engaging step of the spacer. However, since no lubricating oil is present, the ball bearing has no problem of leakage of lubricating oil, has low dust generation properties, and has no problem even if a seal is not provided. Here, the dust generation mainly refers to lubricating oil, but also includes a small amount of metal wear powder and lubricating film powder between the rolling elements and the inner and outer rings. Therefore, it can be said that this ball bearing is low in dust generation because there is no lubricating oil which accounts for most of the dust generation.

Further, according to the magnetic head device of the present invention, a cylindrical housing is rotatably supported by the bearing device according to the present invention, and the housing has a head arm and a voice coil each having a magnetic head at a distal end. A motor is provided for each.

In this magnetic head device, at least one of the rolling surface and the surface of the rolling element is coated with a lubricating film, so that lubricating oil is not required, but a pair of ball bearings having lubricity and low dust generation are provided. Since the bearing device is used, it is possible to omit the sealing of the opposing openings of the pair of ball bearings, and to engage the engaging step of the spacer with the opening, so that a general lubricating oil is used. As compared with the one using a ball bearing, it is possible to obtain good assembling workability while having low dust generation. In addition, since the rotational torque can be reduced because there is no lubricating oil, power consumption can be reduced, and the fluctuation range of the rotational torque can be reduced, so that the magnetic head can be operated with high accuracy.

Further, in the recording disk drive motor according to the present invention, a stator is fixed to an outer peripheral portion of a motor bracket provided with a bearing device according to the present invention at a central portion in a concentric arrangement with the bearing device. A rotor hub having a disk mounting surface for supporting and rotating the recording disk integrally therewith is rotatably supported via the bearing device, and a rotor magnet is opposed to the stator. It is attached to the rotor hub.

In this recording disk drive motor, at least one of the rolling surface and the surface of the rolling element is coated with a lubricating film to eliminate the need for lubricating oil, and has a pair of ball bearings having lubricity and low dust generation. The use of a bearing device equipped with a ball bearing makes it possible to omit seals at opposed openings of a pair of ball bearings, as compared to those using a general ball bearing using lubricating oil. By engaging the engaging step of the spacer, it is possible to obtain good assembling workability with low dust generation. In addition, since the rotational torque can be reduced because there is no lubricating oil, power consumption can be reduced, and the fluctuation range of the rotational torque can be reduced, so that the motor can be operated with high accuracy.

[0013]

Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a bearing device according to one embodiment of the present invention. In this bearing device, in this bearing device, a pair of upper and lower ball bearings 12 and 13 are provided on the outer peripheral surface of a cylindrical fixed shaft 1 with a cylindrical spacer 14 interposed therebetween, in the axial direction (vertical direction) of each other.
Is maintained while maintaining the above positional relationship, and the configuration itself is the same as that of the conventional device shown in FIG. 5, and different configurations will be described below.

The ball bearings 12 and 13 are balls (rolling elements) 1
A lubricating film formed by uniformly coating a fluoropolymer film with a submicron film thickness on the rolling surfaces of the inner ring 7 and the inner and outer rings 18 and 19 is formed. The lubricating film may be the entire rolling surface, but may be formed at least in a range where the ball contacts. The rolling surface refers to a concave surface of the outer rings 18 and 19 while the ball 17 abuts. As a suitable ball bearing of this type, for example, there is a clean pro bearing (trade name) manufactured by Koyo Seiko Co., Ltd. Accordingly, since the ball bearings 12 and 13 have a special lubricating film formed on the rolling surface, no lubricating oil is required, and a general ball bearing 2 using the lubricating oil shown in FIG. , 3, the dust generation is significantly lower. Therefore, the ball bearings 12, 13
Can omit the seal 11 as in the conventional ball bearings 2 and 3, so that the seal 11 is formed in a pair of upper and lower outer side openings (upper ball) in each outer ring 19 of each ball bearing 12 and 13. It is only provided on the step portion 11 above the bearing 12 and below the lower ball bearing 13). As a result, the opposing inward openings of the outer rings 19 in the ball bearings 12 and 13 are not provided with the seals 11, so that the gaps can be used for positioning the spacers 14. . By the way, in the case where the length in the axial direction is further reduced (thinned), the seal of the outer opening may be deleted. In this case, there is a possibility that foreign matter may enter through the outer opening. Therefore, it is preferable to avoid such a problem by bringing the member on the mounting side of the ball bearing into close proximity. In addition, most of the particle generation of ball bearings is caused by lubricating oil, but also includes a small amount of abrasion powder of metal of rolling elements and inner and outer rings. Since there is no oil, it has low dust generation.

