JPH04238A - electric blower - Google Patents

Abstract

PURPOSE:To suppress transmission of vibration to a body by arranging a support rubber on the outer circumference of a motor case cap applied on a motor fan unit casing which is held on a cleaner body. CONSTITUTION:A motor case cap 30 is press fitted to the central part of a casing 29 covering a fan 27, where the outer diameter at the upper part of the press fitted section is set shorter than the inner diameter of the casing 29, and a plurality of bosses 30a are formed thereon. Upon assemblage of the motor case cap 30 and the casing 29, the bosses 30a are welded. The outer circumference thereof is held by a body 33 through a support rubber 31 and a motor fan unit 34 is entirely covered with a motor case 35. Since the motor is held at a low vibration part, transmission of vibration to the body is suppressed and thereby noise is suppressed. While furthermore, since the press fit part of the motor case cap has a small outer diameter, workability is improved at the time of press fit and securing reliability is improved by means of the bosses.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electric blower for a vacuum cleaner.

BACKGROUND OF THE INVENTION Conventionally, electric blowers of this type have been constructed as shown in FIG. 3, for example. 1 forms an outer shell from an air guide (made of resin) 2 and a counter-load side bracket (made of resin) 3, and a shaft 4 that rotates toward the air guide 2 protrudes, to which a rotating fan 6 is fixed with a nut 6. The front of the fan 6 is a motor fan unit covered with a casing 7, and an intake lower a opens in the center of the casing 7, facing the intake port 6a of the 71 fan 6. An exhaust port 3a is opened in the platelet 3 on the opposite load side.

Further, a rotor 8 and a stator 9 are built into the motor 1, and the rotor 8 is wound with a winding 8a, and the stator 9 is wound with a winding 9a. Further, below the rotor 8, a commutator 1o connected to the winding 8a is fixed to the shaft 4, and comes into contact with a carbon brush 12 in a brush holder 11 fixed below the anti-load side bracket 3. It is designed to be able to slide.

The current supplied from the external power source reaches the carbon brush 12 from the stator winding 9a, and flows to the winding 8a of the rotor 8 via the commutator 10. Therefore, the current flowing through the winding 8a of the rotor 8 and the magnetic flux generated by the stator 9 are interlinked, so a rotational torque is generated in the winding 8a of the rotor 8 according to Fleming's left hand rule, and as a result, the rotor 8 Rotate.

When the rotor 8 rotates at high speed, the fan 6 fixed to the rotor 8 rotates at high speed and sucks air, which is converted from dynamic pressure to static pressure by the air guide 2 to cool the rotor 8 and stator 9. After that, it is discharged from an exhaust port 3a formed in the anti-load side bracket 3. Further, the motor fan unit 1 is held in the main body 14 by surrounding the outer periphery of the casing 7 with a support rubber 13 made of a flexible material, and the periphery of the motor fan unit 1 is surrounded by a soundproof plate made of urethane or the like. It was surrounded by 16.

Problems to be Solved by the Invention However, with such a structure, when rotating at high speed due to residual unbalance between the rotor and the fan, vibrations are transmitted to the bearings via the shaft, and vibrations are transmitted to the air guide and the anti-load side bracket. , and even transmitted to the casing.

At this time, the support rubber for holding the motor fan unit is pulled forward by the suction force of the motor fan unit and is compressed, reducing its vibration absorption properties, and the vibration of the casing is directly transmitted through the support rubber. Since the vibration noise is transmitted to the main body, the vibration noise becomes high-pitched, and the vibration noise is carried by the exhaust air and is directly discharged from the motor fan unit, which is extremely annoying when using the vacuum cleaner.

Therefore, the present invention includes a substantially cylindrical motor case cap in the center of the casing, which is surrounded by support rubber and held in the main body, and in which the motor case cap is made of resin and is located below the casing. Since the outer diameter of the upper part of the motor case cap is smaller when it is press-fitted, ease of assembly can be improved. In addition, since the multiple bosses formed in the motor case gap are inserted into the holes formed in the casing and then welded, the motor case gap and casing are securely fixed, improving quality and improving the quality of the motor fan unit. This makes it difficult for vibrations to be transmitted to the main body, reducing noise and making cleaning more comfortable.

Means for Solving the Problems: A stator, a rotor, a fan that rotates together with the rotor, an air guide provided below the fan that holds the load side bearing of the rotor, and an anti-load side plate that holds the opposite load side bearing of the rotor. The motor fan unit is composed of a bracket, the upper part of the fan is covered with a casing, and the casing has a substantially cylindrical motor case cap protruding from the casing in the center thereof, and the motor case cap is It is made of resin, is press-fitted into the casing, and has a small outer diameter at the top of the motor case cap, and is provided with a number of bosses that are inserted into holes formed in the casing and welded. A support rubber made of flexible material is installed around the motor case cap to hold it in the vacuum cleaner body.

