Fan module comprising coaxial counter-rotating fans

Abstract

A fan module for a vehicle engine cooling system includes a pair of coaxial, counter-rotating axial fans. Each fan is supported and driven by a dedicated downstream motor, each motor being supported by a dedicated shroud. The shroud supporting the first motor includes a barrel, a motor carrier surrounded by the barrel, and a guide vane extending between the barrel and the motor carrier. For each guide vane, a line extending between a guide vane nose and a guide vane tail is angled with respect to the fan rotational axis, and the angle is selected to minimize airflow losses through the shroud.

Description

Background Technology

[0001] In some vehicles, cooling fans are used to cool the vehicle's engine during operation. For example, a cooling fan may be placed downstream of a heat exchanger that cools the engine coolant, and the cooling fan draws in air through the heat exchanger. In some vehicles, the cooling fan is driven by the vehicle's engine. However, fuel economy requirements have led to a shift from engine-driven cooling fans to electric motor-driven cooling fans. The use of electric motor-driven cooling fans in larger vehicles may be limited by the available power of the electric motors. Summary of the Invention

[0002] A first method for overcoming motor power limitations involves distributing the power demand between two motors. A second method involves improving fan efficiency, for example, obtaining more air power for the same electrical power. In some aspects, counter-rotating fan modules are provided, whose combination divides the power demand between two motors and provides improved fan efficiency. Advantageously, counter-rotating fan modules include two axial fans and two motors in a single fan module. In the fan module, the two fans and corresponding motors are installed in a compact space (compared to side-by-side fans).

[0003] The operation of a fan inherently results in kinetic energy loss by introducing rotation (vortices) into the air leaving the fan. In the case of a single fan, the energy in the vortex component of the flow is dissipated without doing any useful work. In a fan module, a second axial fan is positioned downstream of the first axial fan relative to the direction of the airflow through the fan module, such that the fan rotates about an axis of rotation that is substantially common to both fans, and that the fans rotate in opposite directions (e.g., the first and second fans rotate in opposite directions). It should be understood that in use, the axes of rotation of the first and second fans may not be precisely collinear. In some embodiments, the term "approximately common" is used to indicate that the fan axes of rotation are collinear within a 12-degree rotation and / or up to 12 percent of the downstream fan diameter, as measured between the intersection of the two fan axes of rotation and a plane passing through the forwardmost portion of the hub of the second fan. In other embodiments, the term "approximately common" is used to indicate that the fan axes of rotation are collinear within a 6-degree rotation and / or up to 6 percent of the downstream fan diameter. In other embodiments, the term "approximately common" is used to indicate that the fan axes of rotation are collinear within a 3-degree rotation and / or up to 3 percent of the downstream fan diameter. The first fan generates airflow through the fan module, which includes both axial and tangential flow components. The second fan has substantially the same diameter as the first fan and is configured to remove the tangential flow component from the airflow through the fan module. As a result, the second fan recovers energy from the vortices in the airflow leaving the upstream fan. Furthermore, the fan module is configured such that the airflow leaving the second fan has little or no vortices, thus eliminating kinetic energy loss due to vortices. Therefore, the combination of two counter-rotating fans can operate more efficiently than a single fan.

[0004] In the fan module, each axial fan is driven by a separate motor. Each motor is supported within a housing by a dedicated motor bracket, and each fan is supported on its corresponding motor, such that the fan is positioned upstream of the respective motor bracket.

[0005] Each shroud includes a cylinder, a motor bracket supporting a respective motor, and spoke-shaped guide vanes supporting the motor bracket within the cylinder. The guide vanes are positioned in the path of airflow through the shroud. Each guide vane has a profile and includes a front end and a rear end opposite the front end. In most cases, it is advantageous to minimize the influence of the guide vanes on the airflow through the shroud. To this end, the shroud of the first axial fan includes guide vanes configured such that a line extending between the front and rear ends is angled relative to the fan's axis of rotation. In some embodiments, this line is angled to align with the vortex of the first fan. In the shroud of the second axial fan, the guide vanes are axially aligned (e.g., parallel to the fan's axis of rotation).

