JPH08275483A - Inner rotor-type brushless motor - Google Patents

Abstract

PURPOSE: To provide an inner rotor-type brushless motor wherein a heat sink can be made small and a control circuit section can be integrally built in the motor by installing a cooling fan on a rotary shaft of the motor and cooling a transistor for driving by means of this cooling fan. CONSTITUTION: A rotating section 9 has such a structure that a magnetic pole for detecting the location of a rotor and a multiplar magnetic pole for detecting a velocity are formed on a submagnet 10 and the submagnet 10 is adhered to one face of a steel late yoke 11 and then a cooling fan 12 is adhered to the other face of the steel plate yoke 11. The rotating section 9 is fastened to a rotary shaft 4 and then is rotated together with it. On the other hand, a transistor for driving 17 of a control circuit section 14 is installed near the cooling fan 12 and the transistor for driving 17 and a transistor fixation plate 18 which also serves as a heat sink are cooled by the ventiation work of the cooling fan 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner rotor type brushless motor incorporating a control circuit section including a driving transistor.

[0002]

2. Description of the Related Art Generally, a conventional inner type brushless motor has a motor including a control circuit section including a driving transistor for controlling a motor, as described in Japanese Patent Laid-Open No. 1-321853. It is generally provided outside the motor in a different shape, not inside.

On the other hand, in recent years, as a market demand, a demand for integrating a motor and a control circuit unit is increasing. In order to meet this requirement, it is necessary to reduce the size of the control circuit unit and also reduce the volume of the heat dissipation plate of the driving transistor of the control circuit unit. Generally, for heat dissipation of the driving transistor, it is common to attach the transistor to a heat dissipation plate made of a material such as aluminum with screws etc., transfer the heat of the transistor to the heat dissipation plate by heat conduction, and let the heat dissipate naturally in the air. In this case, a large heat dissipation plate was used for natural heat dissipation.

[0004]

However, in the prior art, the size of the heat sink becomes large, and the biggest problem in integrating the control circuit unit with the motor is the heat dissipation due to the temperature rise of the driving transistor. For the time being, how to do it efficiently and how to make the heat sink smaller?

An object of the present invention is to provide a cooling fan on the rotating shaft of a motor, and to cool the driving transistor by this cooling fan, thereby reducing the size of the heat radiating plate and forming a motor for the control circuit section. Inner that can be integrated
It is to provide a rotor type brushless motor.

[0006]

In order to achieve the above object, the present invention incorporates a control circuit section for controlling a motor,
In an inner rotor type brushless motor having a rotary shaft that rotates integrally with a rotor to which a main magnet is fixed, the rotor position detecting magnetic pole and the speed detecting multipolar FG.
It is characterized in that a sub magnet having the sensor magnetic poles simultaneously magnetized and a rotating portion integrally formed with a cooling fan for cooling the control circuit portion are integrally rotatably attached to the rotating shaft.

[0007]

According to the present invention, the rotating portion is provided with the sub-magnet in which the rotor position detecting magnetic pole and the speed detecting multi-pole FG sensor magnetic pole are simultaneously magnetized, and the cooling fan for cooling the control circuit portion. Both sides of the yoke are bonded together to be integrally formed, and attached to the rotating shaft so as to be integrally rotatable. A driving transistor and a transistor fixing plate are installed in the vicinity of this rotary cooling fan to cool it. As a result, the transistor fixing plate, which also serves as the heat dissipation plate, can be downsized, and the control circuit unit can be integrated with the motor.

[0008]

EXAMPLE An inner roller according to an example of the present invention will now be described.
The brushless motor will be described with reference to FIGS.

FIG. 1 shows a sectional structure of an inner rotor type brushless motor according to an embodiment of the present invention, and FIG.

First, the motor portion is provided on the stator side for forming the stator 1, the stator winding 2, the steel plate housing 3 for holding the stator 1, and on the rotor side for producing a magnetic field as a motor. Main magnet 5a, main magnet 5a
5, the rotor 5 having the rotor 5 fixed thereto with an adhesive agent, the rotary shaft 4 having the rotor 5 fixed thereto, and the rotary shaft 4 being the end bracket A.
7, rotatably supported by the ball bearing 6 held by the end bracket B8, and further the end bracket A7,
The end bracket B8 is guarded and covered by the steel plate housing 3.

The rotating portion 9 is composed of a sub magnet 10 and a cooling fan 12 with a steel plate yoke 11 sandwiched between them.
Is rotatably fixed to one side end of the No. 3 by a fixing screw A13. One side of the steel plate yoke 11, that is, the control circuit unit 1
A sub magnet 10 having both a magnetic pole for detecting a rotational position and a magnetic pole as an FG sensor is adhered to the surface of No. 4 near the control board 15, and a cooling fan 12 is adhered to the other surface.

On the other hand, as a motor, an FG sensor for speed detection for speed control for detecting the rotor rotation position by the hall element 16 and energizing the stator winding 2 to switch the phase, Further, the cooling fan 12 will be described.

