US20080038111A1

US20080038111A1 - Blower device

Info

Publication number: US20080038111A1
Application number: US11/890,706
Authority: US
Inventors: Takahiro Iwasaki; Shinichi Oda
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2006-08-09
Filing date: 2007-08-07
Publication date: 2008-02-14
Also published as: JP2008038820A; DE102007037195A1

Abstract

A blower device for a vehicle includes at least two blowers having fan shafts arranged in parallel with each other, a single motor for driving and rotating the blowers, and a shroud for holding the two blowers. The motor includes a motor portion and a motor shaft driven by and extending from the motor portion. The shroud has shroud ring portions each of which has a circular shape to cover an outer peripheral portion of the blower, and a shroud plate portion extending from the shroud ring portions to an outside. Furthermore, the fan shafts of the blowers are coupled to the motor shaft via a gear portion, and the motor portion is attached to the shroud plate portion to be offset from a center connection line connecting the centers of the shroud ring portions.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2006-216494 filed on Aug. 9, 2006, the contents of which are incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a blower device having plural blowers. For example, the blower device can be suitably used for a vehicle, for blowing air to a heat exchanger.
2. Description of the Related Art
In a conventional vehicle blower device for blowing air to a heat exchanger having a long length in a vehicle width direction, two axial fans are arranged on a downstream air side of a core portion of the heat exchanger, and the two axial fans are rotated respectively by two motors. That is, plural motors having the same number as plural axial fans are connected to rotation shafts of the plural axial fans, respectively. In this case, however, the number of components of the blower device is increased, and the size and weight of the entire blower device become large.
In view of this problem, JP-U-62-112470 describes a blower device for a vehicle, having a single motor for rotating plural axial fans. The plural axial fans are arranged in an, arrangement direction to opposite to a core portion of a heat exchanger, and the single motor is fixed to a tank portion provided at an end portion of the core portion. A shaft of the motor and rotation shafts of the axial fans are connected with each other via a gear portion. However, in this blower device, the motor is located on an extension line of the arrangement direction, and is interfered by a vehicle body when being mounted on the vehicle, thereby it is difficult to be mounted on the vehicle.

SUMMARY OF THE INVENTION

In view of the foregoing problems, it is an object of the present invention to provide a blower device for a vehicle, which can easily mounted on the vehicle.
It is another object of the present invention to provide a blower device having plural blowers rotated by a single motor through a gear portion.
According to an example of the present invention, a blower device for a vehicle includes a plurality of blowers having fan shafts arranged in parallel with each other, for blowing air toward a heat exchanger mounted to the vehicle, a single motor for driving and rotating the blowers, and a shroud for holding the blowers and for forming air passages from the heat exchanger to the blowers. The shroud includes a plurality of shroud ring portions each of which has a circular shape to surround an outer peripheral portion of the blower, and a shroud plate portion extending smoothly from a rear side of the heat exchanger to the shroud ring portions. Furthermore, the fan shafts are coupled to a motor shaft of the motor via a gear portion, and the motor is located downstream from the shroud plate portion to be offset from a center connection line connecting centers of the shroud ring portions. Accordingly, the motor can be easily mounted to the vehicle on the downstream air side of the shroud plate portion using a space offset from the center connection line, thereby improving mounting performance of the blower device.
For example, the shroud plate portion has an approximately rectangular outer peripheral shape with four corner portions outside of the shroud ring portions. In this case, the motor may be located between one corner portion and the shroud ring portion adjacent to the one corner portion. Alternatively, the motor may be located between adjacent two shroud ring portions to be offset from the center connection line connecting the centers of the adjacent two shroud ring portions.
The blower may include two contrarotating axial fans which are located to be rotated reversely with each other in accordance with rotations of its rotation shafts arranged on an axial line.
Furthermore, adjacent two blowers may be connected to each other via a connection shaft. In this case, the motor shaft may be tilted from an extension line of the connection shaft, or may be approximately perpendicular to an extension line of the connection shaft.
Alternatively, the motor may include a motor portion connected to the motor shaft to rotate the motor shaft, and all upstream area of the motor portion may be covered by the shroud plate portion.
According to another example of the present invention, a blower device includes at least two blowers having fan shafts arranged in parallel with each other, a single motor for driving and rotating the two blowers, and a shroud for holding the two blowers. Furthermore, the motor includes a motor portion and a motor shaft driven by and extending from the motor portion, and the fan shafts of the blowers are coupled to the motor shaft via a gear portion. The shroud has two shroud ring portions each of which has a circular shape to cover an outer peripheral portion of the blower, and a shroud plate portion extending from the shroud ring portions to an outside. In the blower device, the motor portion is attached to the shroud plate portion at a position offset from a center connection line connecting centers of the shroud ring portions. Accordingly, the motor portion can be easily attached at a position offset from an arrangement direction of the blowers.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional objects and advantages of the present invention will be more readily apparent from the following detailed description of preferred embodiments when taken together with the accompanying drawings. In which:

