JPH07322554A - Motor and method for adjusting the vertical axis of the motor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a motor and a method for adjusting the axial droop of the motor, which allows the axial droop adjustment of the rotor to be performed with high accuracy even when the bearing inner diameter is small. [Structure] A housing 13 having a mounting surface, a bearing housing portion 14 integrally mounted to the housing, and radial bearings 15 and 16 press-fitted into the bearing housing portion,
In the motor 10, which includes the rotary shaft 21 supported by the radial bearing and receiving the radial load, the bearing housing portion is loosely fitted into the mounting hole 13d of the housing and is filled in the fitting gap. Motor 1 so that it can be fixedly held to this housing by an adhesive.
Configure 0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for placing a magnetic disk, an optical disk or a magneto-optical disk or a laser polygon mirror on a rotor to drive the rotor, and a magnetic tape or a magneto-optical tape on the rotor. Alternatively, the present invention relates to a method of mounting a motor for winding and driving an optical tape and a bearing for supporting a radial load of the rotor.

[0002]

2. Description of the Related Art Conventionally, such a motor uses a bearing device utilizing a radial bearing, for example, a sintered oil-impregnated bearing, as shown in FIG. 8, for bearing a rotor. The bearing device 1 includes a housing 2 mounted by screwing or the like to a chassis to which a motor is mounted, and two radial bearings arranged in a bearing housing 2a formed integrally with the housing 2. 3 and 4.

In the case of the housing 2, the mounting surface 2b, which is the upper surface of the right end portion, is brought into contact with the motor mounting surface of the chassis (not shown), and is screwed to the mounting surface via the screw hole 2c. It is designed to be screwed in.

The bearing accommodating portion 2a of the housing 2 is also
Is formed such that its inner surface has a central axis O concentric with the centerline of the rotor to be bearing. In this case, the housing 2 is manufactured by, for example, die-casting in order to make the position of the mounting surface 2b and the bearing housing 2a and the axial descent highly accurate.

The radial bearings 3, 4 are, for example, sintered oil-impregnated bearings, and are fixedly held in the bearing housing portion 4a of the housing 2 by being press-fitted therein.

In the bearing device 1 thus constructed, the central axes of the radial bearings 3 and 4 are made to coincide with the motor rotation axis, that is, the central axes of the radial bearings 3 and 4 with respect to the mounting surface 2b of the housing 2. The so-called vertical adjustment to make it vertical is
This is done in several ways:

That is, according to the first method, the housing 2
After press-fitting the radial bearings 3 and 4 into the bearing housing 2a, the axial mounting is adjusted by cutting the mounting surface 2b of the housing 2 with the inner diameter of the radial bearings 3 and 4 as a reference.

Further, according to the second method, the mounting surface 2b of the housing is previously fixed to the bearing accommodating portion 2 of the housing 2.
Axial adjustment is performed by cutting the inner surface of a with high accuracy and press-fitting the radial bearings 3 and 4 in which the runout accuracy of the bearing outer diameter with respect to the inner diameter of the bearing is processed with high accuracy.

Further, according to the third method, in the second method, by reducing the press-fitting allowance of the radial bearings 3, 4 to suppress the deterioration of accuracy due to the press-fitting as much as possible, the axial hanging adjustment can be performed. Done.

[0010]

The bearing device 1 as described above.
In any of the above-described axial hanging adjustment methods,
When the inner diameters of the radial bearings 3 and 4 are relatively large, such as 2 to 3 mm or more, highly accurate axial adjustment is performed.

By the way, in recent years, further miniaturization and higher density have been promoted in a disk rotation driving device such as a magneto-optical disk, and rotational fluctuation of the disk surface during recording / reproducing can be suppressed with high accuracy. Are required to do so.

However, in the above-described method of adjusting the shaft droop of the bearing device 1, when the bearing inner diameter is reduced to, for example, about 1.2 mm, the shaft bends in the press-fitting process, so that the shaft droop adjustment with high accuracy is performed. Therefore, the axle is about 5 ', which is several times that required. This is because the bearing inner diameter used as the machining reference surface is small, so that the rigidity of the machining reference surface becomes insufficient, and as a result, it becomes impossible to obtain a highly accurate axial pendant.

In view of the above points, the present invention provides a motor and a method for adjusting the axial droop of the motor, which allows the axial droop adjustment of the rotor to be performed with high accuracy even when the inner diameter of the bearing is small. It is an object.

