JPH0956105A - Flat spindle motor, method and apparatus for manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the centering work while enhancing the rectangularity by forming the assembling part of the case and the bracket previously to have a play, setting the rectangularity between an output shaft and the fixing face of the housing by shifting any one of them after temporary assembling, and then securing the assembled part by means other than pressure deformation. SOLUTION: A bracket 1 having an upper surface 1a for mounting as cabinet or the like is fitted to the open edge 3a of a bottomed cylindrical case 3 at an outer circumferential step part 1d thus constituting a housing H. A play Hb is taken into account at the assembled part Ha and after a rotor R is assembled temporarily and centered, the assembled part Ha is secured not through pressure deformation but through welding or adhesion. Consequently, the centering work can be facilitated while employing a fixed bearing 2 and the rectangularity of output shaft 7 can be enhanced with respect to the bracket fixing face 1a of the housing H.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in a compact disk drive spindle motor or the like, and particularly facilitates the squareness of the output shaft and the mounting surface of a flat spindle motor having a double-ended bearing. It is designed to be obtained with high accuracy.

[0002]

2. Description of the Related Art A spindle motor for driving an optical medium such as a compact disc is required to have a minimum degree of shaft runout and a very high degree of horizontality of a media chuck table with respect to a mounting surface, that is, a perpendicularity of an output shaft. However, in the case of the so-called double-supported method in which the bearings are arranged in the case and the bracket, respectively, it is necessary to extremely accurately match the fitting between the case and the bracket and the coaxiality of the bearing. Since these members are usually pressed for cost reasons, it is difficult to achieve high precision.
A so-called cantilever system in which two or one long bearings are housed in a cylindrical holder arranged only on one of a case and a bracket is often used.

[0003]

However, when the motor is required to have a low attitude, for example, about 8 mm or less, in the above cantilever system, the length of the output shaft with respect to the dimension between bearings, That is, the media mounting dimension becomes longer, and the tilt of the shaft tends to occur. Therefore, the lower the attitude of the motor is, the more the flat type must be adopted again, but the coaxiality between the bearings of the case and the bracket must be pushed to the limit, or the clearance between the bearing and the output shaft should be increased. Otherwise, even the flat type can hardly be assembled. Therefore, in addition to the squareness, there is a problem that the output shaft shakes, which is a fatal drawback.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems, and it is possible to easily perform centering while using a double-sided fixed bearing, and at the same time, to the mounting surface of the housing. An object of the present invention is to provide a flat spindle motor that can obtain the squareness of the output shaft with high accuracy, reduce the clearance between the bearing and the output shaft, and reduce the runout of the output shaft, and a manufacturing method thereof. is there.

[0005]

In order to solve the above-mentioned problems, as in the invention described in claim 1, a case is constructed by assembling a bearing and a bracket, respectively, to form a housing, and output is made from at least one end of the housing. In a flat spindle motor in which a rotor with a protruding shaft is rotatably supported by the bearing, the case and the bracket are formed so that the assembly part has intentional play in advance, and either one is movable after temporary assembly. This can be achieved by forming the perpendicularity between the output shaft and the mounting surface of the housing and then fixing the assembling portion by means other than pressure deformation. As a means other than the above-mentioned pressure deformation, as described in claim 2, it is preferable that the assembly portion is welded. Also,
As a means other than the above-mentioned pressure deformation, as shown in claim 3, an assembly part may be adhered. In order to manufacture such a flat type spindle motor, as in the invention described in claim 4, the case and the bracket are formed in advance in the assembly portion so as to have a play intentionally, and the rotor is stored and temporarily assembled. Then, while mounting the device on a device where the mounting surface of the output shaft and the housing are perpendicular to each other and energizing the device to rotate the built-in rotor, move the housing on the opposite side to align and then assemble. This can be achieved by fixing the parts by means other than pressure deformation. Further, as a means other than the pressure deformation,
Laser spot welding is desirable as shown in FIG.
As an apparatus for manufacturing the above flat type spindle motor, as shown in claim 6, a bearing portion that rotatably supports an output shaft protruding to the outside of the housing, and an inner diameter of the bearing portion are perpendicular to each other. A housing mounting portion, a means for temporarily holding the flat spindle motor in the housing mounting portion, a means for rotating an internal rotor by energizing the flat spindle motor, and a pressurizing portion for assembling the case and the bracket. This can be achieved by a means provided with means for fixing by means other than deformation. The means for temporarily holding the flat spindle motor of the manufacturing apparatus can be achieved by using a magnet as described in claim 7. Further, as described in claim 8, the manufacturing apparatus may be provided with means for preventing the function of the housing side temporarily holding the housing attachment portion.

