JP3723048B2 - Disk rotation drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disk rotation drive device, such as a hard disk rotation drive device, and more particularly to a disk rotation drive device in which a hub on which a disk is placed is formed by pressing a metal plate material.
[0002]
[Prior art]
For example, in a conventional general disk rotation driving device that rotates a hard disk, a hub on which the disk is mounted and rotates together with the disk is formed by cutting. Although there is an advantage that it is relatively easy to obtain a predetermined machining accuracy, cutting requires a long time for machining, and it is necessary to introduce many production facilities for mass production. There is a limit in terms of cost reduction. In addition, since the production quantity depends on the scale of the production equipment, it is difficult to deal with a sudden change in production quantity, particularly a sudden increase in production, and it is difficult to miss a business opportunity.
[0003]
In order to solve these problems, it has been proposed to form a hub on which a disk is placed and rotated by pressing a metal plate material. An example described in Japanese Patent Laid-Open No. 6-14510 is an example, which will be described with reference to FIG.
In FIG. 9, a lower end portion of a cylindrical bearing holder 62 is fitted to the frame 60 of the motor and is fixed by an appropriate means, and the bearing holder 62 rises at a right angle from the frame 60. An inner peripheral hole of the stator core 64 is fitted to the outer periphery of the bearing holder 62 and is fixed by an appropriate means. The stator core 64 has an appropriate number of salient poles, and a drive coil 66 is wound around each salient pole.
[0004]
Bearings 82 and 82 are fitted on the inner peripheral upper and lower ends of the bearing holder 62, and the shaft 74 of the hub 70 is fitted in the central shaft hole of the bearings 82 and 82. The hub 70 also serves as the rotor case 70 and is formed by pressing a metal plate together with the shaft 74. More specifically, in the hub 70, a cylindrical shaft 74 is formed by integral molding by drawing at the center of a metal plate material, and a flat portion 72 is continuously formed at one end of the shaft 74. A cylindrical peripheral wall 78 is formed integrally with the outer periphery of the portion 72, and a bowl-shaped disc is mounted at an axially intermediate portion of the peripheral wall 78 by bending and folding the peripheral wall outward. The part 76 is integrally formed. The hub 70 having the above-described shape is formed by press-molding a metal plate material several times.
[0005]
A ring-shaped rotor magnet 80 is fixed to the inner peripheral surface of the peripheral wall 78 of the hub 70. The rotor magnet 80 is appropriately magnetized to the number of poles in the circumferential direction. The inner peripheral surface of the rotor magnet 80 faces the outer peripheral surface of each salient pole of the stator core 64 with a predetermined gap. The bearings 82 and 82 are radial bearings, and support the shaft 74 rotatably. Therefore, by controlling the energization to each drive coil 66 according to the rotational position of the rotor magnet 80, the rotor magnet 80 and the hub 70 integrated therewith are mounted on the disk mounting portion 76 by the electromagnetic attractive repulsive force. It can be rotated with a disk (not shown) placed and fixed.
[0006]
Thus, it is already known to form a disk mounting hub by pressing a metal plate. After the disk is placed on the hub, it must be clamped to substantially integrate the disk with the hub. In the conventional example shown in FIG. 9, a female screw 75 is formed at the upper end of the inner periphery of the shaft 74, a disc is placed on the disc placing portion 76, a spring member is placed thereon, and a screw is placed in the center hole. Then, the screw is screwed into the female screw 75 to press the disc against the disc mounting portion 76 by the elastic force of the spring member.
[0007]
However, fixing the spring member with only one screw is unstable because the reaction force concentrates on one screw, and there is a problem that the screw and the spring member are enlarged.
Therefore, it is considered to fix the spring member to the hub using a plurality of screws. That is, the spring member is a ring-shaped member made of an elastic material, and a plurality of holes are formed at equal intervals in the circumferential direction, and a screw is inserted into each hole and screwed into the hub 70. .
[0008]
[Problems to be solved by the invention]
When the hub is formed by pressing a metal plate material as in the conventional example, the thickness of the entire hub is substantially uniform. And since the thickness must be press-workable, there is a limit to the thickness of the entire hub, and it is not possible to increase part of the thickness as needed, as in the case of cutting. . For this reason, the length of the female screw portion tends to be insufficient, and sufficient clamping strength may not be obtained.