[0014]

According to the present invention, the above object is to provide a housing having a mounting surface, a bearing accommodating portion integrally mounted to the housing, and a radial bearing press-fitted into the bearing accommodating portion. A rotor having a rotating shaft supported by the radial bearing and receiving a radial load, wherein the bearing accommodating portion is loosely fitted into a mounting hole of the housing and is fitted therein. Achieved by a motor that is fixed in place with respect to this housing by an adhesive filling the interspace.

Further, according to the present invention, the above object has a housing having a mounting surface, a radial bearing integrally mounted to the housing, a radial load supported by the radial bearing, and a rotating shaft. A motor including a rotor, wherein the radial bearing is loosely fitted in a mounting hole of a housing, and adhesive is filled in a fitting gap of the radial bearing at a predetermined position with respect to the housing. Achieved by the motor being fixed.

In the motor according to the present invention, preferably, the adhesive has a curing shrinkage of 10% or less and a cured product hardness of Shore D90 or less.

In the motor according to the present invention, preferably, the adhesive is an epoxy adhesive, an anaerobic adhesive or an ultraviolet curable adhesive.

In the motor according to the present invention, the adhesive is preferably mixed with organic or inorganic fine particles having a particle size of 50 μm or less.

Further, according to the present invention, the above object is to provide a housing having a mounting surface, a bearing accommodating portion integrally mounted to the housing, a radial bearing press-fitted into the bearing accommodating portion, and the radial bearing. A method of axially adjusting a motor, the method including: a rotor having a rotating shaft supported by and having a radial load; a step of press-fitting a radial bearing into a bearing accommodating portion; Loosely, and the step of holding the mounting surface of this housing in a predetermined position by abutting the mounting surface of this housing against the reference surface of the assembly jig while inserting the radial bearing into the shaft portion of the assembly jig. And a method of filling the fitting gap between the bearing housing and the mounting hole of the housing with an adhesive and curing the adhesive.

[0020]

According to the above construction, the bearing housing portion or the radial bearing in which the radial bearing is press-fitted is loosely fitted into the mounting hole of the housing, and then the bearing housing portion or By accurately positioning the radial bearing with respect to the mounting surface of the housing, the bearing accommodating portion or the radial bearing can be vertically adjusted with respect to the housing with high accuracy. Then, from this state, the bearing accommodating portion or radial bearing is filled with an adhesive in a fitting gap between the bearing accommodating portion or the radial bearing and the mounting hole of the housing and hardened, whereby the bearing accommodating portion or the radial bearing is attached to the housing mounting surface. As a result, the axis is adjusted with high precision and fixed.

As a result, even when the bearing inner diameter of the radial bearing is extremely small, for example, 1.2 mm, the axial adjustment of the mounting surface of the housing with respect to the inner diameter surface of the bearing can be performed by adjusting the rotary shaft inserted in the radial bearing. Since it is performed based on the standard, it is possible to adjust the vertical axis with high accuracy.

When the above-mentioned adhesive has a curing shrinkage of 10% or less and a hardness of the cured product is Shore D90 or less, for example, an epoxy adhesive, an anaerobic adhesive or an ultraviolet curable adhesive, the adhesive is adhered. Since the curing strain due to the curing of the agent is relatively small, the deviation of the axial adjustment due to the curing of the adhesive is suppressed.

When organic or inorganic fine particles having a particle size of 50 μm or less are mixed in the adhesive, the curing shrinkage of the adhesive is substantially reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to FIGS. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 shows an embodiment of a magneto-optical disk drive device as an example of a drive device incorporating a motor according to a preferred embodiment of the present invention. In FIG.
The magneto-optical disk drive device 10 includes a stator 11 and a rotor 20.

The stator 11 has a housing 13 mounted to the chassis 12 by screwing or the like, a bearing accommodating portion 14 integrally attached to the housing 13, and two radial press-fitted bearing inner surfaces of the bearing accommodating portion 14. Bearings 15 and 16, a thrust bearing 17 attached to the lower end of the bearing housing 14, an iron core 18 arranged around the bearing housing 14, and a coil 19 wound around the iron core 18 are provided. There is.