[0006]

According to the means for solving the problems described in claim 1, since the case and the bracket are formed so that the assembling portion has the play intentionally in advance, either the shaft and the bearing can be moved by temporarily moving either one after the temporary assembling. Even if the clearance is extremely small, the bearings can be easily aligned with each other, and then the assembly portion is fixed by means other than pressure deformation, so that the assembly can be assembled without misalignment. As described in claim 2, if the assembling portion is welded as a concrete means other than the pressure deformation, it is possible to firmly and firmly fix the assembly portion. Further, as described in claim 3, as a means other than the pressure deformation, the assembling part is adhered,
After the adjustment, the movable side can be fixed without any change. Further, according to the manufacturing method of the present invention as set forth in claim 4, after the case and the bracket are formed in advance so that the assembly portion has a play intentionally, after the rotor is stored and temporarily mounted, , While rotating the built-in rotor by rotating the built-in rotor by temporarily holding it by a manufacturing device in which the output shaft and the mounting surface of the housing are at a right angle, and then mounting and energizing it, move the housing on the opposite side to a predetermined position. Since it has been adjusted to, the alignment between the shaft and the bearing can be made extremely easy, and the assembled part can be fixed by means other than pressure deformation, so that the shaft is not misaligned. And the perpendicularity of the mounting surface of the housing can be obtained. Further, if the spot welding by the laser beam is adopted as the fixing means other than the pressure deformation in such a manufacturing method as described in claim 5, the housing can be firmly completed. When the manufacturing apparatus of the present invention as set forth in claim 6 is used, even if the clearance between the shaft and the bearing is extremely small, the housing on the side opposite to the mounting side can be moved so that it can be easily aligned and the output shaft is supported. Since the bearing part to be mounted and the housing mounting surface are at a right angle,
Since an extremely accurate squareness is obtained and the case and the bracket are not pressure-deformed as the fixing means, it can be completed while maintaining the centering and the squareness. Further, if the means for temporarily holding the flat spindle motor in the above manufacturing apparatus is a magnet as shown in claim 7, the housing made of an iron plate can be attracted, so that the handling becomes simple. Furthermore, in the above-mentioned manufacturing apparatus, when means for preventing the movement of the housing temporarily holding the housing mounting portion is provided as described in claim 8, when the housing on the non-mounting side is moved even if the holding force is slightly different. , It is possible to prevent the housing on the mounting side from following and moving.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a structure adopted in a face-to-face coreless flat type spindle motor as an embodiment of the present invention will be described with reference to a sectional view of an essential part shown in FIG. In the figure, reference numeral 1 denotes a bracket whose upper surface is a mounting surface 1a to be mounted on a cabinet (not shown) or the like, and an oil-impregnated bearing 2 is fitted into a burring hole 1b arranged in the center and mounted on the outside thereof. Screw holes 1c, 1c are provided. This bracket 1
The outer periphery of is formed to be thinner than the plate thickness at the step portion 1d, and the opening edge 3a of the shallow cylindrical case 3 having a bottom is assembled to form the housing H. Assembly part H of this housing H
As for the a, the play Hb is intentionally taken into consideration as shown in the enlarged view.

