JP2000253614A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spindle motor which is constituted in such a way that the lubricating oil impregnated into a bearing does not leak into the motor even when the motor is rotated at a high speed. SOLUTION: A spindle motor 10 is provided with an impregnated bearing 12 housed in a bearing housing 17, a rotor 20 rotatably supported by a rotating shaft 24 fitted in the bearing 12, and a stator 11 provided around the housing 17. One end of the shaft 24 is supported in the direction of thrust in such a way that the end comes into contact with a thrust board 18 in the housing 17. In this case, the motor 10 is constituted in such a way that the shaft 24 is supported so that the shaft 24 does not move in the direction of thrust by a stopper section 25A substantially liquid-tightly provided on the other side of the housing 17 opened in a motor near the other end of the bearing in the axial direction.

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 a disk-shaped medium, for example, and more particularly to a spindle motor having an impregnated bearing for rotatably supporting a rotor.

[0002]

2. Description of the Related Art Conventionally, such a spindle motor has
For example, it is configured as shown in FIG. That is, in FIG. 4, a spindle motor 1 includes a stator 2, a rotor 4 rotatably supported by a bearing 3 provided on the stator 2, and a turntable 5 attached to an upper end of a rotating shaft of the rotor 4. It is composed of

[0003] The stator 2 includes an iron plate 2a, a stator substrate 2b provided on the plate 2a, a core 2c disposed in an annular shape on the stator substrate 2b, and a coil wound around the core 2c. 2d.

[0004] The bearing 3 is a sintered bearing impregnated with lubricating oil. The plate 2 a and the stator substrate 2 b are provided at the center of the annular shape of the core 2 c of the stator 2 via a bearing housing 3 a. Is fixed perpendicularly to the plate 2a so as to penetrate the plate 2a.

[0005] On the other hand, the rotor 4 has a hollow cylindrical rotor yoke 4a having an open end, and a rotor yoke 4a.
Rotor magnet 4b mounted along the inner peripheral surface of
A bush 4c fixedly held at the center of the rotor yoke 4a, a rotating shaft 4d attached to the bush 4c,
It is composed of

The lower end of the rotating shaft 4d in FIG. 1 is attached to the thrust board 3b attached to the lower end of the bearing housing 3a so as not to move in the axial direction when mounted on the bearing 3. A stopper 6 attached around the rotating shaft 4d near the lower end of the bearing 3 is brought into contact with the washer 3c through the washer 3c.
Abuts from below on the lower end of the.

The turntable 5 has a known structure, and is configured to hold a CD or a CD-ROM, for example.

[0008] The spindle motor 1 thus configured
According to the above, when the drive of the coil 2d of the stator 2 is controlled,
When the magnetic field generated in the coil 2d interacts with the magnetic field of the rotor magnet 4b, the rotating shaft 4d rotates in the bearing housing 3a, and the rotor 4 is driven to rotate.

[0009]

By the way, in recent years, the number of revolutions of the spindle motor has been increasing,
There are a lot of things over 10,000 revolutions / minute. Here, in the spindle motor 1 having the above configuration, at the time of high-speed rotation, the lubricating oil impregnated in the bearing 3 may leach out to the surface of the bearing 3 due to centrifugal force and leak into the rotor 4. Therefore, there is a problem that the lubricating oil is scattered inside the motor, and the life of the spindle motor 1 is shortened.

In view of the above, an object of the present invention is to provide a spindle motor in which lubricating oil impregnated in a bearing is prevented from leaking into the motor even during high-speed rotation.

[0011]

According to the present invention, there is provided an impregnated bearing provided in a bearing housing, a rotor rotatably supported by a rotating shaft mounted in the bearing, and a bearing. And a stator provided around the housing, and one end of the rotating shaft is supported in the thrust direction by abutting a thrust board in the bearing housing on one side of the bearing. In the spindle motor, the rotation axis is
In the vicinity of the other side of the bearing, the bearing housing is supported so as not to move in the thrust direction by a substantially liquid-tight stopper portion on the other side opened into the motor. The feature is achieved by a spindle motor.

[0012] In the spindle motor according to the present invention, preferably, the stopper portion is formed on the outer periphery of the rotating shaft with a first groove formed along the circumferential direction near the other side of the bearing in the axial direction. A second groove formed in the inner circumference of the bearing housing along the circumferential direction outside the bearing from the first groove in the axial direction, and an inner peripheral edge is formed in the first groove. And a substantially disk-shaped stopper having a step in the radial direction such that the outer peripheral edge engages with the second groove.

