JPH0622525A - Stator of brushless motor - Google Patents

Abstract

PURPOSE:To secure the insulation property of a substrate and downsize it and cut down cost by providing a resin wall around a bolt or a rivet insertion hole used at assembling, in a stator where a printed wiring board equipped with a stator iron core, a stator winding, parts for a drive circuit, etc., is molded integrally with synthetic resin. CONSTITUTION:When molding a printed wiring board 4 with resin, a synthetic resin layer 13 is provided between an insertion hole 8 in which to insert a bolt at assembling of a motor and a printed wiring board 4, and further a resin wall 18 is provided, in the axial direction of a bolt 17, around the insertion hole 8. By this resin wall 18, the distance for insulation between the exposed part in a recess 7 of the printed wiring board 4 and a bolt 17 is secured, so the effectively use area by a copper foil of the printed wiring board 4 can be enlarged, and also in case of applying bypass voltage, using a metallic base material for the base material of the printed wiring board 4, therefore there is no necessity to enlarge the thickness of the synthetic resin 13 covering the printed wiring board 4 so as to secure the distance for insulation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of a brushless motor used as a blower fan drive source for a home air conditioner or the like.

[0002]

2. Description of the Related Art In recent years, in air conditioners such as home air conditioners, it is becoming mainstream to control the capacity of a compressor.

In response to the capacity control of the compressor, it is required to widely adjust the amount of air blown to the heat exchanger in multiple stages, and as a fan drive source conventionally used to satisfy these demands. In place of the induction motor, a method of operating a brushless motor, whose speed is easily adjusted, with a DC power source is being adopted.

On the other hand, there is a strong demand for a light, thin, short and compact motor of this type. A stator of a conventional brushless motor has a structure as shown in the vertical cross-sectional view of FIG. 5, and includes a printed wiring board 4 on which a position detection element 5 and a drive circuit component 6 are mounted, and a stator via an insulating layer 2. The stator core 1 provided with the windings 3 is integrally molded with a synthetic resin 13 having an electric insulating property to reduce noise and reduce the size. As an example of a brushless motor having such a structure, Japanese Patent Application Laid-Open No. 61-251462
The gazette is given.

An example of a conventional brushless motor will be described below with reference to the drawings.

FIG. 6 is a side view of the brushless motor shown in FIG. 5 when the stator is assembled. The stator core 1 is provided with a stator winding 3 via an insulating layer 2, while the printed wiring board 4 is provided with a stator winding 3. The position detection element 5 and the drive circuit component 6 are mounted on the same surface, and a part or all of the drive circuit component 6 is
It is arranged so as to be located between the tooth portions of the stator core 1, that is, in the space between the stator winding 3 and the stator winding 3,
The surface of the printed wiring board 4 on which the drive circuit component 6 is mounted is held to face the end surface of the stator core 1, and the stator core 1, the stator winding 3, and the position detection element 5 are held.
Printed wiring board 4 on which components such as drive circuit components 6 are mounted
Is integrally molded and solidified with a synthetic resin 13 (see FIG. 5) to form a stator winding assembly 9.

At this time, resin molding of the stator (stator core 1, stator winding 3, printed wiring board 4) is performed in the state shown in the schematic sectional view of the resin molding die in FIG. That is, the stator winding assembly 9 shown in FIG. 6 is inserted and arranged in the lower mold 10, sealed with the upper mold 11, and the synthetic resin is injected under pressure from the gate 12. The upper mold 11 has pins for supporting the printed wiring board.
14, a plurality of pins such as the insertion hole forming pin 15 are projected. The printed wiring board supporting pins 14 support the printed wiring board 4 and prevent the printed wiring board 4 from being moved or bent due to the fluid pressure of the synthetic resin 13 during resin molding. Thus, after molding, the surface of the printed wiring board 4 is exposed as the recess 7 shown in FIG.

