JPH0678484A - Brushless motor - Google Patents

Abstract

PURPOSE:To supply a low-cost commercial voltage with safety and high reliability. CONSTITUTION:An insulating member 8 is so made up of a pair of coil frames 8a, 8b as to cover an entire core 6 except an inner periphery of a pole tooth 7 and the outer periphery of the core 6 in a brushless motor. Skirts 8d of the frames 8a, 8b are inserted to slots of the core 6, and ends of both the parts 8a are superposed by engaging protrusions 8a with recesses 8h.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, a commercial power supply AC1.
The present invention relates to a brushless motor in which insulation such as 00V drive is important.

[0002]

2. Description of the Related Art A conventional brushless motor is shown in FIGS. Here, a typical inward rotation type brushless motor is shown, but the same applies to the outer rotation type brushless motor. In the rotor 1, a magnetic yoke 3 is fixed to a rotor shaft 2, and segment-type permanent magnets 4 are adhered to the outer periphery of the magnetic yoke 3 so that different poles are alternately located in the circumferential direction.

The stator 5 has a substantially cylindrical iron core 6 formed by punching and stacking, which surrounds the outer periphery of the permanent magnet 4 in a cylindrical shape and projects a plurality of magnetic pole teeth 7 toward the outer peripheral surface of the permanent magnet 4. A winding 9 is wound around the magnetic pole teeth 7 via an insulating member 8. Here, the insulating member 8 is low voltage (12V, 24
In the case of driving (for example, V), the coil frames are formed by a pair of coil frames 8x and 8y, and in the case of driving with a commercial voltage (100V), the coil frame is often formed by integral molding. Coil frame 8x, 8y
Is formed of resin (for example, PBT) so as to cover the periphery of the magnetic pole teeth 7 except the inner and outer circumferences of the iron core 6, and the iron core 6 is mounted from both sides in the axial direction. Further, when the coil frame is formed by integral molding, the iron core 6 is put in a mold, and the portions other than the inner and outer peripheral portions of the iron core 6 are simultaneously molded and covered with resin.

The motor case 10 has a cylindrical shape, and the stator 5 is fixed to the inner peripheral surface by press fitting or adhesion. Further, bearing stands 11 and 12 are attached to the openings at both ends so as to close them. A bearing 13 is provided at the center of the bearing stand 11.
Is attached. A bearing 14 is mounted in the center of the bearing base 12, and a magnetic circuit element 16 (a Hall element or the like) 15 is installed in the bearing base 12 at the center position on the inner peripheral side of the magnetic pole teeth 4 ( In some cases, drive circuit board)
Is fixed.

As described above, the rotor 1 is the double bearing 1
It is rotatably supported by 3 and 14. The magnetic sensitive element 15 detects the magnetic pole of the rotor 1 and controls the switching of the energization of the winding 9 corresponding to each magnetic pole tooth 7 through a drive circuit (in some cases, a drive circuit board is built in). The motor is designed to rotate.

[0006]

In the brushless motor configured as described above, since the iron core 6 of the stator 5 is insulated by the pair of coil frames 8x and 8y, the iron core 6 is axially oriented. In consideration of the variation in length (0 to 0.5 mm), it was necessary to design the abutting portions of the coil frames 8x and 8y to be short and provide a gap. This method can be used as an insulating material in the case of low voltage, but it cannot be adopted because the insulation is insufficient at commercial voltage and it is dangerous.
In these cases, the insulating portion of the iron core is often integrally molded with resin, but this method has a problem in that it requires a large amount of equipment and increases the cost of the motor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a brushless motor that can supply a safe and highly reliable product at a low cost even at a commercial voltage. is there.

[0008]

In order to achieve the above object, the brushless motor of the present invention has a winding core 9 having a magnetic pole tooth 7 projecting toward the center of an iron core 6 formed by punching and stacking iron plates, with a winding 9 interposed via an insulating member 8. A wound stator 5, a rotor 1 composed of a rotor shaft 2, a yoke 3 made of a magnetic material fixed to the outer periphery of the rotor shaft 2, and a plurality of permanent magnets 4 fixed to the outer periphery of the yoke 3. , Bearing bases 1 arranged at both ends of the stator 5
1, 12 and bearings 13 and 14, a magnetic sensitive element 15 for detecting magnetic poles of the rotor 1, and a brushless motor including a control circuit for controlling energization to the winding 9 by a detection signal of the magnetic sensitive element 15, The insulating member 8 is formed by the pair of coil frames 8a and 8b so as to cover the entire iron core 6 except the inner peripheral portion of the magnetic pole teeth 7 and the outer peripheral portion of the iron core 6, and the skirt portion of the pair of coil frames 8a and 8b. 8d is a slot 6a of the iron core 6
The skirts 8d and the tips of both skirts 8d
It is characterized in that they are superposed by fitting the g and the recess 8h.

