JPH0638452A - Brushless motor with external fan - Google Patents

Abstract

PURPOSE:To provide a light and compact circuit integrated type brushless motor fitted with an external fan, where a driving circuit including at least a power element is constituted on the printed board of a metallic base or a ceramic base. CONSTITUTION:This motor is composed of an external fan 1, a bracket 2, a bearing 3, a winding 4, a holding base 5 with a built-in position sensor, a stator 6, a rotor 7, a cable 18, and a printed board 19 of a metallic base or a ceramic base loaded with a driving circuit including the power element 20 being attached closely to the inside of the bracket on fan side, and the printed board and the bracket are made use of as a heat radiator. Furthermore, cooling wind hits directly on the printed board by the external fan by the cut of the bracket 10, and also the cut of the bracket is provided close to the position of the power element on the printed board, whereby a light and compact and long life of highly reliable brushless motor fitted with an external fan can materialized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor with an external fan fan having a built-in drive circuit including at least a power element.

[0002]

2. Description of the Related Art In recent years, electric appliances have been rapidly replaced by brushless motors, which are efficient and easy to change gears, in place of high functionality electric appliances, instead of induction motors.

A conventional brushless motor with an external fan fan for a washing machine will be described below. FIG. 3 shows the structure of a conventional brushless motor with an external fan.

In FIG. 3, 1 is an external fan fan, 2 is a bracket, 3 is a bearing, 4 is a winding wire, 5 is a holder having a built-in position sensor, 6 is a stator, 7 is a rotor, 8 is a cable, and 9 is a motor. It is a drive circuit. In a conventional brushless motor with an external fan, a rotor 7 having a bearing 3 as a motor portion is housed in a stator 6 having windings 4 and is rotatably held by a bracket 2. And
The position sensor for detecting the rotor position is attached to the end of the winding 4 of the stator 6 so as to face the rotor 7. On the other hand, the motor drive circuit 9 is provided outside the motor, and the cable 8 consisting of 10 or more lead wires is provided between the drive circuit and the motor section.
Tied with.

[0005]

However, in the above-mentioned conventional structure, the position detection signal line is externally provided in a large installation space, so that it is affected by noise. On the other hand, if a circuit is built into the motor in order to eliminate this point, the heat generated in the circuit will become an obstacle, and the number of parts will increase.
There were problems such as an increase in the number of assembly steps.

The present invention solves the above problems.
An object of the present invention is to provide a compact brushless motor with a circuit-integrated external fan having good heat dissipation.

[0007]

In order to achieve this object, a brushless motor with an external fan according to the present invention has a fan-side bracket provided with a notch, and a printed circuit board is closely attached to the inside of the bracket. have. Further, the notch of the bracket is provided near the position of the power element on the printed circuit board.

[0008]

With this structure, the heat radiation area is expanded, and by directly applying the cooling air from the external fan fan to the printed circuit board, the heat generated by the drive circuit including the power element can be efficiently radiated.

[0009]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is an external fan fan, 2 is a bracket, 3 is a bearing, 4 is a winding wire, 5 is a holder having a built-in position sensor, 6 is a stator, 7 is a rotor, 18 is a cable, and 19 is metal. A base or ceramic-based printed circuit board, 20 is a power element. As a motor structure, a rotor 7 having a bearing 3 mounted therein is housed in a stator 6 having a winding 4, and is rotatably held by a bracket 2. A position sensor for detecting the rotor position is attached to the end of the winding 4 of the stator 6 so as to face the rotor 7.
Further, the printed circuit board 19 is attached in close contact with the bracket 2.

A brushless motor with an external fan fan configured as described above will be described. The printed circuit board 19 is mounted with a drive circuit including at least a power element,
It is attached closely to the bracket 2. Further, the bracket 2 has a notch 10 as shown in the drawing, and the cooling air from the external fan fan 1 is directly applied to the printed circuit board 19 through the notch. Further, the location of the notch 10 provided in the bracket 2 is configured so as to approximately coincide with the position where the power element 20 of the printed circuit board 19 that is closely attached is arranged.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, 1 is an external fan fan, 3 is a bearing, 4 is a winding wire, 5 is a holding base having a built-in position sensor, and 6
Is a stator, 7 is a rotor, 18 is a cable, 19 is a metal-based or ceramic-based printed circuit board, 20 is a power element, and the above is the same as the configuration of FIG. Further, in this embodiment, in the bracket 2, a part of the cutout is bent toward the external fan fan. The mounting of the printed circuit board 19 on the bracket 2 is the same as in FIG.
Further, with such a configuration, the heat radiation area of the bracket is further increased as compared with the first embodiment, and the wind from the external fan fan can be effectively received.

The notch 1 formed by bending the bracket
In the shape of No. 1, the iron plates on both ends are bent toward the outer fan fan, but it may be on only one side.

In addition, in (Embodiment 1) and (Embodiment 2), in order to secure heat dissipation, the printed board 19 may be attached to the bracket 2 by applying a compound having good heat conductivity.

[0016]

As described above, according to the present invention, the bracket can be used as a radiator and the heat generated by the power element can be efficiently radiated through the printed circuit board.
By mounting a dedicated heat sink on the power element and not using a compound when mounting the printed circuit board, you can contribute to ease of assembly, space saving, and reduction of the number of parts. Further, since the position detection signal line is not provided outside due to the circuit integration, it is not affected by noise and complicated wiring is not required outside. Therefore, the configuration of the present invention can realize a brushless motor with an external fan fan that is easy to handle, compact, and lightweight.

[Brief description of drawings]

FIG. 1 is a structural diagram of a brushless motor with an external fan fan according to a first embodiment of the present invention.

FIG. 2 is a structural diagram of a brushless motor with an external fan fan according to a second embodiment of the present invention.

FIG. 3 is a structural diagram of a brushless motor with an external fan fan in a conventional example.

[Explanation of symbols]

 1 Outer fan fan 2 Bracket 3 Bearing 4 Winding 5 Holding table with built-in position sensor 6 Stator 7 Rotor 8, 18 Cable 9 Motor drive circuit 10 Notch 11 Notch with bent bracket 19 Metal base or ceramic base printed circuit board 20 power elements

Claims (1)

[Claims] In a brushless motor with an external fan, a drive circuit including at least a power element is formed on a metal-based or ceramic-based printed circuit board, and the printed circuit board is closely attached to the inside of a fan side bracket. A brushless motor with a circuit-integrated external fan.