EP1703138A2

EP1703138A2 - Blower

Info

Publication number: EP1703138A2
Application number: EP06003542A
Authority: EP
Inventors: Hirokazu c/o Matsushita Elect.Ind.Co. Ltd. Sakai; Yoshikimi c/oMatsushita Elect.Ind.Co. Ltd Tatsumu; Kazuki c/o Matsushita Elect.Ind.Co. Ltd. Nakao
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp
Priority date: 2005-02-24
Filing date: 2006-02-22
Publication date: 2006-09-20
Also published as: EP1703138A3; JP2006233835A

Abstract

A blower includes a multiblade fan (3) and a scroll casing (4) accommodating the multiblade fan (3) therein. The scroll casing (4) has two side walls (13) opposed to each other, a curved peripheral wall (12a, 12b), and a tongue (9) continuous with the curved peripheral wall (12a, 12b). The scroll casing (4) also has an intake opening defined in one of the two opposed side walls (13) and a discharge opening (8) delimited by the two side walls (13), the curved peripheral wall (12a, 12b), and the tongue (9). The curved peripheral wall (12a, 12b) has a first peripheral wall (12a) continuous with the tongue (9) and a second peripheral wall (12b) formed on a downstream side of the first peripheral wall (12a) with respect to the direction of travel of air so as to be continuous with the first peripheral wall (12a). The first peripheral wall (12a) is concentric with the multiblade fan (3) and has a constant radius of curvature, while the second peripheral wall (12b) has an expansion angle such that a distance (L) between a center (11) of the multiblade fan (3) and the second peripheral wall (12b) increases towards the discharge opening (8).

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a blower for use in, for example, an indoor unit of an air conditioner.

2. Description of the Related Art

Conventionally, the blower of this kind is required to have a high efficiency and a reduced noise level, and generally has a construction as shown in Figs. 4 to 6.
Fig. 4 depicts an indoor unit of an air conditioner, which includes a partition plate 2 mounted within an indoor unit body 1, while the blower includes a fan motor 6 having two motor shafts on opposite sides thereof and secured to the partition plate 2 via a fixture 5, two multiblade fans 3 each secured to one of the two motor shafts, and a scroll casing 4 for covering each multiblade fan 3. When the fan motor 6 is in operation, each multiblade fan 3 is rotated to thereby suck air from intake openings 7 and then discharge the air through a discharge opening 8.
As best shown in Fig. 6, the scroll casing 4 has a curved peripheral wall 10 and a tongue 9 continuous with the peripheral wall 10. In order to enhance the efficiency and reduce the noise level, the peripheral wall 10 has a predetermined expansion angle such that the distance L between the center 11 of the multiblade fan 3 and the peripheral wall 10 continuously increases towards the discharge opening 8 to gradually increase the inside volume of the scroll casing 4, thereby increasing the air quantity to be discharged (see, for example, Patent Document 1).

Patent Document 1: Japanese Laid-Open Patent Publication No. 9-310700

However, because the conventional construction referred to above continuously increases the distance L between the center 11 of the multiblade fan 3 and the peripheral wall 10 from the tongue 9 towards the discharge opening 8, the height H1 and the depth (distance between the center 11 and a rear end) D1 of the scroll casing 4 become large, resulting in an increase of the size of the blower and an increase of the height H2 and the depth (distance between the center 11 of the blower and a rear end) D2 of the unit body 1 in which the blower is mounted.

