JPH05280491A - Blower - Google Patents

Abstract

PURPOSE:To achieve the vibrationproof performance and airtightness of a blower by a fan motor which is lightweight and revolves at a high speed. CONSTITUTION:The back surface of a fan casing 3 is installed through a vibrationproof bush 4 on the front surface of the frame 2 of a fan motor 1, and a packing 5 consisting of an independent foamed member is nipping-installed between the front surface of the frame 2 and the back surface of the fan casing 3, and the resonance frequency of the vibrationproof bush 4 is set between each resonance frequency of the revolution primary component of the fan motor 1 and the frame 2, and the packing 5 is nipped in nearly accordance with the projection plane shape in the axial direction of the frame 2. Accordingly, the resonance of the frame can be suppressed without increasing the primary component of the motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower combined with a fan motor rotating at a high speed.

[0002]

2. Description of the Related Art A turbo fan or the like driven by a brushless motor rotating at a high speed has a conventional structure as disclosed in, for example, Japanese Patent Publication No. 56-10536. That is, the back surface of the fan casing is joined and integrated with the front surface of the frame of the fan motor of the DC brushless motor. A rubber bush for vibration isolation is provided at the joint between the front of the fan motor frame and the back of the fan casing, and packing is inserted in the leak passage around the axis between the front of the frame and the back of the fan casing. The rubber bushing is used for vibration and noise prevention during operation, and the packing is used for air tightness.

[0003]

In the above-mentioned conventional blower, since the rubber bush is a general component merely used as a vibration isolating component, and the packing is also provided as a component for keeping airtightness against the leak passage, it is actually used. The anti-vibration and air-tightness have not been achieved to a satisfactory level. This tendency is particularly strong in a fan motor that is a DC brushless motor that is lightweight and rotates at high speed.

The present invention has been made to solve the conventional problems, and an object thereof is to achieve vibration isolation and airtightness of a blower by a fan motor that is lightweight and rotates at high speed.

[0005]

The blower according to the present invention is such that the resonance frequency of the vibration isolating bush is set to the fan motor by attaching the rear surface of the fan casing to the front surface of the frame of the fan motor through the vibration isolating bush and by sandwiching the packing. The intermediate foaming component of the motor rotation and the resonance frequency of the frame are set in the middle, and the packing is an independent foam material having a shape substantially matching the projection plane shape of the frame in the axial direction.

[0006]

In the blower according to the present invention, the resonance of the frame can be suppressed without increasing the primary component of the motor rotation due to the characteristic of the relative resonance frequency of the anti-vibration bush, and the frame and the fan casing that face each other face each other. Airtightness is improved by the packing widely intervening between them, and the vibration noise of the frame is also reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of a blower showing an embodiment of the present invention, and FIG. 2 is an explanatory view showing characteristics of a vibration isolation bush. The blower shown is a turbo fan in which a lightweight DC brushless motor is configured as a fan motor 1. A fan casing 3 has a rear surface of a fan casing 3 attached to the front surface of a frame 2 of the fan motor 1 via a vibration-proof bush 4 so as to face each other with screws. ing. Between the front surface of the frame 2 and the rear surface of the fan casing 3, a packing 5 made of an independent foam material is sandwiched in a range substantially matching the projection plane of the frame 2 in the axial direction.

The vibration-proof bushing 4 is made of rubber, and its resonance frequency is set between the resonance frequency of the frame 2 and the primary component of the motor rotation of the fan motor 1. That is, the resonance frequency of the anti-vibration bush 4 is fn, and the motor rotation primary component is f
2. If the resonance frequency of the frame is f1, then f
The relationship is 2 <fn <f1.

The blower having the above structure can suppress the resonance of the frame 2 without increasing the primary component of the motor rotation due to the characteristic of the relative resonance frequency of the anti-vibration bush 4, and the frame 2 and the fan that face each other can face each other. Airtightness is improved by the packing 5 widely intervening between the casing 3 and
Vibration noise of the frame 2 is also reduced. Generally, in the anti-vibration design for preventing the resonance sound of the frame 2, the relationship of fn << f1 is considered, but f2, that is, the primary component of the motor rotation may be increased, so fn << f2 << f1 should be set. is there. However, when the weight of the fan motor 1 is light, fn <<
It becomes impossible to set to f2. Therefore, by setting the relationship of f2 <fn <f1 as described above, the resonance sound of the frame 2 can be suppressed sufficiently low without increasing the motor rotation primary component.

[0010]

As is apparent from the above description of the embodiment, according to the present invention, the resonance of the frame can be suppressed without increasing the primary component of the motor rotation due to the characteristic of the relative resonance frequency of the vibration-proof bushing. With the packing widely intervening between the frame and the fan casing facing each other, the airtightness is improved and the vibration noise of the frame is also reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a blower showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the characteristics of the resonance frequency of the vibration-proof bushing according to the embodiment of the present invention.

[Explanation of symbols]

 1 Fan motor 2 Frame 3 Fan casing 4 Anti-vibration bush 5 Packing

Claims (1)

[Claims] 1. A front surface of a fan motor is attached to a front surface of a fan casing via a vibration-proof bush, and a packing made of an independent foam material is sandwiched between the front surface of the frame and a rear surface of the fan casing. The resonance frequency of the anti-vibration bush is set in the middle of the motor rotation primary component of the fan motor and the resonance frequency of the frame, and the packing is sandwiched so as to substantially match the projected plane shape of the frame in the axial direction. Characterized blower.