JPH05153756A - Spindle motor - Google Patents

Abstract

PURPOSE:To obtain a spindle motor wherein high reliability and improved productivity can be contrived by constituting a spindle motor such that a hub member is fixedly bonded to a shaft member by injecting a bonding agent into a hole part communicating with a groove part provided on the peripheral surface of the shaft member. CONSTITUTION:In the case of a spindle motor for driving a recording disk, an armature 6 is fixedly fitted to the external peripheral part and a pair of ball bearings 7, 8 are fixedly fitted to the internal peripheral part of a cylinder part 5, to relatively rotate a hub member 1 relating to a bracket 4 when the armature 6 and a rotor magnet 9 are relatively rotated and driven. In the case of fixedly bonding the hub member 1 to a shaft member 2, after fitting it to an internal peripheral surface 16 of the hub member 1, a bonding agent is injected into an introducing part 17 of a hole part 13 by using a dispenser. Then, the injected bonding agent passes through the hole part 13, reaches a straightening part 3, flows in a groove part 14 and seeps over to gradually flow on its full periphery, and the bonding agent is hardened after a required hardening time by staying in the groove part 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor mounted on an optical / magnetic disk drive, for example, for rotating a recording disk.

[0002]

2. Description of the Related Art FIGS. 6 and 7 show sectional views of a spindle motor for rotationally driving a recording disk (for example, a magnetic disk). In FIG. 6, a hub member a, on which a recording disk (not shown) is mounted, is formed integrally with a shaft member b and is rotatably supported by ball bearings d and e interposed between a stationary member and a bracket c. Supported. The hub member a is relatively rotationally driven coaxially with the bracket c. In the spindle motor shown in FIG. 6, the shaft member b integrally fixed to the hub member a rotates.
It has a so-called shaft rotation type spindle motor configuration.

Further, in FIG. 7, a shaft member j is erected on the shaft core portion of a bracket k which is a stationary member, and through ball bearings q and p mounted on both ends of the shaft member j. ,
The hub member h is rotatably supported. Then, similarly to FIG. 6, the hub member h is rotationally driven relative to the bracket k coaxially. The spindle motor in FIG. 7 has a so-called fixed shaft type spindle motor in which a shaft member j is integrally fixed to a bracket k.

By the way, in the spindle motor of FIG. 6, the assembling order is as follows.
Fix e beforehand. Then, the shaft member b to which the hub member a is fixed is inserted into the ball bearings d and e to be assembled.
In this case, the hub member a is fixed to the shaft member b by adhesion.

On the other hand, in the assembling order of the spindle motor of FIG. 7, the hub member h is fixed to both ends of the shaft member j via the ball bearings q and p so as to be rotatably supported. Next, the shaft member j
Assemble by inserting the lower end of the bracket into the bracket k. In this case, the shaft member i and the bracket k are fixed by adhesion.

[0006]

However, in the case of such adhesive fixing, for example, in order to bond the hub member a and the shaft member b in FIG. 6, an adhesive is previously applied to the hole inner peripheral surface g of the hub member a. After coating, the shaft member b is inserted in that state.
At this time, the gap at the matching portion between the outer peripheral surface f and the inner peripheral surface g of the shaft member b is a slight gap according to the fitting dimension. For this reason, the adhesive exceeding the predetermined coating amount moves along the inner peripheral surface g while being squeezed as the shaft member b is inserted, and finally the excess adhesive ends up at both ends of the alignment portion, that is, the peripheral edge t ,. It bleeds into u and remains attached. Also, when the shaft member j and the bracket k in FIG. 7 are bonded together, the adhesive remains on the peripheral edges r and s of the inner peripheral surface of the hole.

In this way, if there is coating unevenness when applying the adhesive, the adhesive will not spread evenly over the matching surface,
This causes a substantial decrease in adhesive strength. In addition, the adhesive that has spread and adhered will contact the ball bearing unless it is sufficiently removed later (in FIG. 6, the adhesive adhered to the t portion contacts the ball bearing d. Then, the adhesive adhering to the s portion comes into contact with the ball bearing p.) Further, the inside of the disk chamber is contaminated (the adhesive adhering to the u portion of FIG. 6 scatters) and the lead wire n comes into contact. Various inconveniences such as (adhesive attached to part r in FIG. 7) will occur. Therefore, it has been a factor of increasing the production cost in order to maintain high reliability.

The present invention has been made in view of the above problems existing in the prior art, and the problem is that the hub member and the shaft member, or the bracket and the shaft, which are adhesively fixed. Spindles that can be easily and securely bonded and fixed to members, and that stable quality that does not cause bleeding or adhesion of adhesive in the process can be obtained, resulting in high reliability and improved productivity. It is to provide a motor.

