JP3594399B2 - Doubly supported spindle motor, its manufacturing method and its manufacturing apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is suitable for use in a spindle motor for driving a CD-ROM or the like. In particular, the perpendicularity between the mounting surface of a double-supported spindle motor having bearings on a case and a bracket and an output shaft can be easily and accurately obtained. About what you can do.
[0002]
[Prior art]
A spindle motor for driving an optical medium such as a CD-ROM is required to have a very low 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. In the case of a so-called double-sided system in which bearings are arranged on a conventional case and bracket, it is necessary to drive the fitting of the case and bracket and the coaxiality of the bearing with extremely high precision. Since these members are usually press-processed from the viewpoint of cost, it is difficult to achieve high precision. In practice, two or one long bearings are stored in a cylindrical holder provided only on one of the case and the bracket. The so-called cantilever method is often used.
[0003]
[Problems to be solved by the invention]
However, when the motor is required to have a low attitude, for example, about 8 mm or less, the length of the output shaft, that is, the media mounting dimension is longer than the dimension between the bearings in the cantilever method. The inclination of the axis is easy to come out.
Therefore, the lower the flatness of the motor, the lower the flatness, the more it is necessary to adopt the double-supporting method.However, the coaxiality between the bearings of the case and the bracket must be reduced to the limit, or the clearance between the bearing and the output shaft must be increased. Otherwise, the flat type can hardly be assembled. For this reason, there is a problem that the output shaft deflection, which is a fatal defect other than the squareness, becomes large.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-described problems, and it is possible to easily perform alignment while employing a fixed-type bearing of a doubly supported system, and to set a right angle of an output shaft with respect to a mounting surface of a housing. And a method and an apparatus for manufacturing the same, in which the clearance between the bearing and the output shaft can be reduced, and the run-out of the output shaft can be reduced. .
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, it is possible to achieve a case in which the case in which the bearing is fixed and the bracket are configured to be relatively movable, the output shaft and the mounting surface of the housing are set at a right angle, and then assembled so as not to move.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
As an embodiment for solving the above-mentioned problem, a housing (H) is constructed by assembling a bracket (1) and a case (3) provided with a bearing (2) , respectively, as described in claim 1. at least one end of the output shaft (7) in both lifting type spindle motor the rotor (R) which protrudes formed by rotatably supported via the respective bearing in the housing, said bracket (1), the mounting of A portion (1a) extends in the radial direction from the outer periphery of the case (3), and an assembly portion (Ha) with the case is formed. The assembly portion (Ha) has an opening edge ( 3a) is inserted so as not to protrude from the bracket on the upper surface in the axial direction, and the bracket is received and assembled by a step provided on an opening edge of the case. Between the edge (3a), it can be achieved with those previously deliberately form a radial play (Hb), comprising fixed to the case by welding the bracket in the assembly unit.
As the fixing means, it is preferable that the assembly portion is spot-welded by laser irradiation.
In order to manufacture such a spindle motor, a housing (h) is constructed by assembling a bracket (1) with a case (3) in which bearings (2) are arranged, respectively. In a method for manufacturing a doubly supported spindle motor in which a rotor (R) having an output shaft protruding from one end thereof is rotatably supported on the bearing, the case and the bracket are preliminarily assembled with the assembling portion (Ha) at a play (Hb). ), The rotor (R) projecting the output shaft (7) from at least one end of the housing is stored in the housing via the bearings, and temporarily assembled, and then the output shaft is chucked. Then, the mounting surface of the housing is temporarily held on a disk gauge (11), and while rotating the disk gauge, the surface is shaken by a limit gauge (12) or another gauge. Check, if not within the reference after turning in the reference by vertically moving the disk can be achieved in the process in which a fixed to the case by welding the bracket assembly unit.
The fixing means is preferably spot welding by laser.
In the above-mentioned apparatus for manufacturing a doubly supported spindle motor, the case and the bracket are formed in advance so that the assembling portion (Ha) has a play (Hb) intentionally. After the rotor (R) projecting the output shaft (7) from at least one end of the housing is stored in the housing via the bearings and temporarily assembled, the output shaft is chucked, and the mounting surface of the housing is disc gauged. The disc was temporarily held at (11), and the disc gauge was rotated to check the surface wobble with the limit gauge (12) or another gauge. If the disc was not within the standard, the disc was moved up and down to enter the standard. Then, the bracket is used in a method of manufacturing a double-supported spindle motor which is fixed to a case by welding at an assembly portion, and temporarily holds the output shaft (7). Welding mechanism (14), disk gauge (11) for temporarily holding the mounting surface of the bracket, gauge (12) for regulating the amount of surface deviation of the disk gauge, and welding of the bracket to the case at the mounting part (Ha) Or means for temporarily holding the housing mounting surface on the disk gauge may be provided with a magnet (11a).
[0007]
According to the embodiment as set forth in the first aspect, the case and the bracket are formed such that the assembly portion has a play intentionally in advance. Even if the clearance is extremely small, the center of the bearings can be easily brought out, and after the squareness of the mounting surface of the housing is determined, the mounting part is fixed by means other than pressure deformation. It can be assembled without misalignment while maintaining the same.
