JPH0710862U - Magnetic disk drive - Google Patents

Abstract

(57) [Summary] [Purpose] With a simple and inexpensive structure, it is possible to easily achieve thinning while obtaining good assembly accuracy. A mounting hole 233 provided at a center of rotation of a rotor case 232 serving as a hub fixing means is fitted so as to directly contact the rotating shaft 231, and a mounting perpendicularity of the rotor case 232 to the rotating shaft 231 is directly set. As well as
The hub base 235 is made of a stamped metal plate, so that the hub base can be attached with good accuracy while obtaining an inexpensive and thin hub base.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic disk drive device in which a magnetic disk is mounted on a rotatably supported hub base and is driven to rotate.

[0002]

[Prior art]

 Generally, in a magnetic disk drive motor used for an FDD motor or the like, a hub base for mounting a magnetic disk (media) is arranged at the center of rotation of a rotor case. For example, in the structure in which the rotor set 3 is assembled in a laminated manner with respect to the stator set 2 assembled on the substrate 1 side of the motor as in the FDD motor shown in FIG. 10, the core winding 4 is The mounted stator 5 is tightened and fixed to the motor base plate 1 side by a fixing screw 6, and the bearing holder 7 is fixed by the fixing screw 6, whereby the stator set 2 is constituted. ing. A hub base 9 for mounting a magnetic disk is press-fitted on the tip end side of the one-way rotating shaft 8, and a bottomed cylindrical rotor case 10 is mounted on the outer periphery of the hub base 9. It is joined by caulking. A drive magnet 11 is mounted in an annular shape on the outer peripheral portion of the rotor case 10, whereby the rotor set 3 is constructed. The rotary shaft 8 of the rotor set 3 is inserted into the bearing holder 7 of the stator set 2.

At this time, the hub base 9 is finished with high precision by using a cutting body such as brass in order to prevent the rotational shake of the magnetic disk (media) and the like. A solid lubricant of fluorine, for example, is applied to the magnetic disk mounting surface by coating. This solid lubricant is intended to reduce the sliding friction resistance when positioning the magnetic disk mounted in the FDD unit and to improve the wear resistance.

[0004]

However, in the magnetic disk drive device of the conventional structure in which the rotor case 10 is mounted on the rotating shaft 8 with the intermediate member, that is, the hub base 9 interposed therebetween, the rotor case 10 is In addition to the problem that it is difficult to obtain the assembly accuracy, the material cost and processing cost of the hub base 9 itself are high, and a predetermined thickness is required in the axial direction, so the motor is flat and thin. There is a problem that it is difficult to convert.

Therefore, an object of the present invention is to provide a magnetic disk drive device which has a simple and inexpensive structure, can obtain good assembling accuracy, and can be made thin. .

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, a magnetic disk drive device according to a first aspect of the present invention is a magnetic disk drive device in which a hub mount for mounting a magnetic disk is arranged in a central portion of a hub fixing means supported so as to rotate integrally with a rotary shaft. In the disk drive device, a mounting hole that is inserted so as to come into direct contact with the rotating shaft is formed through the center of rotation of the hub fixing means, and the hub base is formed by pressing a metal plate. The hub fixing means is arranged so as to cover the mounting hole of the hub fixing means from one side in the axial direction.

A magnetic disk drive device according to a second aspect of the present invention is the magnetic disk drive device according to the first aspect, wherein the hub fixing means is a rotor case.

A magnetic disk drive device according to a third aspect of the present invention is the magnetic disk drive device according to the first aspect, wherein an annular holding portion that stands upright in the axial direction is provided at the opening edge portion of the mounting hole in the hub fixing means. Is provided.

Further, according to a fourth aspect of the present invention, in the magnetic disk drive device according to the third aspect, the inner peripheral wall of the hub base is in contact with the outer peripheral side of the annular holding portion of the hub fixing means. It has a configuration so that it is mounted.

On the other hand, a magnetic disk drive device according to a fifth aspect of the present invention is the magnetic disk drive device according to the first aspect, wherein at least the magnetic disk mounting surface of the hub base is coated with a wear-resistant solid lubricant. In addition, the outer periphery and the inner periphery of the hub base are pressed from the surface opposite to the surface on which the solid lubricant is adhered to the surface on which the solid lubricant is adhered.

A magnetic disk drive device according to a sixth aspect of the present invention is the magnetic disk drive device according to the first aspect, wherein the hub base is press-formed so that a step portion is provided between the inner diameter portion and the outer diameter portion. It has a configured configuration.

A magnetic disk drive device according to a seventh aspect is the magnetic disk drive device according to the sixth aspect, wherein the step portion is formed on the magnetic disk mounting surface of the hub base, and the step portion is interposed. The outer diameter of the hub base is set to be approximately the same height as or slightly higher than the inner diameter, and the magnetic disk mounting surface of the hub base is located on the rear end side of the mounting hole in the punching direction. It has a configuration arranged.

