JP2640633B2 - Spindle motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor.

[0002]

2. Description of the Related Art In general, a spindle motor includes a bracket body, a hub member rotated relative to the bracket body, and a pair of bearing means interposed between the bracket body and the hub member. A recording member such as a magnetic disk is attached to the hub member. The bearing means includes an inner ring, an outer ring, and a plurality of spherical members interposed between the inner and outer rings, respectively.In a fixed shaft type motor, the inner ring is mounted on a shaft fixed to the bracket body, and the outer ring is Attached to the hub member.

[0003]

However, in the spindle motor, there are problems to be solved such as complicated assembly of the motor itself and an increase in the size of the motor itself in connection with the structure of the bearing means described above. Exists.

An object of the present invention is to provide a spindle motor that can be relatively easily assembled and that can reduce the size of the motor.

[0005]

According to the present invention, there is provided a bracket body, a hub member rotated relative to the bracket body, bearing means interposed between the bracket body and the hub member, and a bracket. Stay attached to the body
And the hub member so that they face the outer peripheral surface of the stator.
In a spindle motor having a rotor magnet attached thereto, the bearing means comprises a bearing sleeve, a bearing shaft disposed in the bearing sleeve, and a plurality of rows of spherical members interposed between the bearing sleeve and the bearing shaft. The bracket body includes the end of the bearing shaft.
Holes for insertion and fixing and the same outside this hole
A centrally arranged cylindrical wall is provided, the outer periphery of the cylindrical wall
The stator is fixed to the surface, the bearing shaft is fixed to the bracket body, and the bearing sleeve is fixed to the hub member .

Further, according to the present invention, a bracket body, a hub member that is rotated relative to the bracket body, bearing means interposed between the bracket body and the hub member, and a bracket attached to the bracket body. And the stator
To the outer peripheral surface of the stator.
In the spindle motor having the rotor magnet , the bearing means includes a bearing sleeve, a bearing shaft disposed in the bearing sleeve, and a plurality of rows of spherical members interposed between the bearing sleeve and the bearing shaft. Insert the end of the bearing sleeve into the bracket body.
Holes for fixation and concentric with the outside of this hole
Arranged cylindrical walls set only is, scan the outer circumferential surface of the cylindrical wall
The theta is fixed, the bearing sleeve is fixed to the bracket body, and the bearing shaft is fixed to the hub member .

[0007]

In such a spindle motor, the bearing means is constituted by a bearing sleeve, a bearing shaft and a plurality of rows of spherical members interposed therebetween, and the bearing means is constituted as a unit comprising the above-mentioned members. Then, the bearing sleeve of the bearing means is fixed to the hub member or the bracket body, and the bearing shaft is fixed to the bracket body or the hub member. Accordingly, the structure of the bearing means is relatively simple, and in this connection, the structure of the motor itself is also simplified. Further, since the bearing means is unitized, the assembling work of the motor is relatively simple and easy. . In addition, the stay
Is fixed to the outer peripheral surface of the cylindrical wall of the bracket body.
Therefore, the fixing work of the stator can be performed irrespective of the bearing means.
When the stator is fixed to the bracket body and the bearing
Assembly can be performed individually and in parallel.
It becomes much better.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In FIG. 1, the illustrated spindle motor includes a substantially disk-shaped bracket body 2 and a substantially cylindrical hub member 4.
A circular hole is formed at a substantially central portion of the bracket body 2, and a peripheral portion defining the hole, that is, an inner peripheral portion,
A hollow cylindrical wall 6 protruding upward is provided integrally. A stator 8 is mounted on the outer peripheral surface of the hollow cylindrical wall 6. The stator 8 has a stator core 10 fixed to the hollow cylindrical wall 6 and a coil 12 wound around the stator core 10. A circuit board 14 is provided on the inner surface (the upper surface in FIG. 1) of the bracket body 2. The circuit board 14 is provided with a drive circuit (not shown) including a Hall element for controlling the rotation of the hub member 4.

