JPH0937496A - Stator structure of rotating electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the supplementation rate of the magnetic flux from a field magnet, and improve the magnetic efficiency by arranging a plate-shaped body made of soft magnetic substance at the flange of a bobbin opposed to a rotor, and connecting it with a stator magnetic pole. SOLUTION: A wiring is applied to a bobbin 24, and the end is wiring to a terminal 25. And, the tip of the stator magnetic pole 21 is inserted into the center hole 26 of the bobbin 24, and it is pushed until the flange 28 reaches the yoke 31 of the stator magnetic pole 21. In this condition, the tip of the stator magnetic pole 21 projects from the top flange 30. In this condition, an auxiliary magnetic plate 38 in the shape of a U-shaped plate consisting of a soft magnetic substance is set in the slit 37 provided at the head of the stator magnetic pole 21, and a knife edge 40 and a slit 37 are tightly engaged with each other. Hereby, the opposition area between the fixed magnetic pole and the rotor magnetic pole can be increased, so the magnetic efficiency can be improved, raising the supplementation rate of magnetic flux.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a rotating electric machine, particularly a stator of a motor, in which a bobbin around which a coil is wound is inserted into a salient pole portion of the stator.

[0002]

2. Description of the Related Art For example, a floppy disk driver used as an auxiliary storage device of a personal computer uses a flat outer rotor type brushless DC motor for driving a floppy disk. In this type of outer rotor type brushless DC motor, the salient poles of the stator protrude in the radial direction around the rotation axis, and the tip of the salient pole faces the rotor magnet and is in the rotation direction of the rotor magnet. Since the pole teeth extend and have a T-shape, the winding portion of the stator coil can be made thin, but the bobbin cannot be inserted into the salient pole of the stator, so the protrusion of each stator Since the poles are directly wound, this process requires a lot of man-hours. In addition, if even one slot is defective during winding, the entire stator structure will be defective, which is a major factor in reducing the yield.

In order to avoid the above-mentioned inconvenience, pole teeth are removed from the tip of the salient pole of the stator, the salient pole is formed in a rod shape, and the coil is wound on a bobbin in a separate step to form a stator coil. The bobbin of this stator coil is inserted and mounted in each salient pole of the stator.

[0004]

[Problems to be Solved by the Invention] Looking at the number of man-hours for manufacturing a motor, the winding process takes the longest time and needs to be rationalized. As a remedy, if the method of winding the stator coil around the bobbin and inserting it into the salient poles as described above is adopted, the working efficiency at the time of winding can be improved, but the tip side of the salient poles of the stator, that is, the rotor. Since the bobbin must be inserted from the side opposite to the rotor magnet, the tooth tip (pole tooth) of the stator salient pole must be the same as or smaller than the inner diameter of the bobbin. As a result, as a matter of course, the pole teeth facing the rotor magnet of the salient pole are narrowed, the rate of capturing the magnetic flux from the field magnet is lowered, the magnetic efficiency is lowered, and the motor characteristic is lowered.

[0005]

The present invention has been made in view of such circumstances, and a bobbin in which a coil is wound around each salient pole portion of an armature core made of a soft magnetic material. It is an object of the present invention to provide a stator structure of a rotating electric machine in which the magnetic flux efficiency from the field magnet does not decrease and the magnetic efficiency does not decrease in the stator structure of the rotating electric machine having the inserted.

When the winding is formed in the bobbin type, the cause of the deterioration of the motor characteristics is the reduction of the tooth width (pole tooth width) for inserting the bobbin. Collar part (auxiliary pole tooth or complementary pole tooth) facing the rotor of the bobbin to cover this reduction in pole tooth width.
As a result of placing the soft magnetic material in the vicinity, the bobbinization of the winding could be achieved without degrading the motor characteristics. As a means for achieving that, in a stator structure of a rotating electric machine in which a bobbin having a coil wound for each salient pole portion is inserted in the salient pole portion of an armature core made of a soft magnetic material, a bobbin facing the rotor is provided. Place the plate-shaped body made of soft magnetic material on the collar part of
A stator structure of a rotating electric machine, wherein the plate-like body is magnetically connected to a stator magnetic pole. The plate-shaped body is formed of a soft magnetic metal, and the plate-shaped body is particularly a soft iron plate.

