JPH09200995A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an oil film by both a lubricating-oil supply means and lubricating oil with an oil-impregnated bearing, and to lengthen the lifetime of the revolution of a motor and stabilize rotational performance by supplying the oil-impregnated bearing with lubricating oil by the lubricating-oil supply means and holding lubricating oil so as to be leaked by a holding means. SOLUTION: An oil-impregnated slide bearing 8 is composed of a sintered alloy having a large number of pores, the pores are impregnated with lubricating oil, the outer circumferential surface of a shaft 1 is supplied with the lubricating oil from the pores in the lubricating section of a slight clearance between the shaft 1 and the oil-impregnated bearing 8 together with the revolution of the shaft 1, and an oil film is formed and the shaft 1 is rotated smoothly. Since the oil-impregnated bearing 8 can be fed directly with lubricating oil at all times by an oil-impregnated member 11 such as sponge, lubricating oil in the oil-impregnated sliding 8 is not exhausted until supply from the oil-impregnated member 11 is completed. Accordingly, the lifetime of a motor 11 can be lengthened until the supply of lubricating oil in the oil-impregnated member 11 is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
OM (read only memory using compact disk)
The present invention relates to an improvement of a motor for mounting and rotating an information recording medium such as an optical disc.

[0002]

2. Description of the Related Art A motor for driving a CD-ROM has a structure shown in FIG.
The motor 40 shown in FIG. 4 is a spindle motor and includes a rotor portion 40a and a stator portion 40b. Rotor part 4
Reference numeral 0a includes a shaft 1, a rotor yoke 2, a rotor magnet 3, a turntable 4, and the like. The stator portion 40b includes a stator substrate 5, a bearing holder 6, a coil 7, an iron core 7a and the like. This bearing holder 6
Holds an oil-impregnated sliding bearing 8, and the oil-impregnated sliding bearing 8 is supported by the thrust receiving member 9 on the inner end portion 2a. Therefore, the shaft 1 can be rotated with respect to the stator portion 40b by the oil-impregnated sliding bearing 8. Cap 41
Is attached to the stator substrate 5 side so that the lubricating oil of the oil-impregnated plain bearing 8 does not leak.

Here, the lubricating action of the oil-impregnated plain bearing 8 will be described. The oil-impregnated plain bearing 8 is formed by sintering a metal, and has a structure in which a lubricating oil is impregnated into a pore (hole) generated at the time of sintering. Winding coil 7
When the shaft 1 rotates together with the rotor portion 10a when a predetermined electric current is applied to the shaft 1, the lubricating oil exudes from the pores in the oil-impregnated sliding bearing 8 into the slight gap between the shaft 1 and the oil-impregnated sliding bearing 8, and the shaft 1 Since an oil film is formed between the oil-impregnated sliding bearing 8 and the oil-impregnated plain bearing 8, the shaft 1 is configured to rotate smoothly together with the rotor portion 10a.

[0004]

At this time, if the lubricating oil impregnated in the oil-impregnated sliding bearing 8 is exhausted due to heat generation due to the rotation of the shaft 1 or external temperature change, the shaft 1 will be exhausted. It becomes impossible to form an oil film for smooth lubrication. Therefore, the shaft 1 and the oil-impregnated plain bearing 8 are seized, and the rotor portion 40a cannot rotate normally. That is, it is no exaggeration to say that the life of the conventional motor 40 of FIG. 4 ends when the lubricating oil in the oil-impregnated sliding bearing 8 is exhausted. As described above, although the life of the conventional motor 40 is governed by the consumption of the lubricating oil impregnated in the oil-impregnated sliding bearing 8, the outer periphery of the oil-impregnated sliding bearing 8 is surrounded, and the oil impregnation is structurally impregnated. The plain bearing 8 has a drawback in that it cannot positively supply lubricating oil from the outside and thus cannot extend the life of the motor. Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a motor having a long life and stable rotation performance.

[0005]

SUMMARY OF THE INVENTION In the present invention, the above object is to provide a rotor portion having a shaft and a magnet for rotational driving, a stator portion having a winding coil for rotational driving and a bearing holder, and a bearing. An oil-impregnated bearing, which is held by a holder and rotatably supports the rotor shaft on the stator, a lubricating oil supply means for supplying lubricating oil to the oil-impregnated bearing, and a lubricating oil supply means on the oil-impregnated bearing side. And a holding means for holding and preventing the lubricating oil from leaking to the outside. In the present invention, the oil-impregnated bearing rotatably supports the shaft of the rotor portion with respect to the stator portion. When the shaft of the rotor portion rotates, the lubricating oil supply means can supply the lubricating oil to the oil-impregnated bearing, and the holding means holds the lubricating oil of the lubricating oil supply means so as not to leak outside. . As a result, the lubricating oil supply means can positively supply the lubricating oil to the oil-impregnated bearing inside the motor. Therefore, the oil film can be formed by both the lubricating oil of the lubricating oil supply means and the lubricating oil of the oil-impregnated bearing. Therefore, a long life of rotation of the motor can be achieved, and stable rotation performance can be obtained.

