JPH11264396A - Air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small sized air blower with low noise by mounting two same shaped front and rear step axial impellers on both side of a rotary shaft of double axial motor supported in a casing by plurality of installing legs, and arranging stationary blades for rectifying turning flow by the front step axial flow impeller on respective installing legs. SOLUTION: An air blower in a ventilating air blower and an air conditioner suspended and fixed to an anchor bolt suspended from a space and the like in the ceiling is formed by mounting two same shaped front and rear step axial flow impellers 5, 6 o both sides of a rotary shaft of a double axial motor 4 supported in a casing 2 by eight installing legs 3. A connecting port parts 9 for composing a suction port 7 and a blowout port 8 are fitted to both ends of the casing 2, and a duct is externally fitted. In this case, a front step stationary blade 17 and a rear step stationary blade 18 are integratedly formed with the front step axial flow impeller 5 side and the rear step axial flow impeller 6 side of each installing leg 3, and the stationary blades 17, 18 are respectively inclined opposite to rotational directions of respective axial flow impellers 5, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilating device having a duct system and a blower serving as a main component of a blowing function in an air conditioner.

[0002]

2. Description of the Related Art In this type of blower, a mixed flow fan is often used in applications of medium air volume and medium static pressure. However, since the impeller of the mixed flow fan has a conical shape that extends downstream from the suction port, the main body of the blower is larger than the diameter of the duct to be connected, and it is difficult to reduce the size. On the other hand, Japanese Patent Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication No. 9-49500 and Japanese Unexamined Patent Application Publication No. 9-49500, a blower in which an axial impeller is incorporated in a cylindrical casing has been developed. However, in order to obtain the same static pressure as that of the mixed flow fan, the impeller is devised as disclosed in Japanese Patent Application Laid-Open No. 9-49500, or the number of revolutions of the impeller is increased although noise is a problem. I have to raise it. A small axial-flow blower with high static pressure has also been developed without using a complicated impeller configuration. This is also called a contra-rotating type, in which two axial impellers rotating in opposite directions are arranged in a cylindrical casing.

[0003]

In the conventional blower using the axial flow impeller as described above, Japanese Patent Application Laid-Open No. 9-49500 is disclosed.
In the method disclosed in Japanese Patent Application Laid-Open Publication No. H11-260, the production of the impeller is troublesome and costly. In addition, what is called a contra-rotating type requires two axial impellers and motors having different rotation directions, and also has a problem that the cost is high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it is an object of the present invention to obtain a medium static pressure with a medium air flow, a low noise, a small size, and a small size. The cost is to get a blower.

[0005]

In order to achieve the above-mentioned object, the present invention is directed to a first aspect of the present invention, wherein the same shape is provided on both sides of a rotating shaft of a dual shaft motor supported by a plurality of mounting feet in a cylindrical casing. A means is used in which two axial-flow impellers of the former stage and the latter-stage are mounted, and a stationary blade for rectifying a swirling flow by the axial-stage impeller of the preceding stage is mounted on each mounting foot.

In order to achieve the above object, a second aspect of the present invention employs means for providing the stationary blade in the first aspect of the present invention on the axial flow impeller side in front of the mounting foot.

In order to achieve the above object, the invention of claim 3 employs means for providing the stationary blade in the means according to claim 1 or 2 on the axial flow impeller downstream of the mounting foot.

In order to achieve the above object, a fourth aspect of the present invention is to provide the above-mentioned means according to any one of the first to third aspects, wherein the stator blades are inclined in a direction opposite to the rotation direction of each axial flow impeller. The means to make it do is adopted.

In order to achieve the above object, a fifth aspect of the present invention employs the means according to any one of the first to fourth aspects, wherein the stationary blade and the mounting foot are integrally formed.

In order to achieve the above object, a sixth aspect of the present invention adopts the means according to the fifth aspect, wherein all of the stationary blade and the mounting foot have the same size and shape.

According to a seventh aspect of the present invention, there is provided the above-mentioned means according to any one of the first to sixth aspects, wherein a chord length of the vane at an arbitrary cross section of the vane and one vane are provided. The chord ratio, which is the ratio of the distance between the leading edge of the blade and the leading edge of the adjacent stationary blade, is set in the range of 0.9 to 1.1.

[0012] In order to achieve the above object, an invention according to claim 8 is characterized in that the number of stationary blades and the number of axial flow impellers in the means according to any one of claims 1 to 7 are relatively simple. Employ means to configure relationships.

According to a ninth aspect of the present invention, there is provided a motor fixing portion for fixing a two-axis motor to an inner diameter end side of a mounting foot in the means according to any one of the first to eighth aspects. The motor fixing part has a motor insertion hole in the center and a mounting foot fixing part surrounding it, and the motor fixing part is located at the free end side of the mounting foot fixing part on the axial flow impeller side at the subsequent stage. Use a means to mount it.