[0009]
Further, if the female screw is cut in the entire plate thickness of the hub 70, the clamping strength will not be insufficient, but the screw tip is exposed inside the hub 70, so that the fineness generated at the time of screwing in will be eliminated. There is a risk that the dust will scatter around and adhere to the surface of the disk. Therefore, after screwing in the screw, it is indispensable to seal the tip of the screw. However, the work process of sealing increases and becomes complicated, and it is difficult to seal completely. From the viewpoint of preventing contamination, there is a difficulty in inferior in reliability.
[0010]
The present invention has been made to solve the above-described problems of the prior art, and is a disk rotation drive device in which a hub is formed by pressing a metal plate material, and has a sufficient disk clamp strength. It is an object of the present invention to provide a disk rotation drive device that can be obtained and can reliably seal dust even when dust is generated by clamping the disk.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is a disk mounting hub, a disk pressing spring member fixed to the hub, and a fixing for fixing the spring member to the hub. A disk rotary drive device having a member and a radial bearing that rotatably supports the hub, wherein the hub is formed by pressing a metal plate material, and the fixing member is constituted by a screw, A ring member that covers the tip of the screw is provided on the opposite side of the hub to the screwed side of the screw.
[0012]
As in the second aspect of the present invention, in the first aspect of the present invention, the radial bearing is disposed on the side where the ring member is provided and rotatably supports a rotating shaft integral with the hub. Lubricating oil is interposed between the shaft and the radial bearing, and an oil retaining groove capable of retaining the leaked lubricating oil by a capillary force is preferably formed between the ring member and the hub.
[0013]
As in the invention of claim 3, in the invention of claim 2, the radial bearing is a sintered oil-impregnated bearing, and a bearing holding portion for holding the radial bearing is provided, and the radial bearing is provided in the bearing holding portion. An oil seal portion is provided between the hub and the hub away from the radial bearing, a ring member is provided on the outer peripheral side of the bearing holding portion, and the ring member is arranged to overlap the oil seal portion in the radial direction. It is good to be.
[0014]
As in the invention of claim 4, in the invention of claim 2, the radial bearing is a fluid bearing, an oil seal portion is provided on the hub side of the radial bearing, and a ring member is provided on the outer peripheral side of the oil seal portion. And the ring member may be disposed so as to overlap the oil seal portion in the radial direction.
[0015]
According to a fifth aspect of the present invention, there is provided a disk having a disk mounting hub having a shaft holding portion formed thereon, a disk pressing spring member fixed to the hub, and a radial bearing that rotatably supports the hub. In the rotary drive device, the hub is formed by pressing a metal plate, and the hub is provided with a ring member that contacts the hub on the opposite side of the spring member. A spring fixing portion protruding to the member side is provided, and the spring member is fixed by the spring fixing portion.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a disk rotation driving device according to the present invention will be described below with reference to the drawings.
In FIG. 1, a hole is formed in a substantially central portion of the motor substrate 2, and a lower end portion of a substantially cylindrical bearing holder 6 is fitted into the hole, and is fixed by an appropriate means such as welding. The holder 6 stands up from the substrate 2 at a right angle. A center hole of the stator core 8 is fitted on the outer peripheral side of the bearing holder 6, and the stator core 8 is fixed to the bearing holder 6 by adhesion, welding, or other appropriate means. The stator core 8 is a laminated core in which a plurality of core bodies are stacked. The stator core 8 has an appropriate number of salient poles radially, and a driving coil 10 is wound around each salient pole. There is a slight space between the drive coil 10 and the substrate 2, and an insulating sheet or a flexible circuit board for connecting the terminal of each drive coil 10 to an external circuit is interposed in this space.
[0017]
A cap 12 is fitted and fixed to the inner peripheral lower end of the bearing holder 6, and the lower end of the bearing holder 6 has a sealed structure. The cap 12 has a circular recess concentrically, and a thrust receiver 14 is fitted in the recess. A radial bearing 5 made of a cylindrical sintered oil-impregnated bearing is fitted on the inner peripheral side of the bearing holder 6, and a shaft 16 is fitted in the central shaft hole of the radial bearing 5. The radial bearing 5 supports the shaft 16 in a freely rotatable manner. Between the shaft 16 and the radial bearing 5, the lubricating oil impregnated in the radial bearing oozes out. As described above, the bearing holder 6 constitutes a bearing holding portion that holds the radial bearing 5.