FIG. 1 is a disassembled perspective view showing a blower device for a vehicle, according to a first embodiment of the present invention;

FIG. 2 is a schematic view showing the blower device when being viewed from a vehicle rear side, according to the first embodiment;

FIG. 3 is a schematic sectional view when being viewed from a vehicle upper side, showing a first blower, according to the first embodiment;

FIG. 4 is a schematic sectional view when being viewed from a vehicle upper side, showing a second blower, according to the first embodiment;

FIG. 5 is a schematic view showing a gear box of the first blower according to the first embodiment;

FIG. 6 is a schematic view showing a blower device when being viewed from a vehicle rear side, according to a second embodiment of the present invention;

FIG. 7 is a schematic sectional view showing a connection gear box according to the second embodiment; and

FIG. 8 is a schematic sectional view when being viewed from a vehicle upper side, showing a blower, according to the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First Embodiment

A first embodiment of the present invention will be now described with reference to FIGS. 1 to 5. In the first embodiment, a blower device of the present invention is typically used for blowing cool air to a heat exchanger such as a radiator and a condenser (refrigerant radiator) mounted on a vehicle. Here, the radiator is a heat exchanger in which engine-cooling water (hot water) from a vehicle engine is heat-exchanged with air, and the condenser is a heat exchanger in which refrigerant circulating in a refrigerant cycle is heat-exchanged with air. In the first embodiment, the radiator is located in the vehicle at a vehicle rear side from the condenser, and the blower device is located at a vehicle rear side of the radiator to blow air to the radiator and the condenser.
FIG. 1 is a disassembled perspective view showing a blower device for a vehicle, when being viewed from a vehicle rear side. The blower device includes a fan shroud 3, and blowers 1 (1A, 1B). In this embodiment, two blowers 1 constructed with a first blower 1A and a second blower 1B are arranged on a vehicle rear side of the heat exchanger (not shown) in an arrangement direction (e.g., vehicle right-left direction). The two blowers 1 are driven and rotated by a single motor 2.
The fan shroud 3 is located at a vehicle rear side of the heat exchanger (not shown) to support the blowers 1. The fan shroud 3 is provided to close a clearance between the blower 1 and the heat exchanger so as to prevent air generated by the blower 1 from bypassing the heat exchanger.
The fan shroud 3 includes two shroud ring portions 31 each of which has a cylindrical shape (ring shape), and a shroud plate portion 32 connected to rear side portions of the shroud ring portions 31 so as to form a smooth air passage from a rear side of the heat exchanger (not shown) to the shroud ring portions 31. Furthermore, in this embodiment, the shroud ring portions 31 and the shroud plate portion 32 are integrally formed. The shroud plate portion 32 has a rectangular outer peripheral shape with four corners.
The shroud ring portion 31 is formed to have a Venturi type passage in which the blower 1 can be freely rotated while a necessary space can be kept between tip ends of blades 11 c, 12 c of the blower 1 and an inner peripheral surface of the shroud ring portion 31. The blowers 1 are supported by rotation shafts 11 a, 12 a and the gear boxes 5. In this embodiment, the two blowers 1 (1A, 1B) are arranged on a surface in a line such that the rotation shafts 11 a, 12 a of the two blowers 1 are arranged in parallel with each other. Therefore, the shroud ring portions 31 are arranged to correspond to the two blowers 1.
FIG. 2 is a schematic view showing the blower device when being viewed from a vehicle rear side. In FIG. 2, the axial fans 11, 12 are omitted to be indicated.
As shown in FIGS. 1 and 2, a motor 2 for driving and rotating the blowers 1 is fixed to a vehicle rear side (downstream air side) of the shroud plate portion 32 through a bracket 4. The motor 2 is fixed at a position offset from a center connection line connecting the centers of the two shroud ring portions 31. The motor 2 is arranged within an area overlapped with the shroud plate portion 32 in an air flow direction. That is, all the upstream area of the motor 2 is arranged within a projected range of the shroud plate portion 32, projected in the air flow direction. Therefore, a motor shaft 21 extends from the motor 2 in a direction slanted from the center connection line connecting the centers of the two shroud ring portions 31. That is, the motor shaft 21 is not lined on the extending line of a connection shaft 25, as shown in FIG. 2. In this embodiment, the motor 2 is located in an area between a corner portion of the shroud plate portion 32 and the shroud ring portion 31 adjacent to the corner portion. For example, the motor 2 may be located about on a line connecting the center of the shroud ring portion 31 and the corner portion of the shroud plate portion 32.