[0009]

According to the above construction, the insulating member 8 is formed of the pair of coil frames 8a and 8b, and the tips of the skirt portion 8d are overlapped with each other by fitting the convex portion 8g and the concave portion 8h. Can be taken large, and sufficient insulation can be secured even at commercial voltage. Further, it is possible to keep the price low compared to the method of simultaneously molding with the iron core 6.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Since the embodiment of the present invention and the conventional example are substantially different only in the insulating member, the same members as those described in the conventional example are denoted by the same reference numerals and detailed description thereof will be omitted. In the rotor 1, a magnetic yoke 3 is fixed to a rotor shaft 2, and segment type permanent magnets 4 are bonded to the outer periphery of the magnetic yoke 3 so that different poles are alternately located in the circumferential direction.

The stator 5 is formed by punching and stacking a substantially cylindrical iron core to surround the outer periphery of the permanent magnet 4 in a cylindrical shape, and a plurality of magnetic pole teeth 7 are projected toward the outer peripheral surface of the permanent magnet 4, and the magnetic poles thereof are formed. A winding 9 is wound around the tooth 7 via an insulating member 8. Here, the insulating member 8 is made of resin (for example, PB).
(For example, T) formed by a pair of molded coil frames 8a and 8b, and has a shape that covers the circumference of the magnetic pole teeth 7 except the inner and outer circumferences of the iron core 6, and is mounted from both ends of the iron core 6 in the axial direction. It is like this. Here, the coil frames 8a and 8b are the same molded product and can be formed at low cost. The coil frames 8a and 8b are formed in the iron core 6 so that the inner and outer diameter portions are slightly smaller and the slot portion is slightly larger than the basic surface 8c, and one side thereof is a skirt to be mounted in the slot 6a of the iron core 6. It has a portion 8d and a plurality of functional walls on the opposite surface.

The skirt portion 8d has a thickness of 0.5 to 1 mm and is substantially the same shape as the slot 6a of the iron core 6 and slightly smaller. The length of the skirt portion 8d is 1.5 mm which is less than 1/2 of the length of the slot 6a. A notch 8f that is half as long as half the thickness of the skirt portion 8d is provided slightly more than 3 mm from the tip of the skirt portion 8d to form unevenness at the tip. Here, the whole skirt 8d
Half (3 in 6 in this embodiment) of the skirt portion 8d
Is formed so that the inner side thereof is the convex portion 8g and the outer side thereof is the concave portion 8h, and the remaining half is formed such that the outer side of the skirt portion 8d is the concave portion 8h and the inner side is the convex portion 8g. Are the convex portions 8g and the concave portions 8h arranged so as to be continuous (S1, FIG. 3).
In S2 and S3, the inner side is a convex portion, in S4, S5 and S6, the outer side is a convex portion, and adjacent skirt portions 8d are alternately arranged so as to have different convex portions (in S1, S3 and S5, the inner side is a convex portion and S2 is a convex portion). , S4 and S6 have convex portions on the outer side. When the coil frames 8a and 8b are attached to the iron core 6, one coil frame 8a is attached to the other coil frame 8b in FIG.
If you rotate it by 80 °, or rotate it by 60 ° or 180 ° if it is arranged alternately,
The convex portions 8g and the concave portions 8h formed on the coil frames 8a and 8b are engaged with each other, and the tips of the skirt portions 8d can be overlapped with each other. In this embodiment, the overlapping portion is 2.5 to 3
mm, and a sufficient insulation distance can be secured.

Further, as shown in FIG. 4, when the skirt portion 8d is provided with a taper 8i which is recessed inward, the skirt portion 8d can be easily mounted on the iron core 6, and in particular, the taper 8i of the skirt portion 8d having the convex portion 8g on the inner side is If you make it big, the coil frame 8
When the tips of the skirt portions 8d of a and 8b are meshed with each other in the concavo-convex shape, the convex portions 8g are prevented from colliding with each other, and the skirt portion 8d can be smoothly mounted. Further, as shown in FIG. 5, a slightly larger curvature R is formed at the root 8j of the skirt 8d of the convex portion 8g on the inner side, and the inner convex portion 8g is slightly displaced inward when the iron core 6 is mounted. Collisions between the convex portions 8g may be avoided.

As shown in FIG. 6, the functional walls 8e of the coil frames 8a and 8b are composed of an outer peripheral wall 8k, an inner peripheral wall 8p and a central wall 8m. The outer peripheral wall 8k is formed by providing a wall having a thickness of about 0.5 to 1 mm and a height of about 5 mm on the entire outer peripheral portion of the basic surface 8c. The central wall 8m is formed on the outer peripheral portion of the slot 6a of the iron core 6 with a thickness of 0.5 to 1 mm and a height of about 10 mm. When winding the winding 9, it is necessary to provide a crossover wire 9a, but the central wall 8m is used as a guide and a treatment is performed so as to be housed inside the outer peripheral wall 8k. An insulation distance from the winding material can be secured from the outer peripheral wall 8k.