Further, the plate-like member has a U shape and is fitted to the tip of the stator magnetic pole, and is fitted to a slit provided at the tip of the stator magnetic pole. The plate-shaped body is approximately the same size as the plane of the tip flange of the bobbin, and the peripheral edge of the hole formed in the center and the corner of the fixed magnetic pole have a biting structure to form the plate-shaped body and the stator magnetic pole. It is fixed. The shape of the hole formed in the center of the plate-like body is a rhombus, a circle including an ellipse, and an octagon.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Since the magnetic flux also passes through the auxiliary pole teeth and the complementary pole teeth provided on the bobbin, the magnetic resistance of the magnetic path between the magnetic pole and the rotating magnetic pole can be reduced. Further, the surface of the auxiliary pole tooth facing the rotating magnetic pole is formed in an arc shape along the inner peripheral surface of the rotating magnetic pole, and the gap between the rotating magnetic pole and the auxiliary pole tooth is controlled in the rotation direction (changing the gap. This also has the effect of improving cogging torque / torque ripple).

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a state in which a rotor is rotatably provided on a printed circuit board to which a stator portion is attached. In FIG. 1, reference numeral 1 is a substrate constituting a floppy disk drive, which is made of a ferromagnetic material such as iron. A plurality of holes 2 are formed in the substrate 1, and a fixed base 3 made of synthetic resin is fixed by injection molding with the holes 2 as a mounting portion. A cylindrical bearing tube 4 is fixed to the center of the fixed base 3. A pivot 5 for supporting the bottom surface of the bearing described later is provided at the bottom of the bearing cylinder 4. Reference numeral 7 denotes a rotating disk which constitutes a rotor and rotates a floppy disk, and has a thin circular dish shape. A rotating magnetic pole 9 made of a ring-shaped permanent magnet is fixed inside the outer periphery 8 of the rotating disk 7. A speed detecting permanent magnet 10 for detecting the rotation speed of the rotating disk 7 is fixed to the lower portion of the outer circumference 8. The rotating magnetic pole 9 composed of the permanent magnet is made of a plastic magnet and has a ring shape. A plurality of permanent magnets are formed on the rotating magnetic pole 9 by magnetization. These permanent magnets are magnetized in the diameter direction of the rotating magnetic pole 9, and the magnetic pole directions of these permanent magnets are reversed adjacent to each other. The rotating disk 7 assembly including the rotating magnetic poles 9 constitutes the rotor 6.

A metal rotary shaft mounting plate 11 is fixed to the center of the rotary disc 7, and a rotary shaft 12 is fixed to the center of the rotary shaft mounting plate 11. The rotating shaft 12 is rotatably supported by the cylindrical bearing tube 4. Rotating disk 7
A hole 13 is formed in the hole, and a drive pin 14 projects from the hole 13. In FIG. 1, 21 is a stator magnetic pole and 22 is a stator winding. The stator magnetic pole 21 is fixed to the substrate 1 by caulking a protrusion 23 protruding from the fixed base 3. Although not shown in the figure, a thin sheet-shaped attracting magnet is attached to the surface of the rotating disk 7 about the rotating shaft 12, and this attracting magnet is provided at the center of the floppy disk which is rotationally driven. The soft iron plate provided is sucked and fixed to the rotating disk 7. FIG.
Further, in FIG. 2, reference numeral 25 is a terminal provided on the bobbin collar portion 28.

Although not shown in the drawing, the stator winding 2
The lead wire drawn from 2 is wound around a terminal 25, and this terminal 25 is connected to a printed wiring formed on the surface of the substrate 1. Reference numeral 18 is a drive IC for driving a three-phase brushless DC motor provided on the substrate 1, and a speed servo controller is also incorporated therein.