[0006] In some aspects, a fan module for an automotive cooling system includes a first fan configured to rotate about a fan rotation axis and a second fan configured to rotate about a second axis. The second fan is positioned downstream of the first fan relative to the airflow direction through the fan module, and the second axis is substantially common to the fan rotation axis. The fan module includes a first motor and a second motor, the first motor being configured to drive the first fan to rotate about the fan rotation axis in a first direction, and the second motor being configured to drive the second fan to rotate about the second axis in a second direction. The second direction is opposite to the first direction. The fan module includes a first shroud supporting the first motor. The first shroud includes a first cylinder about the fan rotation axis, a first motor bracket disposed inwardly relative to the first cylinder, and a first guide vane extending between the first cylinder and the first motor bracket. The fan module also includes a second shroud supporting the second motor. The second shroud includes a second cylinder about the fan rotation axis, a second motor bracket disposed inwardly relative to the second cylinder, and a second guide vane extending between the second cylinder and the second motor bracket. A first motor is supported by a first motor bracket, and a second motor is supported by a second motor bracket. The first motor bracket is positioned downstream of the first fan relative to the direction of airflow through the fan module, and the second motor bracket is positioned downstream of the second fan relative to the direction of airflow through the fan module. Each first guide vane has a first nose facing the direction of airflow through the fan module and a first tail opposite to the first nose. A first line extending between the first nose and the first tail forms a first angle relative to the fan's axis of rotation. Each second guide vane has a second nose facing the direction of airflow through the fan module and a second tail opposite to the second nose. A second line extending between the second nose and the second tail forms a second angle relative to a second axis. The second angle is different from the first angle.

[0007] In some embodiments, the first angle is aligned with the airflow exiting from the first fan.

[0008] In some embodiments, the first angle is a non-zero angle.

[0009] In some embodiments, the second angle is approximately zero.

[0010] In some embodiments, the second line is parallel to the second axis.

[0011] In some embodiments, the fan module includes an air guide that supports a first shroud and is configured to provide an airflow passage between the first fan and the heat exchanger, and a second shroud is supported on the first shroud.

[0012] In some embodiments, the first shield is integrated with the air guide.

[0013] In some embodiments, the first guide vane includes opposing first airflow surfaces extending between a first nose and a first tail, and the distance between the respective first airflow surfaces is smaller than the distance between the first nose and the first tail. Additionally, the second guide vane includes opposing second airflow surfaces extending between a second nose and a second tail, and the distance between the respective second airflow surfaces is smaller than the distance between the second nose and the second tail.

[0014] In some aspects, an automotive cooling system includes a heat exchanger and a fan module configured to draw in air through the heat exchanger. The fan module includes a first fan configured to rotate about a fan rotation axis and a second fan configured to rotate about a second axis. The second fan is positioned downstream of the first fan relative to the airflow direction through the fan module, and the second axis is substantially common to the fan rotation axis. The fan module includes a first motor and a second motor, the first motor configured to drive the first fan to rotate about the fan rotation axis in a first direction, and the second motor configured to drive the second fan to rotate about the second axis in a second direction, wherein the second direction is opposite to the first direction. The fan module includes a first shroud supporting the first motor. The first shroud includes a first cylinder surrounding the fan rotation axis, a first motor bracket disposed inwardly relative to the first cylinder, and a first guide vane extending between the first cylinder and the first motor bracket. The fan module includes a second shroud supporting the second motor. The second shroud includes a second cylinder surrounding the fan rotation axis, a second motor bracket disposed inwardly relative to the second cylinder, and a second guide vane extending between the second cylinder and the second motor bracket. A first motor is supported by a first motor bracket, and a second motor is supported by a second motor bracket. The first motor bracket is positioned downstream of the first fan relative to the direction of airflow through the fan module, and the second motor bracket is positioned downstream of the second fan relative to the direction of airflow through the fan module. A first guide vane has a first nose facing the direction of airflow through the fan module and a first tail opposite to the first nose. A first line extending between the first nose and the first tail forms a first angle relative to the fan's axis of rotation. A second guide vane has a second nose facing the direction of airflow through the fan module and a second tail opposite to the second nose. A second line extending between the second nose and the second tail forms a second angle relative to a second axis. The second angle is different from the first angle.

