JPH1028363A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely insulate the conductor pattern of a motor substrate and a stator core by providing an insulating printed layer silk-printed on the surface of an insulating layer, coating the conductor pattern at the section where the motor substrate and an auxiliary core plate overlap each other. SOLUTION: At the section where a motor substrate 10 and an auxiliary core plate 12 overlap each other, an insulating printed layer 19 is formed by silk printing on the surface of an insulating layer 18b, coating a conductor pattern 17 formed around a screw-tightening hole 10b. Since the printed layer 19 is formed by silk printing, the insulating layer 18b is not scratched by the auxiliary core plate 12, and no short circuit occurs between a stator-core 13 and the conductor pattern 17. In other words, the insulating property of the conductor pattern 17 can be improved, because the pattern 17 is not only coated with the insulating layer 18b, but also with the printed layer 19, in the part of the section where the substrate 10 and core plate 12 overlap each other, such as the circumference of the hole 10b where short-circuits are apt to occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a spindle motor applied to a drive device such as a floppy disk. More specifically, the present invention relates to a structure for fixing a stator core and a motor substrate.

[0002]

2. Description of the Related Art A spindle motor applied to a drive device such as a floppy disk has a stator core having windings wound around salient poles on a motor substrate.
However, since it is necessary to secure a winding space between the salient poles and the substrate, a spacer plate made of resin or the like is interposed between the stator core and the substrate, and the stator core is often floated from the substrate. .

[0003]

However, in a structure using a spacer plate separate from the stator core to secure a winding space, the number of parts and the number of assembling steps are increased, so that the cost of the spindle motor is increased. There is.

Therefore, a structure is conceivable in which an auxiliary core plate is provided at the lowermost portion of the stator core without using the spacer plate as a separate member, and a winding space is secured by the auxiliary core plate.
However, in this structure, since the auxiliary core plate is in contact with the motor substrate, even if the conductor pattern on the motor substrate is covered with the insulating layer, the insulating layer is damaged by the auxiliary core plate, and the conductor pattern and the stator core are separated. There is a problem of short circuit.

[0005] An object of the present invention is to solve the above problems, and without causing a significant cost increase.
An object of the present invention is to provide a spindle motor that can reliably insulate a conductor pattern of a motor substrate from a stator core.

[0006]

In order to solve the above-mentioned problems, the present invention provides a motor substrate having an insulating layer formed on the surface side of a conductive pattern, a motor substrate fixed on the motor substrate, and In a spindle motor having a stator core wound with windings, the stator core includes an auxiliary core plate for securing a winding space between the salient poles and the board, and On the insulating layer covering the conductor pattern at a portion overlapping with the auxiliary core plate, an insulating printing layer silk-printed on the surface of the insulating layer is provided.

In the present invention, the winding space is secured by the auxiliary core plate formed at the bottom of the stator core.
The number of parts and the number of assembly steps do not increase. Therefore, the cost does not increase significantly. In addition, in the portion of the motor substrate surface where the auxiliary core plate overlaps, not only the insulating layer but also the insulating printed layer is formed on the surface of the conductive pattern, so that the insulating layer is not damaged, so that the conductive layer is not damaged. The pattern does not short-circuit with the auxiliary core plate of the stator core.

In the present invention, the motor board is formed with three screw mounting holes for penetrating the auxiliary core plate and fixing screws for fixing the stator core and the motor board, and around the screw mounting holes. Preferably, the conductive pattern is formed, and the printed layer is formed on the insulating layer covering the conductive pattern.

With this configuration, it is possible to improve the insulation at the portion where the motor board and the auxiliary core plate are most likely to be short-circuited, such as around the screw mounting hole. In addition, since the convex portion is formed around the screw mounting hole by the thickness of the printing layer, the auxiliary core plate is in a state of being floated from the surface of the motor substrate by the thickness of the printing layer. Therefore, in the portion where the motor substrate and the auxiliary core plate overlap, a printed layer may be formed on the surface of the insulating layer for all the conductor patterns, but only the conductor patterns around the screw holes are printed on the surface of the insulating layer. Even when the layers are formed, insulation between the stator core and the conductor pattern can be reliably achieved. Moreover, since there are three such portions, the stator core is fixed in a stable state even if the motor substrate is distorted.

In the present invention, the stator core includes a plurality of core plates provided with the salient poles, and the auxiliary core plate made of the same material as the core plate. The core plate is preferably formed by laminating and caulking. With this configuration, since the auxiliary core plate and the core plate are made of the same material and integrated by laminating and caulking, they can be manufactured by a series of pressing steps. Therefore, the stator core can be manufactured at low cost, and the cost of the spindle motor can be reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a spindle motor to which the present invention is applied.

