JPH10108405A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust the elevation of a spindle motor, without changing the arranged position of the thrust bearing of the motor shaft. SOLUTION: A thrust bearing 40 of a motor shaft 28 of this motor 10 is supported by an elastic ring 50, fitted to an annular groove 243 structured on the inner circumference of a bearing holder 24, and its position is regulated. The elastic ring 50, which is of a C-shape, is easily removable from an annular groove 243 by straightening the gap between both ends. Sandwiched between the elastic ring 50 and the thrust bearing 40 is a spacer 70, the thickness of which determines the elevated position of the thrust bearing 40. Thus, because the projecting amount of a motor shaft 28 is adjustable, the elevated height of the motor becomes adjustable. Also, because the thrust bearing 40 is supported by the elastic ring 40, provided on a bearing holder 24 in such a way as to be mountable and detachable, a worker is able to replace or add the spacer 70 easily by removing this elastic ring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor used for a disk drive for rotating a compact disk (CD) or a digital video disk (DVD).

[0002]

2. Description of the Related Art Disk drives are disclosed in, for example,
-296501. As disclosed in this publication, the disk drive includes a spindle motor and a chucking mechanism for chucking the disk so that the disk can be rotated by the spindle motor. Members such as a turntable and a center ring, which are components of the chucking mechanism, are attached to a tip portion of a motor shaft of a spindle motor. In order to support a thrust load acting on the motor shaft from these portions, a thrust bearing that supports the base end of the motor shaft is attached to a cylindrical bearing holder that rotatably holds the motor shaft. .

FIG. 4 shows an enlarged view of a thrust bearing portion of a motor shaft in a spindle motor incorporated in such a disk drive. As shown in this figure, the motor shaft 2 of the spindle motor
8A is rotatably supported on a bearing holder 24A fixed to the stator substrate 22A side of the motor. That is, the cylindrical radial bearing 26 is provided on the inner peripheral surface 242 of the hollow portion 241 in the cylindrical bearing holder 24A.
A is held, and the motor shaft 28A is rotatably supported by the radial bearing 26A.

A disc-shaped washer 36A is fixed to the lower end opening 243 of the hollow portion of the bearing holder 24A, and the disc-shaped thrust bearing 40A is supported at a predetermined position in the motor axial direction by the washer 36A. . The axial end of the motor shaft 28A is supported by the thrust bearing 40A. The washer 36A is provided with a thrust bearing 40.
In order to withstand the force acting on A, it is firmly fixed to the inner peripheral portion of the opening end 243 by a method such as caulking or bonding.

[0005]

SUMMARY OF THE INVENTION Here, CDs and DVDs
In a disk drive for rotating the disk drive, there is a limitation on the height of a spindle motor incorporated therein. That is, the height from the stator substrate of the spindle motor to the turntable on which the disk is mounted is set to a specific size according to the disk drive. A spacer 70A having a predetermined thickness is interposed between the thrust bearing 40A and the washer 36A in order to match the height of the motor in the disk drive to be applied. We are making adjustments.

Here, after the spacer 70A having an appropriate thickness is mounted, the washer 3 is used to support the thrust bearing 40A.
6A is firmly fixed to the bearing holder 24A by caulking or the like. Therefore, once the thrust bearing 40A is assembled, it is not easy to disassemble it.

For this reason, if it is found that the height of the motor shaft is out of the preset height standard after the spacer and the thrust bearing are assembled, these parts are disassembled again and separated. It is not easy to perform an operation such as exchanging a spacer having a thickness of 3 mm.

An object of the present invention is to provide a spindle motor capable of easily adjusting the height in view of the above points.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a bearing holder having a cylindrical shape and a rotatably supported via a bearing on an inner peripheral surface of a hollow portion of the bearing holder. A motor shaft, and a spindle motor having a thrust bearing that supports one end of the motor shaft in the axial direction in a hollow portion of the bearing holder, further comprising a support member that supports the thrust bearing. , And are detachably attached to the bearing holder.

As a structure for detachably attaching a support member for supporting the thrust bearing to the bearing holder, an engaging groove formed on the inner peripheral surface of the hollow portion of the bearing holder, and a detachable mounting groove for the engaging groove. An engagement member functioning as the support member attached is provided, and the thrust bearing can be held at a predetermined position in the hollow portion of the bearing holder by the engagement member.

In this case, a spacer for adjusting the height of the motor may be sandwiched between the thrust bearing and the engaging member.

The engagement groove may be an annular groove, and the engagement member may be a ring-shaped member having elastic characteristics. By elastically deforming the ring-shaped member, the ring-shaped member can be easily attached to and detached from the annular groove.

Here, a C-shaped elastic ring can be used as the ring-shaped member. In this case,
It is desirable to form engagement portions for use in attaching and detaching the elastic ring to and from the engagement groove at both ends of the C-shaped elastic ring. For example, when fitting a C-shaped elastic ring to a bearing holder, these engaging portions are gripped by a jig, the whole is elastically deformed and narrowed, and the engagement is performed in a state of being aligned with the annular groove. Open the part. As a result, the elastic ring returns elastically and automatically fits into the annular groove.

