JP2000116053A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a rotor part from falling off a stator part and further suppress scattering of lubrication oil by providing a washer projecting from the peripheral wall of a rotary shaft to the gap between a protrusion and the upper end of a bearing member, while being engaged to the protrusion that is provided at the upper end of a bearing housing and a groove part being provided at the rotary shaft. SOLUTION: When a rotary shaft 13 moves in a direction where it is pulled out, a washer 17 that is engaged to the rotary shaft 13 is hooked to a protrusion 11 of a bearing housing 4, thus regulating the move of the rotary shaft 13 in a direction where it is pulled out and hence preventing the falling off a rotor 4 from a stator 3. Also, even if a lubrication oil that is filled between the rotary shaft 13 and a bearing member 8 is about to be scattered from the upper end side of the bearing housing 5 due to the rotation of the rotor part 4, the scattering of the lubrication oil can be suppressed by the washer 17 and the protrusion 11 of the bearing housing 5 being located at the upper portion of the bearing member 8, thus reducing the decrease in the filled lubrication oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor for rotating an information disk such as a compact disk.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a spindle motor 20 for rotating an information disk such as a compact disk is mounted on a stator 22 fixed to a substrate 21 and rotatably mounted on the stator 22. Rotor part 23
And is constituted by. The rotor section 23 has a rotor yoke 25 supporting a rotor magnet 24 fixed to a rotating shaft 26. The stator section 22 includes a bearing housing 28 that inserts and supports the rotation shaft 26 of the rotor section 23 and supports a stator core 27. The bearing housing 28 has a bearing member 29 fixedly provided therein, and rotatably supports the rotating shaft 26 of the rotor section 23 via lubricating oil. A bearing plate 30 for rotatably supporting the lower end of the rotating shaft 26 of the rotor portion 23 is mounted on the bottom of the bearing housing 28 and closed.

In a spindle motor 20 of this type, a rotor portion 23 is magnetically attracted to a stator portion 27 by a magnetic force of a rotor magnet 24, and a rotating shaft 26 of the rotor portion 23 is rotated.
Is maintained in a state supported by the bearing housing 28 of the stator portion 22. However, when a force exceeding the magnetic attraction force is applied in a direction in which the rotating shaft 26 comes out of the bearing housing 28, for example, when an external impact is applied,
There is a possibility that the rotor part 23 may fall off from the stator part 22.

Therefore, in this type of spindle motor 20, a groove 31 is provided circumferentially at the lower end of the rotation shaft 26 of the rotor portion 23, and a washer 32 is fitted into the groove 31 so that the rotation shaft 26 Movement in the exit direction (upward) is restricted. That is, after the washer 32 is fitted into the groove 31 of the rotating shaft 26 protruding from the lower end of the bearing housing 28 through the bearing housing 28 of the stator portion 28, the lower end of the bearing housing 28 is closed by the support plate 30. I do. By doing so, the washer 32 is located between the support plate 30 and the lower end of the bearing member 29 inside the lower end side of the bearing housing 28, and even if the rotating shaft 26 moves in the withdrawing direction, the washer 32 is moved. Is hung on the bearing member 29, so that the rotor portion 23 can be prevented from falling off from the stator portion 22.

However, the rotor portion 2 from the stator portion 22
When the washer 32 is provided to prevent the shaft 3 from dropping, the rotating shaft 2 is provided inside the lower end of the bearing housing 28.
A space for accommodating the washer 32 fitted to 6 is required. For this reason, if the thickness of the spindle motor 20 in the longitudinal direction of the rotary shaft 26 is constant, the length of the bearing member 29 that supports the rotary shaft 26 must be shortened. May occur.

On the other hand, in the spindle motor 20 of this type, a relatively large amount of lubricating oil is filled between the bearing member 29 and the rotating shaft 26 in recent years as the rotation speed is increased.

Although the bottom of the bearing housing 28 is closed by the support plate 30, leakage of lubricating oil from the bottom is prevented. However, since the upper end Y of the bearing housing 28 is open, the bearing housing 28 is closed. Lubricating oil scatters from the upper end Y of the bearing housing 28 to the outside, and the amount of lubricating oil filled between the bearing member 29 and the rotary shaft 26 is disadvantageously reduced.

[0008]

SUMMARY OF THE INVENTION In accordance with the present invention, it is possible to prevent the rotor from falling off from the stator without shortening the length of the bearing member. It is an object of the present invention to provide a spindle motor capable of suppressing scattering.