Further, the thrust load applied to the shaft 16 is supported by the thrust receiver 14 when the lower end of the shaft 16 contacts the thrust receiver 14.
A circumferential groove 19 is formed at the lower end of the shaft 16. Near the lower end of the inner periphery of the bearing holder 6, a stop ring 17 is fixed at the lower part of the radial bearing 5, and the inner peripheral edge of the stop ring 17 enters the peripheral groove 19 in a non-contact state to prevent the shaft 16 from coming off. I am doing.
[0018]
The upper end surface of the radial bearing 5 is lower than the upper end surface of the bearing holder 6, and a seal member 45 is fixed to the upper end surface of the bearing holder 6. The seal member 45 extends near the outer peripheral surface of the shaft 16 on the inner peripheral side of the bearing holder 6, and a certain amount of gap is formed between the lower end surface of the seal member 45 and the upper end surface of the radial bearing 5. The bearing holder 6 constitutes a bearing holding part. The seal member 45 is provided between the radial bearing 5 and the hub 22 so as to be separated from the radial bearing 5, thereby constituting the oil seal portion 100.
Further, the upper end surface of the bearing holder 6 is provided so as to be located inside a ring member 32 which will be described in detail later, so that oil leaking outside from the seal member 45 adheres to the lower surface of the hub 22. It has become.
[0019]
On the outer periphery of the upper end portion of the shaft 16 protruding above the seal member 45, a hub 22 having a flat cup shape is fixed by press-fitting. A cylindrical shaft holding portion 41 is formed at the center of the hub 22 by burring, and the upper end portion of the shaft 16 is press-fitted into the shaft holding portion 41 as described above, whereby the shaft 16 and the hub 22 are connected. They are joined together. A step portion 22A is formed in the upper portion of the hub 22, and a placement portion 28 for the disk 40 is formed on the outer peripheral side of the step portion 22A. A lower portion on the outer peripheral side of the placement portion 28 is a cylindrical peripheral wall 24. Yes. A rotor magnet 30 is fixed to the inner surface of the peripheral wall. The inner peripheral surface of the rotor magnet 30 and the outer peripheral surface of each salient pole of the stator core 8 face each other with an appropriate gap. When the energization of each drive coil 10 is controlled according to the rotational position of the rotor magnet 30, the rotor composed of the rotor magnet 30, the hub 22, and the shaft 16 can be rotationally driven together with the disk 40 by the electromagnetic attractive repulsive force. .
[0020]
A ring member 32 is arranged on the inner side (ceiling part) of the hub 22 on the inner peripheral side of the hub 22 with respect to the disk mounting portion 28, that is, on the inner peripheral side of the stepped portion 22A. As shown in FIG. 2, the ring member 32 has a U-shaped groove 33 along a concentric circle on the upper surface side. A disk 40 is mounted on the disk mounting portion 28 of the hub 22, and a circular spring member 36 made of a spring material is mounted thereon. The spring member 36 overlaps the hub 22, and the screw 37 inserted into an appropriate number of holes formed in the spring member 36 is inserted into the screw hole formed in the hub 22 at a position overlapping the hole. Is screwed. The spring member 36 is for holding the disk 40. When the screw 37 is screwed in as described above, the spring member 36 presses the disk 40 with its elasticity, and the disk 40 is fixed onto the disk mounting portion 28 substantially integrally. Has been. The screw 37 constitutes a fixing member for fixing the spring member 36.
[0021]
The tip of the screw 37 penetrates the hub 22 and protrudes downward from the ceiling of the hub 22, but the groove 33 of the ring member 32 is located at a position overlapping the screw 37, and the tip of the screw 37 is in this groove 33. Is entering without contact. Therefore, even if fine powder is generated by screwing the screw 37 into the screw hole of the hub 22, the fine powder is confined in the groove 33 and does not scatter around.