As shown in FIG. 1, a spindle motor 1 serving as a driving device for a 3.5-inch floppy disk or the like includes a rotor assembly 2 and a stator assembly 3.
It is composed of

The rotor assembly 2 includes a rotating shaft 4, a cup-shaped rotor case 5 fixed concentrically to the rotating shaft 4, and a rotor magnet fixed to the inner peripheral surface of the rotor case 5 via a yoke 6. 7 is comprised. A hub base 9 a is attached to the upper end surface of the rotor case 5 concentrically with the rotating shaft 4. Further, at a position shifted from the rotation shaft 4, a drive pin 9b protrudes from a groove 9c formed in the hub base 9a. A metal hub (not shown) attached to the center of the 3.5-inch floppy disk is held by the hub base 9a. A frequency power generation magnet 5 a is attached to the outer peripheral surface of the rotor case 5. The frequency power generation magnet 5a is opposed to a frequency power generation pattern (not shown), and generates a frequency signal in the frequency power generation pattern by rotating the frequency power generation magnet 5a together with the rotor assembly 2. The rotation speed of the rotor assembly 2 can be detected from the frequency signal. The rotor assembly 2 is supported by a thrust bearing 11 attached to a stator assembly 3 described below, and is rotatable about a rotation shaft 4.

The stator assembly 3 includes a motor board 10
A bearing holder 8 attached to a center hole 10 a formed in the motor substrate 10, a thrust bearing 11 attached to the outer peripheral surface of the bearing holder 8, and a concentric arrangement with the thrust bearing 11 on the surface of the motor substrate 10. And a winding 14 wound around a salient pole 15b of the stator core 13.

As will be described later with reference to FIGS. 2 to 4, the stator core 13 has the same shape 3
It comprises a core plate 15 and an auxiliary core plate 12 having no salient poles. These are stacked with the auxiliary core plate 12 at the bottom. The auxiliary core plate 12 provides a space for the winding 14 between the salient poles 15 b of the stator core 13 and the motor board 10.

FIG. 2 is a plan view of the stator core. FIG. 3 is a plan view of an auxiliary core plate used for the stator core. FIG. 4 is a sectional view of a portion corresponding to about 1/2 of the stator core.

As shown in FIG. 2, the core plate 15 has an annular base 15a and a plurality of salient poles 15b projecting radially from the base 15a at equal angular intervals. The tip of the salient pole 15b is a flange 15c that extends in the circumferential direction. The winding 14 is wound around the salient pole 15b. The auxiliary core plate 12
As shown in FIG. 3, an outer peripheral portion 12a having an E-shaped ring shape as a whole and formed in a substantially C-shape, and projecting portions 12b and 12c protruding inward from both ends of the outer peripheral portion 12a.
And a protruding portion 12d protruding inward from a central portion of the outer peripheral portion 12a. Outer peripheral portion 1 of auxiliary core plate 12
2a has a shape completely overlapping the base 15a of the core plate 15,
In the overlapping portion, three holes 13d are formed in both the auxiliary core plate 12 and the core plate 15 at angular intervals of about 120 °.

Here, the core plate 15 and the auxiliary core plate 12 are made of the same magnetic material. Also, the core plate 1
5 and the auxiliary core plate 12 are integrally formed by caulking in a stacked state. Outer peripheral portion 1 of auxiliary core plate 12
As shown in FIG. 3, four caulking holes 12e are formed in 2a at intervals. Therefore, as shown in FIG. 4, in a state where three core plates 15 are stacked on the auxiliary core plate 12, the corresponding portions of the core plate 15 are directed toward the caulking holes 12 e of the auxiliary core plate 12. These are integrated by pressing the
3 is manufactured. Stator core 13 thus configured
Is mounted and fixed on the motor board 10 shown in FIG.

FIG. 5 is a plan view showing a motor board.

As shown in this figure, the motor board 10
It has a center hole 10a to which the bearing holder 8 is attached, and around this center hole 10a, three screw attachment holes 10b are formed at angular intervals of about 120 °. When the stator core 13 is arranged on the motor board 10, these screw mounting holes 10 b are located at positions that overlap the holes 13 d formed in the stator core 13. A printing layer 19 described later is formed in a substantially C shape around the screw mounting hole 10b so as to surround the screw mounting hole 10b.

FIG. 6 is an explanatory view showing an enlarged view of the portion A shown in FIG.

As shown in this figure, the motor board 10
For example, it has a base plate 10c made of iron or the like, an insulating base layer 18a covering the base plate 10c, a conductor pattern 17 formed thereon, and an insulating layer 18b covering the entire surface. With respect to the motor board 10 having such a configuration, the screw 16 fixed from the screw mounting hole 10b penetrates the auxiliary core plate 12 and fits into the hole 13d of the stator core 13,
The stator core 13 and the motor substrate 10 are fastened together. However, in such a configuration, if the insulating film 18b is damaged by the auxiliary core plate 12, the auxiliary core plate 12 and the conductor pattern 17 are short-circuited.