[0009]

In order to achieve the above object, the present invention provides a rotor unit having a rotor magnet fixed to a rotor yoke fixed to a rotating shaft, and rotatably supports the rotating shaft of the rotor unit. A cylinder having a bearing member inserted therein and a support plate abutting against the lower end of the rotary shaft and rotatably supporting the rotary shaft mounted thereon, having a closed bottom, and a stator core opposed to the rotor magnet fixed to the outer periphery. In a spindle motor including a stator portion having a bearing housing having a shape, a ridge protruding inward along the entire periphery of an upper end edge of the bearing housing is provided, and between the ridge and an upper end of the bearing member. A groove is provided along the entire circumference of the peripheral wall of the rotating shaft at a corresponding position, and is fitted in the groove, and from the peripheral wall of the rotating shaft toward a gap between the convex ridge and the upper end of the bearing member. Characterized in that a washer projecting Jo.

According to the present invention, when the rotating shaft moves in the direction of coming out of the bearing housing, the washer fitted to the rotating shaft is hooked on the ridge provided on the bearing housing. Accordingly, the movement of the rotating shaft in the direction in which the rotating shaft comes out is restricted, so that the rotor can be prevented from falling off the stator.

Further, according to the present invention, the washer is
Between the ridge of the bearing housing and the upper end of the bearing member, that is,
Since it is provided at the upper end of the bearing housing, there is no need to provide a space between the lower end of the bearing housing and the lower end of the bearing member as in the conventional case. It can be formed long. This makes it possible to prevent the rotor from falling off the stator without deteriorating the rotation accuracy of the rotating shaft.

Further, in the present invention, the space between the rotating shaft and the bearing member is filled with lubricating oil, and the washer is subjected to an oil-repellent treatment on its surface.

The washer is located at a position above a bearing member, which is a part which has been conventionally opened, and further above the protrusion ridge of the bearing housing projects. Moreover, the washer is subjected to an oil-repellent treatment on its surface.
Thereby, the scattering of the lubricating oil from the upper end side of the bearing housing due to the rotation of the rotor portion is suppressed by the washer and the ridges of the bearing housing, and the lubricating oil attached to the washer is repelled by the washer applied to the washer. Since the oil can be smoothly flown into the bearing housing by the oil treatment, a decrease in lubricating oil can be reduced.

[0014]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory longitudinal sectional view of a spindle motor of the present embodiment, and FIG. 2 is an explanatory view showing an assembly process of the spindle motor of the present embodiment.

The spindle motor 1 of this embodiment is for rotating an information disk such as a compact disk. As shown in FIG. 1, a stator 3 fixed to a metal substrate 2 and a stator 3 are provided. And a rotor unit 4 rotatably attached to the motor.

The stator section 3 includes a cylindrical bearing housing 5 formed of a metal such as brass, and a plurality of stator cores 6 fixed on the outer periphery of the bearing housing 5. A conductor is wound around each stator core 6 to form a coil 7. A metal cylindrical bearing member 8 is inserted and fixed inside the bearing housing 5.
A bearing plate 10 provided with a pivot plate 9 made of wear-resistant synthetic resin is mounted on the bottom of the bearing housing 5.

A projecting ridge 11 is formed at the upper end of the bearing housing 5 to protrude inward over the entire circumference. Due to the ridge 11, the inner diameter of the upper end of the bearing housing 5 is formed to be small.

The bearing housing 5 is fixed to the substrate 2 by a base portion 12 provided on the outer periphery of the bottom portion penetrating the substrate 2 and performing caulking on the outer periphery of the base portion 12, for example. Have been.

The rotor section 4 is provided with the bearing housing 5
A rotating shaft 13 rotatably inserted into the bearing member 8 of the first embodiment, and a disk-shaped metal rotating plate 14 integrally fixed to the rotating shaft 13 are provided. A short cylindrical rotor yoke 15 is formed on the outer peripheral edge of the rotating disk 14 downward, and a rotor magnet 16 is fixed to the inner wall of the rotor yoke 15 so as to face the outer periphery of the stator core 6. ing.

The rotating shaft 13 of the rotor portion 4 is provided with a washer 17 projecting into a gap X between the ridge 11 formed on the bearing housing 5 and the upper end of the bearing member 8. ing. The washer 17 is a discontinuous C-shaped elastic ring member, and is formed of a metal plate material such as spring steel or a synthetic resin plate material. Further, the surface of the washer 17 is subjected to an oil-repellent treatment by applying a fluorine resin or the like.

The rotary shaft 13 is provided with a groove 18 formed over the entire outer wall at a position corresponding to a position between the ridge 11 and the upper end of the bearing member 8. Are elastically fitted.

When the lower end of the rotating shaft 13 is supported in contact with the pivot plate 9 and the peripheral wall of the rotating shaft 13 is rotatably supported by the bearing member 8, the washer 17 is provided with the ridge 11 and the bearing. The member 8 is provided in a non-contact state, and prevents the rotation of the rotor unit 4 from being hindered.