SUMMARY OF THE INVENTION

The present invention has been developed to overcome the above-described disadvantages.
It is accordingly an objective of the present invention to provide a compact blower having a high efficiency and a reduced noise level.
In accomplishing the above and other objectives, the blower according to the present invention includes a multiblade fan and a scroll casing accommodating the multiblade fan therein, wherein the scroll casing has two side walls opposed to each other, a curved peripheral wall, and a tongue continuous with the curved peripheral wall. The scroll casing also has an intake opening defined in one of the two opposed side walls and a discharge opening delimited by the two side walls, the curved peripheral wall, and the tongue.
The curved peripheral wall has a first peripheral wall continuous with the tongue and a second peripheral wall formed on a downstream side of the first peripheral wall with respect to the direction of travel of air so as to be continuous with the first peripheral wall. The first peripheral wall is concentric with the multiblade fan and has a constant radius of curvature, while the second peripheral wall has an expansion angle such that a distance between a center of the multiblade fan and the second peripheral wall increases towards the discharge opening.
This construction is effective to reduce the size of the scroll casing, resulting in a reduction in size of the blower and also in size of an apparatus body in which the blower is mounted
A spot from which the second peripheral wall commences to expand is positioned at a lowermost end of the scroll casing or at a location adjacent thereto, making it possible to reduce the height of the blower and that of the apparatus body.
Alternatively, the spot from which the second peripheral wall commences to expand is positioned at a rearmost end of the scroll casing remote from the tongue or at a location adjacent thereto, making it possible to reduce the height and depth of the blower and those of the apparatus body.
Again alternatively, the spot from which the second peripheral wall commences to expand is positioned at an uppermost end of the scroll casing or at a location adjacent thereto, making it possible to further reduce the height of the blower and that of the apparatus body.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives and features of the present invention will become more apparent from the following description of preferred embodiments thereof with reference to the accompanying drawings, throughout which like parts are designated by like reference numerals, and wherein:

Fig. 1 is a vertical sectional view of an apparatus body accommodating therein a blower according to a first preferred embodiment of the present invention;
Fig. 2 is a vertical sectional view of an apparatus body accommodating therein a blower according to a second preferred embodiment of the present invention;
Fig. 3 is a vertical sectional view of an apparatus body accommodating therein a blower according to a third preferred embodiment of the present invention;
Fig. 4 is a top plan view of an indoor unit of an air conditioner in which a conventional blower is mounted;
Fig. 5 is a vertical sectional view of the indoor unit of Fig. 4; and
Fig. 6 is a vertical sectional view of the conventional blower.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiment 1.

Fig. 1 depicts an apparatus body 20 such as, for example, an indoor unit of an air conditioner accommodating therein a blower according to a first preferred embodiment of the present invention. The blower includes a multiblade fan 3 and a scroll casing 4 accommodating the multiblade fan 3 therein. The scroll casing 4 is made up of two side walls 13 opposed to each other, a curved peripheral wall, and a tongue 9 continuous with the curved peripheral wall. At lease one of the two opposed side walls 13 has a round intake opening (not shown) defined therein. The peripheral wall includes a first peripheral wall 12a continuous with the tongue 9 and a second peripheral wall 12b formed on the downstream side of the first peripheral wall 12a with respect to the direction of travel of air so as to be continuous with the first peripheral wall 12a. The first peripheral wall 12a is concentric with the multiblade fan 3 and, hence, has a constant radius of curvature, while the second peripheral wall 12b has an expansion angle such that the distance L between the center 11 of the multiblade fan 3 and the second peripheral wall 12b continuously increases towards a discharge opening 8 that is delimited by the two side walls 13, the second peripheral wall 12b, and the tongue 9. The fist peripheral wall 12a and the tongue 9 are joined together at a joint J1, while the first peripheral wall 12a and the second peripheral wall 12b are joined together at a joint J2 that is positioned at a lowermost end of the scroll casing 4. The joint J2 is a spot from which the second peripheral wall 12b commences to expand. Because the first peripheral wall 12a has a constant radius of curvature, the spacing D1 between the joint J1 and the multiblade fan 3 is equal to the spacing D2 between the joint J2 and the multiblade fan 3.
Accordingly, the height H3 of the scroll casing 4 becomes lower than the height H1 of the prior art scroll casing 4 as shown in Fig. 6 and, hence, the height H4 of the apparatus body 20 in which the blower is mounted becomes lower than the height H2 of the conventional apparatus body 1, resulting in a reduction in size of the apparatus body 20.
In proximity to the tongue 9, the pressure inside the scroll casing 4 is relatively low and the air quantity drawn into the intake opening is relatively small. Accordingly, even if the first peripheral wall 12a has no expansion angle and a constant radius of curvature, the performance of the blower is not adversely affected.
Although in the above-described embodiment the joint J2 has been described as being positioned at the lowermost end of the scroll casing 4, it may be positioned at a location adjacent thereto.