In the present invention, the above object is held by a rotor portion having a shaft and a magnet for rotational driving, a stator portion having a winding coil and a bearing holder, and a bearing holder for rotational driving, A first oil-impregnated bearing for rotatably supporting the shaft of the rotor portion on the stator portion; and a second oil-impregnated bearing for rotatably supporting the shaft of the rotor portion on the stator portion, which is held by the bearing holder. A lubricating oil supply means for supplying lubricating oil to the oil-impregnated bearing, the lubrication oil supply means being achieved by a motor arranged between the first oil-impregnated bearing and the second oil-impregnated bearing. . In the present invention, the first oil-impregnated bearing and the second oil-impregnated bearing rotatably support the shaft of the rotor portion on the stator portion side. When the shaft rotates, the lubricating oil supply means can supply the lubricating oil to the first and second oil-impregnated bearings, and the lubricating oil supply means includes the first oil-impregnated bearing and the second oil-impregnated bearing. The lubricating oil of the lubricating oil supply means does not leak to the outside because it is arranged between the two. Thus, the lubricating oil supply means can positively supply the lubricating oil to both the first oil-impregnated bearing and the second oil-impregnated bearing,
Both the lubricating oil of the lubricating oil supply means and the lubricating oils of the first oil-impregnated bearing and the second oil-impregnated bearing can ensure the rotation performance of the motor and can extend the life of the rotation of the motor.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limitations are given, the scope of the present invention is not limited to these modes unless otherwise specified to limit the present invention. First Embodiment of the Invention FIG. 1 is a sectional view showing a first embodiment of the present invention. In FIG. 1, a motor 10 is a spindle motor, and this motor 10 is a motor for rotating a CD-ROM disk, for example. The motor 10 generally includes a rotor 10a, a stator 10b, and a bearing 1
0c. The rotor section 10a includes a shaft 1, a magnetic rotor yoke 2, a rotor magnet 3, a turntable 4, and the like. Turntable 4 is CD-RO
A table for detachably mechanically clamping a disc D such as an M disc, and is fixed to the upper end portion of the shaft 1 by, for example, press fitting. The magnetic rotor yoke 2 is
Made of magnetic material such as metal such as iron,
The inner end portion 2a is attached to the intermediate portion of the shaft 1 by, for example, press fitting. A rotor magnet 3 is mounted around the inner surface of the magnetic rotor yoke 2. As the rotor magnet 3, for example, a plastic magnet or the like can be used. This rotor magnet 3
On the inner surface of, the N poles and the S poles are alternately magnetized in multiple poles.

Next, the stator portion 10b will be described. The stator portion 10b includes a stator substrate 5, a bearing holder 6, a winding coil 7, an iron core 7a, and the like. The stator substrate 5 is provided with a wiring portion and the like for supplying electricity to the winding coil 7 from the outside. The winding coil 7 is wound around an iron core 7a. For example, a plurality of winding coils 7 are arranged at equal intervals in the circumferential direction. The winding coil 7 and the iron core 7 a are fixed to the bearing holder 6. The bearing holder 6 is a cylindrical member fixed to the stator substrate 5 by, for example, press-fitting, and is made of, for example, iron. Each winding coil 7 is arranged so as to face the rotor magnet 3 described above.

Next, the bearing portion 10c which is a characteristic portion will be described. The bearing portion 10c includes an oil-impregnated plain bearing 8, a thrust receiving member 9, an oil-impregnated member 11 that is a lubricating oil supply unit, a cap 12 that is a holding unit, and the like. The oil-impregnated sliding bearing 8 is preferably cylindrical and rotatably supported from the middle of the shaft 1 to almost the lower portion thereof, and the thrust receiving member 9 includes an upper end surface 8 a of the oil-impregnated sliding bearing 8 and an inner end 2 a of the magnetic rotor yoke 2. It is located in between. The cap 12 is fixed to the lower end of the bearing holder 6 by caulking or the like, and accommodates the oil-containing member 11. That is, the cap 12 holds the oil-impregnated member 11 while pressing it against the lower end surface side of the oil-impregnated sliding bearing 8 and surrounds the oil-impregnated member 11 so that the lubricating oil of the oil-impregnated member 11 does not leak to the outside. The oil impregnating member 11 is a columnar body having a U-shaped cross section having a recess 11a in the center, and the lower end 1a of the shaft 1 is inserted into the recess 11a.

