JPH08107661A - Stator of brushless motor - Google Patents

Abstract

PURPOSE: To secure an electrically insulated distance between a bolt or a rivet and a printed wiring board by totally covering an area between an insertion hole part for inserting the bolt or the rivet and the printed wiring board. CONSTITUTION: A plurality of pins such as a pin 14 for supporting a printed wiring board and a pin 15 for forming an insertion hole protrude at an upper die 11. An insertion hole part 8 is secured in the pin 15 for forming insertion hole to insert parts for clamping such as a bolt or a rivet 17 when assembling a motor. The layer of synthetic resin 13 is provided between the insertion hole part 8 and the printed wiring board 4 and the area between the insertion hole part 8 and the printed wiring board 4 is totally covered with the synthetic resin 13, thus securing electrically insulated distance between the bolt or the rivet 17 and the printed wiring board 4.

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 this, it is required to widely adjust the amount of air blown to the heat exchanger in multiple stages. Instead of the induction motor as a fan drive source that has been conventionally used to satisfy these demands. Therefore, a method of operating a brushless motor whose speed is easily adjusted by 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. FIG. 4 is a vertical sectional view of a finished product of a conventional brushless motor stator. A printed wiring board 4 on which drive circuit components are mounted and a stator core 1 provided with a stator winding 3 are integrally molded with an electrically insulating synthetic resin to reduce noise and reduce size. An example of a brushless motor having such a structure is Japanese Patent Laid-Open No. 61-2.
51462 public information is given.

A conventional stator of a brushless motor will be described below. FIG. 5 is a side view when assembling a stator of a conventional brushless motor.

A stator winding 3 is laid on the stator core 1 via an insulating layer 2, while a position detecting element 5 and a driving circuit component 6 are mounted on the same surface of a printed wiring board 4 and one of the driving circuit components is mounted. All or part of the stator core 1 is arranged so as to be located between the teeth of the stator core 1, that is, in the space between the windings, and the surface of the printed wiring board 4 on which the drive circuit components are mounted is fixed. The printed wiring board 4 holding the stator core 1, the stator winding 3, and the drive circuit component 6 is held so as to face the end face of the slave core, and the synthetic resin 13 is provided.
And is integrally molded and solidified to form a stator.

At this time, the resin molding of the stator is performed in the state shown in the schematic sectional view of the resin molding die of FIG.

The stator winding assembly 9 is placed in the cavity 10 of the lower mold, sealed with the upper mold 11, and the synthetic resin is injected under pressure from the gate 12.

A plurality of pins such as a printed wiring board supporting pin 14 and a through hole forming pin 15 project from the upper mold 11.

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 flow pressure of the synthetic resin during resin molding. After molding, the surface becomes the concave portion 7 shown in FIG. 6 and the surface of the printed wiring board 4 is exposed.

FIG. 7A is a partial top view of the insertion hole portion in the conventional embodiment, and FIG. 7B is a partial sectional view of the insertion hole portion in the conventional embodiment.

As shown in FIG. 7, the insertion hole forming pin 15 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.

FIG. 7 shows the insertion hole 8 and the printed wiring board 4.
A case where a layer of synthetic resin 13 is provided between the two is shown.

Since the stator is formed in this manner, the stator is formed with a plurality of exposed portions of the printed wiring board when completed.

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

In such a shape, an insulating distance can be secured between the bolt or rivet 17 and the printed wiring board 4 through the synthetic resin 13, but the other printed wiring board 4 is exposed. There is a problem that the insulation distance of the part cannot be secured.

[0018]

However, the above-mentioned conventional configuration has the following problems. 1. Since the printed wiring board has an exposed portion on the surface of the motor, the copper foil of the printed wiring board must bypass the wiring and secure an insulation distance in order to ensure insulation near the exposed portion. Effective area is reduced. 2. In order to improve the heat dissipation characteristics of semiconductor components for driving, use a metal base material as the printed wiring board base material, and ensure a sufficient insulation distance when biasing the metal base material to a certain voltage to stabilize circuit operation. Therefore, it is necessary to increase the thickness of the synthetic resin covering the printed wiring board, which causes problems such as hindering reduction in size, weight, and size.

It is an object of the present invention to solve the above-mentioned conventional problems and to provide a stator of a brushless motor which can be made lighter, thinner, shorter and smaller and contribute to space saving.