The inner peripheral wall 8p has substantially the same shape as the magnetic pole tooth tips 7a of the iron core 6 and has a height of about 8 mm. A plurality of (three in this embodiment) inner peripheral walls 8p are formed in the central inner peripheral portion with
As shown in FIG. 5, a magnetic sensitive element holding hole 8n is provided. A magnetic sensitive element 15 described later is mounted and positioned in the magnetic sensitive element holding hole 8n. The inner peripheral wall 8p has a role of preventing spillage to the inside of the winding, and is also effective for accurate positioning of the magnetic sensitive element 15.

The motor case 10 has a cylindrical shape, and the stator 5 is fixed to the inner peripheral surface by press fitting or adhesion. Further, in the opening of the motor case 10, the bearing stands 11, 1
Two are attached to block it. A bearing 13 is mounted at the center of the bearing base 11. A bearing 14 is mounted in the center of the bearing base 12, and a magnetic circuit element 16 (a Hall element or the like) 15 is installed in the bearing base 12 at the center position on the inner peripheral side of the magnetic pole teeth 7 ( In some cases, the drive circuit board) is fixed.

[0017]

As described above, according to the present invention, the insulating member is formed by the pair of coil frames so as to cover the entire iron core except the inner peripheral portion of the magnetic pole teeth and the outer peripheral portion of the iron core. Since the skirt is inserted into the slot of the iron core and the tips of both skirts are overlapped by the fitting of the convex and concave parts, the insulation distance can be made larger compared to the conventional one with a gap. In addition, it is possible to secure sufficient insulation even with commercial voltage, etc. Also, compared to the conventional method of integrally molding with an iron core, the mold etc. can be kept at a low price, and a safe and highly reliable motor can be manufactured at a low price. Can be provided.

[Brief description of drawings]

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

FIG. 2 (a) is an exploded perspective view of the iron core and the coil frame,
(B) (c) is an enlarged perspective view of a skirt part.

3A and 3B show a coil frame of the same, where FIG. 3A is a partially cutaway front view, FIG. 3B is a left side view, and FIG. 3C is a right side view.

FIG. 4 is a sectional view showing the taper of the skirt portion of the above.

FIG. 5 is a cross-sectional view showing the curvature R of the above skirt.

FIG. 6 is a perspective view for explaining the treatment of the above connecting wire.

FIG. 7 is a perspective view showing the mounting of the above magnetically sensitive element.

FIG. 8 is a cross-sectional view showing a conventional example.

FIG. 9 is an exploded perspective view of a conventional iron core and coil frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotor 2 rotor shaft 3 yoke 4 permanent magnet 5 stator 6 iron core 6a slot 7 magnetic pole tooth 8 insulating member 8a coil frame 8b coil frame 8g convex portion 8h concave portion 9 winding 10 motor case 11 bearing base 12 bearing base 13 Bearing 14 Bearing 15 Magnetically sensitive element 16 Wiring circuit board

Claims (6)

[Claims] 1. A stator in which a winding is wound through an insulating member around a magnetic pole tooth base portion projecting toward the center of an iron core formed by punching and stacking iron plates, and fixed to the rotor shaft and the outer periphery of the rotor shaft. A rotor composed of a yoke made of a magnetic material and a plurality of permanent magnets fixed to the outer periphery of the yoke, bearing pedestals and bearings arranged at both ends of the stator, and a magnetic sensor for detecting magnetic poles of the rotor. In a brushless motor consisting of an element and a control circuit that controls the energization of the winding by the detection signal of the magnetic sensitive element, the insulating member is made of a pair of coil frames except for the inner circumference of the magnetic pole teeth and the outer circumference of the iron core. Formed to cover the entire core,
A brushless motor, characterized in that the skirt portions of a pair of coil frames are inserted into the slots of the iron core, and the tips of both skirt portions are overlapped with each other by fitting the convex portion and the concave portion. 2. A pair of coil frames have the same shape, and a convex portion is formed on the outer side at the tips of half of the skirt portions of the plurality of skirt portions, and a concave portion is formed on the inner side, and the inner portions are formed at the tips of the remaining half skirt portions. 2. The brushless motor according to claim 1, wherein a convex portion is formed on the outer side and a concave portion is formed on the outer side. 3. The brushless motor according to claim 1, wherein a skirt portion covering the slot of the iron core is provided with a taper. 4. The brushless motor according to claim 1, wherein an appropriate curvature is provided at the base of the skirt portion. 5. The brushless motor according to claim 1, wherein an outer peripheral wall is provided on an axial end surface of the coil frame. 6. The brushless motor according to claim 1, wherein an inner peripheral wall having a plurality of magnetic sensitive element holding portions is provided on an axial end surface of the coil frame.