JPH0626494A - Electrically driven air blower - Google Patents

Abstract

PURPOSE:To eliminate requirement to provide the driving circuit of a motor independently of an electrically driven air blower, and also save space. CONSTITUTION:An electrically driven air blower is provided with a fan casing 6 which is provided with a fan 5 driven by a motor therein and being formed larger than the outer diameter of a motor casing 1 for enclosing the motor, and the driving circuit 9 of the motor, and the driving circuit 9 is provided in a space formed by a step difference between the outer circumference part of the motor casing 1 and the fan casing 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower incorporated in a household vacuum cleaner or the like.

[0002]

2. Description of the Related Art In recent years, as household vacuum cleaners have been downsized and output increased, there has been an increasing demand for downsizing of electric blowers incorporated in the vacuum cleaner. Hereinafter, a conventional electric blower will be described with reference to FIG.

As shown in the figure, inside a motor casing 11 is a rotor 1 consisting of a stator 12 and a permanent magnet.
3 and a position detector 14 for detecting the position of the rotor 13 to form a brushless motor, and a substrate 16 in which a drive circuit 15 for driving the brushless motor is incorporated is provided separately from the brushless motor via a lead wire 17. The fan 18 is attached to the shaft of the rotor 13, and the fan casing 19 is provided outside the fan 18. The operation of the electric blower configured as described above will be described below.

Based on the output signal of the position detector 14, a current determined by the drive circuit 15 incorporated in the substrate 16 flows through the stator 12, torque is generated in the rotor 13 to rotate the fan, and air is blown into the fan casing. It was sucked from the suction port of 19, passed through the inside of the motor casing 11, and was discharged to the outside of the motor casing 11.

[0005]

In the structure of such a conventional electric blower, the brushless motor drive circuit 15 is installed separately from the main body of the electric blower, so that it is used in a household cleaner. Drive circuit 15
There was a problem that the product itself would be enlarged by the amount of space.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a space-saving electric blower using a brushless motor which does not require a drive circuit for the brushless motor to be provided separately from the main body of the electric blower.

[0007]

In order to achieve the above-mentioned object, an electric blower of the present invention is formed with a motor casing containing a motor and an outer diameter larger than that of the motor casing, and is internally driven by the motor. A fan casing having a fan and a drive circuit for the motor are provided, and the drive circuit is provided in a space formed by a step between the outer peripheral portion of the motor casing and the outer peripheral portion of the fan casing.

Further, an air hole is formed on the side wall of the fan casing on the motor casing side so that air is diffused toward the outer periphery of the motor casing.

[0009]

According to the present invention, since the drive circuit for driving the motor is provided in the space formed by the step between the motor casing and the fan casing, the present invention does not require a separate space for mounting the drive circuit and thus saves space. Will be achieved.

Further, since a part of the air generated by the fan is diffused toward the outer periphery of the motor casing, cooling of the drive circuit provided at the outer peripheral position of the motor casing is promoted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. As shown in the figure, a brushless motor is constructed by providing a rotor 3 composed of a stator 2 and a permanent magnet and a position detector 4 for detecting the position of the rotor 3 inside a motor casing 1 to form a brushless motor. Attaches the fan 5, and the outside of the fan 5 is the motor casing 1
The main body of the electric blower is configured by being surrounded by a fan casing 6 having a diameter larger than the outer diameter.

Then, a part of the air generated by the fan 5 flows so as to correspond to the outer periphery of the motor casing 1 which becomes the space 7 formed by the step between the outer periphery of the motor casing 1 and the outer periphery of the fan casing 6. The air holes 8 are formed in the side wall of the fan casing 6 on the motor casing 1 side.
And a drive circuit 9 such as a rectifying circuit, a smoothing circuit, and an inverter circuit for driving the brushless motor is provided on the side wall via the substrate 10. Further, a switching element 11 such as a bipolar transistor or a power MOSFET in an inverter circuit is provided in close contact with the outer periphery of the motor casing 1 via a heat radiation fin.

The operation of the electric blower configured as described above will be described below. A current determined by the drive circuit 9 based on the output signal of the position detector 4 flows through the stator 2, whereby torque is generated in the rotor 3 and the rotor 3 rotates.
The fan 5 rotates.

Air is sucked from the suction port 6a of the fan casing 6 by the fan 5, passes through the inside of the motor casing 6, and is discharged from the discharge hole 1a of the motor casing 1 while cooling the rotor 3 and the stator 2.

Further, a part of the air sucked into the fan casing 6 is diffused toward the outer periphery of the motor casing 1 through an air hole 8 formed in the side wall of the fan casing 6, and the drive circuit 9 and the switching element 11 are cooled. Will be done.

As described above, according to the electric blower of the embodiment of the present invention, the drive circuit 9 provided for driving the electric blower is connected to the outer peripheral portion of the motor casing 1 and the outer peripheral portion of the fan casing 6 forming the electric blower. Since it is configured to be mounted in the space 7 formed by the step of
Since it is not necessary to separately provide the space 7 for mounting the drive circuit 9, space can be saved.

Further, since a part of the air generated by the fan 5 is diffused toward the outer periphery of the motor casing 1, cooling of the drive circuit 9 provided at the outer peripheral position of the motor casing 1 is promoted. Becomes

[0018]

As is apparent from the above embodiments, according to the present invention, since the drive circuit for driving the motor is provided in the space formed by the step between the motor casing and the fan casing, the space for installing the drive circuit is separately provided. It is possible to provide an electric blower that does not need to be provided and saves space.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of an electric blower according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a configuration of a conventional electric blower.

[Explanation of symbols]

 1 Motor casing 5 Fan 6 Fan casing 7 Space 8 Air hole 9 Drive circuit 11 Switching element

Claims (4)

[Claims] 1. A motor casing containing a motor,
The motor casing is provided with a fan casing formed to have a larger diameter than the outer diameter and having a fan driven by the motor therein, and a drive circuit for the motor. An electric blower provided in the space formed by the step between and. 2. The switching element is provided on the outer peripheral surface of the motor casing directly or through a heat radiation fin.
Electric blower described. 3. The electric blower according to claim 1, wherein a drive circuit component for driving the motor is provided on a side wall of the fan casing on the motor casing side. 4. The electric blower according to claim 1, wherein an air hole is formed on a side wall of the fan casing on the side of the motor casing toward the outer periphery of the motor casing to disperse air.