[0013] The spindle motor according to the present invention preferably has a claw portion in which the inner peripheral edge of the stopper fits into the first groove.

In the spindle motor according to the present invention, preferably, the claw portion on the inner peripheral edge of the stopper is formed to be thin.

[0015] In the spindle motor according to the present invention, preferably, the stopper portion is provided on an outer periphery of the rotary shaft, in an axial direction, with an annular stopper collar mounted near the other side of the bearing, and with respect to the stopper collar. An annular stopper ring attached to the other side of the bearing housing that opens into the motor so as to contact the other end of the rotating shaft.

According to the above configuration, one end of the rotating shaft of the rotor is supported in the thrust direction by the thrust board on one side of the bearing, and the stopper is provided on the other side of the bearing by, for example, the rotating shaft and the bearing. The stopper mounted on the housing abuts against the end face of the bearing, or the inner edge of the stopper ring attached to the bearing housing abuts on the end face of the stopper collar provided on the rotating shaft, so that the stopper does not move in the thrust direction. , And can be held.

In this case, since the stopper is provided in a liquid-tight manner on the other side of the bearing housing, the bearing is sealed in the bearing housing by the bearing stopper. Therefore, when the rotor rotates at high speed, even if the lubricating oil impregnated in the bearing leaks out, the lubricating oil does not leak out of the bearing housing. Thus, it is possible to reliably prevent the lubricating oil from scattering inside the motor and shortening the life of the motor.

The stopper portion has a first groove formed in the outer periphery of the rotating shaft in the axial direction along the circumferential direction near the other side of the bearing, and a shaft formed in the inner periphery of the bearing housing. With respect to the direction, a second groove formed along the circumferential direction outside the bearing from the first groove, an inner peripheral edge is engaged in the first groove, and the second groove is formed in the second groove. And a stopper formed in a substantially disk shape having a step in the radial direction so that the outer peripheral edge is engaged with the stopper. The bearing is sealed in the bearing housing by the stopper by engaging in one groove and engaging its outer peripheral edge in the second groove provided in the bearing housing.

When the inner peripheral edge of the stopper has a claw to be fitted into the first groove, and when the inner peripheral claw of the stopper is formed to be thin, the inner peripheral edge of the stopper is provided. When the is inserted into the first groove of the rotating shaft, the insertion can be easily performed by deforming the claw portion.

The stopper portion abuts on the outer periphery of the rotating shaft in the axial direction with an annular stopper collar mounted near the other side of the bearing, and comes into contact with the stopper collar from the other end of the rotating shaft. As described above, when the bearing housing is constituted by an annular stopper ring attached to the other side opened in the motor, the stopper ring is formed of a stopper collar whose inner peripheral edge is provided on the rotating shaft. The bearing comes into contact with the end face, and the bearing is sealed in the bearing housing by the stopper portion.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 shows a configuration of a first embodiment of a spindle motor according to the present invention. In FIG. 1, a spindle motor 10 includes a stator 11, a rotor 20 rotatably supported by a bearing 12 provided on the stator 11, and a turntable 30 attached to an upper end of a rotating shaft of the rotor 20. Have been.

The stator 11 includes an iron plate 13,
A stator substrate 14 made of, for example, paper phenol provided on the plate 13, a core 15 made of, for example, a silicon steel plate disposed annularly on the stator substrate 14, and a coil 16 wound around the core 15; Contains.

The bearing 12 is a sintered bearing impregnated with lubricating oil. The bearing 13 is provided at the center of the annular shape of the core 15 of the stator 11 via a bearing housing 17 made of, for example, brass. And is fixed vertically to the plate 13 so as to penetrate the stator substrate 14.

On the other hand, the rotor 20 has a rotor yoke 21 made of, for example, an iron plate having a hollow cylindrical shape with one end opened.
, A rotor magnet 22 attached along the inner peripheral surface of the rotor yoke 21, a brass bush 23 fixed and held at the center of the rotor yoke 21, and a stainless steel rotating shaft 2 attached to the bush 23, for example.
4.

The rotor yoke 21 is formed in a hollow cylindrical shape whose one end is open, and a rotor magnet 22 is fixed in a circumferential direction along an inner peripheral surface of the cylindrical shape by bonding or the like. The rotor magnet 22 is formed of a permanent magnet, or is appropriately magnetized in the circumferential direction.

The rotating shaft 24 is inserted into the bush 23 by press fitting or the like, and is fixed and held.

