Blower Unit for Vehicle

Abstract

A blower unit for generating air for cooling a heat exchanger includes a plurality of blowers, a single motor, a driving shaft, gears, gear boxes and a joint. The blowers are arranged in parallel with each other with respect to a flow of air passing through the heat exchanger. The driving shaft extends from the motor and is connected to rotation shafts of the blowers through the gears. The gear boxes house the gears therein and support the driving shaft and the rotation shafts of the blowers to be rotatable. The driving shaft is divided into a plurality of shaft parts in a longitudinal direction thereof. The adjacent shaft parts are connected to each other through the joint.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2008-1103 filed on Jan. 8, 2008, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a blower unit for a vehicle for generating cooling air for cooling a heat exchanger, such as a radiator, of a vehicle.

BACKGROUND OF THE INVENTION

In a conventional blower unit employed for a heat exchanger having a relatively long core, two axial fans are disposed on a downstream side of the core with respect to a flow of air, and each of the fans is provided with a fan motor. That is, the blower unit has the fan motors with the same number as the number of the fans. In such a case, the entire size and the weight of the blower unit increases. Also, the number of parts increases.

To address the above issues, it is proposed to drive the multiple fans by a single motor. In such a case, a driving shaft extending from the motor is connected to rotation shafts of the multiple fans through gears. The motor is, for example, fixed to a tank of a heat exchanger, which is disposed at an end of a core of the heat exchanger. Such a blower unit is, for example, described in JP-U-62-112470.

SUMMARY OF THE INVENTION

In the blower unit in which the single driving shaft passes through multiple gear boxes to be connected to the rotation shafts of the multiple fans through the gears, if displacement or misalignment occurs between components, such as between the driving shaft and the motor and between the driving shaft and the gear boxes, a connecting portion between the motor and the driving shaft and the gears receive an excess load. Such an excess load is likely to result in deterioration of durability as well as an increase in noise.

The present invention is made in view of the foregoing matter, and it is an object of the present invention to provide a blower unit for a vehicle having multiple fans driven by a single motor through gears, which is capable of improving durability and reducing noise.

According to an aspect of the present invention, a blower unit includes a plurality of blowers, a single motor, a driving shaft, gears, gear boxes and a joint. The blowers are arranged in parallel with each other with respect to a flow of air passing through a heat exchanger of a vehicle. The driving shaft extends from the motor and is connected to rotation shafts of the blowers through the gears. The gears are housed in the gear boxes. The driving shaft and the rotation shafts of the blowers are rotatably supported through the gear boxes. The driving shaft is divided into a plurality of shaft parts in a longitudinal direction thereof. The adjacent shaft parts are connected to each other through the joint in the longitudinal direction of the driving shaft.

Since the driving shaft is divided into the plurality of shaft parts, and the shaft parts are connected through the joint, displacements or misalignment between the components, such as between the driving shaft and the motor and between the driving shaft and the gear boxes, are absorbed. Therefore, durability improves and noise reduces.

For example, the driving shaft has a connecting portion of the shaft parts at a location between the motor and the blower, which is closer to the motor than the other, and/or a location between the blowers. In such a case, the joint can be disposed at a location without interfering with the blowers. Therefore, the size of the joint can be set flexibly. For example, it is possible to increase the size of the joint. If the size of the joint is increased, the effect of absorbing the displacement or misalignment is improved.

For example, the driving shaft has connecting portions of the shaft parts at locations adjacent to the gear boxes.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which like parts are designated by like reference numbers and in which:

FIG. 1 is a perspective view of a blower unit for a vehicle, partly including an exploded view, when viewed from a rear location of the vehicle, such as a downstream location with respect to a flow of air, according to a first embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a blower of the blower unit, when viewed from a top, according to the first embodiment;

FIG. 3 is a schematic cross-sectional view of the blower unit, when viewed from a top, according to the first embodiment; and

FIG. 4 is a schematic cross-sectional view of a blower unit, when viewed from a top, according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

