JP2000054986A - Air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a balance after assembly, and provide a rotary balance with a high accuracy by forming an annular groove for installing a weight around a rotary shaft on a part opposed to a suction port of a centrifugal fan. SOLUTION: In a centrifugal fan 6, a center boss part 8 is pr<zjected around a disk shaped end plate 7, and a plurality of impellers 9 erected on the end plate 7 are arranged around the center boss part 8 at equal intervals. In the center boss part 8, an annular groove 8b is formed around a cylindrical part 8a. The impeller 9 is covered with a divided fan case 2a the center bass part 8 is positioned on a suction port 3 of the fan case 2, the annular groove 8b is opened outward facing to the suction port 3. After an air blower is assembled a rotary balance is measured, a weight 10 is inserted and fixed to a required part of the annular groove 8b, and thereby, a balance is kept. As after assembly, the rotary balance can be ensured with a high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower for blowing air by rotation of a centrifugal fan.

[0002]

2. Description of the Related Art If a centrifugal fan, which is a rotor that rotates at high speed, is imbalanced in weight, vibration occurs at the time of rotation, resulting in noise and a decrease in mechanical performance. Therefore, balancing is performed. Usually, it is common to select a required one of a plurality of blades arranged on the outer periphery of the center boss portion of the centrifugal fan and fix a weight having a required weight at a predetermined position of the blade. It is.

In a resin-made centrifugal fan, an example of disposing a metal weight for balancing on one side in an annular shape (Japanese Utility Model Laid-Open No. 57-82865), or inserting a weight of metal or the like into a central boss portion. There is an example (Japanese Patent Laid-Open No. 4-41934) in which a possible hole is provided at an unbalanced position so that the balance can be adjusted so that the amount of cutting during balancing can be reduced.

[0004]

However, in any of the above-mentioned conventional examples, the balance processing must be performed before the centrifugal fan is mounted on the fan case. I can't work.

[0005] In an example in which a weight is fixed to the blades of a centrifugal fan, after the centrifugal fan is assembled to the fan case, the blades are hidden by the fan case and the weight cannot be attached. Even in the case where the weights are arranged annularly, the weights cannot be balanced by cutting the weights because they are hidden by the fan case after assembly.In addition, even if the insertion holes are provided in the central boss, And the cutting process must be done.

Therefore, high accuracy cannot be expected in the rotational balance after the fan case and the power unit are assembled to the centrifugal fan. The present invention has been made in view of the above point,
The purpose is to balance after assembly.
Another object of the present invention is to provide a blower that can achieve high-precision rotational balance.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a fan case having a generally disk-like shape, having a suction port at the center of one side surface, and forming a discharge port in a direction tangential to the outer periphery. And a centrifugal fan rotatably supported by the centrifugal fan, wherein the centrifugal fan has a weight mounting annular groove formed in an annular shape around a rotation axis at a portion facing the suction port.

After the blower has been assembled, a weight mounting annular groove is formed in the portion of the centrifugal fan facing the suction port of the fan case. By inserting and fixing, the balance can be obtained, and the rotational balance can be secured with exceptionally high accuracy.

According to a second aspect of the present invention, in the blower according to the first aspect, the weight mounting annular groove is formed in a central boss portion of the centrifugal fan. The central boss has a thickness, and the annular groove for attaching the weight can be easily formed, so that the shape can be simplified.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a blower 1 according to the present embodiment, and FIG. 2 is an exploded perspective view thereof.

The generally disk-shaped fan case 2 is divided in half by a plane perpendicular to the rotation center axis, and an air inlet 3 for air suction is provided at the center of one of the divided fan cases 2a.
Are formed in a circular shape, and the divided discharge ports 4a extend in the tangential direction of the outer periphery.

The other divided fan case 2b has a substantially symmetrical shape having a circular opening at the center and a divided discharge port 4b in the tangential direction of the outer periphery, and is formed into a disk-like shape having one discharge port 4 by combining the two. The fan case 2 is configured.

The motor 5 balances and accommodates the inner rotor 5a in the outer stator 5b, allows the drive shaft 5c to pass through the center circular opening of the divided fan case 2b from the outside, and connects the outer stator 5b to the opening of the divided fan case 2b. Stick to the periphery. The centrifugal fan 6 is integrally supported on the drive shaft 5c penetrating the circular opening, and covers one of the divided fan cases 2a to unite and fix the two divided fan cases 2a and 2b.

The centrifugal fan 6 has a central boss 8 projecting from the center of a disk-shaped end plate 7, and a plurality of blades 9 erected on the end plate 7 are arranged around the center boss 8. They are arranged at intervals. The central boss 8 has an annular groove 8b formed around a cylindrical portion 8a at the center where the drive shaft 5c is fitted (see FIG. 3).

The centrifugal fan 6 has divided fan cases 2a, 2
When the motor b and the motor 5 are assembled, the blade 9 is covered with the divided fan case 2a, but the central boss portion 8 is located at the suction port 3 of the fan case 2 so that the annular groove 8b faces the suction port 3 and is outside. Open to face.

Therefore, after the blower 1 is assembled, the rotational balance is measured, and the weight 10 can be easily inserted into and fixed to a required portion of the annular groove 8b so that balance can be easily obtained. High accuracy.

The groove into which the weight 10 can be inserted is the centrifugal fan 6.
Annular groove 8 formed over the entire circumference of the rotation center axis
Since it is b, the weight can be fixed at a required accurate position as a result of the measurement.

[Brief description of the drawings]

FIG. 1 is a perspective view of a blower according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a sectional view of a centrifugal fan.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Blower, 2 ... Fan case, 3 ... Suction port, 4 ... Discharge port, 5 ... Motor, 6 ... Centrifugal fan, 7 ... End plate, 8 ... Central boss, 9 ... Blade, 10 ... Weight.

Claims (2)

[Claims] 1. A blower incorporating a centrifugal fan rotatably supported in a fan case having a substantially disk shape and having a suction port in the center of one side surface and forming a discharge port in a tangential direction on an outer periphery, wherein the centrifugal fan is rotatably supported. A blower, wherein an annular groove for attaching a weight is formed in an annular shape around a rotation axis in a portion facing the suction port. 2. The centrifugal fan according to claim 1, wherein said annular groove for attaching the weight is formed in a central boss portion.
Blower as described.