JPH09261911A - Inboard spindle motor, and its manufacturing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide easy alignment even with an inboard type fixed bearing used, obtain the squareness of an output shaft to the mounting surface of a housing with high accuracy, and minimize the runout of the output shaft by making a clearance between the bearings smaller. SOLUTION: At the assembled part (Ha) of a case 3 and a bracket 1, a housing H is formed so as to have a play Hb intentionally beforehand. A disc gauge 11 is held temporally at a mounting arm part onto the bracket. An output shaft 7 is fixed on a chucking mechanism 14 to regulate the position of the disc gauge with the chucking mechanism and a limit gauge whose squareness has been adjusted and obtain alignment and squareness. The assembled part is laser-deposited under this condition.

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 CD-ROM drive spindle motor and the like, and in particular, the perpendicularity between the mounting surface and the output shaft of a cantilevered spindle motor having bearings in a case and a bracket, respectively. The present invention relates to a device capable of easily obtaining high precision.

[0002]

2. Description of the Related Art A spindle motor for driving an optical medium such as a CD-ROM is required to have a very small 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 right angle of an output shaft. However, in the case of the so-called double-supported system in which the bearings are arranged on the case and the bracket, respectively, it is necessary to drive the fitting between the case and the bracket and the coaxiality of the bearing with extremely high accuracy. It is difficult to achieve high precision because these members are usually pressed from the viewpoint of cost, and in reality, two or one long bearings are stored in a cylindrical holder placed on only one of the case or bracket. The so-called cantilever method 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.

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 output shaft relative to the mounting surface of the housing. To provide a flat type 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 and a manufacturing apparatus therefor. Is.

[0005]

In order to solve the above-mentioned problems, the case and the bracket, to which the bearings are fixed, respectively have a structure in which they can be moved relative to each other, and the perpendicularity between the mounting surface of the output shaft and the housing is obtained, and then the bracket is moved. It can be achieved by assembling so as not to exist.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION As an embodiment for solving the above problems, a housing is constructed by assembling a case and a bracket in which bearings are respectively arranged, and a rotor having an output shaft protruding from at least one end of the housing is described above. In a dual-support spindle motor that is rotatably supported by bearings, the case and the bracket are formed so that the assembly part has intentional play in advance, and after temporary assembly, the output shaft and the output shaft are It is preferable that after the perpendicularity of the mounting surface of the housing is obtained, the assembling portion is fixed by means other than pressure deformation. As a means other than the above-mentioned pressure deformation, it is preferable to weld the assembly part. Further, as a means other than the above-mentioned pressure deformation, an assembly portion may be adhered. In order to manufacture such a flat type spindle motor, the case and the bracket are formed in advance in the assembly portion so that the assembly portion has a play, the rotor is stored and temporarily assembled, and then the output shaft is chucked and the housing is Temporarily hold the disc gauge on the mounting surface of the, check the surface deviation with the limit gauge or other gauge while rotating this disc gauge, and if it is within the standard, move the disc gauge up and down It is advisable to fix the assembly part by means other than pressure deformation without moving it. Further, spot welding by a laser is desirable as a means other than the pressure deformation. As a device for manufacturing the above flat type spindle motor, chucking for temporarily holding the output shaft protruding to the outside of the housing, a disk gauge for temporarily holding the housing mounting surface, and the amount of surface deviation of the disk gauge It may be provided with a means for fixing the assembly part of the restricting gauge, the case and the bracket by means other than the pressure deformation. A magnet is preferably used as the means for temporarily holding the housing mounting surface of the flat spindle motor of the above-described manufacturing apparatus on the disk gauge.

According to the above-described embodiment, since the case and the bracket are formed so that the assembling portion has the play intentionally beforehand, the clearance between the shaft and the bearing is extremely small by moving either one after the temporary assembling. The bearings can be easily centered on each other, and the mounting surface of the housing is angled and then the assembly part is fixed by means other than pressure deformation. It can be assembled without misalignment.
If the assembly portion is welded as a specific means other than the pressure deformation, it is possible to firmly and securely fix the assembly portion. Furthermore, as a means other than the pressure deformation, the assembly part is adhered,
After the adjustment, the movable side can be fixed without any change. Further, according to the above manufacturing method, the case and the bracket are formed in advance so that the assembly portion has play intentionally, so that the output shaft is chucked after the rotor is housed and temporarily mounted. Temporarily hold the mounting surface on the disk gauge, check the surface deviation with a limit gauge or other gauge while rotating this disk gauge, and if it is not within the standard, move the disk gauge up and down to move the housing Move one side relative to the other, put it within the reference, and without moving it as it is, the assembly part was fixed by means other than pressure deformation, so there is no misalignment and the mounting surface of the shaft and housing You can get the right angle. Furthermore, if spot welding with a laser beam is adopted as a fixing means other than the pressure deformation in such a manufacturing method, it can be firmly completed as a housing. When the manufacturing apparatus of the present invention as described above 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 alignment can be easily performed, and the output shaft and the housing mounting surface are Since a highly accurate squareness is obtained and the case and the bracket as the fixing means are not pressure-deformed, the assembly can be completed while maintaining the centering and the squareness. Further, if the mounting surface of the housing in the above-mentioned manufacturing apparatus, that is, the means for temporarily holding the spindle motor is a magnet, the housing made of an iron plate can be adsorbed, so that the handling becomes simple.