[0022]
An oil drain groove 18 is formed in the shaft 16 in the circumferential direction of the shaft 16. In the example shown in FIG. 1, the lower end of the oil draining groove 18 is substantially at the same height as the upper end surface of the seal member 45, and the entire oil draining groove 18 is formed on the outer side in the axial direction than the seal member 20. The seal member prevents the lubricating oil impregnated in the radial bearing 5 from splashing to the outside. However, the lubricating oil may still travel to the outside through the surface of the shaft 16, so this The lubricating oil is captured by the oil drain groove 18 and is prevented from scattering to the outside.
[0023]
Nevertheless, since it is conceivable that the lubricating oil is scattered outside through the ceiling surface of the hub 22 due to the centrifugal force generated by the rotation of the rotor, the ring member 32 is disposed on the outer peripheral side of the bearing holder 6 and the ring member. A minute oil retaining groove 35 is formed between the inner peripheral side of the hub 22 and the ceiling surface of the hub 22, and the lubricating oil to be scattered is captured by the oil retaining groove 35. The ring member 32 is also disposed so as to overlap the oil seal portion 100 in the radial direction. Since the oil retaining groove 35 is a minute space, the lubricating oil captured at one end is retained in the oil retaining groove 35 by the capillary force and does not leak outside. Further, the lubricating oil thinned in the oil retaining groove 35 is prevented from leaking toward the trap because of the centrifugal force generated by the ring member 32 rotating together with the hub 22.
[0024]
According to the embodiment shown in FIG. 1 described above, the hub 22 formed by pressing a metal plate material is penetrated in the thickness direction, and the screw 37 as a fixing member of the spring member is screwed. Therefore, the spring member 36 can be fixed to the hub 22 with sufficient fixing strength, and the ring member 32 that covers the tip of the screw 37 protruding from the hub 22 is provided. Dust can be sealed between the ring member 32 and the hub 22, and contamination of the disk and other peripheral parts by dust can be prevented.
Further, since the oil retaining groove 35 is formed between the ring member 32 and the hub 22 on the inner peripheral side, the radial bearing 5 is a sintered oil-impregnated bearing, and the lubricating oil impregnated therein is supposed to be scattered outside. Even so, the lubricating oil is captured by the oil retaining groove 35, and contamination of the disk and other peripheral portions by the lubricating oil can be prevented.
[0025]
Instead of the groove 33 formed in the ring member 32, as shown in FIG. 3, a bag-like hole 39 is formed at a position overlapping with each screw 37, and minute dust generated when the screw 37 is screwed into the hub 22 is removed. You may make it confine | sealing in the said hole 39. FIG.
[0026]
Next, another embodiment shown in FIG. 4 will be described. In addition, the same code | symbol is attached | subjected to the same component as the component of embodiment shown in FIG. 1, and description is simplified about the same component.
In FIG. 4, the lower half of the substantially cylindrical bearing holder 6 is fixed by press-fitting to the inner peripheral side of a cylindrical portion 4 formed by burring at a substantially central portion of the motor substrate 2. A stator core 8 is fitted on the outer peripheral side of the bearing holder 6 and fixed by appropriate means. The stator core 8 has an appropriate number of salient poles radially, and a drive coil 10 is wound around each salient pole.
[0027]
A cap 12 is fitted into the lower end on the inner peripheral side of the bearing holder 6. A thrust receiver 14 is fitted into the cap 12. A radial bearing 5 made of a sintered oil-impregnated bearing is fitted on the inner peripheral side of the bearing holder 6. A shaft 16 is fitted in the central shaft hole of the radial bearing 5, and the radial bearing 5 supports the shaft 16 in a freely rotatable manner. The thrust load applied to the shaft 16 is supported by the thrust receiver 14. The radial bearing 6 is impregnated with lubricating oil, and this lubricating oil is interposed between the shaft 16 and the radial bearing 5.
[0028]
The upper end surface of the radial bearing 5 is lower than the upper end surface of the bearing holder 6, and the taper seal member 20 is disposed at a step portion between the upper end surface of the bearing holder 6 and the upper end surface of the radial bearing 5. The outer peripheral surface of the taper seal member 20 is press-fitted into the inner peripheral surface of the bearing holder 6 and fixed. A certain amount of gap is formed between the lower end surface of the taper seal member 20 and the upper end surface of the radial bearing 5. This point will be described later in detail.