[0014]

Embodiments of the present invention will now be described with reference to the drawings. The blower according to the present embodiment shown in FIGS. 1 to 11 is suspended and fixed on an anchor bolt 1 suspended in a space above the ceiling as shown in FIG. 3, and is used in a ventilation blower or an air conditioner having a duct system. As shown in FIG. 1, the front and rear stages of the same shape are formed on both sides of a rotating shaft of a dual shaft motor 4 supported by eight mounting feet 3 in a cylindrical casing 2 as shown in FIG. And two axial impellers 5 and 6 are mounted. At both ends of the casing 2, small-diameter connection port parts 9 constituting a suction port 7 and an air outlet 8 are fitted and mounted, and a duct (not shown) is provided.
Is externally fitted to the connection port component 9 to form a duct system for a ventilation blower or an air conditioner. Casing 2 of each connection part 9
At the step portion of the fitting portion, two mounting brackets 11 for hanging and fixing to the anchor bolt 1 are mounted at opposite positions so that the mounting surface 10 faces a horizontal plane crossing the center line of the casing 2. As shown in FIG. 2, a terminal block 12 for connection to a power supply is attached to an outer portion of the casing 2. The terminal block 12 has a charging section covered by a removable cover 13 and is configured as a terminal block section. The center of the terminal block 12 is aligned with the center line of the casing 2 so as not to interfere with installation in a space such as a narrow ceiling. They are lying on a horizontal plane.

As shown in FIGS. 4, 5 and 6, the double shaft motor 4 is mounted on the inner diameter end of eight sheet metal mounting feet 3 arranged at equal intervals in the circumferential direction toward the center of the casing 2. It is attached to the octagonal cylindrical motor fixing portion 14. The motor fixing portion 14 is made of sheet metal, and has a motor insertion hole 15 at the center for inserting and fixing the two-axis motor 4 and an eight-piece mounting foot fixing portion 16 surrounding the motor insertion hole 15.
And is mounted such that the free end side of the mounting foot fixing portion 16 faces the axial impeller 6 at the subsequent stage. A front stage stationary blade 17 and a rear stage stationary blade 18 are integrally formed on the front stage axial flow impeller 5 side and the rear stage axial flow impeller 6 side of each mounting foot 3, respectively. Each of the mounting feet 3 having the front stage stationary blades 17 and the rear stage stationary blades 18 are all composed of one kind of component having the same dimensions and shape, and both the front stage stationary blades 17 and the rear stage stationary blades 18 are axial flow impellers. The rotation directions A and 5 are inclined in the opposite directions as shown in FIG. Front stage stationary blade 17 and rear stage stationary blade 18
As shown in FIG. 9, the chord length L of the blade at an arbitrary cross section thereof, the leading edge of one of the vanes 17, 18 and the adjacent vane 1
The chord ratio, which is the ratio of the interval T to the leading edge of 7, 18 is 0.9 to 0.9.
It is configured to be in the range of 1.1.

The front stage stationary blade 17 and the rear stage stationary blade 18
And the number of blades of the axial impellers 5 and 6 are set to a relatively prime relationship that does not become an integral multiple. For example, the number of vanes 17 in the front stage and the number of vanes 18 in the rear stage are set to eight with respect to the number of blades 3 of the axial flow impellers 5, 6, or the axial flow impeller 5,
For the number of blades 4 of 6, the front stage stationary blade 17 and the rear stage stationary blade 1
The number of 8 is seven. Each mounting foot 3 is screw-fixed to the inner wall of the casing 2 at a mounting flange 19 formed on the outer peripheral end side.

In this blower, the front and rear axial flow impellers 5 and 6 rotate in the same direction by energizing the two-shaft motor 4 to form an airflow from the suction port 7 to the air outlet 8. FIG.
As shown in FIG. 0, the airflow B flowing from the suction port 7 into the preceding axial flow impeller 5 through the duct is substantially perpendicular to the rotation direction of the preceding axial flow impeller 5. The airflow C that has flowed out of the preceding axial flow impeller 5 has a swirl component along the inner periphery of the casing 2 and thus has an angle in the rotation direction A of the previous axial flow impeller 5 with respect to a horizontal plane that crosses the center line. Flow out. A part of the swirling component of the airflow C having this angle is recovered as static pressure by the front stationary blade 17 inclined to the opposite side to the rotation direction A of the front axial flow impeller 5, and further, the rear stationary blade 18 As a result, the remaining swirling component is collected as a static pressure, rectified into an airflow D substantially parallel to the center line, and flows into the axial impeller 6 at the subsequent stage. That is, the airflows B and D smoothly flow substantially perpendicularly to the rotation direction A or substantially parallel to the axial direction of both the axial flow impeller 5 at the front stage and the axial flow impeller 6 at the rear stage.
Flows, so that it is not necessary to eliminate the swirling component by an impeller rotating in the opposite direction as in the contra-rotating type. Therefore, the axial impellers 5 and 6 can be constituted by one kind, and the motor can be constituted by only one double-shaft motor 4, so that the cost can be suppressed and the structure can be reduced in size.