First Embodiment

A first embodiment of the present invention will now be described with reference to FIGS. 1 to 3. In the present embodiment, the present invention is exemplarily employed to a blower unit for a vehicle for generating cooling air for cooling heat exchangers (not shown), such as an engine coolant radiator and a refrigerant radiator. The engine coolant radiator is in communication with an engine coolant circuit of an engine, that is, an internal combustion engine. The engine coolant radiator serves to cool hot engine coolant, which has been heated through the engine. The refrigerant radiator is in communication with a discharge side of a compressor of a refrigerant cycle of a vehicle air conditioner. The refrigerant radiator serves to cool refrigerant, which has been discharged from the compressor. In the present embodiment, the engine coolant radiator is disposed behind the refrigerant radiator with respect to a vehicle front and rear direction.

In the drawing, an up and down arrow, a right and left arrow, and a front and rear arrow denote respective directions when the blower unit is mounted in the vehicle. As shown in FIG. 1, the blower unit generally has blowers 1, a fan shroud 2, and a motor device including a single motor (motor body) 3. The blowers 1 are disposed in parallel with each other behind the engine coolant radiator. For example, the blowers 1 are aligned in a longitudinal direction of a core of the engine coolant radiator. The blowers 1 are driven by the single motor 3.

The fan shroud 2 is disposed on a rear side of the engine coolant radiator. The fan shroud 2 is configured to support the blowers 1 and to cover a space between the engine coolant radiator and the blowers 1, thereby to restrict an airflow caused by the blowers 1 from bypassing the refrigerant radiator and the engine coolant radiator.

The fan shroud 2 includes shroud ring portions 21 and a shroud panel portion 22. The shroud ring portion 21 each have a cylindrical shape, such as a ring shape. The shroud panel portion 22 has a predetermined shape connecting the rear side of the engine coolant radiator to the shroud ring portions 21. The shroud panel portion 22 forms smooth air passages from the rear side of the engine coolant radiator to the ring portions 21. In the present embodiment, respective portions of the fan shroud 2, such as the shroud ring portions 21, the shroud panel portion 22 and the like, are integrally formed with each other. The shroud panel portion 22 has a rectangular outer shape when projected in a flow direction of air.

Each of the shroud ring portions 21 provides a Venturi air passage space therein. Each of the blowers 1 is disposed in the shroud ring portion 21 such that a predetermined clearance is provided between an inner surface of the shroud ring portion 21 and radial outer edges of first and second blades 11c, 12c of fans 11, 12. Inside of the shroud ring portion 21, the fans 11, 12 are rotatably supported.

In the present embodiment, since the two blowers 1 are arranged in parallel with each other, the fan shroud 2 has two shroud ring portions 21. The two shroud ring portions 21 are arranged in parallel with each other at locations corresponding to the blowers 1.

The motor 3 is fixed to a rear side of the shroud panel portion 22, such as on a downstream side of the shroud panel portion 22 with respect to a flow of air, through a bracket 4. The motor 3 is disposed on a centerline passing through centers of the shroud ring portions 21.

Next, a structure of the blowers 1 will be described in detail.

As shown in FIG. 2, each of the blowers 1 has contra-rotating fans 11, 12, such as a first axial fan 11 and a second axial fan 12. The first axial fan 11 and the second axial fan 12 are disposed in series with respect to the flow of air. That is, the first axial fan 11 and the second axial fan 12 are arranged such that first and second rotation shafts 11a, 12a thereof are aligned with each other. The first axial fan 11 is disposed on a front side of the second axial fan 12 with respect to the vehicle front and rear direction. That is, the first axial fan 11 is disposed upstream of the second axial fan 12.

The first and second axial fans 11, 12 are disposed to rotate in opposite directions, but the flow directions of the air caused by the first and second axial fans 11, 12 are the same. A component of turning flow generated at an outlet of the first axial fan 11 in a circumferential direction is cancelled by the contra rotation of the second axial fan 12. Therefore, kinetic pressure of the turning flow generated at the outlet of the first axial fan 11 is recovered as static pressure. Because the static pressure is larger than static pressure generated in a general series of fans, the volume of air passing through the heat exchangers can be increased.