Therefore, an annular engaging step 20 is formed on the lower end surface of the cylindrical spacer 14. When the spacer 14 is concentrically arranged with respect to the fixed shaft 1, the engagement step 20 is formed on the step 10 of the outer ring 19 of the lower ball bearing 13.
It is shaped so that it can be fitted into and engaged with. Therefore,
In this bearing device, at the time of assembly, first, an adhesive is applied to the outer peripheral surface of the fixed shaft 1 at a position where the inner ring 18 of the lower ball bearing 13 is fixed, the lower ball bearing 13 is fitted into the fixed shaft 1 from above, and then The spacer 14 is mounted on the lower ball bearing 13 with its engaging step 20 engaged with the step 10 of the outer ring 19 of the lower ball bearing 13. Then, an adhesive is applied to a position on the outer peripheral surface of the fixed shaft 1 where the inner ring 18 of the upper ball bearing 12 is fixed, and the upper ball bearing 12 is fitted from above the fixed shaft 1,
When a predetermined load is applied to the upper end surface of the inner ring 18 to solidify the adhesive (preload is applied), a bearing device is completed. As a result, the spacer 14 is automatically positioned in an accurate concentric arrangement with respect to the fixed shaft 1 and is reliably prevented from moving in the radial direction by the outer ring 19 of the lower ball bearing 13. It can be fixed without applying.

This bearing device is a conventional ball bearing 1.
The spacer 14 can be accurately and easily positioned concentrically with respect to the fixed shaft 1 without using a dedicated assembling jig or the like arranged on the outer periphery of the spacers 2 and 13. Since it is not necessary to apply an adhesive to the contact surface of the slab, assembly workability is remarkably improved, and even an unskilled worker can assemble with a high yield. In addition, the problem of outgas generated from the adhesive no longer required is eliminated.

FIG. 2 is a longitudinal sectional view showing a bearing device according to another embodiment of the present invention. The bearing device of FIG.
The only difference from FIG. 2 is that the seal 11 is also provided on the step 10 of the inner opening of the upper ball bearing 12.
The point that the bearing device of (b) is different from that of FIG.
Of the outer ring 19 in the upper ball bearing 12
This is only the configuration in which the engaging step portion 20 that engages with is formed. Accordingly, each of the bearing devices of FIGS. 2A and 2B can obtain the same effect as the bearing device of FIG.
In the bearing device of (a), even a very small amount of abrasion powder such as a ball, an inner and outer ring, and a lubricating film can be prevented from leaking, so that further low dust generation can be reliably obtained. FIG. 2 (b)
In the bearing device described above, the spacer 14 and the ball bearings 12 and 13 are engaged and joined, so that the spacer is more stable, or the necessity of distinguishing the front and back of the spacer 14 is eliminated, thereby improving the assembling workability.

Such a bearing device can be applied to various types of rotary driving devices. In particular, those which require mass productivity, those which generate dust, and those which are caused by an adhesive (outgassing) This is suitable for uses such as those which cause problems such as generation of water and application workability). For example, a magnetic head device or a recording disk driving motor in a recording disk device such as a hard disk device described below can be used.

FIG. 3 is a longitudinal sectional view showing a magnetic head device in a recording disk device according to an embodiment constructed using the bearing device of the present invention. This magnetic head device
The bearing device shown in FIG. 1 has its fixed shaft 1 vertically fixedly mounted on a base 21 and is mounted on a pair of ball bearings 1.
Each of the outer rings 19 has a cylindrical housing 22.
Are externally fitted and fixed, and the housing 22 is rotatably held on the fixed shaft 1. That is, each ball bearing 12, 13
The inner ring 18 is bonded to the outer peripheral surface of the fixed shaft 1, and the outer ring 19 is bonded to the inner peripheral surface of the housing 22. This bearing device is assembled according to the procedure described in FIG.