The front stage stationary blade 17 and the rear stage stationary blade 18
Is configured so that the string ratio is in the range of 0.9 to 1.1, so that a large flow rate and a large static pressure can be obtained as shown in FIG. Become a blower. As shown in FIG. 11, when the chord ratio is 0.8, the performance is extremely reduced. Furthermore, the axial impellers 5 and 6 at the front and rear stages
And the number of vanes 17 and 18 at the front and rear stages are not set to be an integral multiple, so that the number of blades at the axial flow impellers 5 and 6 and the vanes 17 and 18 is reduced by the interference of airflow. Generation of frequency noise can be suppressed. Furthermore, since the motor fixing portion 14 is mounted with the free end side of the mounting foot fixing portion 16 facing the axial flow impeller 6 at the subsequent stage, the airflow does not collide with the free end side, and the wind noise is reduced. Generation can be avoided, and noise is also reduced because only four motors are used.

[0019]

As described above, according to the first aspect of the present invention, a low-cost, low-noise, low-cost blower suitable for medium air flow and medium static pressure can be obtained.

According to the second aspect of the present invention, it is possible to simplify the configuration of the stationary blade together with the effect according to the first aspect.

According to the third aspect of the present invention, in addition to the effect according to the first or second aspect, the function of recovering the swirling component to a static pressure is improved.

According to the fourth aspect of the present invention, in addition to the effect according to any one of the first to third aspects, the function of recovering the swirling component to a static pressure is further improved.

According to the fifth aspect of the present invention, the number of parts can be reduced together with the effect according to any one of the first to fourth aspects, and cost reduction can be promoted.

According to the invention of claim 6, together with the effect of claim 5, it is possible to reduce the types of constituent parts.

According to the seventh aspect of the present invention, it is possible to obtain a large flow rate and a high static pressure together with the effects according to any one of the first to sixth aspects.

According to the eighth aspect of the present invention, it is possible to suppress the generation of the discontinuous frequency sound together with the effect according to any one of the first to seventh aspects.

According to the ninth aspect of the present invention, it is possible to prevent wind noise caused by the motor fixing portion together with the effect according to any one of the first to eighth aspects.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a blower according to an embodiment.

FIG. 2 is a plan view showing the blower according to the embodiment.

FIG. 3 is a side view showing the blower according to the embodiment in an attached state.

FIG. 4 is a front view showing a mounting foot and a motor fixing portion of the blower according to the embodiment.

FIG. 5 is a side view showing a mounting foot and a motor fixing portion of the blower according to the embodiment.

FIG. 6 is a side view showing a motor fixing portion of the blower according to the embodiment.

FIG. 7 is a side view showing a mounting foot and a stationary blade of the blower according to the embodiment.

FIG. 8 is an explanatory diagram showing a relationship between a stationary blade of the blower according to the embodiment and a rotation direction of an axial impeller.

FIG. 9 is an explanatory diagram related to the chord ratio of the blower according to the embodiment.

FIG. 10 is an explanatory diagram illustrating an airflow flowing through a stationary blade and an axial impeller of the blower according to the embodiment.

FIG. 11 is an explanatory diagram showing a relationship between a string saving ratio and air blowing performance.

[Explanation of symbols]

2 casing, 3 mounting foot, 4 double shaft motor,
5 Axial impeller at the front stage, 6 Axial impeller at the rear stage,
14 Motor fixing part, 15 Motor insertion hole, 1
6 Attachment foot fixing part, 17 Front stage stationary blade, 18 Rear stage stationary blade.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shoji Yamada 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (9)

[Claims] 1. An axial flow impeller having a front stage and a rear stage having the same shape are mounted on both sides of a rotating shaft of a double shaft motor supported by a plurality of mounting legs in a cylindrical casing. A blower having a foot provided with a stationary blade for rectifying a swirling flow generated by the axial flow impeller of the preceding stage. 2. The blower according to claim 1, wherein the stationary blade is provided on the axial flow impeller side in front of the mounting foot. 3. The blower according to claim 1, wherein the stationary blade is provided on the axial flow impeller downstream of the mounting foot. 4. The blower according to claim 1, wherein the stationary blades are inclined in a direction opposite to a rotation direction of each of the axial impellers. 5. The blower according to claim 1, wherein the stationary blade and the mounting foot are integrated. 6. The blower according to claim 5, wherein the blower is constituted by stationary vanes and mounting feet all having the same dimensions and shape. 7. The blower according to claim 1, wherein a chord length of the vane at an arbitrary cross section of the vane, a leading edge of one vane, and an adjacent vane are provided. A blower having a chord ratio, which is a ratio of an interval to a leading edge of the fan, in a range of 0.9 to 1.1. 8. The blower according to claim 1, wherein the number of stationary blades and the number of blades of the axial impeller are configured to be relatively prime. 9. The blower according to claim 1, further comprising: a motor fixing portion for fixing a two-axis motor on an inner diameter end side of the mounting foot, wherein the motor fixing portion is provided at the center. A blower having a motor insertion hole and a mounting foot fixing portion surrounding the motor insertion hole, wherein the motor fixing portion is mounted such that the free end side of the mounting foot fixing portion faces the axial flow impeller in the subsequent stage.