Further, the rotating shaft 24 is connected to the stator 11
When mounted on the bearing 12 supported via the bearing housing 17, the lower end in the drawing is attached to the lower end of the bearing housing 17 by caulking or the like so as not to move in the axial direction. It comes into contact with the thrust board 18 via a thrust washer 19 made of, for example, nylon.

The turntable 30 has a known configuration, and is configured to hold a CD or a CD-ROM, for example.

The above configuration is substantially the same as that of the conventional spindle motor 1 shown in FIG. 3, but the configuration of the spindle motor 10 according to the present invention is different in the following points. That is, the rotating shaft 24 is positioned in the thrust direction with respect to the bearing housing 17 by the stopper 25A near the upper end of the bearing 12.

The stopper 25 constituting the stopper portion 25A is made of, for example, a resin, and is formed in an annular shape as shown in FIG. 2, and has a claw portion 25a projecting inward from an inner peripheral edge thereof. A projection 25b having a step upward from the outer peripheral edge and projecting outward is provided. As a result, the stopper 25 is formed in a crank shape near the outer edge in the radial cross section.

On the other hand, the rotating shaft 24 has a first groove 24a extending in the circumferential direction near the upper end of the bearing 12.
Are formed, and the bearing housing 17 is provided with the bearing 1.
A second groove 17a extending in the circumferential direction is formed slightly above the upper end of 2.

As a result, the stopper 25 has its inner peripheral claw 25a engaged with the first groove 24a of the rotary shaft 24 and its outer peripheral projection 25b fitted to the second housing 24 of the bearing housing 17. The lower surface of the stopper 25 abuts on the upper end surface of the bearing 12 at an interval of, for example, 0.2 mm or less by engaging in the groove 17a, thereby forming the stopper portion 25A. The bearing 12 is positioned and held with respect to the direction, and the bearing 12 is sealed in the bearing housing 17.

The inner peripheral edge of the stopper 25 is provided with a claw 25a that fits into the first groove 24a, and the inner peripheral claw 25a of the stopper 25 is formed to be thin. When the inner peripheral edge of the stopper is inserted into the first groove 24a of the rotating shaft 24, the stopper 25a is deformed, so that the stopper can be easily inserted.

The spindle motor 1 according to the embodiment of the present invention
0 is configured as described above and operates as follows. The spindle motor 10 drives and controls the coil 16 of the stator 11 so that the magnetic field generated in the coil 16 interacts with the magnetic field of the rotor magnet 22 so that the rotating shaft 24 rotates in the bearing housing 17. The rotor 20 is driven to rotate.

In this case, the stopper 25 has its inner peripheral claw 25a engaged with the first groove 24a provided on the rotary shaft 24, and its outer peripheral projection 25b fitted to the bearing housing 1.
7 is engaged in the second groove 17a. As a result, the bearing 12 is sealed in the bearing housing 17 by the stopper 25. Therefore, even if the lubricating oil impregnated in the bearing 12 leaks out when the rotor 20 rotates at a high speed, the lubricating oil is prevented from leaking out of the bearing housing 17 by the stopper 25 constituting the stopper portion 25A. You. As a result, lubricating oil is scattered inside the motor, and the life of the motor is shortened.
It can be reliably prevented.

FIG. 3 shows the configuration of a second embodiment of the spindle motor according to the present invention. 3, the spindle motor 40 has substantially the same configuration as the spindle motor 10 shown in FIG. 1, and is different only in the following points. That is, the stopper 2 shown in FIG.
In the configuration of 5A, in the spindle motor 40, the rotating shaft 24 does not include the first groove 24a, and further includes an annular stopper collar 41 fixed around the rotating shaft 24 instead of the stopper 25. ing. On the contrary,
The bearing housing 17 does not have the second groove 17a on the inner surface near its upper end, but has an annular stopper ring 42 attached to its upper end. Thereby, the stopper collar 41 attached around the rotation shaft 24 is
The stopper portion A is configured by contacting the stopper ring 42 attached to the upper end of the bearing housing 17 from below.

In the embodiment shown in FIG. 3, the inner peripheral surface of the bearing housing 17 and the outer end edge of the stopper collar 41 are illustrated with a space provided, but the inner peripheral surface is, for example, 0.2 mm or less. As a result, the inner peripheral edge of the stopper ring 42 is formed so as to cover the upper surface of the outer peripheral edge of the stopper collar 41 without hindering the rotation of the rotary shaft 24, thereby positioning and holding the rotary shaft 24 in the thrust direction and holding the same. The bearing 12 is hermetically sealed in a bearing housing 17.

