JPH05282804A - Magnetic disk unit - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of an actuator for use with magnetic disc units by making the actuator to be made up of an arm supporting a magnetic head at the end portion thereof and provided with a hole, a fixed shaft extending through the hole, and a plurality of ball bearings mounted on the outer periphery of the shaft on both sides of the arm for axially pinching the arm. CONSTITUTION:On the outer periphery of a shaft 32, a pair of ball bearings 34 and 36 is mounted on both sides of an arm 35, which is pinched with the end faces of the outer rings 38 and 39 of the bearings. The precision bearings and the shaft may be the existing ones and require no further machining, and it is only needed to provide the arm 35 with a single hole 46 through which the shaft 32 is merely allowed to extend. In addition, since the outer rings 38 and 39 of the pair of bearings 34 and 36 are connected to the arm 35 by the frictional force due to the axial pressing and the adhesive force of a bonding agent, no excessive force is applied radially of the outer rings 38 and 39, causing no deformation and no loss in the bearings. Moreover, since the arm 35, bearings 34 and 36 and outer rings 38 and 39 are connected together by bonding members 49 and 50, the mass-producibility is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device suitable for mounting on a small portable personal computer or the like.

[0002]

2. Description of the Related Art Magnetic disk devices are widely used as devices for recording and reproducing information. Among such magnetic disk devices, a Winchester type magnetic disk device is usually configured as shown in FIG. That is, this magnetic disk device has a disk stack 2 in which a plurality of magnetic disks 1 on both sides of which information is recorded are laminated at regular intervals, a spindle motor 3 for rotationally driving the disk stack 2, and a magnetic disk 1 for each magnetic disk 1. A plurality of magnetic heads 4 for reading and writing information, and each magnetic head 4
It is composed of a rotary drive type actuator 5 that supports the spindle motor 3 and a spindle motor 3 and a control device (not shown) that drives and controls the actuator 5.

The actuator 5 includes a plurality of arms 6 for supporting the magnetic heads 4, a bearing 7 for rotatably supporting the arms 6, and a voice coil motor type drive for integrally rotating the arms 6. It is composed of a motor 8. Each arm 6 includes an arm body 9 and a suspension 10 having one end fixed to the arm body 9 and the other end supporting the magnetic head 4.

The magnetic disk device having such a structure records and reproduces information as follows. That is, the information is grouped into groups called sectors and recorded on the magnetic disk 1, and the position information for positioning the magnetic head 4 is recorded for each sector. The spindle motor 3 drives the disk stack 2 to rotate. When the drive motor 8 is driven in this state, each arm 6 moves to the bearing 7
, And each magnetic head 4 moves in the radial direction along the recording surface of each magnetic disk 1 with this rotation. At this time, the position signal recorded on the magnetic disk 1 is read by the magnetic head 4 at any time, and this position information is fed back to the control device to drive the drive motor 8. Then, when the predetermined position information of the magnetic disk 1 is transmitted to the control device, the control device drives the drive motor 8 to position the magnetic head 4 at that position.

When the magnetic head 4 is positioned, the magnetic disk device records and reproduces information in a portion other than the recording area for position information.

However, the conventional magnetic disk device configured as described above has the following problems. That is, a bearing 7 that rotatably supports each arm 6
If the support accuracy of is low, the magnetic head 4 cannot be accurately positioned. For this reason, conventionally, the arm 6 or the die-cast member integrally connected to the arm 6 is subjected to a cutting process to provide a tapered hole that widens as it approaches the opening edge, and the ball is inserted into the tapered hole. It is arranged and supported by a pivot bearing. This method is not limited to the disk stack type, and is also applied to a magnetic disk device having only one magnetic disk.

However, in the above-described structure, if the machining accuracy of the tapered hole is poor, the loss in the bearing 7 becomes large and the positioning accuracy deteriorates. Therefore, high-precision processing is required, and there is a problem that mass productivity is reduced.

[0008]

As described above, in the conventional magnetic disk device, it is necessary to form the bearing portion for rotatably supporting the arm of the actuator by precision machining in order to secure the positioning accuracy. However, there is a problem that mass productivity cannot be improved due to this.