[0009]

In order to achieve the above object, in a spindle motor of the present invention, a hub member for mounting a recording disk and a hub member integrally fixed to the hub member are rotatably supported. In a spindle motor including a shaft member, a groove portion for accumulating an adhesive on an inner peripheral surface of the hub member or an outer peripheral surface of the shaft member among alignment portions of the hub member and the shaft member. Is provided over substantially the entire circumference, and the hub member is provided with a hole communicating with the groove, and the hub member and the shaft member are bonded and fixed by injecting an adhesive into the hole. It is supposed to be.

A spindle motor having a stationary member, a shaft member integrally fixed to the stationary member, and a hub member on which a recording disk is mounted and which rotates relative to the shaft member coaxially therewith. In the matching portion between the stationary member and the shaft member, the inner peripheral surface of the stationary member or the outer peripheral surface of the shaft member is provided with a groove portion for accumulating the adhesive over substantially the entire circumference. The stationary member is provided with a hole communicating with the groove, and the stationary member and the shaft member are bonded and fixed by injecting an adhesive into the hole.

[0011]

In the spindle motor of the first aspect, the hub member and the shaft member are fitted in advance, and the adhesive injected from the hole is guided to the portion where the hub member and the shaft member are aligned. .. The injected adhesive flows into the groove portion provided in the matching portion, and further, the adhesive spreads along the groove portion over substantially the entire circumference of the matching portion. As a result, the hub member and the shaft member are bonded and fixed uniformly, and the adhesive does not seep out of the matching portion.

Further, in the spindle motor of claim 2,
The stationary member and the shaft member are fitted in advance, and the adhesive injected from the hole is guided to a portion where the stationary member and the shaft member are aligned. The injected adhesive flows into the groove portion provided in the matching portion and spreads along the groove portion over substantially the entire circumference of the matching portion. As a result, the stationary member and the shaft member are fixed by uniform bonding, and the adhesive does not seep out of the matching portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a spindle motor according to the present invention will be described in detail with reference to FIGS. FIG. 1 shows a spindle motor for driving a recording disk (for example, a magnetic disk) shown as the first embodiment of the present invention, and the drawing is a sectional view of the left half thereof. The spindle motor described as the first embodiment is a shaft rotation type spindle motor in which a hub member and a shaft member are integrally fixed and driven to rotate, which will be described below. In FIG. 1, 1 is
It is a bowl-shaped hub member. A predetermined number of recording disks (not shown) are mounted by the hub outer peripheral portion 11 and the flange portion 23, and they are integrally rotated as the hub member 1 is rotationally driven. A rotor magnet 9 and a yoke member 10 which is attached to the rotor magnet 9 and which is made of a ferromagnetic material are annularly arranged on an annular side wall portion 28 inside the hub member 1.

The reference numeral 2 indicates a rotation axis of the hub member 1.
It is a shaft member that is coaxially fixed. Reference numeral 4 is a bracket forming a stationary member. The bracket 4 is fixed to a base member (not shown) of the drive device, and rotatably supports the hub member 1. A cylindrical portion 5 having a cylindrical shape is formed integrally with the bracket 4 coaxially with the rotation axis. An armature 6 is fitted and fixed to the outer peripheral portion of the cylindrical portion 11 and is arranged so as to face the rotor magnet 9. On the other hand, a pair of ball bearings 7 and 8 are fitted and fixed to the inner peripheral portion of the cylindrical portion 11, and the shaft member 2 is rotatably supported via these. When the armature 6 and the rotor magnet 9 are driven to rotate relative to each other, the hub member 1 rotates relative to the bracket 4.

FIG. 2 is a sectional view showing the spindle motor shown in FIG. 1 in an enlarged manner centering around the ball bearing 7. In addition, FIG. 3 is a perspective view of the hub member 1 as viewed obliquely from above. In FIGS. 1 to 3, the hub member 1 and the shaft member 2 are fixed by adhesion, and 3 is a matching portion thereof. That is, matching part 3
On the inner peripheral surface 16 of the hole of the hub member 1 and the outer peripheral surface 1 of the shaft member 2.
5 shows a part where 5 is fitted. The processing size of the corresponding hub member 1 and shaft member 2 is set in the matching portion 3 in accordance with the fitting dimensional accuracy of ordinary bonding. The groove portion 14 is formed on the outer peripheral surface 15 of the shaft member 2 in the alignment portion 3.
Are provided annularly (over substantially the entire circumference). The groove portion 14 is provided on the outer peripheral surface 15 in a direction substantially perpendicular to the rotation axis. Further, the cross-sectional shape of the groove portion 14 is formed in a rectangular shape.