A bag-shaped bearing hole 3 is provided at the bottom of the case 3.
b is provided and a bearing 2 similar to the bracket 1 is fitted. At the bottom of the case surrounding the bearing 2, a pair of brushes 4 and 4 are planted via a brush base 5 formed by resin molding integrally with the case, and a ring-shaped magnet 6 is placed. To be done. R is a plurality of air-core coils R1
.., R2, ... Are integrally formed of synthetic resin J together with the output shaft 7 and are arranged with a gap between the bracket 1 and the magnet 6 and through the output shaft 7 the bearing 2 2 is rotatably supported. The rotor R is further provided with a cylindrical commutator 8
Is arranged, and the free ends of the brushes 4 and 4 are slidably contacted to receive electric power. In the figure, Ra is a suction plate for urging the rotor R toward the magnet 6 side, and this urging force is a receiving plate 3c on which the base end of the output shaft 7 is pivotally supported.
Can be accepted by.

Since the bracket 1 constitutes a magnetic circuit of the magnet 6, it is made of a magnetic material. Therefore, by mounting the case 3 with the rotor R built therein, even if there is a play Hb in the mounting portion Ha, the magnet is formed. It can be temporarily assembled with a magnetic force of 6. Then, after the centering is completed, the assembled portion is fixed by welding or adhesion to be described later so as not to be deformed under pressure, and the assembly is completed.

Next, a manufacturing method and a manufacturing apparatus for completing the flat type spindle motor having such a structure will be described with reference to the sectional view of the essential part shown in FIG. In the figure, 11
Is a part of a device that makes a perpendicularity between the mounting surface 1a of the bracket 1 that constitutes the housing H and the output shaft 7. The bearing 11a that rotatably supports the output shaft is provided inside the bearing 11a. A housing mounting portion 11b and a temporary holding neodymium magnet 11c which are orthogonal to each other are arranged. A protrusion 11d for preventing movement of the bracket 1 is provided on a part of the housing mounting portion 11b, and a plurality of laser spot welding fiberscopes S are arranged on the outside. On the other hand, 12 is a part of a device for moving the case 3 back and forth and left and right, and a part 11 of the device.
A non-round hole 12a slightly eccentric with respect to
By fitting a case into the non-round hole and rotating the case with a belt V or the like, the case 3 has a motion of slightly rotating in the front, rear, left, and right directions.

Now, the rotor R is attached to the bracket 1 and the case 3.
The output shaft 7 is housed in the housing H consisting of
As shown in FIG. 3, the protrusion 11d and the mounting hole 1c are aligned with each other while being fitted into the bearing portion 11a of the first unit, and the mounting surface of the bracket is temporarily held in the housing mounting portion 11b by the holding neodymium magnet 11c by using the attraction force. . After that, while applying a low voltage to the external lead-out terminal T,
When the device 12 is fitted into the case 3 and rotated, the current sharply decreases when the centering is obtained. Therefore, the case 3 is stopped moving at this position. A schematic diagram of this movement positional relationship is shown in FIG.
As shown in. That is, the bearing 2 on the case 3 side
Even if is shifted as shown by the imaginary line at the beginning, the case 3 can be adjusted to the front, rear, left and right to obtain the alignment at the position indicated by the solid line. The assembling portion Ha is spot-welded by driving a laser device (not shown) while maintaining this state. At this time, the welded portion does not protrude above the bracket mounting surface 1a beyond the step 1d. After that, by pushing the tip of the output shaft with the protrusion pin P, the main body is removed from the device 11 to complete the process.

With such a manufacturing method and manufacturing apparatus,
Even if the centers of the bearings 2 and 2 of the bracket 1 and the case 3 are deviated from each other, alignment can be performed, and at the same time, the perpendicularity between the mounting surface 1a of the bracket 1 and the output shaft 7 can be obtained with extremely high accuracy.