As described above, in the spindle motor of the present invention, the support member for supporting the thrust bearing is detachably attached to the bearing holder. Therefore, since the disassembling operation can be easily performed, operations such as replacement, addition, and removal of the spacer for adjusting the height of the motor can be easily performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a spindle motor to which the present invention is applied. The spindle motor 10 shown in FIG.
Is a spindle motor used in a disk drive for a digital video disk (DVD), and includes a motor body 20 having a motor shaft 28, and a turntable 16 fixed to the distal end side of the motor shaft 28 for mounting the DVD 12. And a chucking mechanism 15. The DVD 12 is fixed to the turntable 16 by the chucking mechanism 15 and rotates together with the turntable 12.

The motor main body 20 has a stator substrate 22, and a cylindrical bearing holder 24 is fixed to the stator substrate 22. A cylindrical radial bearing 2 is provided on an inner peripheral surface 242 of a hollow portion 241 of the bearing holder 24.
The motor shaft 28 is rotatably supported by the bearing 26. A stator core 30 is arranged on the outer peripheral surface of the bearing holder 24 so as to concentrically surround the bearing holder 24.

The stator core 30 is formed by laminating a plurality of core plates, and a plurality of salient poles 301 projecting radially are formed on the outer periphery. A coil winding 302 is wound around these salient poles 301. The ring magnet 32 is arranged so as to face the outer peripheral edge of each salient pole 301 via a slight gap. The ring magnet 32 is fixed to an inner peripheral surface of a cup-shaped rotor case 34 fixed to the turntable 16.

The motor shaft 28 has an annular groove 281 formed on the outer peripheral surface at the lower end thereof.
A stopper ring 282 is fitted in the stopper. When the motor shaft 28 moves upward in the drawing toward the direction of the axis L, the slip-off preventing ring 28 abuts against the lower annular end surface of the bearing holder 24, so that the motor shaft 28 escapes upward from the radial bearing 26. There is no.

A thrust bearing 40 is arranged on the lower end opening side of the hollow portion 241 of the bearing holder 24. As shown in FIG. 2, the thrust bearing 40 has a substantially disk shape, and a flat circular contact surface 401 is formed at the center of the upper surface. The lower end portion 28a of the motor shaft 28 in the axial direction is in contact with the contact surface 401. Therefore, the thrust bearing 40 supports the load of the entire rotor such as the rotor case 34.

Below the thrust bearing 40, a disk-shaped spacer 70 having a fixed thickness is arranged.
Are supported by an elastic ring 50 described later. The elastic ring 50 is detachably fitted in an annular groove 243 formed in the inner peripheral surface 242 of the bearing holder 24. Thus, in this example, the thrust bearing 40 is
And is supported by an elastic ring 50. Below the elastic ring 50, a disk-shaped washer 36 for closing the lower end opening 24a of the bearing holder hollow portion 241 is attached. The washer 36 is provided in the hollow portion 241 of the bearing holder.
It is attached to the bearing holder 24 with a fixing force that does not come off from the lower end opening 24 a of the thrust bearing 40, and is not for supporting the thrust bearing 40.

The shape of the elastic ring 50 is shown in FIG. In this figure, (A) is a plan view of the elastic ring 50, and (B) is a cross-sectional view of a portion cut along line 3B-3B. The elastic ring 50 is formed from an elastic metal such as phosphor bronze or stainless steel. Instead of the elastic metal, it may be molded from a resin material exhibiting elastic characteristics. In the normal state, the contour shape of the elastic ring 50 has a shape close to a perfect circle as shown by a solid line in the figure, but when the both ends 501 and 502 are pushed in a direction of approaching, the whole elastically deforms. In this case, both end portions can be formed in a narrowed shape as shown by imaginary lines. When the force applied to both ends is released, the elastic ring 50 elastically returns to its original shape.

Also, both ends 501 of the elastic ring 50,
The 502 is formed with engagement holes 51a and 51b, respectively. The engagement holes 51a and 51b are
When the elastic ring 50 is attached to and detached from the jig, a jig (not shown) is engaged with these engagement holes to deform the elastic ring 50 as described above.

Referring again to FIG. 1, the elastic ring 50 is fitted and fixed in the annular groove 243 formed in the inner peripheral surface 242 on the lower end opening side of the bearing holder 24 as described above. The inner diameter of the annular groove 243 is substantially the same as the outer diameter of the elastic ring 50. 1, the depth D of this annular groove 243 (the distance from the inner peripheral surface 242 of the bearing holder to the inner peripheral surface of the annular groove 243) is smaller than the width W of the elastic ring 50. (W> D). For this reason, the annular groove 243
The elastic ring 50 fitted in the inner peripheral edge portion of the annular groove 243 projects inward. A disk-shaped spacer 70 having a fixed thickness is supported on the annular projecting portion 53, and the thrust bearing 40 is mounted on the spacer 70.