The housing 13 is manufactured as, for example, a pressed part, and in the illustrated case, the upper surface of the right end portion is formed as a mounting surface 13a serving as a mounting reference surface for the chassis 12. And this mounting surface 1
As shown in FIG. 2, 3a is brought into contact with the motor mounting surface 12a of the chassis 12 and is screwed to this mounting surface by the screw 13c through the screw hole 13b.

Further, in the housing 13, the bearing accommodating portion 14 is loose, for example, 0.01 mm to 0.1 mm.
The mounting hole 13d is fitted so as to have the fitting gap. In the illustrated case, the housing 13 is formed such that the periphery of the mounting hole 13d extends slightly upward so that the bearing housing 14 can be held securely.

The bearing accommodating portion 14 is formed so that the inner diameter surface of the bearing has a central axis O concentric with the central line of the rotating shaft to be borne.

The radial bearings 15 and 16 are, for example, sintered oil-impregnated bearings, and are fixedly held in the bearing accommodating portion 14 by being press-fitted into the bearing accommodating portion 14.

Further, the coil 19 wound around the iron core 18 is connected to an external power source to supply power.

On the other hand, the rotor 20 corresponds to the radial bearing 1 described above.
5, the rotary shaft 21 inserted into the rotary shaft 21, the lower end of which contacts the thrust bearing 17, the turntable 22 mounted on the upper end of the rotary shaft 21, and the turntable 22.
, A cylindrical magnet 24 extending downward from the outer peripheral portion of the turntable 22, and a permanent magnet attached to the inner surface of the yoke 24 so as to face the iron core 18. 25 are provided.

By mounting an information recording medium such as a magneto-optical disk on the upper surface of the turntable 22, the magneto-optical disk is rotationally driven at a predetermined speed.

The chuck magnet 23 fixes the magneto-optical disk mounted on the upper surface of the turntable 22 by a magnetic attraction force.

Here, the mounting of the bearing accommodating portion 14 of the stator 11 to the housing 13 is performed as follows using the assembly jig shown in FIGS. 2 and 3. 2 and 3, the assembly jig 30 includes a reference surface 31 formed on the upper surface, and a reference shaft 32 protruding upward from the reference surface 31.

The reference surface 31 is mounted on the mounting surface 13 of the magneto-optical disk drive device 10 by turning the housing 13 upside down.
a is abutted, and in the illustrated case, a screw hole 3 for fixing and holding the housing 13 is further provided.
1a is provided. As a result, this housing 13
The mounting screw 13c is screwed into the screw hole 31a through the screw hole 13b, so that the mounting screw 13c is fixedly held to the reference surface 31.

The reference axis 32 is the reference surface 31.
On the other hand, it is attached in a state in which the vertical adjustment is performed with high accuracy in advance.

In the assembly jig 30 thus formed, the bearing housing portion 14 into which the radial bearings 15 and 16 and the thrust bearing 17 have been previously press-fitted is attached to the mounting hole 1 of the housing 13.
3d is loosely fitted and mounted. At this time, the mounting surfaces 13 a of the housing 13 are brought into contact with the reference surface 31 of the assembly jig 30 while fitting the radial bearings 15 and 16 of the bearing housing portion 14 into the reference shaft 32 of the assembly jig 30. Then, the housing 13 is fixedly held to the reference surface 31 by the screw 13c.

As a result, the housing 13 is held with its mounting surface 13a in contact with the reference surface 31 of the assembly jig 30. At the same time, the bearing accommodating portion 14 loosely fitted into the housing 13 is slightly inserted in the mounting hole 13d of the housing 13 by the radial bearings 15 and 16 press-fitted therein being fitted into the reference shaft 32. It will be moved to and the vertical adjustment will be made. At this time, since the reference shaft 32 is vertically adjusted with respect to the reference surface 31 with high accuracy, the radial bearings 15 and 16 and the bearing accommodating portion 14 are also adjusted with respect to the mounting surface 13a of the housing 13. It will be adjusted with high accuracy.

After that, an adhesive is filled and cured in the fitting gap between the bearing housing portion 14 and the mounting hole 13d of the housing 13. As a result, this bearing housing 1
4 and the radial bearings 15 and 16 are fixed to the housing 13 in a state in which the vertical adjustment is performed with high precision with respect to the mounting surface 13a of the housing 13. In this case, the adhesive is
The bearing accommodating portion 14 and the radial bearings 15 and 16 are used so that the hardening accuracy is small so that the axial hanging accuracy does not decrease. For example, as the adhesive, an epoxy adhesive having a curing shrinkage of 10% or less and a cured product hardness Shore D90 or less, an anaerobic adhesive, an ultraviolet curable adhesive, or the like is used.

