JPS63220738A - Motor cantilever bearing structure - Google Patents

Abstract

PURPOSE:To make a cutting work unnecessary and enable an accurate right- angle to be formed between a clamp face and a rotating shaft by forming an apparatus into a separate structure where a pair of bearings are pressed into an outer casing and a housing, respectively. CONSTITUTION:A head of outer casing 20 obtained by press molding is bent inwardly to form a cylindrical part 21. A bearing 4 is pressed into said cylindrical part 21. A housing 22 provided with a collar part 23 touching a horizontal plane of said outer casing 20 and a cylindrical part 24, into which a bearing 3 is pressed, is fitted over an output shaft 2. The top face of said housing 22 forms a clamp face. A recess is formed in the central part of a back cover 13 and a thrust bearing 8 is arranged at said recess.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cantilever bearing structure for a motor, and in particular to a cantilever bearing structure for a motor that aims to improve the perpendicularity accuracy of the motor output shaft to the mounting surface of a direct drive motor. Regarding cantilever bearing structure.

(Prior Art) Generally, in devices where the position of the output shaft of the motor relative to the motor mounting surface affects the characteristics of the device, such as digital audio disk devices, information is engraved with high density on the disk. In a device that uses a laser beam or the like to detect the disc, the positional accuracy of the disc and the sensor affects the playback characteristics.

Therefore, in order to read information without errors, it is required for a direct drive motor that directly drives a disk to improve the perpendicularity accuracy of the motor output shaft to the motor mounting surface.

FIG. 8 is a sectional view showing an example of a general conventional direct drive motor.

The rotating shaft 2 to which the armature 1 is mounted is attached to an outer cylinder 5 which is press-formed via bearings 3 and 4, and a rear cover 6 which is press-formed.
is supported by The disk-shaped rear cover 6 is fitted into the lower end of the outer cylinder 5, and has a recess 7 formed in its center. A thrust bearing 8 is provided.

A magnet 9 serving as a stator is attached to a portion of the inner circumferential surface of the outer cylinder 5 that faces the armature 1 . The upper surface of the outer cylinder 5 has a flat portion, and this flat surface serves as a mounting surface. The angle η between this mounting surface and the rotating shaft (output shaft) 2 must be set to be a right angle.

When assembling the motor, the upper end of the rotating shaft 2 is fitted into a bearing 3 fixed to an outer cylinder 5. Next, the bearing 4 fixedly installed in the recess 7 of the rear cover 6 is fitted into the lower end of the rotating shaft 2, and the peripheral edge of the rear cover 6 is fitted into the lower end of the outer cylinder 5.

By the way, as mentioned above, the angle η is required to be a right angle, but as shown in FIG.
The clearance α between the fitting part between the rear cover 6 and the rear cover 6, and the axial misalignment β between the bearings 3 and 4
There may be cases where mechanical precision cannot be achieved. Also, the 10th
As shown in the figure, the shaft 2 has an inclination T with respect to the mounting surface of the outer cylinder 5.
There is a problem in that it is not possible to achieve perpendicular accuracy if it is assembled as is.

In order to solve this problem, conventionally, as shown in FIG. 11, a configuration has been proposed in which a housing 10 in which a mounting surface and a bearing part are integrated is used, and the surface angle θ can be determined with high accuracy.

As shown in FIG. 12, this housing 10 has bearings 3 and 4 press-fitted into the shaft portion. The housing 10 is the first
As shown in FIG. 3, it is arranged so as to be interposed between the outer cylinder 12 and a mounting plate 11 for a disk device or the like. The outer cylinder 12 has an opening into which the housing 10 can be inserted, and the rear cover 13, which is fitted into the lower part of the outer cylinder 12, is provided with a recess large enough to accommodate the thrust bearing 8.

[Problem that the invention seeks to solve]

However, in such a conventional motor cantilever bearing structure, since the housing is manufactured by cutting, there are problems in that mass productivity is poor and costs increase.

The purpose of the present invention is to provide a cantilevered motor that can solve the problems of the prior art, improve mass productivity, reduce costs, and ensure perpendicularity between the motor mounting surface and the rotating shaft. The purpose of the present invention is to provide a bearing structure.