[0013]

Other Embodiments In the above-described embodiments, the bracket side is used as the mounting surface, but the case and the bracket may be assembled in reverse, and the case side may be used as the mounting surface. Further, although the spot welding by the laser is shown as the fixing means of the assembling part, the entire circumference may be adhered by using an ultraviolet curable adhesive as a means other than the pressure deformation. Furthermore, in the above-described embodiment, the protrusion 11d for preventing the movement of the bracket 1 may not be inserted in the mounting hole 1c, but a guide discard hole may be separately provided and fitted therein. Further, the application of the configuration of the present invention can be applied to a double shaft type motor in which the output shaft projects from both ends of the housing.

[0014]

As described above, in the double-ended flat spindle motor of the present invention and the manufacturing method and manufacturing apparatus thereof, the case and the bracket are formed so that the assembly is intentionally preliminarily provided with play. Despite the use of bearings, centering is easy, and at the same time, the squareness of the output shaft with respect to the mounting surface of the housing can be obtained with high accuracy. Furthermore, the clearance between the bearing and shaft can be reduced to reduce runout of the output shaft. Therefore, it is extremely useful.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view of an essential part of an embodiment of a flat spindle motor according to the present invention.

FIG. 2 is a cross-sectional view of a main part of the motor manufacturing apparatus.

FIG. 3 is a cross-sectional view of essential parts in which the motor is assembled in the manufacturing apparatus.

FIG. 4 is a schematic diagram of a positional relationship of operations for obtaining the centering of the motor.

[Explanation of symbols]

 1 bracket 1a mounting surface 2 bearing 3 case H housing Ha assembly part Hb play 4 brush 5 brush base 6 magnet R rotor 7 output shaft 11, 12 part of manufacturing equipment 11a bearing 11b housing mounting part 12a non-round hole

Claims (8)

[Claims] 1. A flat spindle motor in which a case having a bearing and a bracket are assembled to form a housing, and a rotor having an output shaft protruding from at least one end of the housing is rotatably supported by the bearing. , The case and bracket are formed so that the assembly part is intentionally preliminarily provided with play, and after temporary assembly, either one is moved to align the output shaft and the mounting surface of the housing, and then the A flat type spindle motor in which the assembly part is fixed by means other than pressure deformation. 2. The flat spindle motor according to claim 1, wherein an assembly portion is welded as a means other than the pressure deformation. 3. The flat spindle motor according to claim 1, wherein an assembly portion is bonded as means other than the pressure deformation. 4. A flat spindle motor comprising: a housing in which bearings are arranged and a bracket are assembled to form a housing, and a rotor having an output shaft protruding from at least one end of the housing is rotatably supported by the bearings. In the manufacturing method, the case and the bracket are preliminarily formed with play in the assembling part, the rotor is housed, and after the temporary assembly, the rotor is mounted on a device in which the mounting surface of the output shaft and the housing is perpendicular to each other. While rotating the built-in rotor by energizing the housing, move the housing on the opposite side to align the output shaft and the mounting surface of the housing so that the mounting surface has a right angle. A method for manufacturing a fixed flat spindle motor. 5. The method for manufacturing a flat spindle motor according to claim 4, wherein the means other than the pressure deformation is spot welding by laser irradiation. 6. A flat spindle motor comprising: a housing in which bearings are arranged and a bracket are assembled to form a housing, and a rotor having an output shaft protruding from at least one end of the housing is rotatably supported by the bearings. In the manufacturing apparatus, a bearing portion that rotatably supports the output shaft, a housing mounting portion that is perpendicular to the inner diameter of the bearing portion, a means for temporarily holding the flat spindle motor in the housing mounting portion, and the flat type A flat type spindle motor including means for rotating the built-in rotor by energizing the spindle motor, means for moving the housing on the side opposite to the mounting portion, and means for fixing the assembly portion of the case and the bracket by means other than pressure deformation. Manufacturing equipment. 7. The flat spindle motor manufacturing apparatus according to claim 6, wherein the means for temporarily holding the flat spindle motor is a magnet. 8. The manufacturing apparatus according to claim 6, further comprising means for preventing the movement of the housing, which is temporarily held, in the housing mounting portion.