The spindle motor 4 configured as described above
0 operates almost in the same manner as the spindle motor 10 shown in FIG.
5A, the inner edge of an annular stopper ring 42 attached to the upper end of the bearing housing 17 has a stopper collar 4 attached to the rotating shaft 24 over the entire periphery thereof.
1 is in contact with the upper end surface. As a result, the bearing 12 is sealed in the bearing housing 17 by the stopper collar 41 and the stopper ring 42. Therefore, even if the lubricating oil impregnated in the bearing 12 leaches out when the rotor 20 rotates at a high speed, the lubricating oil is released by the stopper collar 41 and the stopper ring 42 into the bearing housing 1.
7 is prevented from leaking out. This allows
It is possible to reliably prevent the lubricating oil from scattering inside the motor and shortening the life of the motor.

In the above embodiment, the bearing 12
Is configured as an impregnated sintered bearing, but it is clear that other types of bearings may be used as long as they are impregnated with lubricating oil.

Further, in the above embodiment, the spindle motor 10 for rotating and driving a CD or CD-ROM has been described. However, the present invention is not limited to this, and the present invention can be applied to a spindle motor for rotating and driving other disk-shaped media. Obviously, the invention can be applied.

[0041]

As described above, according to the present invention, one end of the rotating shaft of the rotor is supported in the thrust direction by the thrust board on one side of the bearing, and the stopper portion is provided on the other side of the bearing. Thereby, for example, the stopper mounted on the rotating shaft and the bearing housing abuts against the end face of the bearing,
Alternatively, the inner edge of the stopper ring attached to the bearing housing abuts against the end surface of the stopper collar provided on the rotating shaft, so that the stopper ring can be positioned and held so as not to move in the thrust direction.

In this case, since the stopper is provided in a liquid-tight manner on the other side of the bearing housing, the bearing is hermetically sealed in the bearing housing by the stopper. Therefore, when the rotor rotates at high speed, even if the lubricating oil impregnated in the bearing leaks out, the lubricating oil does not leak out of the bearing housing. Thus, it is possible to reliably prevent the lubricating oil from scattering inside the motor and shortening the life of the motor.

Thus, according to the present invention, it is possible to provide an extremely excellent spindle motor in which the lubricating oil impregnated in the bearing is prevented from leaking into the motor even during high-speed rotation.

[Brief description of the drawings]

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

FIG. 2 is a plan view of a stopper in the spindle motor of FIG.

FIG. 3 is a schematic sectional view showing a configuration of a second embodiment of the spindle motor according to the present invention.

FIG. 4 is a schematic sectional view showing a configuration of an example of a conventional spindle motor.

[Explanation of symbols]

 10, 40 Spindle motor 11 Stator 12 Bearing 13 Plate 14 Stator substrate 15 Core 16 Coil 17 Bearing housing 17a Second groove 18 Thrust board 19 Thrust washer 20 Rotor 21 Rotor yoke 22 Rotor magnet 23 Bush 24 Rotary shaft 24a First groove 25A Stopper part 25 Stopper 25a Claw part 25b Convex part 30 Turntable 41 Stopper collar 42 Stopper ring

Claims (5)

[Claims] An impregnated bearing provided in a bearing housing, a rotor rotatably supported by a rotating shaft mounted in the bearing, and a stator provided around the bearing housing. A spindle motor in which one end of the rotating shaft is supported in the thrust direction by abutting a thrust board in a bearing housing on one side of the bearing. In the vicinity of the other side of the bearing, the bearing housing is supported so as not to move in the thrust direction by a substantially liquid-tight stopper portion on the other side opened into the motor. Features spindle motor. A first groove formed in the outer periphery of the rotating shaft along the circumferential direction near the other side of the bearing in the axial direction; and an inner periphery of the bearing housing. A second groove formed along the circumferential direction outside the bearing from the first groove in the axial direction, and an inner peripheral edge is engaged in the first groove and the second groove is formed. A substantially disk-shaped stopper having a step in the radial direction such that an outer peripheral edge is engaged with the stopper. 3. The stopper according to claim 2, wherein an inner peripheral edge of the stopper is provided with a claw that fits into the first groove.
A spindle motor according to item 1. 4. The spindle motor according to claim 3, wherein a claw portion on an inner peripheral edge of the stopper is formed to be thin. 5. An annular stopper collar attached to the outer periphery of the rotary shaft in the axial direction near the other side of the bearing, and the stopper portion is provided at the other end of the rotary shaft with respect to the stopper collar. The spindle motor according to claim 1, further comprising: an annular stopper ring attached to the other side of the bearing housing that opens into the motor so as to abut.