JPH0576153A - Electric motor-driven blower - Google Patents

Abstract

PURPOSE:To prevent leakage of air discharged from a rotary fan and passed between the rotary fan and a fan case to reversely flow into an inlet part of the rotary fan of an electrically-driven blower used for a vacuum cleaner or the like. CONSTITUTION:The blower is provided with a fan case spacer 7 of resin, having an almost cylindrical sealing part 7b protruding on the side of a rotary fan, so as to set a labyrinth clearance (d) in a radial direction detween the sealing part 7b and a suction port of the rotary fan opposed to the sealing part 7b, to 0 to 0.3 mm.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In recent years, the competition for higher output of household vacuum cleaners has become more and more intense, and there has been a demand for a high-output and high-efficiency electric motor as a basic component of the electric blower. However, conventionally, this type of electric blower has been disclosed in Japanese Patent Laid-Open No. 3-151.
The configuration as shown in Japanese Laid-Open Patent Publication No. 598 has been general. The configuration will be described below with reference to the drawings.

FIG. 4 is an external view of a partial cross section showing the structure of a conventional electric blower, and FIG. 5 is an enlarged view showing the details of the above structure.

In FIGS. 4 and 5, 1 is a motor having a stator 2 and a rotor 3 rotating at high speed inside, 4 is a rotary fan fixed to a rotary shaft 3a of the rotor 3 and rotating with the rotor 3, and 5 is a rotary fan. 4 is a fan case that is located in front of 4 and covers the rotary fan 4 that is press-fitted and fixed to the frame of the motor 1. At the center of the fan case 5, there is a suction port 4a of the rotary fan 4 and a labyrinth gap d in the radial direction.
And a substantially cylindrical suction port 5a facing each other is opened.

Regarding the blower configured as described above,
The operation will be described below. When power is applied to the motor 1, the rotor 3 rotates at high speed. Next, as the rotor 3 rotates, the rotary fan 4 fixed to the rotary shaft 3a rotates. Therefore, when the rotary fan 4 rotates at high speed, air is sucked from the suction port 5a of the fan case 5 and is guided into the motor 1 through the inside of the rotary fan 1. After that, the air introduced into the motor 1 is discharged to the outside while cooling the motor 1.

[0006]

However, in the above-mentioned conventional configuration, the suction port 4a of the rotary fan 4 and the suction port 5a of the fan case 5 facing the suction port 4a.
The labyrinth gap d between the rotating fan 4 and the fan case 5 causes abnormal noise (generally, the rotating fan 4
Is an aluminum material and the fan case 5 is an iron plate,
When contacted, an unusual noise is generated. In order to avoid), it was necessary to secure at least 0.5 mm. Therefore, the air discharged from the outlet of the rotary fan 4 as shown in FIG. 5 does not smoothly flow into the motor 1 but passes through between the rotary fan 4 and the fan case 5 to the inlet of the rotary fan 4. There was a leak. This leads to a reduction in vacuum pressure, and eventually a reduction in air output. Further, this drawback has a problem that the influence becomes larger as the electric blower has a higher output.

In view of the above drawbacks, the present invention provides an electric blower capable of suppressing air leakage as much as possible by a relatively easy method.

[0008]

In order to solve the above problems, an electric blower according to the present invention is made of a resin having a substantially cylindrical sealing portion projecting toward the rotary fan in the central portion of a fan case that covers the rotary fan. And holding and fixing the fan case spacer, and a labyrinth gap in the radial direction between the sealing portion and the suction port of the rotary fan facing the sealing portion is 0 to 0.3 mm. is there.

[0009]

According to the present invention, the structure described above can prevent the air discharged from the outlet of the rotary fan from flowing back to the inlet of the rotary fan through the space between the rotary fan and the fan case. It is possible to suppress the pressure drop and finally increase the air output.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view of a partial cross section showing the structure of the electric blower of the present invention, and FIG. 2 is an enlarged view showing the details of the above structure. FIG. 3 is a graph showing the relationship between the labyrinth clearance and the efficiency of the electric blower. 1 and 2, 1 is a motor, 2 is a stator, 3 is a rotor, and 4 is a rotary fan, and these are the same as those in the conventional example. A fan case 6 holds and fixes a resin-made fan case spacer 7 having a substantially cylindrical suction port 7a protruding toward the rotary fan 4 side and a sealing portion 7b at the center. Further, the labyrinth gap d in the radial direction between the sealing portion 7b and the suction port 4a of the rotary fan 4 facing the sealing 7b is set to be 0 to 0.3 mm.