Embodiment 2.

Fig. 2 depicts an apparatus body 20 accommodating therein a blower according to a second preferred embodiment of the present invention.
The blower shown in Fig. 2 differs from that shown in Fig. 1 in that in the former the joint J2 between the first peripheral wall 12a and the second peripheral wall 12b is positioned at a rearmost end of the scroll casing 4 remote from the tongue 9.
Accordingly, the scroll casing 4 comes to have a height H5 and a depth D5, which are respectively less than the height H1 and the depth D1 of the prior art scroll casing 4 as shown in Fig. 6 and, hence, the height H6 and the depth D6 of the apparatus body 20 in which the blower is mounted become lower than the height H2 and the depth D2 of the conventional apparatus body 1, respectively, resulting in a reduction in size of the apparatus body 20.
Because the first peripheral wall 12a having no expansion angle and a constant radius of curvature covers a wide range of the scroll casing 4, there is a tendency towards a slight reduction in performance, but the blower can still have a sufficient performance.
Although in the above-described embodiment the joint J2 has been described as being positioned at the rearmost end of the scroll casing 4, it may be positioned at a location adjacent thereto.

Embodiment 3.

Fig. 3 depicts an apparatus body 20 accommodating therein a blower according to a third preferred embodiment of the present invention.
The blower shown in Fig. 3 differs from that shown in Fig. 1 in that in the former the joint J2 between the first peripheral wall 12a and the second peripheral wall 12b is positioned at an uppermost end of the scroll casing 4.
Accordingly, the scroll casing 4 comes to have a height H7 and a depth D7, which are respectively less than the height H1 and the depth D1 of the prior art scroll casing 4 as shown in Fig. 6 and, hence, the height H8 and the depth D8 of the apparatus body 20 in which the blower is mounted become lower than the height H2 and the depth D2 of the conventional apparatus body 1, respectively, resulting in a reduction in size of the apparatus body 20.
In this embodiment also, there is a tendency towards a slight reduction in performance. However, because the blower has a reduced spacing D1 or D2 between the peripheral wall 12a or 12b and the multiblade fan 3 at upper and lower portions thereof, the apparatus body 20 comes to have a considerably reduced height while holding the reduction in performance to a minimum.
Although in the above-described embodiment the joint J2 has been described as being positioned at the uppermost end of the scroll casing 4, it may be positioned at a location adjacent thereto.
As explained hereinabove, because the blower according to the present invention can be formed into a reduced size, it is applicable to a scirocco fan (centrifugal multiblade fan) for use in, for example, an air conditioner.

Claims

A blower comprising a multiblade fan (3) and a scroll casing (4) accommodating the multiblade fan (3) therein, the scroll casing (4) having two side walls (13) opposed to each other, a curved peripheral wall (12a, 12b), and a tongue (9) continuous with the curved peripheral wall (12a, 12b), the scroll casing (4) also having an intake opening defined in one of the two opposed side walls (13) and a discharge opening (8) delimited by the two side walls (13), the curved peripheral wall (12a, 12b), and the tongue (9),
characterized in that
the curved peripheral wall (12a, 12b) has a first peripheral wall (12a) continuous with the tongue (9) and a second peripheral wall (12b) formed on a downstream side of the first peripheral wall (12a) with respect to the direction of travel of air so as to be continuous with the first peripheral wall (12a),
the first peripheral wall (12a) is concentric with the multiblade fan (3) and has a constant radius of curvature, and
the second peripheral wall (12b) has an expansion angle such that a distance (L) between a center (11) of the multiblade fan (3) and the second peripheral wall (12b) increases towards the discharge opening (8).
The blower according to claim 1, wherein a spot from which the second peripheral wall (12b) commences to expand is positioned at a lowermost end of the scroll casing (4) or at a location adjacent thereto.
The blower according to claim 1, wherein a spot from which the second peripheral wall (12b) commences to expand is positioned at a rearmost end of the scroll casing (4) remote from the tongue (9) or at a location adjacent thereto.
The blower according to claim 1, wherein a spot from which the second peripheral wall (12b) commences to expand is positioned at an uppermost end of the scroll casing (4) or at a location adjacent thereto.