[0008]

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, in which mounting arms 1a, 1a are extended and an oil-impregnated bearing 2 is mounted in a burring hole 1b arranged in the center. The outer periphery of the bracket 1 is a step portion 1c and is thinner than the plate thickness. The housing H is formed by assembling the opening edge 3a of the case 3 having a shallow bottomed cylindrical shape. The mounting portion Ha of the housing H is intentionally designed with play Hb 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 and is formed of a magnetic material, the rotor R is built in and the case 3 is assembled, so that even if there is play Hb in the assembly portion Ha, the magnet is formed. It can be temporarily assembled with a magnetic force of 6. After the aligning and output shaft 7 and the mounting arm portions 1a, 1a have a right angle, the assembled portion is fixed by welding, bonding or the like described later so as not to be deformed under pressure.

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 cross-sectional view of the main part shown in FIG. In FIG.
Is a disk gauge that is a part of a device that determines the perpendicularity between the mounting surface 1a of the bracket 1 and the output shaft 7 that form the housing H.
Is fixed, and the flatness and parallelism of the top and bottom are accurately created. The disk gauge 11 is temporarily held on the lower surface of the housing mounting arm (chassis mounting reference surface) with the magnetic force of a rare earth magnet. Reference numeral 12 is a limit gauge that sandwiches the disc gauge 11 with a very narrow gap (0.01 mm) and provides a perfect perpendicularity to the chucking mechanism. A rubber roller 13 is in contact with the outer diameter of the disc gauge 11, and the disc gauge 11 is gently rotated by a motor (not shown) or the like. Instead of the rubber roller 13, a V-groove (not shown) may be formed on the disk gauge to drive the belt (not shown).

Now, the rotor R is attached to the bracket 1 and the case 3.
After being temporarily assembled by utilizing the magnetic force of the magnet 6, the output shaft 7 is chucked to the chucking mechanism 14, and the disc gauge 11 is attached to the mounting arm portion 1a by the magnetic force of the rare earth magnet 11a. It is temporarily held by being attracted to the lower surface of 1a. After that, if you match well, the disk gauge 11 is the limit gauge 1.
Since the space between the two is loosely fitted, when the rubber roller 13 is rotated, the rubber roller 13 is smoothly rotated to obtain the centering of the output shaft and the perpendicularity between the output shaft and the lower surface of the mounting arm portion. If it is not loosely fitted, the squareness between the output shaft and the lower surface of the mounting arm cannot be obtained, and if the disc gauge 11 is manually moved up and down, the bracket 1 is moved in the radial direction with respect to the case 2. It becomes movable, and the same purpose as described above can be achieved by loosely fitting and rotating smoothly. Then, the assembling portion Ha is spot-welded by the fiberscope S by driving the laser device (not shown) while maintaining this state. At this time, the welded portion does not protrude above the upper surface on the opposite side of the bracket mounting surface 1a from the step 1d. After that, remove the output shaft 7 from the chucking mechanism 14,
Completed by removing the bracket 1 from the disk gauge 11.

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.

[0014]

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. 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. Also, instead of the limit gauge, a normal linear gauge or the like can be used.

[0015]

As described above, in the double-ended spindle motor, the method of manufacturing the same, and the apparatus for manufacturing the same of the present invention, since the case and the bracket are preliminarily formed so as to have a play, the fixed type bearing is used. Even though it is adopted, alignment can be done easily, 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. Moreover, the clearance between the bearing and the shaft can be made small and the runout of the output shaft can be reduced. It can be 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.

[Explanation of symbols]

 1 bracket 1a mounting arm 2 bearing 3 case H housing Ha assembly Hb play 4 brush 5 brush base 6 magnet R rotor 7 output shaft 11 disk gauge as part of manufacturing equipment 11a housing mounting 12 limit gauge 13 rubber roller 14 Chucking mechanism

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H02K 15/16 H02K 15/16 A

Claims (7)

[Claims] 1. A doubly supported 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. In the case and the bracket, the assembly portion is formed beforehand so as to have a play intentionally, and after temporary assembly, one of the two is moved so that the perpendicularity between the mounting surface of the output shaft and the housing is obtained. A double-sided spindle motor that is fixed by means other than pressure deformation. 2. The double-sided spindle motor according to claim 1, wherein an assembly portion is welded as a means other than the pressure deformation. 3. The double-sided spindle motor according to claim 1, wherein an assembly portion is bonded as means other than the pressure deformation. 4. A doubly supported 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. In the manufacturing method described above, the case and the bracket are formed in advance so that the assembly part has play intentionally, the rotor is stored, the output shaft is chucked after the temporary assembly, and the mounting surface of the housing is temporarily held by the disk gauge. While rotating this disk gauge, check the surface shake with a limit gauge or another gauge.If it is not within the standard, move the disk up and down to bring it into the standard, and then press the assembly part except for deformation. A method of manufacturing a doubly supported spindle motor that is fixed by means. 5. The method for manufacturing a doubly supported spindle motor according to claim 4, wherein the means other than the pressure deformation is spot welding by laser irradiation. 6. A doubly supported 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. In the manufacturing apparatus described above, a chucking mechanism that temporarily holds the output shaft, a disk gauge that temporarily holds the mounting surface of the housing, a gauge that regulates the amount of surface deviation of the disk gauge, and an assembly part of the case and the bracket are added. An apparatus for manufacturing a double-sided spindle motor having means for fixing other than pressure deformation. 7. The device for manufacturing a both-end type spindle motor according to claim 6, wherein the means for temporarily holding the housing mounting surface of the both-end type spindle motor on a disk gauge is a magnet.