Further, as shown in the plan view (1) of FIG. 8 and its AA cross-sectional view (2), the insertion hole forming pin 15 has bolts or rivets 17 and other tightening parts inserted therein during motor assembly. Therefore, the through hole portion 8 is secured.
Further, when the insertion hole forming pin 15 shown in FIG. 7 is integrated with the printed wiring board supporting pin 14, the recess 7 and the insertion hole portion 8 are integrally formed on the motor surface as shown in FIG. 8 (2). Composed. A layer of synthetic resin 13 is provided between the insertion hole 8 and the printed wiring board 4, and the bolt or rivet 17 is provided.
The synthetic resin 13 in the insertion axis direction is formed on the same plane 8a as the printed wiring board 4. Because it is formed in this way,
The stator is formed in a state of having the exposed portions of the plurality of printed wiring boards 4 when completed.

Further, at the time of assembling the motor, bolts or rivets 17 penetrate the printed wiring board 4 and are assembled as shown in FIG.

In such a shape, the insulation distance of the portion 8b via the synthetic resin 13 can be secured between the bolt or rivet 17 and the printed wiring board 4, but the other printed wiring board 4 is exposed. Portion (Fig. 8 (2)
Although not shown in FIG. 3, there is a problem that it is impossible to secure an insulation distance of (the end 4a of the printed wiring board 4 is exposed to the end of the insertion hole 8).

[0011]

The structure of the conventional brushless motor as described above causes the following problems.

(1) Printed wiring board 4 on the surface of the motor
Since the exposed portion of the printed wiring board 4 has an exposed portion, the copper foil 19 of the printed wiring board 4 must bypass the wiring and secure an insulation distance in order to ensure insulation near the exposed portion, and the effective area of the printed wiring board 4 decreases. To do.

(2) A metal base material is used as the base material of the printed wiring board 4 in order to improve the heat dissipation characteristics of the drive circuit component 6 (for example, a semiconductor), and further the metal base material is used to stabilize the circuit operation. When biasing a certain voltage, the thickness of the synthetic resin 13 covering the printed wiring board 4 must be increased to secure the insulation distance, which causes problems such as hindering reduction in size, weight, thinness, and the like. is doing.

It is an object of the present invention to provide a stator for a brushless motor which solves the above-mentioned conventional problems and enables a reduction in size, weight, size and size, which contributes to space saving.

[0015]

SUMMARY OF THE INVENTION The present invention comprises a stator core, a stator winding, and a printed wiring board on which components for a drive circuit are mounted, and is integrally molded and fixed with synthetic resin having electrical insulation. The through hole provided in the stator for inserting a bolt or a rivet at the time of assembling the stator formed as described above, and a concave portion where a part of the mold abuts and the printed wiring board is exposed during resin molding are integrally formed. In the constituted stator, a resin wall is provided around the insertion hole portion in the insertion axis direction of the bolt or the rivet.

[0016]

According to the present invention, not only the insulation distance of the portion through the synthetic resin is secured between the bolt or the rivet which is inserted into the insertion hole and the printed wiring board, but also the other printed wiring board is provided. The insulation distance of the exposed portion can be secured.

[0017]

1 is a vertical cross-sectional view of a completed stator of a brushless motor according to an embodiment of the present invention, in which a stator core 1 is provided with a stator winding 3 via an insulating layer 2, while The position detecting element 5 and the drive circuit component 6 are adhered to the same surface of the printed wiring board 4, and a part or all of this drive circuit component is fixed between the teeth of the stator core 1, that is, fixed. It is arranged so as to be located in the space between the child winding 3 and the stator winding 3, and the surface of the printed wiring board 4 on which the drive circuit component 6 is mounted is held facing the end surface of the stator core 1. , The stator core 1, the stator winding 3, the printed wiring board 4 on which the position detecting element 5, the drive circuit component 6 and the like are mounted are integrally molded and solidified with a synthetic resin 13 to assemble the stator winding. 9 (see FIG. 2).

The resin molding of the stator is performed in the state shown in the schematic sectional view of the resin molding die of FIG. That is, the stator winding assembly 9 is inserted and arranged in the lower mold 10, sealed with the upper mold 11, and the synthetic resin 13 is injected under pressure from the gate 12. A plurality of pins such as a printed wiring board supporting pin 14 and an insertion hole forming pin 15 project from the upper mold 11.

The printed wiring board supporting pin 14 supports the printed wiring board 4 and is made of synthetic resin at the time of resin molding.
This is for preventing the printed wiring board 4 from moving or bending due to the flow pressure of 13 or the like, and the surface of the printed wiring board 4 is exposed as the concave portion 7 shown in FIG. 1 after molding.