[0013]

[Action]

 According to the means having the constitution described in claims 1 and 2, since the mounting hole provided in the rotation center portion of the hub fixing means is fitted so as to directly contact the rotation shaft, the rotation shaft is attached to the rotation shaft. On the other hand, since the mounting perpendicularity of the hub fixing means is directly set and the hub base is made of pressed metal plate, an inexpensive and thin hub base can be obtained. It can be installed with good accuracy.

According to the means of the constitution described in claims 3 and 4, the action and effect of the means according to claims 1 and 2 are further improved.

Further, according to the means of the constitution described in claim 5, in addition to the action and effect of the means according to claims 1 and 2, the punching of the hub base damages the solid lubricant adhered surface. It has been successfully performed.

Further, according to the means of the constitution described in claim 6, in addition to the action and effect of the means according to claims 1 and 2, formation of a burr that hinders the adhesion of the magnetic disk can be achieved. It is designed to be avoided by the step.

On the other hand, according to the means of the constitution described in claim 7, in addition to the operation and effect of the means according to claim 6, the burr formed on the peripheral edge of the mounting hole is mounted on the hub base. The stepped portion escapes from the side of the magnetic disk to maintain good adhesion of the magnetic disk to the hub base.

[0018]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, as shown in FIG. 1, an FDD motor according to an embodiment of the present invention includes a stator set 22 mounted on a side of a motor board 21 and a stator set 22 mounted on the stator set 22 in a stacked manner from the upper side in the drawing. And a rotor set 23 that is formed. The core winding 222 is attached to the stator 221 that constitutes the stator set 22, and the stator 221 is fixed to the bearing holder by the fixing screw 223 that axially penetrates the portion of the stator 221 near the center. It is clamped and fixed to the motor base plate 21 side together with 224. Further, as shown in FIG. 2, a bearing 225 is mounted in the bearing holder 224.

Further, a rotating shaft 231 forming the rotor set 23 is rotatably inserted into the bearing 225 in the bearing holder 224 forming the stator set 22. The insertion tip portion (lower end portion in the drawing) of the rotating shaft 231 is supported by the thrust bearing 226, and the tip end portion (upper end portion in the drawing) of the rotating shaft 231 protruding from the bearing holder 224 has a cylindrical shape with a bottom. The rotor case 232 is attached so as to rotate integrally. At this time, an attachment hole 233 is provided at the center of rotation of the rotor case 232, and an annular flange-shaped holding portion 234 that stands in the axial direction is provided at the opening edge of the mounting hole 233 such as burring. The holder 234 is press-fitted onto the rotary shaft 231. That is, the rotor case 232 is coupled so as to directly contact the rotating shaft 231.

Further, the rotor case 232 is provided as a hub fixing means, and a hub base 235 for mounting a magnetic disk (media) is mounted on a surface (upper surface in the drawing) in a central portion of the rotor case 232. It is placed and fixed. The hub base 235 is formed by pressing a disk-shaped metal plate, and the inner wall surface of the mounting hole formed in the center of the hub base 235 has an annular holding shape in the rotor case 232. It is press-fitted and fixed while being in contact with the outer peripheral surface of the portion 233. At this time, the hub base 235 may be firmly fixed to the rotor case 232 side with an adhesive or the like. Further, a wear resistant solid lubricant 236 made of fluorine or the like is coated on the magnetic disk mounting surface (upper surface in the drawing) of the hub base 235. The solid lubricant 236 is coated so as to have a thickness of several microns to several tens of microns.

On the other hand, a drive magnet 234 is annularly mounted on the inner peripheral wall surface of the outer peripheral flange portion 232 a of the rotor case 232. The drive magnet 234 is arranged so as to face the stator 221 of the above-mentioned stator set 22 via a predetermined gap.