The spindle motor 10 constructed as described above
, The thrust bearing 40 and the spacer 70 are inserted in this order from the side of the lower end opening 24a of the bearing holder 24, and then the elastic ring 50 is inserted into the annular groove 2 on the inner peripheral surface of the bearing holder.
These parts can be assembled to the bearing holder 24 by fitting them into the bearing 43. That is, in a state where the engagement holes 51a and 51b at both ends of the elastic ring 50 are narrowed by the jig, the positioning is performed on the annular groove 243, and both ends of the elastic ring are opened. As a result, the elastic ring 50 elastically returns to its original shape, automatically fits into the annular groove 243, and is held at that position. After this, the bearing holder 2
The washer 36 may be attached to the lower end opening 24a of the fourth unit 4 and closed.

Here, when the height H from the stator substrate 22 to the turntable 16 (hereinafter simply referred to as the motor height H) is out of the standard, the elastic ring 50 is used.
May be removed and the spacer 70 may be replaced or added. In this case, if the elastic ring 50 is narrowed by holding both ends thereof, the elastic ring 50 can be easily removed from the bearing holder 24. Therefore, operations such as replacement and addition of the spacer 70 can be performed extremely easily.

The spindle motor 10 is not limited to a motor used for a DVD disk drive, but can also be used for a compact disk (CD) or floppy disk (FD) disk drive.

The shape of the elastic ring 50 is not limited to the C-shape, but may be any other shape. For example, the shape may be a U-shape or a perfect circle.

Further, the engaging portions formed at both ends of the elastic ring 50 may be engaging projections or the like instead of the engaging holes 51a and 51b.

[0030]

As described above, in the spindle motor of the present invention, the support member for supporting the thrust bearing is detachable from the bearing holder. Therefore, since the support member can be easily removed from the bearing holder, operations such as replacement, addition, and removal of the height adjustment spacer disposed between the support member and the thrust bearing can be easily performed. Therefore, height adjustment of the motor is simplified.

In the present invention, since the elastic ring as the support member is fitted into the annular groove formed on the inner peripheral surface of the bearing holder, the elastic ring is attached and detached by a simple operation of elastically deforming the elastic ring. be able to.

In addition, since the C-shaped elastic ring is employed and the engaging portions at both ends of which the jig can be engaged are formed, the work of attaching and detaching the elastic ring can be performed more easily. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view of a spindle motor to which the present invention is applied.

FIG. 2A is a plan view of an elastic ring, and FIG.
It is sectional drawing of the part cut | disconnected by the B-2B line.

FIG. 3A is a plan view of a thrust bearing, and FIG. 3B is a cross-sectional view of a portion cut along line 3B-3B.

FIG. 4 is an explanatory diagram showing a structure of a support portion of a thrust bearing of a motor shaft in a conventional spindle motor.

[Explanation of symbols]

 Reference Signs List 10 spindle motor 20 motor main body 24 bearing holder 24a lower end opening of bearing holder 241 hollow portion 242 inner peripheral surface 243 annular groove 26 radial bearing 28 motor shaft 40 thrust bearing 50 elastic ring 501, 502 Both ends 51a, 51b of elastic ring 53 Projection of elastic ring

[Procedure amendment]

[Submission date] October 18, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 4

FIG. 3

Claims (6)

[Claims] 1. A bearing holder having a cylindrical shape, a motor shaft rotatably supported via a bearing on an inner peripheral surface of a hollow portion of the bearing holder, and a motor shaft of the motor shaft in the hollow portion of the bearing holder. A spindle motor having a thrust bearing that supports one end in the axial direction, comprising: a support member that supports the thrust bearing at a predetermined position in the motor axial direction; the support member is attached to and detached from the bearing holder. A spindle motor characterized in that it is mounted as possible. 2. An engagement groove according to claim 1, further comprising: an engagement groove formed on an inner peripheral surface of the hollow portion of the bearing holder; and an engagement member removably attached to the engagement groove and functioning as the support member. A spindle motor, wherein the thrust bearing is held at a predetermined position in a hollow portion of the bearing holder by the engagement member. 3. The spindle motor according to claim 2, wherein a spacer for adjusting a position of the thrust bearing in a motor axial direction is disposed between the thrust bearing and the engagement member. . 4. The spindle motor according to claim 2, wherein the engagement groove is an annular groove, and the engagement member is a ring-shaped member having elastic characteristics. 5. The spindle motor according to claim 4, wherein the ring-shaped member is a C-shaped elastic ring. 6. The elastic member according to claim 5, wherein the C-shaped elastic ring is provided at both ends thereof with engagement portions used for attaching and detaching the elastic ring to and from the engagement groove. Spindle motor.