[0020]

To achieve this object, the stator of the brushless motor of the present invention has a structure in which the space between the insertion hole and the printed wiring board is entirely covered with synthetic resin having electrical insulation. ing.

[0021]

With the above structure, an electrical insulation distance can be secured between the bolt or rivet inserted in the insertion hole and the printed wiring board.

[0022]

An embodiment of the present invention will be described below with reference to the drawings.

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

In FIG. 1, a stator winding 3 is provided on a stator core 1 with an insulating layer 2 interposed therebetween, while a printed circuit board 4 is mounted with a position detecting element 5 and a driving circuit component 6 on the same surface and is driven. A surface of the printed wiring board 4 on which the drive circuit components are mounted, in which a part or all of the circuit components are arranged so as to be located in the space between the tooth portions of the iron core 1, that is, between the windings. While holding the stator core facing the end face of the stator core, and integrally molding and solidifying the printed wiring board 4 on which the stator core 1, the stator winding 3 and the drive circuit component 6 are mounted with the synthetic resin 13. Forming the stator.

The resin molding of the stator is performed in the state shown in the schematic sectional view of the resin molding die of FIG. The stator winding assembly 9 is placed in the cavity 10 of the lower mold, sealed with the upper mold 11, and synthetic resin is injected under pressure from the gate 12.

A plurality of pins such as a printed wiring board supporting pin 14 and a through hole forming pin 15 project from the upper mold 11.

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 during resin molding. After molding, the surface of the printed wiring board 4 is exposed as the recess 7 shown in FIG.

As shown in FIG. 3, the insertion hole forming pin 15 is for securing the insertion hole portion 8 for inserting a tightening component such as a bolt or a rivet 17 when the motor is assembled.

FIG. 3A is a partial top view of a brushless motor according to an embodiment of the present invention, and FIG. 3B is a sectional view of parts of the brushless motor according to an embodiment of the present invention.

In FIG. 3, a layer of synthetic resin 13 is provided between the insertion hole 8 and the printed wiring board 4, and the space between the insertion hole 8 and the printed wiring board 4 is entirely covered with the synthetic resin 13.

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

[0032]

As described above, the following effects can be obtained by using the configuration of the present invention. 1. By providing a resin wall in the insertion hole of the bolt or rivet, the insulation distance between the charging part of the printed wiring board and the bolt or rivet is secured, so the copper foil of the printed wiring board needs to bypass the wiring. Since the printed wiring board can be effectively used, downsizing and cost reduction can be realized. 2. Even when a metal base material is used as the printed wiring board base material and the metal base material is biased to a certain voltage, it is necessary to increase the thickness of the synthetic resin covering the printed wiring board to secure the insulation distance. It is possible to realize light, thin, short, compact and low cost.

[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.

FIG. 2 is a schematic cross-sectional view of a resin molding die for a stator of a brushless motor according to an embodiment of the present invention.

FIG. 3A is a partial top view of a brushless motor according to an embodiment of the present invention. FIG. 3B is a partial sectional view of a brushless motor according to an embodiment of the present invention.

FIG. 4 is a vertical sectional view of a finished product of a conventional brushless motor stator.

FIG. 5 is a side view of the conventional brushless motor when the stator is assembled.

FIG. 6 is a schematic sectional view of a resin molding die for a stator of a conventional brushless motor.

FIG. 7A is a partial top view of an insertion hole portion in a conventional embodiment. FIG. 7B is a partial sectional view of an insertion hole portion in a conventional embodiment.

[Explanation of symbols]

 1 Stator Iron Core 2 Insulating Layer 3 Stator Winding 4 Printed Wiring Board 5 Position Detection Element 6 Drive Circuit Parts 7 Recess 8 Insertion Hole 9 Stator Winding Assembly 10 Lower Mold 11 Upper Mold 12 Gate 13 Synthetic Resin 14 Pins for supporting printed wiring boards 15 Pins for forming insertion holes 16 Finished stator 17 Bolts or rivets 19 Copper foil

Claims (1)

[Claims] 1. A stator comprising a stator core, a stator winding, and a printed circuit board on which drive circuit components are mounted, and is integrally molded and solidified with a synthetic resin having electric insulation properties. Alternatively, the stator of the brushless motor is characterized in that a hole provided in the stator for inserting a rivet and the periphery of the hole of the printed circuit board are entirely covered with resin.