[0029]
A cylindrical shaft holding portion 41 formed by burring at the center of the hub 22 is press-fitted into the outer periphery of the upper end portion of the shaft 16 projecting upward from the taper seal member 20 so that the shaft 16 and the hub 22 are integrated. Are combined. The upper portion of the hub 22 is formed in a step shape to serve as a mounting portion 28 for the disk 40, and the lower portion on the outer peripheral side of the mounting portion 28 is a cylindrical peripheral wall 24. A rotor magnet 30 is fixed to the inner surface of the peripheral wall. A flange portion 26 is formed by bending outward from the lower end of the peripheral wall 24, and a stopper 27 formed by cutting and raising a part of the substrate 2 is positioned immediately above the flange portion 26. The rotor including the hub 22 and the rotor magnet 30 is prevented from coming out of the bearing 5.
[0030]
A ring member 32 is arranged on the inner side (ceiling part) of the hub 22 on the inner peripheral side of the hub 22 with respect to the disk mounting part 28. The ring member 32 has an appropriate number of upward protrusions 34, and each protrusion 34 passes through a hole formed in the hub 22, and also passes through a hole of a spring member 36 superimposed on the hub 22. . The head of each protrusion 34 has a large diameter. As shown in FIG. 5A, the hole 53 of the spring member 36 has a diameter slightly larger than the diameter of the head of the protrusion 34 of the hub 22 shown in FIG. Following the portion, the diameter is smaller than the diameter of the head of the protrusion 34 and is slightly larger than the diameter of the protrusion 34 other than the head, and the diameter is larger and smaller. A hole 53 is formed along a circle concentric with the rotation center of the rotor.
[0031]
When attaching the spring member 36, the disk 40 is placed on the disk mounting portion 28, and then the spring member 36 is pushed down against its elasticity, while the hole 53 of the spring member 36 has a large diameter. The head of the projection 34 is fitted to the upper surface of the spring member 36 and the spring member 36 is rotated relative to the hub 22 around the rotation center of the rotor. By this relative rotation, the protrusion 34 faces the small-diameter portion of the hole 53 of the spring member 36, and the hub 22 and the spring member 36 are attracted by the jaw portion of the protrusion 34 and the main body of the ring member 32. 34 is adapted to latch the spring member 36 on the hub 22. The spring member 36 is formed in a ring shape by an elastic material, and its outer peripheral edge presses the disc 40 placed on the placement portion 28 on the hub 22 with an elastic force, so that the disc 40 is substantially integrated with the hub 22. . In FIG. 5, reference numerals 59 and 29 are necessary when the spring member 36 is mounted, and indicate holes into which pins of jigs used at that time are fitted. Thus, the projection 34 constitutes a spring fixing portion that fixes the spring member 36 to the hub 22.
[0032]
A minute space 35 is formed between the ring member 32 and the ceiling surface 22. As will be described later in detail, the space 35 has a role of capturing the lubricating oil to be scattered.
[0033]
As shown in FIG. 6, a male screw 47 may be cut on the outer periphery of the protrusion 34, and a nut 49 may be screwed into the male screw 47 from above the spring member 36 to attach the spring member 36.
Further, as shown in FIG. 7, a bag-like screw hole 31 is formed in the ring member 32, and a screw 37 penetrating the hole of the spring member 36 and the hub 22 is screwed into the bag-like screw hole 31 and the spring member 36. May be attached. In this case, the hole of the hub 22 may be a screw hole, and the screw 37 may be screwed into the screw hole and the screw hole 31 of the ring member 32.
6 and 7, the same operational effects as the embodiment shown in FIG. 4 can be obtained.
[0034]
An appropriate gap is formed between the lower surface of the taper seal member 20 and the upper end surface of the sintered oil-impregnated bearing 5. This gap is provided to prevent the lubricating oil impregnated in the sintered oil-impregnated bearing 5 from scattering to the outside. As a guideline for the gap, it is preferable to set the capillary force generated by the porous bearing of the radial oil-impregnated bearing 5 to be larger than the capillary force generated in the gap. By doing so, the suction force of the lubricating oil by the porous of the radial bearing 5 is larger than the capillary force by the gap, and the lubricating oil is less likely to intervene in the gap, thereby effectively preventing the scattering of the lubricating oil. Can do.