The above-described hub base 235 is formed by punching a large number of plate materials 235 ′ at the same time using a standard or strip-shaped plate material 235 ′ as shown in FIGS. 3 (a) and 3 (b), for example. . As the plate material 235 ', steel plate, brass, stainless plate, or the like is used. At the time of press-molding the hub base 235, pressing is performed in a half-blanked state as shown in FIG. 4A, and then the surface is coated with the solid lubricant 236 as shown in FIG. The die device 30 is set as shown in FIG. First, as shown in FIG. 6B, the upper punch 31 punches out a portion corresponding to the outer peripheral portion of the hub base 235, and then the hub base 235 is attached by the punching punch 32 as shown in FIG. 6C. The part corresponding to the hole is punched out. There is no particular problem even if the outer diameter punching and the inner diameter punching are separated by this pressing method. At this time, the outer periphery of the hub base 235 is pressed out from the surface opposite to the surface on which the solid lubricant 236 is adhered to the surface on which the solid lubricant 236 is adhered, and the inner periphery of the mounting hole of the hub base 235 is removed. Similarly, the solid lubricant 236 is pressed out from the surface opposite to the adhered surface of the solid lubricant 236 toward the adhered surface of the solid lubricant 236. As a result, as shown in FIG. 7, in the outer peripheral portion of the hub base 235, “drip” A is generated on the solid lubricant adhered surface (magnetic disk mounting surface) side and the solid lubricant adhered surface "Burr" B is generated on the surface opposite to. At the inner periphery of the mounting hole of the hub base 235, "burrs" B occur on the solid lubricant adhered surface (magnetic disk mounting surface) side, and the surface of the hub base 235 opposite to the solid lubricant adhered surface. "Who" A on the side. According to the press molding in such a direction, the solid lubricant 236 can be satisfactorily punched without causing damage such as chipping or peeling on the adhered surface.

As described above, in the apparatus of the above-described embodiment, the holding portion 234 of the mounting hole 233 provided at the center of rotation of the rotor case 232 directly contacts the rotating shaft 231 without the hub base 235. It is fitted. Therefore, the mounting perpendicularity of the rotor case 232 with respect to the rotating shaft 231 can be directly and easily obtained accurately. Further, since the hub base 235 is made of a pressed metal plate product, an inexpensive and thin hub base can be obtained, and even in that case, the hub base 235 can be attached with good accuracy.

Further, when press-forming the hub base 235, as shown in FIGS. 4B and 4C, a press in a half-pressed state is performed so that a step is formed between the inner diameter portion 235a and the outer diameter portion 235b. If the solid lubricant 236 is coated as shown in FIGS. 5 (b) and 5 (c) after molding, the hub base 235 formed by these is formed as shown in FIGS. 8 (c) and (d). In the case of mounting as described above, it is convenient to prevent the formation of burrs that hinder the adhesion of the magnetic disk. In particular, as shown in FIG. 4C, if the inner diameter portion 235b and the outer diameter portion 235a are in the half-blanked state in opposite directions, the thickness T ₁ of the hub base 235 with respect to the original thickness T of the plate material 235 'is adjusted appropriately. Therefore, the plate thickness of the hub base can be controlled arbitrarily and with high accuracy.

Each hub base 235 in FIGS. 8A, 8B, 8C, and 8D is directly fixed to the rotary shaft 231. Further, each rotor case 232 in FIGS. 8B and 8D is not provided with the holding portion (see reference numeral 234 in FIG. 1) as in the above-described embodiment. In particular, the magnetic disk mounting surface (the upper surface in the drawing) of each hub base 235 in FIGS. 8C and 8D is arranged at the rear end side of the mounting hole in the punching direction, and the inner diameter of the magnetic disk mounting surface is set. It is press-molded so as to have a step 235a between the portion and the outer diameter portion. Further, the outer diameter portion of the hub base 235 is set to be substantially the same height as or slightly higher than the inner diameter portion via the step portion 235a. According to the embodiment shown in FIGS. 8C and 8D, even if a burr is formed on the peripheral edge of the mounting hole, the stepped portion from the side of the magnetic disk mounted on the hub base 235 is formed. 235a allows it to escape, and the adhesion of the magnetic disk to the hub base 235 is maintained well.

In the embodiment shown in FIG. 9 in which the members corresponding to FIG. 1 are represented by the same reference numerals, the disk-shaped hub support plate 237 constituting the hub fixing means is opposite to the rotor case 232 in the axial direction. It is provided separately on the side. At the opening edge of the mounting hole 238 provided at the center of rotation of the hub support plate 237, an annular flange-shaped holding portion 239 which stands up in the axial direction is formed by processing such as burring. The part 239 is press-fitted to the rotary shaft 231. That is, the hub support plate 237 is coupled so as to directly contact the rotary shaft 231. A hub base 235 for mounting a magnetic disk (media) is mounted and fixed on the surface (upper surface in the drawing) of the hub support plate 237 in the central portion. Even in such an embodiment, the same operation and effect as those of the above-described embodiment can be obtained.

The invention made by the present inventor has been specifically described based on the embodiments, but the invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, the present invention can be similarly applied to various motors used in all kinds of units other than the FDD unit. Further, the present invention can be similarly applied to a motor having a fixed shaft.

