JPS6270696A - Electric motor fan - Google Patents

Abstract

PURPOSE:To realize a quiet motor fan, by furnishing holes at a casing near the outer periphery of an impeller, and closing the holes with a support rubber made of a form rubber. CONSTITUTION:A support rubber 18 to support an electric motor fan at an apparatus 19 is formed of a foam rubber. Plural holes 20 are furnished at a casing 17 at the front near the outer periphery of an impeller 11. These holes 20 are closed airtight by the support rubber 18. A high frequency sound generated by the rotation of the impeller 11 is absorbed to the support rubber of a form rubber. Therefore, high frequency sounds including NZ sound can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric blower used in a vacuum cleaner or the like.

2. Prior Art Conventionally, this type of electric blower was manufactured using a
The configuration was as shown in Publication No. 168.

That is, as shown in FIG. 4, an impeller 2 and an air guide 3 are provided in a casing 1, and by rotating the impeller 2 at high speed with a motor 4, air volume and vacuum pressure are obtained.

Problems to be Solved by the Invention However, in a structure in which the air guide 3 is provided on the outer periphery of the impeller 2, as in the electric blower described above, the impeller 2
When the air flow discharged from the air guide 3 flows into the air guide 3, noise that is thought to be caused by collision at the air guide inlet has become a problem. This occurs as a product of the number of blades Z of the impeller 2 and the rotation speed N (rpm) of the impeller 2, and is commonly called NZ sound.

The present invention solves these conventional problems and aims to reduce the noise of an electric blower with a simple configuration.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to provide a hole in the casing located near the outer periphery of the impeller, and close this hole with support rubber made of foamed rubber. .

Effect This technical means works as follows. That is, high frequency sound including NZ sound generated by the high speed rotation of the impeller is absorbed by the support rubber made of foamed rubber through the holes in the casing. In addition, when an electric blower is attached to a device, even if the support rubber is compressed, some of the support rubber escapes through the holes, so the rubber hardness does not increase, and this reduces the noise generated by the rotation speed of the electric blower. .

EXAMPLES Below, examples will be explained according to the drawings. Figures 1 to 3
In the figure, a centrifugal impeller 1 with multiple blades is shown.
1 is attached to a shaft 13 of a motor 12, and an air guide 14 is provided on the air blowing side of this impeller 11. The impeller 11 and the air guide 14 have an intake port 15 on the top wall, and the motor frame 1
The lower part of the peripheral wall of the casing 6 is surrounded by a casing 17 which is airtightly attached. Reference numeral 18 denotes a support rubber for supporting the electric blower on a device 19 such as a vacuum cleaner, and is made of foamed rubber. Further, 2Q is a plurality of holes provided in the front surface of the casing 17 near the outer periphery of the impeller 11, and the holes 20 are hermetically closed by the support rubber 18.

In the above configuration, first, the air flow sent out from the outer periphery of the impeller 11 is guided into the inside of the motor 12 via the air guide 14, and then the inside is cooled and exhausted from the exhaust port 12'. .

By the way, the problem with noise from electric blowers is N.
I mentioned earlier that this is called the Z sound. In this study, the NZ sound occurs around 5.3KH2 and is very harsh to the ears.

In the configuration of the above embodiment, the high frequency sound generated by the rotation of the impeller 11 passes through the hole 20 of the casing 17 and is absorbed by the support rubber 18 made of foamed rubber.
High frequency sounds including Z sound can be reduced. In addition, even if the support rubber 18 is BJIed when attached to a device 19 such as a vacuum cleaner, a part of it escapes from the hole 2o of the casing 17, so the hardness of the rubber does not increase and increases with the rotation speed of the electric blower. N sound can be reduced.

By the way, 20 φ8 holes 20 are provided in the casing 17 located on the front surface of the outer periphery of the impeller 11 with an outer diameter of 102 mm.
In combination with the support comb 18, which is made of foam rubber and has a wall thickness of 12 mm, the noise level of the vacuum cleaner can be reduced to approximately 3.5 d.
The number of B people decreased.

Note that the diameter and number of holes 2o in the casing 17 are not limited.

Effects of the Invention As described above, according to the present invention, it is possible to reliably reduce high-frequency sound and vibration noise, which are a particular problem in electric blowers, and the means for doing so is to utilize support rubber. Therefore, the noise reduction structure is simplified, and it has excellent effects such as having no adverse effect on the performance of the electric blower.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of important parts of an electric blower showing an embodiment of the present invention, Fig. 2 is an overall sectional view thereof, Fig. 3 is an exploded perspective view, and Fig. 4 is an exploded perspective view showing a conventional electric blower. It is a diagram. 11... Impeller, 12... Motor, 1A... Casing, 18... Support rubber, 19... Equipment, 20... ····hole. Name of agent: Patent attorney Toshio Nakao and one other personff
---Go to page 17---Pushing's tumor 2 Figure 3 @Figure 4

Claims (1)

[Claims] A centrifugal impeller driven by a motor, an air guide having a passage that guides the air flow sent out by the impeller to the motor, a casing containing these impellers and the air guide, and a casing attached to the outer periphery of the casing for attachment to equipment. An electric blower comprising a support rubber covered with the casing, a hole is provided in a portion of the casing near the outer periphery of the impeller and covered by the support rubber, and the support rubber is made of foamed rubber.