Next, the structure of the blowers 1 will be described. In the first embodiment, of the two blowers 1, one blower 1 on the side near the motor 2 is referred to as a first blower 1A, and the other blower 1 far from the motor 2 is referred to as a second blower 1B. The first blower 1A is shown in FIG. 3, and the second blower 1B is shown in FIG. 4.
As shown in FIGS. 3 and 4, the blower 1 (1A, 1B) is a contrarotating blower including a first axial fan 11 and a second axial fan 12 which are contrarotated from each other. The first axial fan 11 and the second axial fan 12 are located in series, such that rotation shafts 11 a, 12 a of the axial fans 11, 12 are arranged on the same axial line. The first axial fan 11 is located on a vehicle front side (upstream air side) of the second axial fan 12, for example.
The first axial fan 11 and the second axial fan 12 are located to be rotated reversely from each other. However, both the first axial fan 11 and the second axial fan 12 are set to induce the same air flow. Accordingly, the rotation flow component part in a circumferential direction, generated at an outlet of the first axial fan 11, is reversed by the contra-rotating of the second axial fan 12. Therefore, the dynamic pressure part of the rotation flow, generated at the outlet of the first axial flow fan 11 can be recovered as the static pressure. As a result, a high static pressure can be generated as compared with a general axial fan, thereby increasing an air amount sent from the blower 1 to the heat exchanger.
The first axial fan 11 includes a boss portion 11 b, and a plurality of blades 11 c arranged radially outside from the boss portion 11 b. Similarly, the second axial fan 12 includes a boss portion 12 b, and a plurality of blades 12 c arranged radially outside from the boss portion 12 b. Each of the boss portions 11 b, 12 b is formed into a one-side opened box shape (e.g., recess shape having approximately U-shaped cross section). The boss portion 11 b includes a circular bottom portion 11 d, and a side wall portion 11 e protruding approximately perpendicularly from the edge portion of the bottom portion 11 d. Similarly, the boss portion 12 b includes a circular bottom portion 12 d, and a side wall portion 12 e protruding approximately perpendicularly from the edge portion of the bottom portion 12 d.
One end of the rotation shaft 11 a is connected to a center portion of the bottom portion 11 d, and one end of the rotation shaft 12 a is connected to a center portion of the bottom portion 12 d. The blades 11 c are connected to the outer surface of the side wall portion 11 e of the boss portion 11 b, and the blades 12 c are connected to the outer surface of the side wall portion 12 e of the boss portion 12 b. In the first embodiment, the first and second axial fans 11, 12 are located, such that recess portions of the boss portions 11 b, 12 b are opposite to each other, and the end portions of the side wall portions 11 e, 12 e are opposite to each other, in an axial direction of the rotation shafts 11 a, 12 a.
Next, the structure of the first blower 1A will be described. FIG. 5 shows a gear box 5 of the first blower 1A when being viewed from a vehicle rear side. In FIG. 5, a first driven gear 23 for the second axial fan 12 is omitted. As shown in FIG. 3, the gear box 5 includes a driving gear 22, two first driven gears 23 and a second driven gear 24. The driving gear 22 is fixed to the motor shaft 21 at a position corresponding to the first blower 1A. As the driving gear 22, a screw gear or a bevel gear may be used.
In the first blower 1A, the rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 are located perpendicularly to the connection shaft 25. One end of the rotation shaft 11 a is connected to the boss portion 11 b, and the other end of the rotation shaft 11 a is connected to the first driven gear 23. Similarly, one end of the rotation shaft 12 a is connected to the boss portion 12 b, and the other end of the rotation shaft 12 a is connected to the first driven gear 23. The first driven gears 23 are engaged with the driving gear 22, such that the rotation driving force of the motor 2 is transmitted to the rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 and both the first and second axial fans 11, 12 are rotated reversely. As the first and second driven gears 23, 24, screw gears or bevel gears may be suitably used. In this embodiment, the driving gear 22 is engaged respectively with the first driven gears 23 from a vehicle upper side.