[0035]
The inner peripheral side of the taper seal member 20, that is, the surface facing the outer peripheral surface of the shaft 16, has an inclined portion 21 formed of a tapered surface whose inner diameter gradually increases outward from the radial bearing 5 side. There is also a gap between the lowermost end portion of the inclined portion 21, that is, the portion closest to the outer peripheral surface of the shaft 16, and the outer peripheral surface of the shaft 16. Lubricating oil is interposed in the gap by the surface tension.
[0036]
An oil drain groove 18 is formed in the shaft 16 in the circumferential direction of the shaft 16. In the illustrated example, the lower end of the oil drain groove 18 is substantially at the same height as the upper end surface of the taper seal member 20, and the entire oil drain groove 18 is formed on the outer side in the axial direction than the taper seal member 20. As described above, the structure prevents the lubricant from splashing to the outside due to the surface tension of the lubricant interposed in the gap between the shaft 16 and the taper seal member 20. Since the lubricating oil may advance to the outside, the lubricating oil is captured by the oil drain groove 18 and is prevented from being scattered outside.
[0037]
Nevertheless, since it is conceivable that the lubricating oil is scattered outside along the ceiling surface of the hub 22 due to the centrifugal force due to the rotation of the rotor, the ceiling surface of the hub 22 on the inner peripheral side of the ring member 32 as described above. A minute space 35 is formed between them and the lubricating oil to be scattered is captured in this space 35.
[0038]
In the present invention, for example, a minute gap is formed between the rotating shaft and a sleeve disposed on the outer periphery thereof, and at least one of the outer peripheral surface of the rotating shaft and the inner peripheral surface of the sleeve is a herringbone-like dynamic pressure. The present invention can also be applied to one having a fluid dynamic pressure bearing in which a generating groove is formed and lubricating oil is interposed between the outer peripheral surface of the rotating shaft and the inner peripheral surface of the sleeve. FIG. 8 shows an example.
[0039]
In FIG. 8, a substantially cylindrical bearing holder 6 is integrally formed at a substantially central portion of the motor substrate 2, and the bearing holder 6 rises at a right angle from the substrate 2 body. A center hole of the stator core 8 is fitted on the outer peripheral side of the bearing holder 6, and the stator core 8 is fixed to the bearing holder 6 by an appropriate means. The stator core 8 has an appropriate number of salient poles radially, and a drive coil 10 is wound around each salient pole. A sleeve 5 is fitted and fixed on the inner peripheral side of the bearing holder 6, and a rotating shaft 16 is inserted on the inner peripheral side of the sleeve 5. A dynamic pressure generating groove is formed on at least one of the inner peripheral surface of the sleeve 5 and the outer peripheral surface of the rotating shaft 16, and for generating dynamic pressure between the inner peripheral surface of the sleeve 5 and the outer peripheral surface of the rotating shaft 16. Of lubricating oil is present. When the rotating shaft 16 rotates with respect to the sleeve 5, dynamic pressure is generated in the lubricating oil by the dynamic pressure generating groove, and the rotation of the rotating shaft 16 is supported by the sleeve 5 in a non-contact manner. Therefore, a radial bearing 135 made of a fluid bearing is formed between the sleeve 5 and the rotary shaft 16.
[0040]
A ring-shaped thrust plate 138 is fixed to the outer periphery of the lower end portion of the rotating shaft 16. A counter plate 139 is fixed to the lower end portion of the sleeve 5. There are appropriate gaps between the upper surface of the counter plate 139 and the lower surface of the thrust plate 138, and between the upper surface of the thrust plate 138 and the stepped surface of the sleeve 5 opposite to the upper surface of the thrust plate 138. A dynamic pressure groove is formed on at least one surface constituting these gaps, and a thrust fluid dynamic pressure bearing is formed.