The cooling fan 12 is formed of a molded product such as a pressed steel plate, an aluminum die cast or plastic, and is rotated to ventilate the driving transistor 17 of the control circuit unit 14 and the surrounding electric components. .

Next, the configuration of the rotor position detection and speed detection FG sensor will be described in more detail. First, the same number of magnetic poles as the main magnet 5 is magnetized as the rotor position detecting magnetic pole 10a of the sub magnet 10, and
When fixing with the fixing screw 13, the magnetic pole of the main magnet 5 can be detected by the magnetic pole of the sub magnet 10 by aligning with the magnetic pole of the main magnet 5.

As shown in FIGS. 5 and 6, when the rotor position detecting magnetic pole 10a of the sub-magnet 10 is magnetized, the speed detecting multi-pole FG sensor-magnetic pole 10b is magnetized simultaneously or sequentially. By doing so, the magnetic poles for the rotor position detection and the speed detection FG sensor can be shared by one sub magnet 10.

Next, the structure of the hall element 16, the speed detection FG pattern and the driving transistor 17 of the control circuit section 14 will be described with reference to FIGS.

The control board 15 is provided with an FG pattern for speed detection, an opening portion 15a for positioning the hall element 16 is provided, the hall element 16 is installed, and its lead portion is installed. Solder the circuit pattern to the sub magnet 10
To face.

Further, the driving transistor 17 is fixed to a transistor fixing plate 18 also made of an aluminum material, which also serves as a heat dissipation plate, with a fixing screw B21, and the tip end of the transistor fixing plate 18 is held and fixed to the control board 15 by solder, screws or the like. Excuse me. The lead portion of the driving transistor 17 is soldered to the circuit pattern portion of the control board 15.

Further, in the control circuit section 14, resistors, capacitors, crystal oscillators, etc. for motor driving operation and rotation speed control are mounted on the control board 15 for solder connection, and these parts are connected to the connector 19. By connecting to the power source via the external connection lead sensor 20, the control circuit section 14 that can be driven and operated is provided.

The control circuit portion 14 is attached and fixed to the end bracket B8 with the fixing screw 22 of the control board 15. Further, the cover fixing screw 24 also attaches and fixes the cover 23 to the end bracket B8.

With the above construction, when the motor is driven, the cooling fan 12 of the rotating portion 9 mounted on the motor rotating shaft 4 is rotated and the driving transistor 17 and the transistor fixing plate 18 are cooled. And other resistance,
The condenser and the like can also be cooled. The shape and size of this cooling fan 12 is set to a capacity within which the temperature rise of the driving transistor 17 is suppressed.

With the above structure, the driving transistor 17 is provided.
It is possible to reduce the size of the heat radiating plate without requiring a large heat radiating plate for cooling the control circuit 14, and to integrate the control circuit 14 with the motor.

[0023]

According to the present invention, the rotor magnet position detection and the rotation speed signal detection by the FG sensor are performed by the sub-magnet portion with the rotation cooling fan, and the driving transistor and the driving transistor fixing plate are also cooled. Since it can be performed, the driving transistor fixing plate which also serves as the heat dissipation plate can be made small, and the control circuit section can be made compact. As a result, the control circuit unit can be integrated with the motor, and the cost can be greatly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional structure diagram of an inner rotor type brushless motor according to an embodiment of the present invention.

FIG. 2 is a view on arrow A in FIG.

FIG. 3 is a plan view of a control circuit unit of the inner rotor type brushless motor shown in FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

5 is a cross-sectional view of a sub-magnet with a rotary cooling fan of the inner rotor type brushless motor of FIG.

FIG. 6 is a diagram showing a magnetic pole state of the sub magnet of FIG. 5;

[Explanation of symbols]

1 ... Stator, 2 ... Stator winding, 3 ... Steel plate housing, 4
... Rotary shaft, 5 ... Main magnet, 6 ... Ball bearing, 7 ... End bracket A, 8 ... End bracket B, 9 ... Rotating part, 10 ... Sub magnet, 11 ... Steel yoke, 12 ...
Cooling fan, 14 ... Control circuit section, 15 ... Control board, 16
... Hall element, 17 ... Driving transistor, 18 ... Transistor fixing plate, 10a ... Rotor magnetic pole detection magnetic pole, 10
b ... Magnetic pole for FG sensor

Claims (3)

[Claims] 1. An inner rotor type brushless motor comprising a control circuit section for controlling a motor and having a rotating shaft which rotates integrally with a rotor to which a main magnet is fixed. A sub magnet having a detection magnetic pole and a speed detection multi-pole FG sensor magnetic pole simultaneously magnetized, and a rotary unit integrally formed with a cooling fan for cooling the control circuit unit are attached to the rotary shaft so as to be integrally rotatable. Characteristic inner rotor type brushless motor. 2. The inner rotor type brushless motor according to claim 1, wherein the cooling fan cools the driving transistor and the transistor fixing plate of the control circuit section. 3. The inner rotor type brushless motor according to claim 1, wherein the rotor position detecting magnetic poles of the sub magnet have the same number of magnetic poles and the same magnetic pole position as the main magnet. Ta.