Both the first driven gears 23 are engaged with the second driven gear 24 connected to the connection shaft 25. With this, the rotation driving force of the motor 2 is transmitted to the second driven gear 24 via the driving gear 22 and the first driven gear 23. The connection shaft 25 extends from the second blower 1B, and the one end portion of the connection shaft 25 is fixed to a center portion of the second driven gear 24.
The rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 are rotatably supported in the gear box 5 through bearings (not shown), respectively. The gear box 5 is formed to house the first driven gears 23, the driving gear 22 and the second driven gear 24. The driven gears 23, 24 and the driving gear 22 are located in the gear box 5, and the motor shaft 21 and the connection shaft 25 are rotatably supported in the gear box 5 through bearings (not shown).
Next, the structure of the second blower 1B will be described. As shown in FIG. 4, the gear box 5 of the second blower 1B has therein a third driven gear 26 and two fourth driven gears 27. Furthermore, as shown in FIGS. 3 and 4, one end portion of the connection shaft 25 is connected to the second driven gear 24 of the first blower 1A, and the other end portion of the connection shaft 25 is connected to the third driven gear 26 of the second blower 1B.
In the second blower 1B, the rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 are located perpendicularly to the connection shaft 25. One end of the rotation shaft 11 a is connected to the boss portion 11 b, and the other end of the rotation shaft 11 a is connected to the fourth driven gear 27. Similarly, one end of the rotation shaft 12 a is connected to the boss portion 12 b, and the other end of the rotation shaft 12 a is connected to the fourth driven gear 27. The fourth driven gears 27 are engaged with the third driven gear 26, such that the rotation driving force of the motor 2 is transmitted to the rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 of the second blower 1B via the driving gear 22 and the first to fourth driven gears 23, 24, 26, 27. With this operation, both the first and second axial fans 11, 12 of the second blower 1B are rotated reversely.
In the second blower 1B, the rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 are rotatably supported in the gear box 5 through bearings (not shown), respectively. The gear box 5 is formed to house the third driven gear 26 and the fourth driven gear 27. The driven gears 26, 27 are located in the gear box 5, and the connection shaft 25 is rotatably supported in the gear box 5 through a bearing (not shown). As the third and fourth driven gears 26, 27, screw gears or bevel gears may be suitably used.
The gear boxes 5 of the blowers 1 (1A, 1B) are attached to stays (not shown) extending approximately horizontally from one end to the other end of the fan shroud 3.
According to the first embodiment, the motor 2 is located at a downstream air side (vehicle rear side in this example) of the shroud plate portion 32, where generally no component is attached. In addition, the location position of the motor 2 is set to be covered completely by the shroud plate portion 32, on its upstream air side of the motor 2. That is, when being viewed from an air flow direction, all the motor 2 is overlapped with the shroud plate portion 32. Accordingly, it can prevent the motor 2 from being interfered with a vehicle body when the blower device is mounted to the vehicle.
In addition, the motor 2 is located at a corner area of the shroud plate portion 32 offset from the extending line of the connection shaft 25. In this embodiment, the motor shaft 21 extends in a direction tilted from the extending line of the connection shaft 25 such that the motor 2 is located to be offset from the extending line of the connection shaft 25. That is, all the motor 2 is offset from the center connection line connecting the centers of the shroud ring portions 31. The connection shaft 25 is connected to a gear portion of the first blower 1A and a gear portion of the second blower 1B. For example, in this embodiment, the gear portion of the first blower 1A is constructed with the driving gear 22, and first and second driven gears 23 and 24 which are housed in the gear box 5, and the gear portion of the second blower 1B is constructed with the third and fourth gears 26, 27 which are housed in the gear box 5.
Accordingly, by using the space on the corner portion of the shroud plate portion 32 outside the shroud ring portions 31, the motor 2 can be effectively attached. Therefore, the motor 2 can be easily mounted to the vehicle, and the mounting performance of the blower device including the motor 2 can be improved.