[0041]
A shaft holding portion 41 formed at the center of the hub 22 is fitted to the outer periphery of the upper end portion of the rotating shaft 16 protruding from the upper end of the sleeve 5, and the rotating shaft 16 and the hub 22 are coupled. A drive magnet 30 is fixed to the inner surface of the peripheral wall of the hub 22. The inner peripheral surface of the drive magnet 30 and the outer peripheral surface of the stator core 8 face each other with a gap therebetween, and the hub 22 is rotationally driven by controlling energization to the drive coil 10. The lower end portion of the peripheral wall of the hub 22 is an outward flange, and the upper surface of the collar is a disk mounting surface 140.
[0042]
A plurality of disks and spacers are alternately inserted using the outer peripheral surface of the peripheral wall of the hub 22 as a guide, and placed on the disk mounting surface 140. A spring member is placed thereon, and the above-described screw is screwed into a screw hole 137 formed in the hub 22 so that the disk is integrally attached to the hub 22 by the pressing force of the spring member. The tip of the screw protrudes downward from the ceiling of the hub through the hub 22. Therefore, the ring member 32 having the groove 33 similar to the above-described embodiment is fixed to the ceiling surface of the hub 22 and the tip of the screw is surrounded by the groove 33, so that the screw is screwed into the screw hole 137. The derivative is confined in the groove 33. Instead of the groove 33, a bag-like hole 39 as shown in FIG. 3 may be formed.
[0043]
The inner peripheral surface of the upper end of the sleeve 5 is a tapered surface 121 having a diameter that gradually increases outward (upward). A gap having a wedge-shaped cross section is formed between the tapered surface 121 and the outer peripheral surface of the rotating shaft 16 facing the tapered surface 121, and this gap can hold the lubricating oil of the fluid bearing by capillary force. It is a seal part. In other words, the oil seal portion is provided on the hub 22 side of the radial dynamic pressure bearing including the sleeve 5 and the rotating shaft 16. An oil drain groove 18 is formed on the rotary shaft 16 in the circumferential direction of the rotary shaft 16 above the oil retaining groove. Furthermore, the ring member 32 is provided on the outer peripheral side of the oil seal portion, and the ring member 32 is disposed at a position overlapping the oil seal portion in the radial direction. The upper surface near the inner periphery of the ring member 32 is cut into a step shape, and an oil retaining groove 35 is formed between the ceiling surface of the hub 22 and the inner periphery side of the ring member 32.
[0044]
The embodiment described above with reference to FIG. 8 can provide the same effects as those of the above-described embodiment.
The present invention can be applied to a disk rotation drive device using a ball bearing in addition to a sintered oil-impregnated bearing and a fluid bearing.
[0045]
The bearing holder 6 may be a bag-shaped bearing holder whose lower end is sealed, or may be a cylindrical bearing holder whose both ends are open.
[0046]
The bearing device according to the present invention can be applied to a spindle motor for a hard disk drive, and can be applied to various other motors or rotating equipment.
[0047]
【The invention's effect】
According to the first aspect of the present invention, a screw as a fixing member of the spring member is screwed into a hub formed by pressing a metal plate material, and the tip of the screw protruding from the hub Since the ring member that covers is provided, the spring member can be fixed to the hub with sufficient fixing strength, and minute dust generated by screwing the screw can be sealed between the ring member and the hub, Contamination of the disk and other peripheral parts due to dust can be prevented.
[0048]
According to the second aspect of the present invention, in the first aspect of the present invention, the oil retaining groove that can retain the leaked lubricating oil by the capillary force is formed between the ring member and the hub. Even if the lubricating oil tries to scatter to the outside, the lubricating oil is captured by the oil retaining groove, and contamination of the disk and other peripheral portions by the lubricating oil can be prevented.
[0049]
According to a third aspect of the present invention, in the second aspect of the present invention, a bearing holding portion for holding the radial bearing is provided, and the bearing holding portion is spaced from the radial bearing between the radial bearing and the hub. A radial bearing comprising a sintered oil-impregnated bearing is provided with an oil seal portion, a ring member is provided on the outer peripheral side of the bearing holding portion, and the ring member is arranged so as to overlap the oil seal portion in the radial direction. Even if the lubricating oil leaks from the oil, it is blocked by the oil seal portion and further blocked by the ring member, so that it is possible to effectively prevent the lubricating oil from scattering to the outside.