FIG. 2 is an enlarged view of the bearing portion 10c and the shaft 1 of FIG. The oil-impregnated plain bearing 8 is, for example, a sintered metal having many minute pores (holes), and the porous oil is impregnated with lubricating oil. Oil-impregnated plain bearing 8
As the sintered metal for forming the alloy, for example, an alloy made of copper, iron, tin or the like can be adopted. The oil impregnating member 11 is
This is for positively supplying the lubricating oil to the oil-impregnated plain bearing 8 and is obtained by impregnating the resin or fiber with the lubricating oil.
When the oil-impregnated member 11 is made of resin, a resin capable of forming a nest such as polyurethane can be used,
When the oil-impregnated member 11 is made of fibers, chemical fibers such as nylon and vinyl can be used. Regardless of whether resin or fiber is used, it is important not to cause a chemical reaction with the lubricating oil. As the lubricating oil with which the oil-impregnated member 11 and the oil-impregnated sliding bearing 8 are impregnated, the same mechanical oil as the lubricating oil with which the sliding bearing is impregnated can be adopted.

Next, the operation of the motor shown in FIGS. 1 and 2 will be described. Each winding coil 7 of the stator portion 10b
On the other hand, when power is supplied from the outside in a predetermined energization pattern, a magnetic field is generated in the winding coil 7, and the magnetic field lines pass through the iron core 7a and the magnetic field lines passing from the rotor magnet 3 of the rotor portion 10a to the rotor yoke 2. Interact with. As a result, the rotor portion 10a rotates about the shaft 1 with respect to the stator portion 10b, and the disk D clamped on the turntable 4 is continuously rotated.

By the way, when the rotor portion 10a rotates with respect to the stator portion 10b in this way, the oil-impregnated member 11 and the oil-impregnated sliding bearing 8 function as follows with respect to the shaft 1. The oil-impregnated sliding bearing 8 is a sintered metal having many fine pores, and the porous oil is impregnated with lubricating oil. However, as the shaft 1 rotates, a slight gap between the shaft 1 and the oil-impregnated sliding bearing 8 is generated. The lubricating oil is supplied to the outer peripheral surface 1c of the shaft 1 from the porous portion of the oil-impregnated sliding bearing 8 via the path A to the lubricating portion R (see FIG. 2). By supplying the lubricating oil to the outer peripheral surface 1c of the shaft 1, an oil film is formed on the lubrication portion R, and the shaft 1 can rotate smoothly. However, as time passes, the oil-impregnated plain bearing 8
When the lubricating oil present therein is depleted, an oil film cannot be formed on the outer peripheral surface of the shaft 1, so that so-called seizure occurs, the shaft 1 cannot rotate smoothly, and the oil-containing member 11 is Otherwise, there is a possibility that inconvenience such as inability to read the disc D may occur in the CD-ROM drive device.

However, in the first embodiment of the present invention, in order to prevent such an inconvenience, the oil-impregnated member 11 such as a sponge always supplies the lubricating oil directly to the oil-impregnated sliding bearing 8 via the route B in FIG. Therefore, the lubricating oil in the oil-impregnated plain bearing 8 will not be exhausted until the supply from the oil-impregnated member 11 is completed. Therefore, the motor 1 of FIG. 1 and FIG.
A value of 0 can extend the life until the supply of the lubricating oil in the oil-containing member 11 is completed. Further, the lubricating oil is directly supplied to the shaft 1 and the lubricating portion R which is a gap in the oil-impregnated sliding bearing 8 through the path C, so that the rotational life of the motor 10 can be extended, and smooth and stable rotation can be achieved. Can be obtained. Thus, the motor 10 according to the first embodiment of the present invention
Has an oil-impregnated bearing 11 and can positively supply the lubricating oil to the oil-impregnated sliding bearing 8 and the lubrication portion R. Therefore, in the case of only supplying the lubricating oil in the oil-impregnated sliding bearing of the conventional motor, In comparison, the motor 10 of the present invention can remarkably improve the rotation life of the motor and the stable rotation performance.