From one outer peripheral surface of the housing 22, a plurality of (in this embodiment, four in this example) head arms 23 are arranged in parallel with each other and horizontally projecting vertically. A magnetic head 27 for reading / writing information from / to a recording disk 24 such as an HD is mounted on the tip of the head arm 23 in close proximity to the surface of the recording disk 24. The recording disk 24
Is attached to a recording disk drive motor such as a spindle motor shown in FIG.

A magnetic head 2 is provided on the outer peripheral surface of the housing 22 on the side opposite to the position where the head arm 23 is formed.
7 is provided with a voice coil motor 28 as a positioning power source. The voice coil motor 28 detects a track position with respect to the magnetic head 27 by reading a dedicated disk surface on which position information is written in advance by a servo head, for example. The magnetic head 27 is controlled to rotate so that the magnetic head 27 always tracks on within 90 degrees. As a result, the magnetic head 27 moves on the recording disk 24 to read and write data. The magnetic head device is provided with a recording disk 24, a recording disk driving motor, and the like housed in a sealed container (HDA) in which a cover 29 is fixedly adhered to a base 21.

Since the above-mentioned magnetic head device is constituted by the above-mentioned bearing device, it has a low dusting property and a good assembling operation as compared with a general ball bearing using lubricating oil. In addition to the fact that the ball bearing constituting this bearing device has no lubricating oil, the fluctuation range of the rotational torque can be reduced. Thus, when the dimensional control of the distance between the magnetic head and the recording disk is strict as in the magnetic head device, the dimensional control can be easily satisfied by applying the bearing device to the magnetic head device. Further, since the rotation torque can be reduced, the power consumption required for the predetermined rotation is reduced.

In the above embodiment, a fixed shaft type magnetic head device has been described as an example. However, the magnetic head device of the present invention has a housing integrated with a support shaft rotatably supported by a pair of ball bearings. It goes without saying that the same effect can be obtained by applying the bearing device of the present invention to a shaft rotation type in which the shaft 22 rotates. Further, the bearing device in the magnetic head device of FIG. 3 can be replaced with the bearing device of FIG. 2A or the bearing device of FIG. 2B.

FIG. 4 is a longitudinal sectional view showing a spindle motor (recording disk drive motor) in a recording disk device according to an embodiment constructed using the bearing device of the present invention. FIG. 1 illustrates a fixed shaft type. A fixed shaft 32 made of a ferromagnetic material is attached to a base 31 provided at the center of a motor bracket 30 serving as a motor base. It is press-fitted into the hole 33 and vertically fixed. Further, a stator 34 formed by winding a stator coil 34b around a stator core 34a is externally fixed to the outer peripheral surface of the base 31.

The rotor hub 37 for integrally rotating and driving the recording disk 24 has a substantially cylindrical inner cylindrical wall portion 37.
The outer cylindrical wall portion 37b has a structure in which the outer cylindrical wall portion 37b is externally fitted and fixed to the outer cylindrical wall portion 37b. 38 are protruded. The rotor hub 37 is shown in FIG.
It is rotatably supported on a fixed shaft 32 via a pair of ball bearings 12 and 13 in a bearing device equivalent to that shown in FIG.