The first axial fan 11 has a first boss part 11b and first blades 11c radially extending from the first boss part 11b. The first boss part 11b has a tubular shape with a closed end. Thus, the first boss part 11b has a substantially U-shaped cross-section. The first boss part 11b includes a first bottom wall 11d having a circular shape and a first side wall 11e extending from an edge of the first bottom wall 11d. The first side wall 11e is substantially perpendicular to the first bottom wall 11d. The first rotation shaft 11a extends from the center of the first bottom wall 11d. The first blades 11c extend from an outer surface of the first side wall 11e.

Likewise, the second axial fan 12 has a second boss part 12b and second blades 12c radially extending from the second boss part 12b. The second boss part 12b has a tubular shape with a closed end. Thus, the second boss part 12b has a substantially U-shaped cross-section. The second boss part 12b includes a second bottom wall 12d having a circular shape and a second side wall 12e extending from an edge of the second bottom wall 12d. The second side wall 12e is substantially perpendicular to the second bottom wall 12d. The second blades 12c extend from an outer surface of the second side wall 12e.

The first and second axial fans 11, 12 are arranged such that openings of the first and second boss parts 11b, 12b are opposed to each other. In other words, the first and second axial fans 11, 12 are arranged such that ends of the first and second side walls 11e, 12e are opposed to each other.

Driving gears 32 are fixed on a driving shaft 31, which extends from the motor 3, at locations corresponding to the two blowers 1. The driving gears 32 are, for example, bevel gears.

In each blower 1, the first and second fans 11, 12 are arranged such that the first and second rotation shafts 11a, 12a are perpendicular to the driving shaft 31. A first driven gear 11f is fixed to an end of the first rotation shaft 11a. A second driven gear 12f is fixed to an end of the second rotation shaft 12a. The first and second driven gears 11f, 12f are engaged with the driving gear 32, respectively. Thus, a driving force generated from the motor 3 is transmitted to the first and second rotation shafts 11a, 12a through the driving shaft 31 and the gears 32, 11f, 12f, and hence the first and second rotation shafts 11, 12 are rotated in the opposite directions. The first and second driven gears 11f, 12f can be bevel gears, for example.

A gear box 5 is disposed in a space provided between the first and second boss parts 11b, 12b, for example. The first and second rotation shafts 11a, 12a are rotatably supported by the gear box 5 through first and second bearings 11g, 12g. The gear box 5 houses the first and second driven gears 11f, 12f as well as the driving gear 32. Also, the gear box 5 rotatably supports the driving shaft 31 through a bearing 33, similar to the first and second rotation shafts 11a, 12a.

As shown in FIG. 1, the gear boxes 5 are supported by stays 23 that are extended in a horizontal direction, such as in a longitudinal direction of the driving shaft 31, and fixed to the fan shroud 2. In the present embodiment, for example, two stays 23 are arranged parallel to each other and support upper and lower ends of the gear boxes 5.

FIG. 3 shows a schematic cross-section of the blower unit when viewed from a top. In FIG. 3, an internal structure of the gear box 5 is not illustrated. In the present embodiment, the fan shroud 2 has the two shroud ring portions 21 aligned in the longitudinal direction of the driving shaft 31. Hereinafter, one of the shroud ring portions 21, which is closer to the motor 3 than the other, is referred to as a first shroud ring portion 21A, and the other, which is further from the motor 3 than the first shroud ring portion 21A, is referred to as a second shroud ring portion 21B.

As shown in FIG. 3, the driving shaft 31 is divided into three shaft parts 310 in the longitudinal direction thereof. Specifically, the driving shaft 31 is divided at a first location between the motor 3 and the first shroud ring portion 21A and a second location between the first shroud ring portion 21A and the second shroud ring portion 21B, that is, between the two blowers 1.

Joints 6 are provided between the adjacent shaft parts 310. The adjacent shaft parts 310 are connected to each other in the longitudinal direction of the driving shaft 31 through joints 6. That is, the joints 6 are located between the motor 3 and the first shroud ring portion 21A and between the first shroud ring portion 21A and the second shroud ring portion 21B. For example, each of the joints 6 is made of a metal, and has a substantially cylindrical shape having an axis coincident with a longitudinal axis of the driving shaft 31.