[Means for solving problems]

In the present invention, bearings are press-fitted into two members formed by press working of metal plate materials, and a cantilever bearing structure for a motor output shaft is formed by a motor outer cylinder assembly in which the two members are joined and integrated. By supporting the motor output shaft with the motor outer cylinder assembly, the motor is mounted with a configuration that maintains the perpendicularity accuracy of the motor output shaft with respect to the surface, thereby achieving the above object.

[Effect]

By aligning the outer cylinder and housing in advance, the pair of bearings installed in the cylindrical part of the outer cylinder and the cylindrical part of the housing will make the angle between the mounting surface and the rotation axis normal. Since the bearings are positioned in this way, a cantilever bearing structure for the motor can be constructed without cutting.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to FIGS. 1 to 7.

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is an explanatory diagram of the assembly of the bearing portion of the embodiment of FIG.

The same reference numerals are used for some parts, so duplicate explanations are omitted, but the neck of the press-formed outer cylinder 20 is bent inward to form the cylindrical part 21, and this cylindrical part The bearing 4 is press-fitted into the housing 21, and the housing 22, which includes a flange 23 that contacts the horizontal surface of the outer cylinder 20 and a cylindrical part 24 into which the bearing 3 is press-fitted, is fitted onto the output shaft. The upper surface of the housing 22 serves as a mounting surface.

Next, the assembly order of the bearing portion in the above configuration will be explained.

When assembling, the shaft 31 and this shaft 31! , ': A jig X3O equipped with a reference 1Ij32 having a facing angle θ is used. The surface angle θ is maintained at extremely high perpendicularity.

Further, a recess into which the cylindrical portion 24 is set during assembly is bored at the base of the shaft 31.

A plurality of through holes 2 are provided in the periphery of the cylindrical portion 21 of the outer cylinder 20.
6 is provided by press working.

Moreover, the bearings 4 and 3 are press-fitted in advance into the cylindrical parts 21 and 24, respectively.

Place the housing 22 upside down and place the bearing 3 on the jig 3.
0, and the collar 23 of the housing 22 with the jig 3.
2 surface. Next, turn the outer cylinder 20 upside down,
The bearing 4 is fitted onto the shaft 31 of the jig 30, and the flat surface of the outer cylinder 20 is brought into contact with the collar 23. In this state, the bearings 3 and 4, which determine the attitude of the rotating shaft 2, are positioned at a highly accurate perpendicularity θ using the reference shaft 31 and the reference surface of the jig 30.

Next, adhesive is injected into the small hole 26 provided in the flat surface of the outer cylinder 20 using the adhesive injection nozzle 40, and the adhesive is injected into the small hole 26 provided in the flat surface of the outer cylinder 20.
0 and the housing 22 are fixed.

Once the adhesive has solidified, the completed casing is removed from the jig 30. The output shaft of the rotating shaft 2 equipped with the armature 1 is connected to the outer cylinder 2.
Each of the bearings 4 and 3 is penetrated from inside 0. Next, the motor rear cover 13 with the thrust bearing 8 attached thereto is fitted into the outer cylinder 20, and the rotor is fixed, thereby completing the motor.

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

In this embodiment, the relationship between the housing and the outer cylinder in the embodiment shown in FIG. 1 is reversed. That is, the neck portion of the outer cylinder 25 whose flat surface is used as a mounting surface is pressed outward to form a cylindrical portion 27, into which the bearing 3 is press-fitted, and is fixed to the inner surface of the root portion of the cylindrical portion 27. And bearing 4
A cylindrical portion 28 into which is press-fitted is provided with a housing 29 formed by press working.

FIG. 4 shows an explanatory diagram of the assembly order of the bearing portion of the embodiment shown in FIG. 3. In this embodiment, a jig 40 is used. The jig 40 has a reference surface 41, and this reference surface 4
A recess is provided at a predetermined position of 1, and a reference shaft 42 held at an angle θ with respect to a reference plane 41 is disposed within the recess.

First, turn the outer cylinder 25 upside down and place the bearing 3 on the shaft 4 of the jig 40.
2 and bring the mounting surface of the outer w125 into contact with the reference surface 41. Next, the bearing 4 is fitted onto the shaft 42 with the flange of the housing 29 facing downward, and the housing 29 and the outer cylinder 2 are
5. Thereby, the bearings 3 and 4 are positioned so that the rotating shaft 2 maintains a highly accurate perpendicularity θ with respect to the mounting surface.