The bearing device is mounted in the following structure. That is, the lower ball bearing 13 is bonded to the inner peripheral surface of the inner cylindrical wall portion 37 a of the rotor hub 37, and thereafter, the receiving plate 39 is fixed, and the inner ring 18 is bonded to the outer peripheral surface of the fixed shaft 32. The spacer 14 has a lower engaging step 2.
0 is engaged with the step portion 10 above the fixed lower ball bearing 13 to be placed on the lower ball bearing 13 in a concentric arrangement with respect to the fixed shaft 32 and to use an adhesive means. It is fixed by preventing movement in the radial direction. The upper ball bearing 12 is formed by connecting the lower step 10 to the spacer 14.
The spacer 14 is engaged with the engagement step 20 above the spacer 14.
The outer ring 19 is adhered to the inner peripheral surface of the inner cylindrical wall portion 37 a and the inner ring 18 is adhered to the outer peripheral surface of the fixed shaft 32. As a result, the spacer 14 is provided with the double ball bearing 1.
The movement in the vertical direction is also prevented by being sandwiched by the members 2 and 13, and is completely fixed.

A cylindrical rotor yoke 40 is fixed to the inner peripheral surface of the lower portion of the outer cylindrical wall portion 37b of the rotor hub 37, and the rotor magnet 41 fixed to the inside of the rotor yoke 40 is fixed in a predetermined radial direction with respect to the stator core 34a. Are arranged in opposition to each other with a gap of. An annular holder member 42 for supporting the magnetic fluid sealing device 43 in a cantilever manner is attached to the upper opening of the inner cylindrical wall portion 37a of the rotor hub 37 by press-fitting means. The magnetic fluid sealing device 43 seals between the inner cylinder wall 37a and the fixed shaft 32. Furthermore, the motor bracket 3
A small gap 47 is formed between the groove 44 on the outer peripheral side of the base portion 31 of the base member 0 and the outer cylindrical wall portion 37b of the rotor hub 37, and the small gap 47 is a labyrinth that prevents passage of dust and the like. A seal structure is formed.

The spindle motor is housed in a sealed container comprising a base 21 and a cover 29 together with the magnetic head device shown in FIG. 3 to constitute a recording disk device. In this spindle motor, when a current is applied to a stator coil 34b of the stator 34, a magnetic action is generated between the stator 34 and the rotor magnet 41, so that the rotor hub 3
Reference numeral 7 denotes a rotating unit that uses the fixed shaft 32 as a rotation support shaft.
As a result, the recording disk 24, which is externally fitted to the rotor hub 37 and supported on the disk mounting surface 38, is driven to rotate integrally with the rotor hub 37, and the data is read by the magnetic head 27 in the magnetic head device shown in FIG. Is read and written.

Since the spindle motor is constituted by the above-described bearing device, it has low dusting and good assembly workability as compared with the one using a general ball bearing using lubricating oil. In addition to being able to get
Since there is no lubricating oil in the ball bearings constituting the bearing device, the fluctuation range of the rotational torque can be reduced. Thus, when the control of the rotational accuracy is strict as in the case of the spindle motor, the management can be easily satisfied by applying the bearing device to the spindle motor. Further, since the rotation torque can be reduced, the power consumption required for the predetermined rotation is reduced.

In the above embodiment, the lubricating film in the ball bearing is the rolling surface. However, the lubricating film may be provided on the surface of the ball 17 as a rolling element, or may be provided on both. Although the spindle motor of the fixed shaft type has been described as an example, the spindle motor of the present invention is a shaft rotating type in which the rotor hub rotates integrally with a support shaft rotatably supported by a pair of ball bearings. Of course, the same effect can be obtained by applying the bearing device of the present invention. Also,
The bearing device in the spindle motor of the above embodiment,
The bearing device of FIG. 1 or the bearing device of FIG.

[0031]

As described above, according to the bearing device of the present invention, when assembling, the spacer is supported only by fitting the stepped portion of the spacer into the end of the outer ring of the opposing ball bearing. Since it can be automatically positioned in an accurate concentric arrangement with respect to the shaft, and can be reliably prevented from moving in the radial direction by the outer ring, it can be fixed without using an adhesive. Therefore, the spacers can be accurately and easily positioned concentrically with respect to the support shaft without using an assembling jig, and it is not necessary to apply an adhesive.
The assembly workability is remarkably improved, and even a worker who does not require skill can assemble with a high yield. In addition, since the ball bearing has a lubricating film formed on at least one of the rolling surface and the surface of the rolling element, lubricating oil is not required, and dust generation is extremely low. There is no trouble due to not providing a seal on the side where is provided.