If the attachment portion is welded as the fixing means as described in claim 2, the fixing can be performed with high strength and surely.
According to the manufacturing method as set forth in the third aspect, the case and the bracket are formed so as to have play on the assembly portion in advance, so that the rotor is stored and temporarily mounted, Chucking the shaft and temporarily holding the mounting surface of the housing on a disk gauge, check the surface runout with a limit gauge or another gauge while rotating this disk gauge, and raise or lower the disk gauge if it is not within the standard. By moving one of the housings relative to the other, it was moved into the reference, and was not moved, and the assembly was fixed by means other than pressure deformation. The right angle between the shaft and the mounting surface of the housing can be obtained.
Further, if spot welding using a laser beam is employed as a fixing means in such a manufacturing method, the housing can be firmly completed.
Further, by using the manufacturing apparatus of the present invention as described in claim 5, 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 the center can be easily aligned, and the output shaft and the output shaft can be easily aligned. Since the housing mounting surface has a very accurate squareness and does not deform the case and the bracket under pressure as a fixing means, it can be completed while maintaining alignment and squareness.
In addition, if the mounting surface of the housing in the manufacturing apparatus, that is, the means for temporarily holding the spindle motor is a magnet, the housing made of an iron plate can be attracted, so that the handling is simplified.
[0008]
【Example】
Next, as an embodiment of the present invention, a configuration employed in a face-to-face coreless flat spindle motor will be described with reference to a cross-sectional view of a main part shown in FIG.
In the drawing, reference numeral 1 denotes a bracket, which has mounting arms 1a, 1a extending therethrough, and an oil-impregnated bearing 2 mounted on a burring hole 1b arranged at the center. The housing H is formed by assembling the opening edge 3 a of the formed, shallow bottomed cylindrical case 3. As shown in the enlarged view, play Hb is intentionally taken into consideration at the assembly portion Ha of the housing H.
[0009]
A bag-shaped bearing hole 3b is provided at the bottom of the case 3, and a bearing 2 similar to the bracket 1 is fitted therein. A pair of brushes 4 and 4 are implanted at the bottom of the case surrounding the bearing 2 via a brush base 5 formed of resin integrally with the case, and a ring-shaped magnet 6 is mounted thereon. Is done. R is a coreless rotor in which a plurality of air-core coils R1 # and R2 # are integrally formed with a synthetic resin J together with an output shaft 7, and is disposed between the bracket 1 and the magnet 6 with an air gap therebetween. It is rotatably supported by the bearings 2 and 2 via a shaft 7. The rotor R is further provided with a cylindrical commutator 8, and the free ends of the brushes 4, 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, and this urging force is received by a receiving plate 3c on which the base end of the output shaft 7 is pivotally supported.
[0010]
Since the bracket 1 is formed of a magnetic material so as to constitute a magnetic circuit of the magnet 6, the case 3 is assembled with the rotor R built therein. Can be temporarily assembled. After the centering and the output shaft 7 and the mounting arms 1a, 1a are taken at a right angle, the assembly is fixed by welding or bonding as described below so as not to deform the assembly under pressure.
[0011]
Next, a manufacturing method and a manufacturing apparatus for completing the flat spindle motor having such a configuration will be described based on a cross-sectional view of a main part shown in FIG.
In the figure, reference numeral 11 denotes a disk gauge which is a part of a device for forming a right angle between the mounting surface 1a of the bracket 1 constituting the housing H and the output shaft 7, and a strong rare earth magnet 11a is fixed to a thin inside of a lower surface. , Upper and lower flatness and parallelism are accurately created. The disk gauge 11 is temporarily held on the lower surface (chassis mounting reference surface) of the housing mounting arm by the magnetic force of the rare earth magnet.
Reference numeral 12 denotes a limit gauge sandwiching the disk gauge 11 with a very small gap (0.01 mm), and has a perfect perpendicularity to the chucking mechanism. A rubber roller 13 is in contact with the outer diameter of the disk gauge 11, and the disk gauge 11 is slowly rotated by a motor (not shown) or the like.
Instead of the rubber roller 13, a V-groove (not shown) may be formed on a disk gauge to drive the belt (not shown).
[0012]
Now, after storing the rotor R in the housing H composed of the bracket 1 and the case 3 and temporarily assembling it using the magnetic force of the magnet 6, the output shaft 7 is chucked to the chucking mechanism 14 and the disk gauge 11 is connected to the rare earth magnet 11a. Is temporarily held by being attracted to the lower surfaces of the mounting arms 1a, 1a with the magnetic force of.
Thereafter, if the discs are properly fitted, the disc gauge 11 is loosely fitted between the limit gauges 12, so that when the rubber roller 13 is rotated, the disc roller 11 smoothly rotates to align the output shaft and the lower surface of the mounting arm with respect to the output shaft. In the case where the output shaft is not loosely fitted, the perpendicularity between the output shaft and the lower surface of the mounting arm cannot be obtained, and the disk gauge 11 is moved up and down manually or the like. For example, the bracket 1 is movable in the radial direction with respect to the case 2, and the same object as described above can be achieved by loosely fitting and smoothly rotating. Then, by driving a laser device (not shown) while maintaining this state, the assembly portion Ha is spot-welded with the fiberscope S. At this time, the welded portion does not protrude above the upper surface opposite to the bracket mounting surface 1a from the step 1d.