FIG. 3 is a view showing the structure of the insertion hole portion. The insertion hole forming pin 15 is a plan view (1) of FIG. 3 and its AA.
As shown in the sectional view (2), it is for securing the insertion hole portion 8 for inserting a fastening component such as a bolt or a rivet 17 when the motor is assembled. When the insertion hole forming pin 15 is integrated with the printed wiring board supporting pin 14, the recess 7 and the insertion hole 8 are integrally formed on the motor surface as shown in FIG. 3 (2).

As shown in FIG. 3 (2), in the embodiment of the present invention, a layer of synthetic resin 13 is provided between the insertion hole 8 and the printed wiring board 4, and the periphery of the insertion hole 8, that is, a bolt or A resin wall 18 is provided in the insertion axis direction of the rivet 17. Since the stator is formed in this manner, the stator is formed with the exposed portions of the plurality of printed wiring boards 4 when completed.

Further, when the motor is assembled, the bolts or rivets 17 are assembled by penetrating the printed wiring board 4.
At this time, the thickness of the resin wall 18 is a thickness that can secure an insulating distance at least between the bolt or rivet 17 and the printed wiring board 4 via the synthetic resin 13,
The finished stator 16 of FIG. 1 can be obtained. The recess 7
Has at least the pin 14 for supporting the printed wiring board.
Any shape may be used as long as it can support the printed wiring board 4 and secure an insulation distance, and an example thereof is shown in the plan view (1) of FIG. 4 and its AA cross-sectional view (2).

[0023]

As described above, the stator of the brushless motor of the present invention has the following effects.

(1) Through hole 8 for bolt or rivet 17
Since the resin wall 18 is provided in the axial direction of the bolt or the rivet, the insulation distance between the exposed portion of the printed wiring board 4 and the bolt or the rivet 17 is secured. There is no need to detour around, the printed wiring board can be effectively used, and downsizing and cost reduction can be realized.

(2) When a metal base material is used as the base material of the printed wiring board 4 and the metal base material is biased to a certain voltage, the synthetic material covering the printed wiring board for ensuring the insulation distance is used. There is no need to increase the resin thickness,
Light, thin, short, compact and low cost can be realized.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a completed stator of a brushless motor according to an embodiment of the present invention.

2 is a schematic cross-sectional view of a resin molding die of the stator in FIG.

FIG. 3 is a plan view showing the structure of the insertion hole portion in FIG. 1 (1).
FIG. 3 is a sectional view (2) taken along the line AA.

FIG. 4 is a plan view (1) showing a structure of an insertion hole portion in another embodiment of the present invention and a sectional view (2) taken along a line AA thereof.

FIG. 5 is a vertical cross-sectional view of a stator of a conventional brushless motor.

FIG. 6 is a side view of the brushless motor shown in FIG. 5 when the stator is assembled.

7 is a schematic cross-sectional view of a resin molding die of the stator shown in FIG.

8 is a plan view (1) of the insertion hole portion shown in FIG. 5 and A thereof.
It is a sectional view (2) taken along the line A-A.

[Explanation of symbols]

1 ... Stator core, 2 ... Insulating layer, 3 ... Stator winding,
4 ... Printed wiring board, 5 ... Position detecting element, 6 ... Drive circuit component, 7 ... Recessed portion, 8 ... Insertion hole portion, 9 ... Stator winding assembly, 10 ... Lower mold, 11 ... Upper mold, 12 … Gate, 13… Synthetic resin, 14… Printed wiring board support pin, 15… Insertion hole forming pin, 16… Stator finished product,
17… bolts or rivets, 18… resin walls, 19… copper foil.

Claims (1)

[Claims] 1. A stator comprising a stator core, a stator winding, and a printed wiring board on which drive circuit parts and the like are mounted, and which is integrally molded and fixed with a synthetic resin having electrical insulation properties during assembly. In the stator in which a through hole provided in the stator for inserting a bolt or a rivet and a recess for exposing a part of a mold during resin molding to expose the printed wiring board are integrally formed, A stator for a brushless motor, characterized in that a resin wall is provided around the hole in the insertion axial direction of the bolt or rivet.