The hub member 1 is provided with a hole portion 13 which communicates from the inner peripheral surface 16 of the hub member 1 in the matching portion 3 toward the outside (upper end portion in the drawing) of the hub member 1. The matching portion 3 side of the hole portion 13 is provided corresponding to the groove portion 14, and an introduction portion (of an adhesive agent) 17 is opened outside the hub member 1. The cross-sectional shape of the hole 13 is formed into a substantially circular shape, and as shown in FIG. 3, it is provided at two locations in a rotationally symmetrical manner.

Therefore, when the hub member 1 and the shaft member 2 are bonded and fixed, after the shaft member 2 is fitted into the inner peripheral surface 16 of the hub member 1 (for example, by light press-fitting), the adhesive dispenser 26, etc. Using, the adhesive is injected into the introduction portion 17 (hole portion 13). Then, the injected adhesive is injected into the hole 1
3 to reach the matching portion 3 and flow into the groove portion 14. The adhesive gradually flows along the entire circumference of the groove 14 and spreads over it. Further, the adhesive stays in the groove 14 (shown at 27).
Then, after a required curing time, the adhesive is cured.

Since the state of inflow into the holes 13 and the grooves 14 (capillary phenomenon due to surface tension) differs depending on the type and viscosity of the adhesive used, the shapes and sizes of the holes 13 and the grooves 14 are changed. Further, in order to adjust the amount of the adhesive, it is desirable to increase the number of grooves 14 in addition to the shape thereof. When the viscosity of the adhesive is relatively high, the holes 13 may not flow into the lubrication even if the adhesive is injected. At that time, the other hole portion 29 provided facing the hole portion 13 acts as an air vent (exhaust) hole. Therefore, in such a case, a dispenser having a relatively high delivery pressure may be used. The hole 1 provided in the hub member 1
3, 29 can also be used as holes for preventing rotation when the recording disk is attached and fixed to the hub member 1.

Since the adhesive does not seep out to the portion 14 of the inner bottom surface portion 18 of the hub member 1, it does not adhere to the inner ring portion 21 of the ball bearing 7 that abuts on this portion 14. Since the upper side surface of the outer ring portion 18 and the inner bottom surface portion 18 of the hub member 1 are arranged close to each other, this forms a labyrinth seal structure, and fine particles of lubricant or the like scattered from the ball bearing 7 are generated in the spindle motor. Substantially prevent leakage to the outside. In addition to this, the flange portion 23 of the hub member 1 and the bottom surface portion 2 of the bracket 2 in FIG.
Similarly, the labyrinth seal structure is formed by 4 and the side wall 25. Further, 12 is a seal member for sealing the lower part of the spindle motor.

Next, a second embodiment of the spindle motor according to the present invention will be described with reference to FIGS. 4 and 5. This spindle motor is a fixed shaft type spindle motor in which a shaft member is integrally fixed to a stationary member. FIG. 4 is a sectional view thereof, and FIG. 5 is a perspective view of the spindle motor which is viewed upside down.

In FIG. 4, one end of the shaft member 42 is fixed to the bracket 44, which is a stationary member, by adhesion. An armature 45 is fitted in a substantially central portion of the shaft member 42, and ball bearings 48, 60 are mounted on both sides of the armature 45. Through the pair of ball bearings 48 and 60, the hub member 4
1 is rotatably supported. (A bearing cap (spacer member) 62 is provided on the outer ring side of the ball bearing 60 to fix the lower side of the hub member 41.) The rotor magnet 46 and the yoke member 47 are provided on the inner peripheral wall of the hub member 41. And are attached in a ring shape. Therefore, the hub member 41 is coaxially rotated with respect to the bracket 44 by the relative rotational drive of the armature 45 and the rotor magnet 46.

A shaft member 42 is provided above the spindle motor.
A labyrinth seal structure is formed by the annular fixing portion 51 attached to the hub member 41 and the annular rotating member 63 attached to the hub member 41. Similarly, the bottom surface portion 50 of the bracket 44 and the hub member are formed on the lower portion of the spindle motor. A labyrinth seal structure is formed by the collar portion 41 of 41. This effectively prevents the unclean air inside the spindle motor from contaminating the disk chamber.