Second Embodiment

A second embodiment will be now described with reference to FIGS. 6 to 8. In the second embodiment, the parts having the same functions as those of the first embodiment are indicated by the same reference numbers as those of the first embodiment, and the detail explanation thereof is omitted. FIG. 6 shows a blower device of the second embodiment, in which the axial fans 11, 12 are omitted.
As shown in FIG. 6, in the second embodiment, the motor 2 is attached to the shroud plate portion 32 between the two shroud ring portions 31 while being offset from a center connection line connecting the centers of the shroud ring portions 31. In the example of FIG. 6, the motor 2 is located at an upper side from the center connection line connecting the centers of the adjacent two shroud ring portions 31. Furthermore, a motor shaft 21 connected to the motor 2 extends in a direction approximately perpendicular to the center connection line, that is, the arrangement direction of both the blowers.
In this embodiment, as shown in FIG. 6, two connection shafts 25 connected to gear boxes 5 of the two blowers 1 are separated, and the two connection shafts 25 are coupled to the motor shaft 21 via a connection gear box 6.
FIG. 7 is a schematic sectional view of the connection gear box 6 when being viewed from a vehicle rear side. A gear portion located in the connection gear box 6 includes a driving gear 22, and two first driven gears 71 engaged with the driving gear 22. As shown in FIGS. 6 and 7, an end portion of the motor shaft 21 extending from the motor 2 is fixed to the driving gear 22 in the connection gear box 6. The two connection shafts 25 are arranged approximately perpendicular to the motor shaft 21. Each connection shaft 25 is fixed to the first driven gear 71 of the connection gear box 6, and the first driven gears 71 are engaged with the driving gear 22, so that the rotation driving force of the motor 2 is transmitted to the two connection shafts 25 via the motor shaft 21 and the connection gear box 6.
The motor shaft 21 and the two connection shafts 25 are rotatably supported in the connection gear box 6 through bearings (not shown) of the connection gear box 6. As the driving gear 22 and the first driven gears 71 accommodated in the gear box 6, screw gears or/and bevel gears may be used.
Next, the structures of the two blowers 1 will be described. Because the two blowers 1 have the same structure, the blower 1 on the right side of FIG. 6 is described with reference to FIG. 8. FIG. 8 is a schematic view showing the right side blower 1 when being viewed from a vehicle upper side. As shown in FIG. 8, the gear box 5 includes therein a second driven gear 72 and two third driven gears 73. The other end portion of the connection shaft 25 on the side without being fixed to the first driven gear 71 is fixed to the second driven gear 72 of the gear box 5. The rotation shafts 11 a, 12 a of the two axial fans 11, 12 are respectively arranged approximately perpendicular to the extending line of the connection shaft 25.
One end of the rotation shaft 11 a of the axial fan 11 is connected to the boss portion 11 b, and the other end of the rotation shaft 11 a is connected to the third driven gear 73. Similarly, one end of the rotation shaft 12 a of the axial fan 12 is connected to the boss portion 12 b, and the other end of the rotation shaft 12 a is connected to the third driven gear 73. The third driven gears 73 are engaged with the first driven gear 72, such that the rotation driving force of the motor 2 is transmitted to the rotation shafts 11 a, 12 a of the first and second axial fans 11, 12, via the first to third driven gears 71, 72, 73. Thereby, both the first and second axial fans 11, 12 are rotated reversely.
The rotation shafts 11 a, 12 a of the first and second axial fans 11, 12 are rotatably supported in the gear box 5 through bearings (not shown), respectively. The gear box 5 is formed to house the second driven gear 72 and the third driven gears 73. The driven gears 72, 73 are located in the gear box 5, and the connection shaft 25 is rotatably supported in the gear box 5 through bearings (not shown). As the second and third driven gears 72, 73, screw gears or/and bevel gears may be suitably used.
According to the second embodiment, the motor 2 is located to be offset from the extension line of the connection shaft 25, and is attached to the shroud plate portion 3 at a position covered by the shroud plate portion 3 from a vehicle front side. That is, the motor 2 is located at a position offset from the center connection line connecting the centers of the shroud ring portions 31. Therefore, similarly to the above-described first embodiment, the motor 2 can be easily mounted without interfering with a vehicle body. As in the example of FIG. 6, the motor shaft 21 is approximately perpendicular to the extending line of the connection shaft 25, that is, approximately perpendicular to the center connection line connecting both the centers of the shroud ring portions 31 (fans 11, 12). Therefore, the motor 2 can be located using a space between the shroud ring portions 31 on the shroud plate portion 32.