Thereafter, the output shaft 7 is removed from the chucking mechanism 14 and the bracket 1 is peeled off from the disk gauge 11 to complete the operation.
[0013]
With such a manufacturing method and a manufacturing apparatus, even if the centers of the bearings 2 and 2 of the bracket 1 and the case 3 are misaligned, the centering can be performed, and at the same time, the squareness between the mounting surface 1a of the bracket 1 and the output shaft 7 is obtained. Can be obtained with extremely high accuracy.
[0014]
[Other embodiments]
In the above-described embodiment, the bracket is used as the mounting surface. However, the case and the bracket may be reversely combined and the case may be used as the mounting surface.
In addition, although the spot welding by laser is shown as a fixing means of the assembling part, the whole circumference may be bonded by using an ultraviolet curing adhesive as a means other than the pressure deformation.
Further, as an application of the configuration of the present invention, the present invention can also be applied to a double-shaft motor in which the output shaft protrudes from both ends of the housing.
Further, instead of the limit gauge, a normal linear gauge or the like can be used.
[0015]
【The invention's effect】
In the double-supported spindle motor and the method and apparatus for manufacturing the same according to the present invention, the case and the bracket are intentionally formed so as to have play beforehand as described above, so that the centering is performed while employing the fixed bearing. It is very useful because it is possible to obtain the squareness of the output shaft with respect to the mounting surface of the housing with high precision, and to reduce the clearance between the bearing and the shaft to reduce the runout of the output shaft. It will be.
[Brief description of the drawings]
FIG. 1 is a partially enlarged cross-sectional view of a main part of a double-supported flat spindle motor according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part of the motor manufacturing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bracket 1a Mounting arm part 2 Bearing 3 Case H Housing Ha Assembly part Hb Play 4 Brush 5 Brush base 6 Magnet R Rotor 7 Output shaft 11 Disk gauge 11a as a part of manufacturing equipment Housing mounting part 12 Limit gauge 13 Rubber roller 14 Chucking mechanism

Claims (6)

A housing (H) is formed by assembling a case (3) with a bearing (2) and a bracket (1), and a rotor (R) having an output shaft (7) protruding from at least one end of the housing is placed in the housing. A two-sided spindle motor rotatably supported through the bearings,
The bracket (1) has a mounting portion (1a) extending in the radial direction from the outer periphery of the case (3), and an attachment portion (Ha) to the case is formed,
The mounting portion (Ha) is inserted so that the opening edge (3a) of the case does not protrude from the bracket to the upper surface in the axial direction, and is received by the step provided on the opening edge of the case and assembled. so,
A doubly supported spindle motor in which a radial play (Hb) is intentionally formed in advance between the mounting portion and the opening edge (3a), and the bracket is fixed to the case by welding at the mounting portion. 2. The double-supported spindle motor according to claim 1, wherein the fixing portion is formed by spot welding an assembly portion by laser irradiation. A housing (h) is formed by assembling a case (3) with a bearing (2) and a bracket (1), and a rotor (R) having an output shaft protruding from at least one end of the housing is rotatable with respect to the bearing. In the method for manufacturing a double-supported spindle motor supported by the above, the case and the bracket are formed in advance so as to have a play (Hb) intentionally at an assembly portion (Ha), and an output shaft is formed at least from one end of the housing. After the rotor (R) protruding (7) is stored in the housing via the bearings and temporarily assembled, the output shaft is chucked, and the mounting surface of the housing is temporarily held on the disk gauge (11). While rotating the disk gauge, check the surface runout with the limit gauge (12) or another gauge, and if it is not within the standard, move the disk up and down to the standard After turning, the doubly supported type spindle motor manufacturing method comprising fixed to the case by welding the assembly portion of the bracket. 4. The method according to claim 3, wherein said fixing means is spot-welded by laser irradiation. The case and the bracket are formed in advance so that the attachment portion (Ha) has a play (Hb) intentionally, and the rotor (R) that projects the output shaft (7) from at least one end of the housing is inserted into the housing. After being stored through the bearings and temporarily assembled, the output shaft is chucked, the mounting surface of the housing is temporarily held on the disk gauge (11), and the limit gauge (12) or another gauge is rotated while rotating the disk gauge. A method of manufacturing a double-supported spindle motor in which the disc is checked for deviation, and if it is not within the standard, the disk is moved up and down to enter the standard, and then the mounting portion of the bracket is fixed to the case by welding. A chucking mechanism (14) for temporarily holding the output shaft (7), a disk gauge (11) for temporarily holding the mounting surface of the bracket, The gauge (12) for restricting the runout of the disk gauge, said bracket assembly portion (Ha) doubly supported type spindle motor of the manufacturing device provided with means for securing by welding to the case with. 6. The apparatus according to claim 5, wherein the means for temporarily holding the housing mounting surface on the disk gauge is a magnet (11a).

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