The bracket body 2 further includes a bearing means 1
6 is mounted. The illustrated bearing means 16 includes a hollow cylindrical bearing sleeve 18 (constituting an outer ring) and a bearing shaft 20 disposed in the bearing sleeve 18. Inner peripheral surface of bearing sleeve 18 and bearing shaft 20
Are formed with two annular grooves 22 and 24, respectively, and a plurality of spherical members 26 are rotatable between the annular groove 22 of the bearing sleeve 18 and the annular groove 24 of the bearing shaft 20. The bearing sleeve 18, the bearing shaft 20, and the spherical member 26 constitute a unitized bearing means movably disposed along the annular grooves 22 and 24. Therefore, the bearing sleeve 18 and the bearing shaft 20 are relatively rotatable via the two rows of the plurality of spherical members 26 arranged at intervals in the axial direction of the bearing shaft 20.

In the illustrated example, a bearing shaft 20 is fixed to the bracket body 2 and a bearing sleeve 18 is fixed to the hub 4. An annular projection projecting inward in the radial direction is fixed to the base of the hollow cylindrical wall 6 of the bearing sleeve 18, and the annular projection 28 projects from one end (lower end) of the bearing sleeve 18 in the bearing shaft 20. The ends are fixed by means such as press fitting. The hub member 4 has a cylindrical main body 30, a flange 32 provided at one end (lower end) of the main body 30, and an end wall 34 provided at the other end (upper end) of the main body 30. The end wall 34 is fixed to the other end (upper end) of the bearing sleeve 18 by means such as press fitting. The main body 30 of the hub member 4 covers the stator 8 mounted on the cylindrical wall 6 of the bracket main body 2, and a rotor magnet 38 is attached to the inner peripheral surface thereof via a yoke member 36. . A recording member (not shown) such as a magnetic disk is
The main body 30 is mounted as required.

The illustrated motor is further configured as follows to prevent grease or the like used in the bearing means 16 from adhering to a recording member (not shown). That is,
The radial distance l between the outer peripheral surface of the bearing sleeve 18 and the inner peripheral surface of the cylindrical wall portion 6 is set small to prevent the passage of relatively large particles such as grease. This interval l is 0.3 to prevent contamination of the recording member surface.
mm or less, more preferably 0.1 mm or less. In addition, the distance L in which the bearing sleeve 18 and the cylindrical wall portion 6 overlap in the radial direction is sufficiently ensured to more effectively prevent the above-mentioned particles from passing. Such distance L
Is preferably set to 4 mm or more, more preferably 6 mm or more. Then, the ratio (L / l) between the distance L and the interval l
Should be about 15 or more, more preferably 60 or more. With this configuration, as easily understood from FIG. 1, the space between the outer peripheral surface of the bearing sleeve 18 and the inner peripheral surface of the cylindrical wall portion 6 functions as a so-called air curtain. Particles are effectively prevented from penetrating through the space. Then, by using the bearing means 16 as described above, the inner peripheral surface of the cylindrical wall portion 6 extending in the axial direction substantially in parallel and the outer peripheral surface of the bearing sleeve 18 substantially do not employ a so-called labyrinth structure. Intrusion of particles such as grease can be prevented. In the example of FIG. 1, an annular seal member 40 is provided on the inner peripheral surface of one end of the bearing sleeve 18. The sealing member 40 can be formed of, for example, synthetic rubber or the like, and its free end is brought close to or in contact with the bearing shaft 20 to prevent particles such as grease from flowing into the space. A cap member 42 is attached to the end wall 34 of the hub member 4 as shown by a two-dot chain line in FIG. Therefore, particles such as grease from the other end of the bearing means 16 (the end face opposite to the side on which the seal member 40 is provided) are sealed by the cap member 42 and adhere to the recording member (not shown). Never.

In the embodiment shown in FIG. 1, the bearing shaft 20 is fixed and the bearing sleeve 18 is rotated. As shown in FIG. 2, the bearing sleeve 18 is fixed and the bearing shaft 20 is rotated. The same can be applied to. In FIG. 2, members that are substantially the same as the members illustrated in FIG. 1 are described with the same reference numerals.