The bracket 44 and the shaft member 42 are fixed by adhesion, and 43 in FIG. 4 is a matching portion thereof. That is, the fitting inner peripheral surface 57 of the bracket 44 and the outer peripheral surface 52 of the shaft member 42 indicate the fitted parts. The shaft member 4 in the matching portion 43
The outer peripheral surface 52 of No. 2 is provided with a groove portion 58 in an annular shape (over substantially the entire circumference) and is arranged substantially perpendicular to the rotation axis. Corresponding to the groove portion 58, the bracket 4
4 is provided with a hole 54 that extends from the matching portion 43 to the lower side of the bracket 44 and communicates with the outside. As shown in FIG. 4, the holes 54 are provided at two locations facing each other in a rotationally symmetrical manner.

In order to bond and fix the bracket 44 and the shaft member 42, they are fitted in advance and then injected into the hole portion 54 (introducing portion 53 in FIG. 5) using the adhesive dispenser 65 shown in FIG. To do. The description of the action of the inflow of the adhesive is omitted because it is the same as that described in the first embodiment. Therefore, according to the spindle motor shown in the second embodiment, both ends 66, 67 of the matching portion 43 are formed.
The adhesive does not seep into the area. Therefore, the portion 66 does not adhere to the inner ring portion 59 of the ball bearing 60, and no inconvenience due to contact occurs. Also part 6
In No. 7, since it does not adhere to the armature lead wire 56 led out from the shaft member 42, it does not adhere to peripheral parts or the like secondarily, which is convenient.

Although the embodiment of the spindle motor according to the present invention has been described above, the present invention is not limited to such an embodiment, and various changes and modifications can be made without departing from the scope of the present invention. .. For example, the holes 13, 5
The size, shape, number and the like of 4 are freely designed, and can be appropriately selected depending on various conditions such as the type and viscosity of the adhesive, the tip shape of the dispenser used when injecting the adhesive, and the like .. Further, the shapes and numbers of the grooves 14 and 58 in which the adhesive stays and permeates can be similarly changed in design depending on the surrounding conditions. Further, in the present embodiment, the groove is provided in the shaft member together with the first embodiment and the second embodiment, but the present invention is not limited to this, and it may be provided in the hub member (or bracket) side. Needless to say.

[0026]

According to the spindle motor of the present invention, the hub member or the bracket which is adhesively fixed to the shaft member is provided with the groove portion in which the adhesive agent is retained over substantially the entire circumference at the position where these are aligned, and The hub member or the bracket is provided with a hole communicating with the groove. For this reason, it is not necessary to previously apply the adhesive to one of the two members to be adhesively fixed as in the prior art, and the unevenness of the coating process and the variation in the adhesive force due to the coating amount do not occur. Further, since no excess adhesive or the like leaks out from the matching portion, the inside of the disk chamber is not contaminated and the bearing members, lead wires, etc., which are the adjacent parts, are not inconvenienced.

Therefore, since the spindle motor has the above-mentioned structure, it is possible to obtain a spindle motor which can obtain stable quality, high reliability and improved productivity.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a spindle motor according to the present invention.

FIG. 2 is an enlarged sectional view showing a part of the spindle motor shown in FIG.

3 is a perspective view showing a part of the spindle motor shown in FIG. 1. FIG.

FIG. 4 is a sectional view showing a second embodiment of the spindle motor according to the present invention.

5 is a perspective view of a part of the spindle motor shown in FIG. 4, viewed from the lower side.

FIG. 6 is a sectional view showing a conventional spindle motor.

FIG. 7 is a sectional view showing a conventional spindle motor.

[Explanation of symbols]

 1,41 Hub member 2,42 Shaft member 3,43 Alignment part 4,44 Bracket 6,45 Armature 9,46 Rotor magnet 13,29,54 Hole part 14,58 Groove part 7,8,48,61 Ball bearing

Claims (2)

[Claims] 1. A spindle motor comprising: a hub member for mounting a recording disk; and a shaft member that is integrally fixed to the hub member and rotatably supports the hub member, the hub member and the shaft member. A groove portion for retaining the adhesive is provided over substantially the entire circumference on the inner peripheral surface of the hub member or the outer peripheral surface of the shaft member among the matching parts with the hub member. A spindle motor, characterized in that a communicating hole is provided, and the hub member and the shaft member are bonded and fixed by injecting an adhesive into the hole. 2. A spindle motor comprising: a stationary member; a shaft member integrally fixed to the stationary member; and a hub member on which a recording disk is mounted and which rotates relative to the shaft member coaxially. In the matching portion between the stationary member and the shaft member, the inner peripheral surface of the stationary member or the outer peripheral surface of the shaft member is provided with a groove portion for accumulating an adhesive over substantially the entire circumference, The stationary member is provided with a hole communicating with the groove, and the stationary member and the shaft member are bonded and fixed by injecting an adhesive into the hole, and the spindle motor is characterized in that: ..