Function When the motor fan unit is constructed using the above-mentioned means,
Since the motor fan unit is held on the outer periphery of the motor case cap provided in the center of the casing, the motor fan unit can be held in an area where slanut vibration is small, so vibrations are less likely to be transmitted to the main body, resulting in low vibration. Not only can noise be reduced, but also the ease of assembling the motor case cap and casing can be improved, and the reliability of their fixation can also be improved.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. In Figures 1 and 2, 21 is a rotor, and shaft 2
Bearings 23 are press-fitted on both sides of the bracket 2, and an exhaust port 24a is opened below the anti-load side bracket 24. The anti-load side bracket 24 holds the outer periphery of the stator 26 at its center. A winding 25 a that generates a magnetic field for rotating the rotor 21 is wound around the stator 26 . On the load side, the bearing 23 of the rotor 21 is held by a housing 26a formed on the air guide 26, and the bearing 23 on the anti-load side of the rotor 23 is held by a housing 24b formed on the anti-load side bracket 24. .

Further, a shaft 22 protrudes from the load side of the rotor 21 through an air guide 26, and a fan 27 is fixed thereto by a nut 28 to rotate together with the rotor 21. A casing 29 covers the upper part of the fan 27, and a motor case cap 3o is press-fitted into the center of the casing 29.
9, and a plurality of bosses 30a are formed. Motor case cap 3o
After the casing 29 is assembled, the boss 30a is welded. The outer periphery of the motor fan unit 34 is held by the main body 33 via a support rubber 31, and the outer periphery of the motor fan unit 34 is entirely covered by a motor case 36.

Next, the operation of the above configuration will be explained.

In the figure, when an alternating current voltage is applied to the motor 34 and an alternating current flows through the windings 25a constituting the stator 26, magnetic flux for rotating the rotor 21 is generated and interlinks with the rotor 21. Possibly rotor 2
1 rotates, and a fan 27 fixed to the rotor 21 rotates at high speed. Then, the air is sucked in by the fan 27 through the motor cane cap 3o, and the air is sucked into the rotor 2 by the fan 27.
1 and the windings 26 & of the stator 26 are cooled down and then discharged from an exhaust port 24 a formed below the anti-load side bracket 24 .

Here, there is a residual imbalance between the rotor 21, the fan 21, and the fan 27. Therefore, when the rotor 21 and the fan 27 rotate at high speed (approximately 3200 rpm), vibrations occur on the shaft 22. The bearing 23 is transmitted to the casing 29 via the air guide 26.

Since the motor fan unit swings around the center of gravity of the rotor 21, the thrust vibration in the center of the casing 29 is reduced.

Therefore, vibration noise is reduced and comfortable cleaning can be achieved.

Further, since the outer diameter D1 of the upper part of the press-fitting portion of the motor case cap 3o is small, workability during press-fitting is good.

In other words, the boss 30a can be easily inserted at the beginning of assembly, and at the same time the boss 30a is inserted into the hole of the casing 29, positioned, and then press-fitted, resulting in good workability.

Furthermore, the reliability of fixing is improved by the plurality of bosses 30a formed on the motor case cap 3o.

Effects of the Invention The present invention arranges support rubber around the outer periphery of the motor case cap provided on the motor fan unit casing and holds it on the vacuum cleaner body, making it possible to hold the vacuum cleaner in an area with low vibration, thereby reducing vibration transmission to the main body. This makes it possible to realize a low-noise vacuum cleaner, and since the outer diameter of the upper part of the motor case cap is smaller than the inner diameter of the casing, it is very easy to assemble when press-fitting.
Workability can be improved, and the reliability of fixing to the casing can also be improved by fixing with a plurality of bosses.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a motor fan unit showing an embodiment of the present invention, and FIG. 2 is a partial sectional view of the same motor cane cap.
FIG. 3 is a sectional view showing a conventional motor fan unit. 21... Rotor, 26... Air guide, 27... Fan, 29... Casing, 3 case cap, 30a... Boss ,
Boat rubber, 35...Motor cane. Name of agent: Patent attorney Shige Takashi Awano0...
Mo31...and 1 other person

Claims (3)

[Claims] (1) A stator, a rotor, and a fan that rotates together with the rotor; an air guide (made of resin) provided below the fan that holds the bearing on the load side of the rotor; and an air guide (made of resin) that holds the bearing on the non-load side of the rotor. The motor fan unit is composed of a load side bracket (made of resin), the upper part of the fan is covered with a casing, and the casing has a substantially cylindrical motor case cap protruding from the casing in the center. , the motor case cap is made of resin and is press-fitted into the casing, and the motor case cap is provided with a number of bosses to reduce the outer diameter above the press-fitting part of the motor case cap. , which is inserted into a hole formed in the casing and welded, and a support rubber made of flexible material is installed around the motor case cap to hold it in the vacuum cleaner body. Blower. (2) The electric blower according to claim 1, wherein the taper angle of the press-fit portion of the casing is larger than the taper angle of the press-fit portion of the motor case cap. (3) The electric blower according to claim 1, wherein the shape of the tip of the press-fitting portion of the casing is slightly bent inward.