Further, in the magnetic head device of the present invention, at least one of the rolling surface and the surface of the rolling element is coated with a lubricating film, so that lubricating oil is not required, but a pair of balls having lubricity and low dust generation are provided. Since the bearing device provided with the bearing is used, it is possible to obtain good assembling workability while having low dust generation. In addition, when the dimensional control of the distance between the magnetic head and the recording disk is strict as in the case of a magnetic head device because the fluctuation range of the rotational torque is small, the dimensional control can be easily performed by applying this bearing device to the magnetic head device. Can be satisfied. Further, since the rotation torque can be reduced, the power consumption required for the predetermined rotation is reduced.

Further, according to the recording disk drive motor of the present invention, at least one of the rolling surface and the surface of the rolling element is coated with a lubricating film to eliminate the need for lubricating oil and to achieve lubricity and low dust generation. Since a bearing device having a pair of ball bearings is used, it is possible to obtain good assembling workability with low dust generation. Further, since the fluctuation range of the rotational torque is small, when the control of the rotational accuracy is strict as in the case of the motor for driving the recording disk, the control can be easily satisfied by applying this bearing device to the spindle motor. Further, since the rotation torque can be reduced, the power consumption required for the predetermined rotation is reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a bearing device according to an embodiment of the present invention.

FIGS. 2A and 2B are longitudinal sectional views showing a bearing device according to another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view illustrating a magnetic head device in a recording disk device according to an embodiment configured using the bearing device of the present invention.

FIG. 4 is a longitudinal sectional view showing a recording disk drive motor in the recording disk device according to one embodiment configured using the bearing device of the present invention.

FIG. 5 is a longitudinal sectional view showing a bearing device used in a conventional recording disk device.

[Explanation of symbols]

 Reference Signs List 1 fixed shaft (support shaft) 11 seal 12, 13 ball bearing 14 spacer 18 inner ring 19 outer ring 20 engaging step 22 housing 23 head arm 24 recording disk 27 magnetic head 28 voice coil motor 30 motor bracket 32 fixed shaft (support shaft) 34 Stator 37 Rotor hub 38 Disk mounting surface 41 Rotor magnet

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hikaru Onodera 1-20-13 Osaki, Shinagawa-ku, Tokyo Nidec Corporation Tokyo Branch F-term (reference) 3J101 AA02 AA34 AA43 AA52 AA62 BA53 BA54 BA56 FA46 GA53 5D109 BA14 BA18 BA20 BA25 BB03 BB13 BB16 BB21 BB27 BC12 BC18

Claims (3)

[Claims] 1. A support shaft, a pair of ball bearings having respective inner rings fixed to the support shaft, and a pair of ball bearings arranged concentrically with respect to the support shaft to abut against end faces of respective outer rings or inner rings of the two ball bearings. A bearing device provided with a cylindrical spacer interposed in a contact state to set a mutual positional relationship between the two ball bearings, wherein the pair of ball bearings includes at least one of the rolling surface and the surface of the rolling element. The lubricating film is coated on at least one of the openings facing each other, and at least one of the openings is a gap without providing a seal, and the spacer is the ball provided with the gap. At the end of the bearing facing the outer ring or the inner ring, an engaging step portion is formed which is fitted concentrically with the support shaft and is engaged with the open end of the outer ring or the inner ring. A bearing device. 2. A cylindrical housing is rotatably supported by the bearing device according to claim 1.
A magnetic head device comprising: a head arm provided with a magnetic head at a distal end; and a voice coil motor. 3. The bearing device according to claim 1, wherein a stator is fixed to an outer peripheral portion of a motor bracket provided at a central portion in a concentric arrangement with respect to the bearing device, and supports the recording disk to be integral therewith. A rotor hub having a disk mounting surface on an outer peripheral portion for rotating the rotor hub is rotatably supported via the bearing device, and a rotor magnet is attached to the rotor hub in an arrangement opposed to the stator. Recording disk drive motor.