[0028]

[Effect of device]

 As described above, in the magnetic disk drive device having the structure described in claim 1, claim 2, claim 3 and claim 4, the mounting hole provided in the center of rotation of the hub fixing means is attached to the rotary shaft. While fitting so as to make direct contact, the mounting right angle of the hub fixing means with respect to the rotating shaft is directly obtained, and the hub base is made of pressed metal plate to obtain an inexpensive and thin hub base. Since the hub base is configured so that it can be mounted with good accuracy, it is possible to obtain good assembly accuracy with a simple and inexpensive structure, and it is possible to easily reduce the thickness.

Further, in the magnetic disk drive device having the structure described in claim 5, in addition to the structure of the means described in claim 1, punching of the hub base is favorable without damaging the solid lubricant adhered surface. Therefore, the reliability of the magnetic disk drive device can be further improved in addition to the operation and effect of the means according to the first aspect.

Further, in the magnetic disk drive device having the structure described in claim 6, in addition to the structure of the means described in claim 1, a bar is formed to prevent the adhesion of the magnetic disk to the hub base. Since the step portion is formed so as not to exist, it is possible to further improve the reliability of the magnetic disk drive device in addition to the operation and effect of the step described in claim 1.

Further, in addition to the structure of the means according to claim 6, the magnetic disk drive device of the structure described in claim 7 is a magnetic disk of a hub base arranged at the rear end side of the mounting hole in the punching direction. On the mounting surface, a step is formed to allow the burr formed on the periphery of the mounting hole to escape from the magnetic disk side, and the outer diameter part of the hub base is approximately the same height as the inner diameter part through the step part. It is configured to maintain good adhesion of the magnetic disk to the hub base by setting it slightly higher or slightly higher, so that the action and effect of the means according to claim 6 are further improved. be able to.

[0032]

[Brief description of drawings]

FIG. 1 is a half cross-sectional explanatory view showing the structure of an FDD motor according to an embodiment of the present invention.

2 is a partially enlarged cross-sectional explanatory view showing a structure of a central portion of the FDD motor shown in FIG.

3A and 3B show a state in which a hub base is press-extracted, in which FIG. 3A is a plan view and FIG. 3B is a side cross-sectional view.

FIG. 4 is a side cross-sectional explanatory view showing various half-blanked states in press molding of a hub base.

5 is a side cross-sectional explanatory view showing a state immediately after coating of each hub base corresponding to FIG. 4. FIG.

FIG. 6 is a cross-sectional explanatory diagram showing a press molding process using a die device.

FIG. 7 is a cross-sectional explanatory view showing a hub base immediately after pressing.

FIG. 8 is a cross-sectional explanatory view showing the structure of another embodiment according to the present invention.

FIG. 9 is a semi-transverse sectional view showing the structure of an FDD motor according to another embodiment of the present invention.

FIG. 10 is a half cross-sectional explanatory view showing a structural example of a conventional FDD motor.

[Explanation of symbols]

 22 stator set 23 rotor set 231 rotary shaft 232 rotor case (hub fixing means) 233 mounting hole 234 holding portion 235 hub base 237 hub support plate (hub fixing means)

Claims (7)

[Scope of utility model registration request] 1. A magnetic disk drive device in which a hub base for mounting a magnetic disk is arranged in a central portion of a hub fixing means supported so as to rotate integrally with a rotary shaft, wherein a rotation center of the hub fixing means. In the portion, a mounting hole that is fitted and inserted so as to be in direct contact with the rotating shaft is formed so as to penetrate, and the hub base is formed by pressing a metal plate, and the mounting hole of the hub fixing means is formed in the axial direction. A magnetic disk drive device, which is arranged so as to cover from one side. 2. The magnetic disk drive device according to claim 1, wherein the hub fixing means is a rotor case. 3. The magnetic disk drive device according to claim 1, wherein an annular holding portion standing upright in the axial direction is provided at an opening edge portion of the mounting hole in the hub fixing means. Disk drive. 4. The magnetic disk drive device according to claim 3, wherein an inner peripheral wall of the hub base is mounted so as to contact the outer peripheral side of the annular holding portion of the hub fixing means. Magnetic disk drive. 5. The magnetic disk drive device according to claim 1, wherein at least the magnetic disk mounting surface of the hub base is coated with a wear-resistant solid lubricant, and the outer circumference and inner circumference of the hub base are Is pressed from the surface opposite to the surface on which the solid lubricant is adhered toward the surface on which the solid lubricant is adhered. 6. The magnetic disk drive according to claim 1, wherein the hub base is press-molded to have a step portion between the inner diameter portion and the outer diameter portion. apparatus. 7. The magnetic disk drive device according to claim 6, wherein the step portion is formed on the magnetic disk mounting surface of the hub base, and the outer diameter portion of the hub base is approximately the inner diameter portion through the step portion. A magnetic disk drive device which is set to have the same height or a little higher, and the magnetic disk mounting surface of the hub base is arranged at the rear end side of the mounting hole in the punching direction.