Next, the outer cylinder 25 and the housing 29 are fixed with adhesive using the adhesive injection nozzle 40. The armature 1 and rear cover 13 are attached to the casing thus created in the same manner as described above.
The motor is completed by fixing or installing.

In each of the above embodiments, the outer cylinder and the housing are fixed with an adhesive, but other methods such as welding, caulking, press-fitting, etc. can also be used.

For example, FIGS. 6 and 7 show a method for manufacturing the embodiment shown in FIG. 1 by plasma welding.

FIG. 5 shows a third embodiment of the present invention, in which the flat surface of the outer cylinder 20 and the flange of the housing 23 are on the same plane. For this reason, the flat surface of the outer cylinder 20 is provided with a step in the thickness of the plate of the housing 23. Since the assembly method is the same as in each of the above embodiments, the explanation will be omitted.

FIG. 6 is a second embodiment of manufacturing the structure of the first embodiment of the invention.

In this embodiment, a convex portion 51 that can be fitted into the small hole 26 of the outer cylinder 20 is
A housing 50 having a protruding structure is provided in place of the housing 23 shown in FIG.

FIG. 7 shows an explanatory diagram of the assembly order of the bearing portion of the embodiment shown in FIG. 6. A jig 60 having the same shape as shown in FIG. 4 is used as a jig, and a jig 4 is used to fix the outer cylinder 20 and the housing 50 by plasma welding as in the case of FIG.
0 uses plasma welding, so a conductor is used as the material for the reference surface 61, and an insulator is used for the holding member 62 of the shaft 42.

Place the bearing 3 of the housing 50 in the jig 6 with the four parts 51 facing upward.
0 shaft 42. Next, the bearing 4 of the outer cylinder 20 is fitted into the shaft 42 of the jig 60, and the small hole 26 is fitted into the convex part 51 of the housing 50 while rotating the outer cylinder 20. When the two are superimposed, plasma welding is performed on the small hole 26 using the electrode 45, and the outer cylinder 25 is
and fix the housing 50. The motor is completed by attaching each component to the casing thus created as described above.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, each of the pair of bearings has a separate structure that is press-fitted into the outer cylinder and the housing, so the cutting process that was conventionally required is no longer necessary, and the mounting surface and rotating shaft are separated. It is possible to accurately achieve perpendicular precision between 1 and 2, and it is also possible to improve mass productivity and reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing one embodiment of the present invention, Fig. 2 is a first assembly explanatory diagram for manufacturing the embodiment of Fig. 1, and Fig. 3 shows a second embodiment of the invention. Front sectional view, Figure 4 is the 3rd
The bearing part assembly explanatory diagram of the embodiment shown in the figure, FIG.
6 is a perspective view showing a second assembly example for manufacturing the first embodiment of the present invention, and FIG. 7 is an explanatory diagram of the assembly of the bearing part of the embodiment of FIG. 6. , Fig. 8 is a front cross-sectional view showing an example of a conventional direct drive motor, Fig. 9 is a cross-sectional view showing eccentricity of the bearing, Fig. 10 is an explanatory diagram of shaft inclination in a conventional motor, and Fig. 11 is a cross-sectional view showing the eccentricity of the bearing. To achieve perpendicularity between the mounting surface of the motor and the rotating shaft. 1 is a front cross-sectional view showing a conventional improved disk drive motor. 1... Armature, 2... Rotating shaft, 3.4-- −−−−・−・−Bearing, 8−・−・−
-1--Thrust bearing, 9...--Magnet, 13...--Rear cover, 20.25--
------・Outer cylinder, 21.24.27.28・-・・
-・-Block part, 22.29.50-・・-・・・Housing, 26-・−・・・・Small hole, 51-1---・
−・−Protrusion. Agent Patent Attorney Yasushi Ooto Figure 10

Claims (1)

[Claims] (1) Bearings are press-fitted into two members formed by press working of metal plate materials, and a cantilevered bearing structure of the motor output shaft is formed by a motor outer cylinder assembly that is integrated by joining the two members, A cantilever bearing structure for a motor, characterized in that the perpendicularity of the motor output shaft to the motor mounting surface is maintained by pivotally supporting the motor output shaft with the motor outer cylinder assembly.