Second Embodiment of the Invention FIG. 3 is a sectional view showing a second embodiment of the present invention. The second embodiment of FIG. 3 is different from the first embodiment of FIG. 1 in that the bearing holder 6 has a cylindrical first oil-impregnated sliding bearing 33.
a, the second oil-impregnated sliding bearing 33b is held, and the oil-impregnated member 31 which is a lubricating oil supply means is arranged between the oil-impregnated sliding bearings 33a and 33b. FIG.
Other configurations of the motor 30 of the second embodiment are the same as those of the first embodiment in FIG. 1. This oil-impregnated member 31
Is made of the same material as the oil-impregnated member 11 of FIG.
Since it is arranged between the first oil-impregnated bearing 33a and the second oil-impregnated bearing 33b, the lubricating oil impregnated in the oil-impregnated member 31 is prevented from leaking to the outside. The upper surface and the lower surface of the oil-impregnated member 31 are in direct contact with the first oil-impregnated sliding bearing 33a and the second oil-impregnated sliding bearing 33b, respectively. Moreover, as a precaution, a cap 45 for preventing oil leakage is attached to the lower portion of the bearing holder 6. The oil-impregnated member 31 of the second embodiment shown in FIG. 3 can directly supply lubricating oil to the first oil-impregnated sliding bearing 33a and the second oil-impregnated sliding bearing 33b when the shaft 1 is rotating. At the same time, the lubrication part R between the first oil-impregnated plain bearing 33a and the shaft 1
It is also possible to directly supply the lubricating oil between the first and second oil-impregnated sliding bearings 33b and the lubricating portion R2 between the shaft 1. Therefore, the motor 30 of FIG. 3 can extend the life of rotation of the motor 30 until the supply of the lubricating oil from the oil impregnation member 31 is completed, and smooth rotation and stable rotation can be obtained.

As described above, in the first and second embodiments of the present invention, the oil-impregnated member is arranged adjacent to or in contact with the oil-impregnated sliding bearing, and the oil-impregnated member is connected to the oil-impregnated sliding bearing. Since the lubricating oil can be positively supplied inside the motor, the rotational life of the motor can be extended. That is, in the conventional motor, the formation of the oil film depends only on the lubricating oil in the sliding bearing, but in the embodiment of the present invention, the oil film is formed by the lubricating oil impregnated in the oil-containing member and the oil-containing sliding bearing. Since both of the lubricating oils impregnated in the motor can be used, the rotational life of the motor can be significantly extended as compared with the conventional motor.

The present invention is not limited to the above embodiment. For example, in the above embodiment,
Although the oil-impregnated sliding bearing is adopted as the oil-impregnated bearing, the oil-impregnated bearing is not limited to this, and other kinds of oil-impregnated bearings can be adopted. Further, although the motor of the embodiment is used as a motor for driving a CD-ROM, the motor is not limited to this and can be used as a motor for rotating another type of disk or a rotation target.

[0017]

As described above, according to the present invention,
A long life can be achieved and stable rotation performance can be obtained.

[Brief description of drawings]

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

FIG. 2 is an enlarged view showing the vicinity of a bearing portion and a shaft of the motor shown in FIG.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional motor.

[Explanation of symbols]

 1 Shaft 7 Winding coil 6 Bearing holder 8 Oil-impregnated plain bearing (Oil-impregnated bearing) 10a Rotor portion 10b Stator portion 10c Bearing portion 11 Oil-impregnated member (lubricating oil supply means) 12 Cap (holding means) 31 Oil-impregnated member (lubricating oil supply means) 33a First oil-impregnated plain bearing (first oil-impregnated bearing) 33b Second oil-impregnated plain bearing (second oil-impregnated bearing)

Claims (7)

[Claims] 1. A rotor unit having a shaft and a magnet for rotational driving, a stator unit having a winding coil for rotational driving and a bearing holder, and a shaft held in the bearing holder for rotating the shaft of the rotor unit to the stator unit. Oil-bearing for supporting as much as possible, lubricating oil supply means for supplying lubricating oil to the oil-bearing bearing, and holding means for holding the lubricating oil supply means on the oil-bearing side to prevent the lubricating oil from leaking to the outside. And a motor. 2. The motor according to claim 1, wherein the oil-impregnated bearing is a sintered metal having minute cavities, and the lubricating oil supply means is a resin or fiber containing lubricating oil. 3. The motor according to claim 1, wherein the holding means is a cap-shaped container that houses the lubricating oil supply means. 4. The motor according to claim 1, wherein the oil-impregnated bearing is a slide bearing, and a turntable for clamping a disc is attached to the shaft of the rotor portion. 5. A rotor portion having a shaft and a magnet for rotational driving, a stator portion having a winding coil and a bearing holder, and a shaft holder of the rotor portion held by a bearing holder for rotational driving to rotate the shaft of the rotor portion to the stator portion. A first oil-impregnated bearing for rotatably supporting it, and a second oil-impregnated bearing for rotatably supporting the rotor shaft on the stator portion, which is held by the bearing holder, and supplies lubricating oil to the oil-impregnated bearing. Lubricating oil supply means for
And a lubricating oil supply means arranged between the first oil-impregnated bearing and the second oil-impregnated bearing. 6. The motor according to claim 5, wherein the oil-impregnated bearing is a sintered metal having minute cavities, and the lubricating oil supply means is a resin or fiber containing lubricating oil. 7. The motor according to claim 5, wherein the oil-impregnated bearing is a slide bearing, and a turntable for clamping a disc is attached to the shaft of the rotor portion.