With the above arrangement, when the rotating shaft 13 moves in the direction in which the rotating shaft 13 comes out (upward), the washer 17 fitted to the rotating shaft 13 is hooked on the ridge 11 of the bearing housing 5. The movement in the direction in which the rotor section comes out is restricted, whereby the rotor section 4 can be prevented from falling off the stator section 3. Moreover, the washer 17
Is provided at the upper end side of the bearing housing 5, so that the bearing plate 10 and the bearing member 8
There is no need to provide a space between the bearing member 8 and the lower end thereof, and the length of the bearing member 8 can be made relatively long.

Further, even if the lubricating oil filled between the rotating shaft 13 and the bearing member 8 tries to scatter from the upper end side of the bearing housing 5 with the rotation of the rotor section 4, the lubricating oil is kept above the bearing member 8. The scattering of the lubricating oil is suppressed by the washer 17 and the ridge 11 of the bearing housing 5 which are located, and the lubricating oil adhered to the washer 17 is removed by the washer 17.
The oil repellent treatment described above allows the fluid to flow smoothly into the bearing housing, so that the amount of lubricating oil filled between the rotating shaft 13 and the bearing member 8 can be reduced.

Next, an assembling process of the spindle motor 1 of the present embodiment will be described. First, as shown in FIG. 2A, the washer 17 is inserted from the bottom side of the bearing housing 5 (the upper side in the figure is turned upside down), and then the bearing member 8 is inserted. The outer diameter of the bearing member 8 is slightly larger than the inner diameter of the bearing housing 5, and the bearing member 8 is firmly inserted into the bearing housing 5 by press-fitting the bearing member 8. Is done.

Subsequently, as shown in FIG. 2B, a bearing housing 5 is erected on the substrate 2, a stator core 6 is mounted and fixed on the outer periphery of the bearing housing 5, and
Is inserted from the upper end side of the bearing housing 5. At this time, in the state shown in the figure, the washer 17 is pushed out along the outer wall of the rotating shaft 13 of the rotor unit 4.

Next, as shown in FIG. 2C, the rotating shaft 13 of the rotor portion 4 is inserted into the groove 18 of the rotating shaft 13 until the washer 17 is elastically fitted. At this time, the lower end of the rotating shaft 13 projects below the normal position. Then, the bearing plate 10 is mounted on the bottom of the bearing housing 5 and fixed by caulking or the like. by this,
At the same time as the bottom of the bearing housing 5 is closed, the lower end of the rotating shaft 13 abuts on the pivot plate 9 of the support plate 10 and is pushed upward, and as shown in FIG. It is located between the upper end of the member 8.

As described above, simply inserting the bearing plate 10 after inserting the rotating shaft 13 of the rotor section 4 into the bearing housing 5 of the stator section 3 allows the stator section 3 of the rotor section 4 to be mounted.
The spindle motor 1 which is prevented from falling off from the spindle motor can be easily assembled.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view of a spindle motor according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing an assembly process of the spindle motor according to the embodiment.

FIG. 3 is an explanatory longitudinal sectional view of a conventional spindle motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spindle motor, 3 ... Stator part, 4 ... Rotor part, 5 ... Bearing housing, 6 ... Stator core, 8 ... Bearing member, 10 ... Bearing plate, 11 ... Protrusion, 13 ... Rotating shaft, 15
... rotor yoke, 16 ... rotor magnet, 18 ... groove, 17 ... washer.

Claims (2)

[Claims] 1. A rotor unit having a rotor magnet fixed to a rotor yoke fixed to a rotating shaft, and a bearing member rotatably supporting the rotating shaft of the rotor unit are inserted therein and contact with a lower end of the rotating shaft. A support plate that rotatably supports the rotating shaft is mounted and the bottom is closed,
A spindle motor comprising a stator portion having a cylindrical bearing housing having a stator core opposed to the rotor magnet fixed to the outer periphery, wherein a protruding ridge is provided which protrudes inward along the entire periphery of an upper end edge of the bearing housing. A groove is provided along the entire circumference of the peripheral wall of the rotary shaft at a position corresponding to a position between the convex ridge and the upper end of the bearing member. The groove is fitted into the groove and the convex ridge is formed from the peripheral wall of the rotary shaft. A spindle motor provided with a washer that protrudes in a flange shape toward a gap between the bearing member and an upper end thereof. 2. The lubricating oil is filled between the rotating shaft and the bearing member, and the washer is subjected to an oil-repellent treatment on a surface thereof. Spindle motor.