Further, in order to further reduce the curing strain of the adhesive, it is preferable to mix organic or inorganic fine particles having a particle size of 50 μm or less in a weight ratio of 60 parts or less.

In the above description, the housing 13
Is attached to the reference surface 31 of the assembly jig 30 with the mounting screw 13
Although it is fixedly held by being screwed by c, the present invention is not limited to this, and as shown in FIG. 4 and FIG. The mounting surface 13a of 13 may be pressed against the reference surface 31.

Magneto-optical disk drive 1 according to the present embodiment
0 is configured as described above, and by feeding power to the coil 19 of the stator 11 from the outside, the coil 1
A magnetic field is generated in the magnetic field 9, and the magnetic field lines thereof interact with the magnetic field lines passing through the iron core 18 and the permanent magnet 25 of the rotor 20 and passing through the yoke. As a result, the rotor 20 is rotated around the rotation shaft 21. Thus, the magneto-optical disk mounted on the turntable 22 of the rotor 20 is rotationally driven at a predetermined speed.

Here, since the rotary shaft 21 is supported against the radial load by the radial bearings 15 and 16 which are vertically adjusted with high accuracy with respect to the mounting surface 13a of the housing 13 as described above, The rotational shake of the table 22 and the magneto-optical disk mounted on it is extremely small.

As a result, in the housing 13 itself, even if the mounting hole 13d of the bearing accommodating portion 14 is not accurately formed with respect to the mounting surface 13a, the bearing accommodating portion 14 is
The vertical adjustment of the mounting surface 13a of the housing 13 is performed with high accuracy. Therefore, the housing 13 is manufactured at low cost by, for example, press molding.

FIG. 6 shows the essential parts of another embodiment of the motor according to the present invention. 6, a motor 40 has a bearing 41 made of synthetic resin or metal with respect to a mounting hole 13d of a housing 13 configured similarly to the embodiment of FIG.
However, it is designed to be attached directly. In this case, the bearing 41 is loosely fitted into the mounting hole 13d of the housing 13, and after the axial adjustment is performed as described above, the fitting gap between the bearing 41 and the mounting hole 13d is filled with the adhesive. -It is fixed and held by being hardened.

FIG. 7 shows the essential parts of a further embodiment of the motor according to the present invention. In FIG. 7, the motor 50
Is a bearing accommodating portion 14 in which radial bearings 15 and 16 are press-fitted and thrust bearings 17 are mounted in mounting holes 13d of a housing 13 configured similarly to the embodiment of FIG.
However, it is held fixed.

In this case, the mounting hole 13d of the housing 13
Is enlarged so that the lower part has a step in the drawing,
It is formed to have an annular groove 13e. As a result, after the bearing accommodating portion 14 is vertically adjusted with respect to the housing 13, when the adhesive is filled in the fitting gap between the bearing accommodating portion 14 and the mounting hole 13d, the adhesive is kept in the annular groove 13e. And the surface area exposed to the outside increases. Therefore, when the ultraviolet curable adhesive is used as the adhesive, the curing of the adhesive is promoted, and the bearing accommodating portion 14 is more securely fixed and held to the housing 13 by this adhesive. Become.

As described above, in the above-described embodiment, the bearing accommodating portion or the radial bearing into which the radial bearing is press-fitted is loosely fitted into the mounting hole of the housing, and then the assembly jig is used. After the bearing accommodating part or the radial bearing is adjusted with respect to the housing with high accuracy, the adhesive is filled into the fitting gap between the bearing accommodating part or the radial bearing and the mounting hole of the housing to cure the adhesive. This bearing accommodating portion or radial bearing will be adjusted with high precision and fixed to the mounting surface of the housing.

Therefore, even when the bearing inner diameter of the radial bearing is extremely small, for example, 1.2 mm, the axial adjustment of the mounting surface of the housing with respect to the inner diameter surface of the bearing is adjusted with reference to the rotary shaft inserted in the radial bearing. Therefore, it is possible to adjust the vertical axis with high accuracy.

