JPS6334465Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the structure of a brushless motor in which a plurality of stator coils and rotor magnets wound and fixed in a ring shape oppose each other in the axial direction.

A conventional device of this kind is shown in FIG. FIG. 1a is a sectional view, and FIG. 1b is an exploded perspective view. In this drawing, 1 is a printed circuit board, and the circular part 2 on the left side of the drawing
A plurality of stator coils 3 wound and fixed in a ring shape are installed in a substantially annular shape, and a printed circuit board 1
Necessary electrical components 5 are attached to the right rectangular portion 4 of the figure. A plurality of stator coils 3 on a printed circuit board 1
A spacer 6 is attached to the center of the spacer, and an iron plate 7 serving as a yoke is attached onto the spacer with screws 8. A rotor shaft 10 supported by a bearing 9 provided on the upper surface of the iron plate 7 is provided with a case 12 to which a flat rotor magnet 11 is mounted, which opposes the lower surface of the plurality of stator coils 3 via an axial gap.

In the conventional device having such a configuration, the necessary electrical components 5 are mounted at a position apart from the stator coil 3, so there is a drawback that the device is large in size. In addition, this conventional device connects the stator coil 3 to the printed circuit board 1.
Since the iron plate 7 that serves as a yoke is installed on the back of the printed circuit board 1, the printed circuit board 1
It is necessary to separately provide the iron plate 7 and the iron plate 7, which has the disadvantage of increasing the size. Therefore, it is possible to eliminate the printed circuit board 1 and mount the stator coil 3 on a steel plate, but in this case, a printed circuit board to which the necessary electrical components 5 are attached must be separately mounted on the steel plate, and it is necessary to provide a separate printed circuit board. .

The present invention has been devised in view of these points, and one embodiment of the present invention will be described below based on the drawings.

FIG. 2 is a sectional view of the brushless motor, FIG. 3 is an enlarged sectional view of the board, and FIG. 4 is an exploded perspective view thereof. In these drawings, A is a substrate, which is composed of an iron plate 20 and an enamel insulating film 21 provided on the surface of the iron plate. The insulating film is formed by baking at, for example, 850°C. Reference numeral 22 denotes a stator coil which is wound and fixed in a ring shape, and a plurality of stator coils are mounted on the substrate A in a substantially annular shape as shown in FIG. A holding cylinder 24 for a bearing 23 is provided at the center of the board A, and a generator stator part 27 having a generator coil 25 and a generator magnet 35 and having uneven teeth 26 on the outer peripheral surface is attached to the lower end thereof. It will be done. A rotor case 29 is provided at the lower end of the rotor shaft 28 supported by the bearing 23.
is installed, and each stator coil 2 is installed in the case.
2 and a rotor magnet 30 that opposes the rotor magnet 2 through an axial gap.
and a generator rotor portion 32 having uneven teeth 31 on its inner peripheral surface. The concave and convex teeth 31 of the rotor section are similar to the concave and convex teeth 2 of the generator stator section 27 as shown in FIG.
In the magnetic path of the generator magnet 35, the generator coil 27, the uneven teeth 26, 31, and the rotor case 29, the air gap length between the uneven teeth 26 and 31 changes as the rotor rotates. By doing so, a voltage having a frequency corresponding to the rotational speed of the rotor is detected based on a change in the induced electromotive force generated in the generator coil 25.

Then, a printed circuit 32 is formed around the stator coil 22 of the substrate A using silver paste or the like, as shown in FIG. Further, a printed circuit 32 between a pair of adjacent stator coils 22, 22 has a magnetic sensing element 3 for detecting the rotational position of the rotor magnet 30, etc.
3 is provided. In the embodiment, a Hall element is used as the magnetic sensing element, and the rotational position of the rotor magnet 30 is detected by the Hall element. Further, a resistor 34 may be formed on the printed circuit 32 using a resistor paste or the like, and various electrical components such as chip components or discrete components can be provided using printing technology or the like.

Since the enamel insulating film 21 provided on the surface of the iron plate 20 is baked at a high temperature, for example, 850° C., a high-grade material such as ruthenium oxide is placed between the patterns of the printed circuit 32 on the insulating film 21. The high printing resistance can be fired at high temperatures up to approximately 650℃. When the insulating film on the surface of the iron plate is made of epoxy resin, etc., which has a low melting point, a carbon film resistor must be used as a resistor in the printed circuit because the melting point of the insulating film, such as epoxy resin, is low. Deteriorate. In addition, since the enamel insulating film is formed by high-temperature firing, when providing printed circuits on both the front and back sides of substrate A, the high temperature It also becomes possible to form

As described above, in the present invention, the substrate on which a plurality of stator coils wound and fixed in a ring shape is attached is composed of an iron plate and an enamel insulating film provided on the surface of the iron plate, and the substrate around the attachment position of the stator coils is The printed circuit is equipped with a printed circuit, and since the enamel insulating film has higher heat resistance and better heat conduction than a resin insulating film, the printed circuit can be formed by laser cutting, etc. , it is possible to improve the precision of the formation position of the printed circuit, and it is also possible to use high-quality parts for the printed circuit, and due to the good heat conduction of the enamel insulating film, the stator coil or the above-mentioned parts can be Even when the stator generates heat, it can be dissipated through the insulating film, making it possible to cluster the stator coil and components, and compared to conventional equipment, the board around the stator coil can be used more effectively. Miniaturization becomes possible.

[Brief explanation of the drawing]

1A and 1B are a sectional view and an exploded perspective view of a conventional device; FIGS. 2 to 5 show an embodiment of a brushless motor according to the present invention; FIG. 2 is a sectional view thereof;
FIG. 3 is an enlarged sectional view of the board, FIG. 4 is an exploded perspective view of the brushless motor, and FIG. 5 is a partial perspective view of the enamel iron plate board viewed from below. A...Substrate, 20...Iron plate, 21...Enamel insulation film, 22...Stator coil, 32...
printed circuit.

Claims (1)

[Scope of utility model registration request] The substrate is composed of an iron plate and an enameled insulating film provided on the surface of the iron plate, and a plurality of stator coils wound and fixed in a ring shape are mounted on the substrate in a substantially annular shape, and the area around the mounting position is A brushless motor comprising a printed circuit on the substrate.