With the above structure, when power is applied to the motor 1, the rotor 3 rotates at high speed. Next, as the rotor 3 rotates, the rotary fan 4 fixed to the rotary shaft 3a rotates. Therefore, when the rotary fan 4 rotates at high speed, air is sucked from the suction port 7b of the fan case spacer 7 and is guided into the motor 1 through the inside of the rotary fan 4. Here, the air discharged from the outlet of the rotary fan 4 has a labyrinth gap d in the radial direction between the sealing portion 7b of the fan case spacer 7 and the suction port 4a of the rotary fan 4 facing the sealing portion 7b.
Since it is set to 0 to 0.3, the rotary fan 4
Therefore, it cannot flow back to the inlet of the rotary fan 4 through the space between the fan case 6 and the fan case 6, and can be smoothly guided to the inside of the motor 1 from the outlet of the rotary fan. Therefore, as can be seen from the graph of labyrinth gap-efficiency in FIG. 3, the efficiency UP of 0.5% can be achieved at the labyrinth gap 0.3 mm, and the efficiency UP of 1.8% can be achieved at the 0 mm.

[0013]

As described above, in the electric blower of the present invention, the fan case spacer made of resin having the substantially cylindrical sealing portion protruding toward the rotary fan is held and fixed at the center of the fan case that covers the rotary fan. Then, the labyrinth gap in the radial direction between the sealing portion and the suction port of the rotary fan facing the sealing portion is set to be 0 to 0.3 mm, which is generated between the fan case and the rotary fan. Since it is possible to prevent air from leaking, the vacuum pressure is increased and an electric blower with high output can be obtained.

As for the abnormal sound generated when the rotary fan and the fan case come into contact with each other, which has been considered a problem in the conventional electrically-conducting blower, the fan case spacer is made of resin to eliminate the abnormal sound peculiar to metal and to reduce the noise. It will be extremely significant as it can be an electric motor.

[Brief description of drawings]

FIG. 1 is an external view of a partial cross section showing a configuration of an electric blower of the present invention.

FIG. 2 is an enlarged cross-sectional view showing details of the configuration of the electric blower of the present invention.

FIG. 3 is a graph showing the relationship between the labyrinth gap and the efficiency of the electric blower.

FIG. 4 is an external view of a partial cross section showing the configuration of a conventional electric blower.

FIG. 5 is an enlarged view showing details of the configuration of a conventional electric blower.

[Explanation of symbols]

 1 Motor 2 Stator 3 Rotor 4 Rotating Fan 6 Fan Case 7 Fan Case Spacer 7b Sealing Section

Claims (4)

[Claims] 1. A motor having a stator and a rotor that rotates at high speed inside, a rotary fan that is fixed to the rotor shaft and rotates together with the rotor, and a rotary fan that is positioned in front of the rotary fan and is press-fitted and fixed to the frame of the motor. A fan case spacer made of resin having a substantially cylindrical sealing portion protruding toward the rotary fan is held and fixed in the center of the fan case. 2. The fan case and the fan case spacer are
The electric blower according to claim 1, wherein the plurality of convex portions projecting from the fan case spacer are welded to be held and fixed. 3. A sealing portion of a fan case spacer,
The electric blower according to claim 1, wherein a labyrinth gap in a radial direction between a suction port of the rotary fan facing the sealing portion is 0 to 0.3 mm. 4. The labyrinth gap between the sealing part of the fan case spacer and the suction port of the rotary fan is such that the sealing part is brought into contact with the suction port of the rotary fan when the fan case having the fan case spacer is press-fitted. The electric blower according to claim 1, wherein the abutting sealing portion is formed by rotating and rotating a rotary fan afterward.