The driving shaft 31 extends in an alignment direction of the two blowers 1, that is, in a vehicle width direction corresponding to a right and left direction. The single driving shaft 31 is constructed by connecting the three shaft parts 310 with the two joints 6 in the alignment direction of the two blowers 1.

As discussed above, the driving shaft 31 includes the multiple shaft parts 310, and the multiple shaft parts 310 are connected through the joints 6. As such, displacement or misalignment between the driving shaft 31 and the motor 3 and between the driving shaft 31 and the gear boxes 5 can be absorbed. Accordingly, durability of the blower unit improves, and noise reduces.

In a case where the joints 6 are located between the opposed first and second blades 11c, 12c of the blower 1, it is necessary to provide a predetermined clearance between the first and second blades 11c, 12c to prevent the joint 6 from contacting the first and second blades 11c, 12c. In such a case, the dimension of the blower 1 is increased in the vehicle front and rear direction, depending on the size of the joint 6. Further, if a space for mounting the blower unit is limited in an engine compartment of the vehicle, it is necessary to reduce the size of the joints 6. In such a case, it is difficult to sufficiently achieve the effect of absorbing the displacement or misalignment.

In the present embodiment, on the other hand, the driving shaft 31 has connecting portions of the adjacent shaft parts 310 at the first location between the motor 3 and the first shroud ring portion 21A and the second location between the first shroud ring portion 21A and the second shroud ring portion 21B. Namely, the joints 6 are disposed in areas without interfering with the first and second blades 11c, 12c of the blowers 1. Accordingly, the size of the joints 6 can be flexibly decided. For example, the size of the joints 6 can be increased without considering the clearance between the first and second blades 11c, 12c. Therefore, the effect of absorbing the displacement or misalignment can be sufficiently achieved. As a result, the durability further improves, and the noise further reduces.

Second Embodiment

A second embodiment of the present invention will be described with reference to FIG. 4. Hereinafter, parts similar to the first embodiment are designated with the same reference numbers, and a description thereof is not repeated.

FIG. 4 shows a schematic cross-section of the blower unit of the second embodiment when viewed from a top. In FIG. 4, an internal structure of the gear box 5 is not illustrated. Hereinafter, one of the blowers 1, which is closer to the motor 3 than the other, is referred to as a first blower 1A, and the other, which is further from the motor 3 than the first blower 1B, is referred to as a second blower 1B.

As shown in FIG. 4, the driving shaft 31 is divided into five shaft parts 310 in the longitudinal direction thereof. Specifically, the driving shaft 31 is divided at a first location between the motor 3 and the first shroud ring portion 21A, second and third locations, which are on axially opposite sides of the gear box 5 of the first blower 1A within the first shroud ring portion 21A, and a fourth location adjacent to the gear box 5 of the second blower 1B within the second shroud ring portion 21B. The second location is adjacent to the gear box 5 on a side closer to the motor 3, and the third location is adjacent to the gear box 5 on an opposite side further from the motor 3. The fourth location is adjacent to the gear box 5 of the second blower 1B on a side closer to the motor 3.

The joints 6 are provided between the adjacent shaft parts 310. The adjacent shaft parts 310 are connected to each other through the joints 6. In the present embodiment, the joints 6 are disposed at the first location between the motor 3 and the first shroud ring portion 21A, the second and third locations, which are on axially opposite sides of the first and second boss parts 11b, 12b of the first blower 1A, and the fourth location, which is adjacent to the first and second boss parts 11b, 12b of the second blower 1B on a side closer to the motor 3. The second and third locations are outside of the first and second boss parts 11b, 12b within the first blower 1A. The fourth location is outside of the first and second boss parts 11b, 12b within the second blower 1B.

Accordingly, the driving shaft 31 extending in the alignment direction of the first and second blowers 1A, 1B, such as in the vehicle width direction, is constructed by connecting the five shaft parts 310 through the four joints 6.