Other Embodiments

Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.
For example, in the above-described embodiments, the two blowers 1 are arranged on the same plane to be driven by the single motor 2 such that the rotation shafts 11 a, 12 a of the blowers 1 are located in parallel with each other. However, a single blower 1 may be used, or plural blowers 1 more than two may be arranged on the same plane such that the rotation shafts 11 a, 12 a of the blowers 1 are in parallel with each other.
In the above-described embodiments, the double contrarotating fans are used for the blower 1. However, a series of axial fans may be used for the blower 1.
In the above-described embodiments, the motor 2 is fixed to the fan shroud 3 through the bracket 4, and the gear box 5 is fixed to the fan shroud 3 through a stay (not shown). However, the motor 2 may be directly fixed to the fan shroud 3 without the bracket 4, and the gear box 5 may be directly fixed to the fan shroud 3 without using the stay.
In the above-described second embodiment, the motor shaft 21 connected to the motor 2 is coupled to both the connection shafts 25 via the connection gear box 6. However, the motor shaft 21 may be coupled to the connection shafts 25 via a universal joint, etc.
In the above-described second embodiment, the connection shafts 25 between the two gear boxes 5 are separated into the two parts at its longitudinal center. However, a single connection shaft without being separated may be used for coupling the motor shaft 21 with the gear boxes 5.
Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.

Claims

1. A blower device for a vehicle, comprising:

a plurality of blowers having fan shafts arranged in parallel with each other, for blowing air toward a heat exchanger mounted to the vehicle;

a single motor for driving and rotating the blowers, the motor having a motor shaft;

a shroud for holding the blowers and for forming air passages from the heat exchanger to the blowers, wherein the shroud includes a plurality of shroud ring portions each of which has a circular shape to surround an outer peripheral portion of the blower, and a shroud plate portion extending smoothly from a rear side of the heat exchanger to the shroud ring portions; and

a gear portion through which the fan shafts are coupled to the motor shaft,

wherein the motor is located downstream from the shroud plate portion to be offset from a center connection line connecting centers of the shroud ring portions.

2. The blower device according to claim 1, wherein:

the shroud ring portions are defined in the shroud plate portion;

the shroud plate portion has an approximately rectangular outer peripheral shape with four corner portions outside of the shroud ring portions; and

the motor is located between one corner portion and the shroud ring portion adjacent to the one corner portion.

3. The blower device according to claim 1, wherein:

the motor is located between adjacent two shroud ring portions to be offset from the center connection line connecting the centers of the adjacent two shroud ring portions.

4. The blower device according to claim 1, wherein:

each of the blowers includes two contrarotating axial fans which are located to be rotated reversely with each other in accordance with rotations of its rotation shafts arranged on an axial line.

5. The blower device according to claim 1, wherein:

adjacent two blowers are connected to each other via a connection shaft; and

the motor shaft is tilted from an extension line of the connection shaft.

6. The blower device according to claim 1, wherein:

adjacent two blowers are connected to each other via a connection shaft; and

the motor shaft is approximately perpendicular to an extension line of the connection shaft.

7. The blower device according to claim 1, wherein:

the motor includes a motor portion connected to the motor shaft to rotate the motor shaft; and

all upstream area of the motor portion is covered by the shroud plate portion.

8. A blower device comprising:

at least two blowers having fan shafts arranged in parallel with each other;

a single motor for driving and rotating the two blowers, wherein the motor includes a motor portion and a motor shaft driven by and extending from the motor portion;

a shroud for holding the two blowers, wherein the shroud includes two shroud ring portions each of which has a circular shape to cover an outer peripheral portion of the blower, and a shroud plate portion extending from the shroud ring portions to an outside; and

a gear portion through which the fan shafts of the blowers are coupled to the motor shaft,

wherein the motor portion is attached to the shroud plate portion at a position offset from a center connection line connecting centers of the shroud ring portions.

9. The blower device according to claim 8, wherein:

the two blowers are coupled to each other via a connection shaft; and

the motor shaft is tilted from an extension line of the connection shaft.

10. The blower device according to claim 8, wherein:

the two blowers are coupled to each other via a connection shaft; and

the motor shaft is approximately perpendicular to an extension line of the connection shaft between the two shroud ring portions.