Therefore, according to the present invention, the bearing portion for rotatably supporting the arm of the actuator can be assembled by a simple machining without the need for precise cutting, and further, the bearing can be assembled with a small loss. It is an object of the present invention to provide a magnetic disk device that can contribute to improvement in mass productivity.

[0010]

In order to achieve the above object, the magnetic disk device according to the present invention has an improved actuator. That is, the actuator has an arm that supports the magnetic head at its tip and is provided with a hole, a fixed shaft that penetrates through the hole of the arm, and an outer periphery of the fixed shaft that moves the arm. A plurality of ball bearings that are respectively mounted on both sides and that sandwich the arms in the axial direction with each other's outer rings,
It is provided with an adhesive member for connecting each outer ring of these ball bearings and the arm.

[0011]

As a result of taking the above measures, the following effects occur. Precision ball bearings and shaft materials are generally available on the market and do not need to be manufactured again. In the present invention, the ball bearings are mounted on both sides of the outer periphery of the fixed shaft with the arm as a boundary, and the arm is clamped by the end faces of the outer rings of these ball bearings. Only a simple hole needs to be provided. In addition, the outer rings of the pair of ball bearings are connected to the arm by the frictional force due to the axial pressure and the adhesive fixing force. Therefore, no extra force is applied to the outer ring of the ball bearing in the radial direction. Therefore, the outer ring is less deformed, and the occurrence of shaft loss can be suppressed.

Further, since the arm and the outer ring of the pair of ball bearings are connected by an adhesive member, it is possible to use an arm formed by pressing an aluminum flat plate having a certain degree of flatness. Processing becomes very easy. A U / V (ultraviolet ray curable) adhesive, which has less shrinkage during solidification, less gas generation, and a short solidification time, is suitable for the adhesive member.

[0013]

Embodiments will be described below with reference to the drawings.

FIG. 1 shows a magnetic disk device according to an embodiment of the present invention.

This magnetic disk device includes a magnetic disk 21 having information recorded on both sides and the magnetic disk 2.
1, a spindle motor 22 for rotationally driving 1, magnetic heads 23a, 23b (see FIG. 2) arranged so as to sandwich the magnetic disk 21 for reading and writing information from and to the magnetic disk 21, and a rotation for supporting the magnetic heads 23a, 23b. Drive type actuator 24 and magnetic heads 23a and 23b
Flexible printed wiring 2 that connects to the external circuit
5, a connector (not shown) that connects the wiring 25 and the drive input end of the actuator 24 to an external circuit, and a case 26 that houses them. Note that FIG.
The inside 27 indicates a filter for filtering dust inside. Further, the lid of the case 26 is omitted in FIG.

The actuator 24 is specifically constructed as shown in FIG. That is, reference numeral 31 in the drawing denotes a base provided in the case 26, and one end side of the shaft 32 is fixed to the base 31 by press fitting or screwing.

On the outer periphery of the shaft 32, the spacer ring 33, the ball bearing 34, the arm 35, and the ball bearing 3 having the same dimensions as the ball bearing 34 are arranged in this order from the bottom of the drawing.
6. The spacer ring 37 is fitted and mounted.

The spacer ring 33 has an outer diameter smaller than the inner diameter of the outer ring 38 of the ball bearing 34. Similarly, the spacer ring 37 also has a ball bearing 36.
The outer ring 39 has an outer diameter smaller than the inner diameter of the outer ring 39.

The arm 35 has an arm body 40 formed by pressing an aluminum flat plate or the like, and one end side of each of the arm body 40 is fixed by bolts 41 and nuts 42 to both end side surfaces of the arm body 40. The magnetic heads 23a and 23b described above on the inner surface of the other end
And suspensions 43a and 43b that support the. The central portion of the arm body 40 is fitted on the shaft 32 described above. That is, in the center of the arm body 40, the outer rings 38 of the ball bearings 34, 36,
A hole 46 smaller than the inner diameter of 39 and larger than the outer diameters of the inner rings 44 and 45 is formed, and the hole 46 is fitted to the shaft 32. At the time of fitting, the holes 46 are aligned so that the peripheral portions of the holes 46 contact only the end faces of the outer rings 38, 39 of the ball bearings 34, 36.