[0050]
According to the invention of claim 4, in the case where the radial bearing is constituted by a fluid bearing, the oil seal portion is provided on the hub side of the radial bearing, and the ring member is provided on the outer peripheral side of the oil seal portion. Since the oil seal portion is arranged so as to overlap with the radial direction, even if the lubricating oil leaks from the fluid bearing, it is blocked by the oil seal portion and further blocked by the ring member. The effect of can be obtained.
[0051]
According to the fifth aspect of the present invention, a disk mounting hub having a shaft holding portion formed thereon, a disk pressing spring member fixed to the hub, and a radial bearing for rotatably supporting the hub. The hub is formed by pressing a metal plate material, and the hub is provided with a ring member that contacts the hub on the side opposite to the spring member. Since the spring fixing portion protruding to the member side is provided and the spring member is fixed by the spring fixing portion, the spring member can be fixed to the hub with sufficient fixing strength as in the first aspect of the invention. It is possible to seal the minute dust generated by screwing in between the ring member and the hub, and prevent contamination of the disk and other peripheral parts by dust. It can be.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a disk rotation driving device according to the present invention.
FIG. 2 is a perspective view showing a ring member in the embodiment.
FIG. 3 is a perspective view showing another example of a ring member that can be used in the embodiment.
FIG. 4 is a sectional view showing another embodiment of the disk rotation driving device according to the present invention.
5A is a plan view of a spring member, and FIG. 5B is a plan view of a hub in the other embodiment.
FIG. 6 is a cross-sectional view showing a modification of the fixing member for fixing the spring member to the hub, which can be applied to the present invention.
FIG. 7 is a cross-sectional view showing still another modified example of the fixing member.
FIG. 8 is a sectional view showing still another embodiment of the disk rotation driving device according to the present invention.
FIG. 9 is a cross-sectional view showing an example of a conventional disk rotation driving device.
[Explanation of symbols]
5 Radial bearing
16 axes
18 Oil drain groove
20 Taper seal member
22 Hub
32 Ring member
34 Projection as a spring fixing part
36 Spring member
37 Screws as fixing members
100 Oil seal
105 Oil retaining groove

Claims (5)

A disk having a disk mounting hub, a disk pressing spring member fixed to the hub, a fixing member for fixing the spring member to the hub, and a radial bearing for rotatably supporting the hub A rotary drive device,
The hub is formed by pressing a metal plate material, and the fixing member is formed of a screw.
2. A disk rotation driving device according to claim 1, wherein a ring member that covers the tip of the screw is provided on the opposite side of the hub to the screwing side of the screw. The radial bearing is arranged on the side where the ring member is provided and rotatably supports a rotating shaft integral with the hub.
Lubricating oil is interposed between the rotating shaft and the radial bearing,
2. The disk rotation driving device according to claim 1, wherein an oil retaining groove capable of retaining the leaked lubricating oil by a capillary force is formed between the ring member and the hub. The radial bearing is a sintered oil impregnated bearing, provided with a bearing holding portion for holding the radial bearing,
The bearing holding portion is provided with an oil seal portion spaced from the radial bearing between the radial bearing and the hub,
3. The disk rotation drive device according to claim 2, wherein the ring member is provided on the outer peripheral side of the bearing holding portion, and the ring member is disposed so as to overlap the oil seal portion in the radial direction. The radial bearing is a fluid bearing,
An oil seal is provided on the hub side of the radial bearing,
3. The disk rotation driving device according to claim 2, wherein the ring member is provided on the outer peripheral side of the oil seal portion, and the ring member is disposed so as to overlap the oil seal portion in the radial direction. A disk rotation driving device having a disk mounting hub formed with a shaft holding portion, a disk pressing spring member fixed to the hub, and a radial bearing that rotatably supports the hub,
The hub is formed by pressing a metal plate, and the hub is provided with a ring member that contacts the hub on the opposite side of the spring member.
The disk rotation drive device according to claim 1, wherein the ring member is provided with a spring fixing portion protruding toward the spring member, and the spring member is fixed by the spring fixing portion.

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