Therefore, displacement or misalignment between the driving shaft 31 and the motor 3 and between the driving shaft 31 and the gear boxes 5 are absorbed. Accordingly, the durability of the blower unit improves, and the noise reduces.

Other Embodiments

In the above embodiments, the present invention is employed to the blower unit in which the two blowers 1 are aligned in the longitudinal direction of the driving shaft 31. However, the present invention can be employed to a blower unit in which a single blower is arranged, or three or more than three blowers are arranged.

Further, the connecting portions of the shaft parts 310 are not limited to the above discussed locations. Also, the number of the connecting portions of the shaft parts 310 and the number of the joints 6 are not limited to the above described numbers.

For example, in the first embodiment, the driving shaft 31 may have a connecting portion of the shaft parts 310 at least one of between the motor 3 and the first shroud ring portion 21A and between the first and second shroud ring portions 21A, 21B. As another example, in the second embodiment, the driving shaft 31 may have further another connecting portion of the shaft parts 310 between the first and second shroud ring portions 21A, 21B.

The blower 1 is not limited to have the contra-rotating fans. The blower 1 may have a single axial fan.

In the above embodiments, the motor 3 is fixed to the fan shroud 2 through the bracket 4, and the gear boxes 5 are fixed to the fan shroud 2 through the stays 23. However, the motor 3 and the fan shroud 2 may be fixed in various other ways. For example, the motor 3 and the gear boxes 5 can be directly fixed to the fan shroud 2, respectively.

Additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader term is therefore not limited to the specific details, representative apparatus, and illustrative examples shown and described.

Claims

1. A blower unit for generating air passing through a heat exchanger of a vehicle, the blower unit comprising: a plurality of blowers arranged in parallel with each other with respect to a flow of air passing through the heat exchanger, the blowers having rotation shafts;a single motor;a driving shaft extending from the motor, the driving shaft being divided into a plurality of shaft parts in a longitudinal direction thereof;gears connecting the driving shaft and the rotation shafts of the blowers;gear boxes housing the gears therein, the gear boxes supporting the driving shaft and the rotation shafts to be rotatable; anda joint disposed between adjacent shaft parts and connecting the adjacent shaft parts in the longitudinal direction of the driving shaft.

2. The blower unit according to claim 1, wherein the driving shaft has a connecting portion of the shaft parts at least one of between the motor and one of the blowers, which is located closer to the motor than the other, and between adjacent blowers.

3. The blower unit according to claim 1, wherein the driving shaft has connecting portions of the shaft parts at locations adjacent to the gear boxes.

4. The blower unit according to claim 1, further comprising: a fan shroud including a plurality of shroud ring portions aligned in the longitudinal direction of the driving shaft, whereinthe blowers are correspondingly disposed in the shroud ring portions,each of the blowers has a first axial fan and a second axial fan,the first axial fan has a first boss part and a plurality of first blades radially extending from the first boss part,the second axial fan has a second boss part and a plurality of second blades radially extending from the second boss part,the first axial fan and the second axial fan are opposed to each other with respect to the driving shaft, andthe gear box is disposed in a space provided between the first and second boss parts.

5. The blower unit according to claim 4, wherein the driving shaft is divided into the shaft parts at a first location between the motor and one of the shroud ring portions, which is located closer to the motor than the other, and at a second location between adjacent shroud ring portions.

6. The blower unit according to claim 4, wherein the driving shaft is divided into the shaft parts at a first location between the motor and a first shroud ring portion, second and third location, which are adjacent to the first and second boss parts of a first blower on axially opposite sides of the first and second boss parts within the first shroud ring portion, and a fourth location adjacent to the first and second boss parts of a second blower within a second shroud ring portion, the first blower being one of the plurality of blowers and located closer to the motor than the other, the second blower being another one of the plurality of blowers and located further from the motor than the first blower, the first shroud ring portion being one of the plurality of shroud ring portions and located closer to the motor than the other, the second shroud ring portion being another one of the plurality of shroud ring portions and located further from the motor than the first shroud ring portion.