Next, the structure of the stator winding 22 wound around the stator magnetic pole 21 will be described in detail. FIG. 3 is an exploded perspective view showing a state in which the bobbin 24 forming the stator winding 21 is pulled out from the stator magnetic pole 21. In FIG. 3, the bobbin 24 is not wound. The bobbin 2
4 is made of, for example, PBT resin or the like. The bobbin 24 has a cylindrical main body 27 in which a hole 26 having a quadrangular cross section through which the stator magnetic pole 21 penetrates is provided in the center, a flange portion 28 is formed at one end thereof, and a terminal is provided on the upper surface of the flange portion 28. A terminal block 29 that holds 25 is provided. A tip collar 30 is provided on the other end of the bobbin 24. The area of the side surface of the tip flange 30 is formed to be significantly larger than the area of the hole 26 in which the stator magnetic pole protruding from the yoke portion 31 is exposed. Slits 37 are formed in the vertical direction on both side surfaces near the tip of the stator magnetic pole 21. The cross section of the slit 37 is triangular. Reference numeral 38 is an auxiliary magnetic pole plate to be fitted into the tip of the stator magnetic pole 21. The planar shape of the auxiliary magnetic pole plate 38 has a slightly “U” shape in plan view, and is made of a soft magnetic material, and by extension, a soft iron plate. A knife edge 40 is formed inside the leg 39 of the auxiliary magnetic pole plate 38.

Although not shown in FIG. 3, the bobbin 24
A winding is applied to the terminal, and its end is wired to the terminal 25. Then, the tip end side of the stator magnetic pole 21 is inserted into the hole 26 at the center of the bobbin 25, and the collar portion 28 reaches the base yoke portion 31 of the stator magnetic pole 21 and is pushed in until it stops. In this state, the tip of the stator magnetic pole 21 projects from the tip flange 30.
In this state, the auxiliary magnetic pole plate 38 is fitted on the tip of the stator magnetic pole 21. Of course, the knife edge 40 is tightly fitted in the slit 37 provided at the tip of the stator magnetic pole 21, and the auxiliary magnetic pole plate 38 does not easily come off from the stator magnetic pole 21. FIG.
FIG. 6 is a cross-sectional view showing a state where the auxiliary magnetic pole plate 38 is fitted into the tip of the stator magnetic pole 21. As can be seen from FIG. 4, the tip of the stator magnetic pole 21 and the auxiliary magnetic pole plate 38 are formed in a plane.

A stator magnetic pole 21 incorporating a stator winding 22 in which a bobbin is wound is fixed to the fixed base 3. After that, the rotating shaft 12 of the rotor 6 holding the rotating magnetic poles 9 which are magnetized in multiple poles on the surface facing the outer circumference of the stator magnetic pole 21 is inserted into the bearing cylinder 4 to form an outer rotor type brushless DC motor.

In the above embodiment, since the auxiliary pole plate 38 has a flat U-shape in plan view, the auxiliary pole plate 38 does not exist below the tip of the stator pole 21. Therefore, the rate of capturing the magnetic flux from the field magnet is lowered. The following embodiment eliminates such an inconvenience. As shown in FIG. 5, in this embodiment, an elliptical, octagonal or rhombic stator pole insertion hole 41 is bored in the center of the auxiliary magnetic pole plate 38, and the fixed magnetic pole 2 is inserted in this hole 41.
The tip of No. 1 is tightly fitted, and the corner portion of the stator magnetic pole 41 is engaged with the peripheral edge of the stator magnetic pole insertion hole 41 to fix the auxiliary magnetic pole plate 38.

FIG. 6 is a view showing still another embodiment of the present invention. Complementary pole teeth 34 made of a ferromagnetic material such as an iron plate is formed on the flange portion 33 of the bobbin 32 by insert molding to be integrated with the bobbin 32. It has been made into. In addition to the insert mold, attachment of the complementary pole teeth 34 to the bobbin 32 may be performed by welding, adhesion, or the like.

In the above embodiment, since the surface of the auxiliary pole tooth 34 or the auxiliary magnetic pole plate 38 facing the rotating magnetic pole 9 is a flat surface, the gap between them becomes large. In order to avoid such an inconvenience and to reduce the gap 36 between the rotating magnetic pole 9 and the auxiliary magnetic pole plate 38, as shown in FIG. It may be formed in an arc shape along the peripheral surface.

The present invention can be applied not only to a brushless DC motor, but also to all motors or generators that form a salient pole using a soft magnetic core, and of course both inner rotor / outer rotor types. It is obvious that it can also be applied to.