In FIG. 2, a short cylindrical wall 6 'is integrally provided substantially at the center of the bracket body 2', and a stator 8 is mounted on the outer peripheral surface of the cylindrical wall 6 '. The bearing means 16 of FIG. 2 has substantially the same configuration as that of FIG. 1, and the bearing sleeve 18 of the bearing means 16 is fixed to the cylindrical wall 6 'by means such as press fitting.

On the other hand, the hub member 4 'comprises a hub body 52 and a hub bush 54. The hub main body 52 includes a cylindrical main body 30 and a flange 3 in substantially the same manner as in FIG.
2 and an end wall portion 34, and the end wall portion 34 is a hub bush 5
4, it is fixed to a protruding end of the bearing shaft 20 protruding from the bearing sleeve 18.

In the embodiment shown in FIG. 2, a hollow cylindrical wall 56 extending in the axial direction is further provided integrally with the hub bush 54, and the inner peripheral surface of the hollow cylindrical wall 56 and the outer peripheral surface of the bearing sleeve 18 are formed integrally. The space between them functions as a so-called air curtain. That is, the relationship between the hollow cylindrical wall 56 of the hub member 4 'and the bearing sleeve 18 of the bearing means 16 is the same as that of the hollow cylindrical wall 5 of the bracket body 2 in FIG.
The relationship between the bearing 6 and the bearing sleeve 18 of the bearing means 16 is substantially the same. With this configuration, the same effect as that of FIG. 1 is achieved in the embodiment of FIG.

Although the embodiments of the spindle motor according to the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made without departing from the scope of the present invention. .

[0017]

According to the spindle motor of the present invention, the bearing means is constituted by a bearing sleeve, a bearing shaft and a spherical member, the bearing sleeve is fixed to the hub member or the bracket body, and the bearing shaft is fixed to the bracket body or the hub member. Fixed. Therefore, the structure of the motor can be simplified in relation to the structure of the bearing means, and the assembling operation thereof is also facilitated. In addition, regardless of bearing means,
The stator is fixed to the cylindrical wall of the cutout body.
Therefore, fixation of the stator to the bracket body and bearing means
Can be performed individually and in parallel, and the motor assembly work
Is significantly better.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a second embodiment of the spindle motor according to the present invention.

[Explanation of symbols]

 2 and 2 'Bracket body 4 and 4' Hub member 6 Cylindrical wall 8 Stator 16 Bearing means 18 Bearing sleeve 20 Bearing shaft 26 Spherical member 54 Hub bush 56 Hollow cylindrical wall

Claims (4)

(57) [Claims] And 1. A bracket body, and the hub member to be rotated relative to the bracket body, and a bearing hand stage interposed between said bracket body and said hub member, said Burake
A stator attached to the slot body and the hub member
Rotor attached to the outer peripheral surface of the data
Wherein the bearing means comprises: a bearing sleeve; a bearing shaft disposed in the bearing sleeve; and a plurality of rows of spherical members interposed between the bearing sleeve and the bearing shaft. And the end of the bearing shaft is inserted into the bracket body.
Hole for insertion and fixation and concentric with the outside of the hole
Is provided, and an outer peripheral surface of the cylindrical wall is provided.
A spindle motor , the bearing shaft being fixed to the bracket body, and the bearing sleeve being fixed to the hub member . 2. The spindle motor according to claim 1, wherein two rows of spherical members are disposed between the bearing sleeve and the bearing shaft at an axial interval. 3. A bracket body, and the hub member to be rotated relative to the bracket body, and bearing means interposed between said bracket body and said hub member, said Burake
A stator attached to the slot body and the hub member
Rotor attached to the outer peripheral surface of the data
Wherein the bearing means comprises: a bearing sleeve; a bearing shaft disposed in the bearing sleeve; and a plurality of rows of spherical members interposed between the bearing sleeve and the bearing shaft. And the end of the bearing sleeve is inserted into the bracket body.
Hole for insertion and fixation and concentric with the outside of the hole
Is provided, and an outer peripheral surface of the cylindrical wall is provided.
A spindle motor , the bearing sleeve being fixed to the bracket body, and the bearing shaft being fixed to the hub member . 4. The spindle motor according to claim 3, wherein two rows of spherical members are disposed between the bearing sleeve and the bearing shaft at an axial interval.