Therefore, according to the present invention, in the portion where the motor substrate 10 and the auxiliary core plate 12 overlap, the conductor pattern 17 formed around the screw mounting hole 10b is provided on the surface of the insulating layer 18b covering the same. The insulating printing layer 19 is formed by silk printing. Here, the printing layer 19 may be formed by, for example, printing characters for displaying a component name, a component mounting position, and the like on the surface of the motor substrate at the time of silk-printing. There is an advantage that the number of processes does not increase.

In this manner, the screw mounting hole 10 is formed in the portion where the motor substrate 10 and the auxiliary core plate 12 overlap.
Since the conductor pattern 17 is covered not only with the insulating layer 18b but also with the printed layer 19 in the area where the short circuit is most likely to occur, such as around the area b, the insulation can be improved. Also,
Since the protrusions are formed around the screw mounting holes 10 b by the thickness of the print layer 19, the auxiliary core plate 12 is in a state of floating by the thickness of the print layer 19 from the surface of the motor substrate 10. Therefore, the motor substrate 10 and the auxiliary core plate 12
In the part where the pattern overlaps, the printed layer 19 may be formed on the surface of the insulating layer 18b for all the conductor patterns 17,
Even when the printed layer 19 is formed on the surface of the insulating layer 18b only for the conductor pattern 17 around the screw mounting hole 10b, the insulation between the stator core 13 and the conductor pattern 17 can be ensured. Moreover, since there are three such portions, even if the motor substrate 10 is distorted, the stator core 12 is fixed in a stable state.

As described above, in the spindle motor 1 to which the present invention is applied, since the winding space is secured by the auxiliary core plate 12 formed at the lowermost part of the stator core 13, the number of parts and the number of assembling steps do not increase. Therefore, the cost does not increase significantly. In the portion of the surface of the motor substrate 10 where the auxiliary core plate 12 overlaps, not only the insulating layer 18b but also the insulating printed layer 19 is formed on the surface of the conductor pattern 17, so that the insulating layer 18b is not damaged. It is hard to stick,
The conductor pattern 17 is the auxiliary core plate 12 of the stator core 13.
And do not short circuit.

Further, in the present invention, since the auxiliary core plate 12 and the core plate 15 are made of the same material and integrated by laminating and crimping, the stator core 13 can be manufactured by a series of pressing steps. Therefore, the stator core 13 can be manufactured at low cost, and the cost of the spindle motor 1 can be reduced.

[0028]

As described above, in the spindle motor according to the present invention, the insulating printed layer formed by silk printing is formed on the insulating layer covering the conductor pattern at the portion overlapping the auxiliary core plate of the stator core. Have been. For this reason, since the insulating layer is not damaged by the auxiliary core plate, the stator core and the conductor pattern do not short-circuit.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a spindle motor to which the present invention is applied.

FIG. 2 is a plan view of a stator core.

FIG. 3 is a plan view showing an auxiliary core plate.

FIG. 4 is a sectional view of a portion corresponding to about 約 of a stator core.

FIG. 5 is a plan view showing a motor board.

FIG. 6 is an explanatory view showing a state in which a portion A in FIG. 1 is enlarged.

[Explanation of symbols]

 Reference Signs List 1 spindle motor 2 rotor assembly 3 stator assembly 4 rotating shaft 5 rotor case 7 rotor magnet 10 motor board 10b screw mounting hole 11 bearing 12 auxiliary core plate 13 stator core 14 winding 15 core plate 15b salient pole 16 screw 17 conductor pattern 18b insulating layer 19 Printing layer

Claims (3)

[Claims] 1. A spindle motor comprising: a motor substrate having an insulating layer formed on a surface side of a conductor pattern; and a stator core fixed on the motor substrate and having windings wound around salient poles. Comprises an auxiliary core plate for securing a winding space between the salient poles and the substrate, on the insulating layer covering the conductor pattern in a portion of the motor substrate surface overlapping the auxiliary core plate. Is a spindle motor having an insulating printed layer silk-printed on the surface of the insulating layer. 2. The motor board according to claim 1, wherein the motor board is formed with three screw mounting holes for passing through the auxiliary core plate and fixing screws for fixing the stator core and the motor board. A spindle motor, wherein the conductor pattern is formed around the substrate, and the printing layer is formed on the insulating layer covering the conductor pattern. 3. The auxiliary core according to claim 1, wherein the stator core includes a plurality of core plates having the salient poles and the auxiliary core plate made of the same material as the core plate. A spindle motor, wherein the plate and the plurality of core plates are stacked and caulked.