On the upper end surface of the shaft 32 in the figure, one end side of a connecting plate 47 for connecting the shaft 32 to an element of a drive motor 61 described later to enhance rigidity is applied, and this one end side is attached by a screw 48. It is fixed to the shaft 32. This connecting plate 4
By fixing 7, the pressurization is applied to the laminated portion including the spacer ring 33, the ball bearing 34, the arm 35, the ball bearing 36, and the spacer ring 33, and the pressurization causes the arm 35 to move to the outer shaft 38 of the ball bearing 34.
And an outer ring 39 of the ball bearing 36, and is sandwiched in the axial direction. Then, the outer peripheral surface of the outer ring 38 of the ball bearing 34, the arm 35, and the ball bearing 36.
The outer peripheral surface of the outer ring 39 and the arm 35 are joined by adhesive members 49 and 50, respectively. The adhesive member 4
U / V (ultraviolet curing type) adhesives, which have a small shrinkage during solidification, a small amount of gas generation, and a short solidification time, are used as Nos. 9 and 50. Of course, other adhesives can be used.

On the other hand, on the left side of the shaft 32 in the drawing, the arm 3 is provided.
Voice coil motor type drive motor 6 for rotating 5
1 is provided. The drive motor 61 includes a frameless flat coil 62 having one end fixed to the arm 36, a permanent magnet 63 arranged with one magnetic pole surface facing the flat coil 62, and an N pole of the permanent magnet 63. The yoke 6 that guides the magnetic flux generated from the S pole through the flat coil 62.
It is composed of 4, 65 and the like. The connecting member 47 described above is connected to the yoke 65.

In this way, a pair of ball bearings 34 and 36 are mounted on both sides of the shaft 32 with the arm 35 as a boundary, and the outer rings 38 and 36 of these ball bearings 34 and 36 are mounted.
The arm 35 is sandwiched between the end faces of 39. As the precision ball bearing and shaft material can be used as they are, existing ones do not have to be processed again, and only the simple hole 46 for allowing the shaft 32 to pass through is provided in the arm 35. .. Since the outer rings 38, 39 of the pair of ball bearings 34, 36 are connected to the arm 35 by the frictional force due to the axial pressure and the fixing force of the adhesive, the outer rings 38, 39 have an extra radial direction. No force is applied. Therefore, the deformation of the outer rings 38, 39 can be suppressed, and the occurrence of loss in the bearing can be suppressed.
In addition, the arm 35 and the pair of ball bearings 34, 36
Since the outer rings 38, 39 are also connected by the adhesive members 49, 50, it is possible to use the arm 35 formed by press working an aluminum flat plate having a certain degree of flatness, and eventually workability is improved. Therefore, mass productivity can be improved.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0024]

As described above, according to the present invention, the manufacturing can be facilitated without deteriorating the positioning accuracy of the magnetic head, which contributes to the mass productivity.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a magnetic disk device according to an embodiment of the present invention.

FIG. 2 is a sectional view of an actuator incorporated in the magnetic disk device.

FIG. 3 is a schematic perspective view of a conventional magnetic disk device.

[Explanation of symbols]

21 ... Magnetic disk, 23a, 23b ...
Magnetic head, 24 ... Actuator, 3
4, 36 ... Ball bearing, 35 ... Arm,
38, 39 ... Outer ring, 40 ... Arm body,
44, 45 ... Inner ring, 49, 50 ... Adhesive member, 61 ... Drive motor

Claims (2)

[Claims] 1. A magnetic disk driven to rotate, a magnetic head for recording information on and reading information from the magnetic disk, and a magnetic head supporting the magnetic head on the recording surface of the magnetic disk. In a magnetic disk device comprising a rotary drive type actuator that moves along, an actuator for supporting the magnetic head at a tip portion thereof and an arm provided with a hole, and an actuator for penetrating the hole of the arm. A fixed shaft, a plurality of ball bearings mounted on both sides of the arm on the outer periphery of the fixed shaft, and sandwiching the arm in the axial direction with each other's outer rings; A magnetic disk drive, comprising: an adhesive member for connecting an arm. 2. The magnetic disk drive according to claim 1, wherein the adhesive member is an ultraviolet curable adhesive.