Further, the housing itself is formed by press molding or the like because it is not necessary to make the mutual position of the mounting surface and the mounting hole and the axial descent highly accurate. Therefore,
It will be manufactured at low cost. When the above-mentioned adhesive has a curing shrinkage of 10% or less and a cured product hardness of Shore D90 or less, for example, an epoxy adhesive, an anaerobic adhesive or an ultraviolet curable adhesive, the adhesive is cured. Since the hardening strain due to is relatively small, more precise axial adjustment can be obtained.

When organic or inorganic fine particles having a particle size of 50 μm or less are mixed in the above-mentioned adhesive, the deviation of the axial adjustment due to the curing of the adhesive is further suppressed.

In the above-mentioned embodiment, the case of the motor incorporated in the magneto-optical disk drive has been described, but the present invention is not limited to this, and a motor incorporated in other various devices or a single motor may be used. It is obvious that the present invention can be applied.

[0054]

As described above, according to the present invention, even if the inner diameter of the bearing is small, the axial adjustment of the rotor can be performed with high accuracy, and the axial adjustment method thereof. Will be provided.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a magneto-optical disk drive device incorporating a motor according to the present invention.

FIG. 2 is a schematic perspective view showing how the motor of FIG. 1 is attached to a chassis.

3 is a schematic cross-sectional view showing an axial adjustment state by an assembly jig of the motor shown in FIG.

FIG. 4 is a schematic perspective view of the assembly jig of FIG.

5 is a schematic cross-sectional view showing an axial adjustment state by an assembly jig according to another configuration of the motor of FIG.

FIG. 6 is a schematic cross-sectional view of an essential part of a second embodiment of a motor according to the present invention.

FIG. 7 is a schematic cross-sectional view of an essential part of a third embodiment of a motor according to the present invention.

FIG. 8 is a schematic cross-sectional view of a main part of an example of a conventional motor.

[Explanation of symbols]

 10 Magneto-optical disk drive device 11 Stator 12 Chassis 13 Housing 13a Mounting surface 13d Mounting hole 14 Bearing housing 15 Radial bearing 16 Radial bearing 17 Thrust bearing 18 Iron core 19 Coil 20 Rotor 21 Rotation shaft 22 Turntable 23 Chuck magnet 24 Yoke 25 Permanent Magnet 30 Assembly Jig 31 Reference Surface 32 Reference Axis 40 Motor 41 Radial Bearing 50 Motor

Claims (8)

[Claims] 1. A housing having a mounting surface, a bearing accommodating portion integrally attached to the housing, a radial bearing press-fitted into the bearing accommodating portion, and a rotation supported by the radial bearing and receiving a radial load. A motor including a rotor having a shaft, wherein the bearing accommodating portion is loosely fitted to a mounting hole of the housing, and the housing is provided with an adhesive filled in the fitting gap. The motor is characterized in that it is fixed at a predetermined position. 2. A motor comprising: a housing having a mounting surface; a radial bearing integrally mounted to the housing; and a rotor having a rotary shaft supported by the radial bearing and receiving a radial load. The motor is characterized in that the radial bearing is loosely fitted in a mounting hole of a housing and is fixed at a predetermined position with respect to the housing by an adhesive agent filled in a fitting gap. 3. The motor according to claim 1, wherein the adhesive has a cure shrinkage of 10% or less and a cured product hardness of Shore D90 or less. 4. The motor according to claim 1, wherein the adhesive is an epoxy adhesive. 5. The motor according to claim 1, wherein the adhesive is an anaerobic adhesive. 6. The motor according to claim 1, wherein the adhesive is an ultraviolet curable adhesive. 7. The motor according to claim 1, wherein the adhesive contains organic or inorganic fine particles having a particle size of 50 μm or less. 8. A housing having a mounting surface, a bearing accommodating portion integrally mounted to the housing, a radial bearing press-fitted into the bearing accommodating portion, and a rotation supported by the radial bearing and receiving a radial load. A method for adjusting the axial descent of a motor, including a rotor having a shaft, the steps of press-fitting a radial bearing into a bearing housing, loosely fitting the bearing housing into a mounting hole of a housing, and While inserting the bearing into the shaft of the assembly jig,
The step of bringing the mounting surface of the housing into contact with the reference surface of the assembly jig to hold it at a predetermined position, and the step of filling and hardening the adhesive in the fitting gap between the bearing housing and the mounting hole of the housing. A method for adjusting the vertical axis of a motor, which is characterized in that