[0019]

As described above, according to the present invention, since the facing area between the fixed magnetic pole and the rotor magnetic pole can be increased with a simple structure, the capturing rate of the magnetic flux from the field magnet is improved, Magnetic efficiency is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a front view showing an embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a state in which a bobbin is pulled out from a stator magnetic pole.

FIG. 4 is a partial cross-sectional view showing a fitted state of a stator magnetic pole and an auxiliary magnetic pole plate.

FIG. 5 is a front view showing another embodiment of the present invention.

FIG. 6 is a partial perspective view showing still another embodiment of the present invention.

FIG. 7 is a partial perspective view showing still another embodiment of the present invention.

[Explanation of symbols]

 1 ... Substrate 2 ... Hole 3 ... Fixed base 4 ... Bearing tube 5 ... Pivot 6 ... Rotor 7 ...・ Rotating disk 8 ・ ・ ・ Outer circumference 9 ・ ・ ・ Rotating magnetic pole 10 ・ ・ ・ Permanent magnet for position detection 11 ・ ・ ・ Rotation shaft mounting plate 12 ・ ・ ・ Rotation shaft 13 ・・ ・ ・ ・ Hole 14 ・ ・ ・ Drive pin 15 ・ ・ ・ Spring plate 16 ・ ・ ・ Mounting base 17 ・ ・ ・ Arm 18 ・ Drive IC 21 ・ ・ ・-Stator magnetic pole 22-stator winding 23-projection 24-bobbin 25-terminal 26-hole 27-main body 28-・ ・ ・ Collar part 29 ・ ・ ・ Terminal block 30 ・ ・ ・ ・ ・ Tip collar 31 ・ ・ ・ Yoke part 32 ・ ・ ・ Bobbin 33 ・ ・ ・ ・ ・ Flange part 34 ・ ・ ・・ Supplement Complete pole plate 35 ...... collar part 36 ... slot 37 ... slit 38 ... auxiliary pole plate 39 ... leg 40 ... knife edge 41: Fixed magnetic pole insertion hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsutoshi Suzuki 1743 Asana-cho, Iwa-gun, Shizuoka Prefecture Minebea Co., Ltd. Development Technology Center (72) Inventor Masaaki Inagaki 1743 Asana-cho, Iwata-gun, Shizuoka Prefecture -1 Minebea Co., Ltd. Development Technology Center

Claims (10)

[Claims] 1. In a stator structure of a rotary electric machine in which a bobbin wound with a coil for each salient pole portion is inserted into a salient pole portion of an armature core made of a soft magnetic material, a collar portion of the bobbin facing the rotor is provided. A stator structure for a rotating electric machine, wherein a plate-shaped body formed of a soft magnetic material is arranged, and the plate-shaped body is magnetically connected to a stator magnetic pole. 2. The stator structure for a rotating electric machine according to claim 1, wherein the plate-shaped body is formed of a soft magnetic metal. 3. The stator structure for a rotating electric machine according to claim 2, wherein the plate-shaped body is a soft iron plate. 4. The stator structure for a rotary electric machine according to claim 1, wherein the plate-like member has a U shape and is fitted to the tip of the stator magnetic pole. 5. The stator structure for a rotary electric machine according to claim 4, wherein the plate-like member is fitted in a slit provided at the tip of the stator magnetic pole. 6. The plate-shaped body is approximately the same size as the plane of the tip flange of the bobbin, and the peripheral edge of the hole formed in the center and the corners of the fixed magnetic poles are fixed to the plate-shaped body by a biting structure. The stator structure for a rotating electric machine according to claim 1, wherein the child magnetic poles are fixed. 7. The stator structure for a rotary electric machine according to claim 6, wherein the shape of the hole formed in the center of the plate-like body is a rhombus. 8. The stator structure for a rotating electric machine according to claim 6, wherein the shape of the hole formed in the center of the plate-like body is a circle including an ellipse. 9. The stator structure for a rotary electric machine according to claim 6, wherein the shape of the hole formed in the center of the plate-like body is an octagon. 10. The stator structure for a rotating electric machine according to claim 1, wherein the rotating electric machine is an outer rotor type brushless DC motor.