[0015] In some embodiments, the first angle is aligned with the airflow exiting from the first fan.

[0016] In some embodiments, the first angle is a non-zero angle.

[0017] In some embodiments, the second angle is approximately zero.

[0018] In some embodiments, the second line is parallel to the second axis.

[0019] In some embodiments, an air guide supports a first shroud and is configured to provide an airflow passage between a first fan and a heat exchanger, and a second shroud supports the first shroud.

[0020] In some embodiments, the first shield is integrated with the air guide.

[0021] In some embodiments, the first guide vane includes opposing first airflow surfaces extending between a first nose and a first tail, and the distance between the respective first airflow surfaces is smaller than the distance between the first nose and the first tail. Additionally, the second guide vane includes opposing second airflow surfaces extending between a second nose and a second tail, and the distance between the respective second airflow surfaces is smaller than the distance between the second nose and the second tail.

[0022] In some aspects, a method of manufacturing a fan module for a vehicle is provided. The fan module includes a first fan, a first motor configured to drive the first fan to rotate about a fan rotation axis in a first direction, and a first shroud supporting the first motor relative to the first fan via a first motor bracket disposed downstream of the first fan relative to the direction of airflow through the fan module. The fan module includes a second fan disposed downstream of the first fan relative to the direction of airflow through the fan module, and a second motor configured to drive the second fan to rotate about a second axis in a second direction, wherein the second direction is opposite to the first direction, and the second axis is approximately common to the fan rotation axis. The fan module includes a second shroud supporting the second motor relative to the second fan via a second motor bracket disposed downstream of the second fan relative to the direction of airflow through the fan module. The method includes assembling a first sub-assembly including the first fan, the first shroud, the first motor bracket, and the first motor; assembling a second sub-assembly including the second fan, the second shroud, the second motor bracket, and the second motor; and assembling the first sub-assembly and the second sub-assembly to provide a third sub-assembly, wherein the second fan is disposed downstream of the first fan relative to the direction of airflow through the first fan.

[0023] In some embodiments, the fan module includes an air guide, and the method includes assembling a third sub-component with the air guide.

[0024] In some embodiments, the first shield is integrally formed with an air guide, and the method steps of assembling the first sub-assembly with the second sub-assembly to provide the third sub-assembly include securing the second sub-assembly to an end of the first shield.

[0025] In some embodiments, the first shield includes a first cylinder about a fan rotation axis, a first motor bracket disposed inwardly relative to the first cylinder, and a first guide vane extending between the first cylinder and the first motor bracket. The second shield includes a second cylinder about a fan rotation axis, a second motor bracket disposed inwardly relative to the second cylinder, and a second guide vane extending between the second cylinder and the second motor bracket. Each first guide vane has a first nose facing the direction of airflow away from the first fan and a first tail opposite the first nose, and a first line extending between the first nose and the first tail forms a first angle relative to the fan rotation axis. Each second guide vane has a second nose facing the direction of airflow away from the second fan and a second tail opposite the second nose, and a second line extending between the second nose and the second tail forms a second angle relative to a second axis. The second angle differs from the first angle. Attached Figure Description

[0026] Figure 1 It is a perspective view of a fan module that includes two coaxial, counter-rotating axial fans.

[0027] Figure 2 Is it like along Figure 1 Line 2-2 Figure 1 Side view cross-sectional view of the fan module.

[0028] Figure 3 Is it so? Figure 2 The attached figure label " Figure 3 "Instructions" Figure 2 A magnified view of a portion of the image.

[0029] Figure 4 yes Figure 1 An exploded view of the fan module.

[0030] Figure 5 Is it like along Figure 1 Line 5-5 seen Figure 1 A side cross-sectional view of a portion of the fan module.

[0031] Figure 6 As indicated by the attached diagram " Figure 6 "Instructions" Figure 5 A magnified view of a portion of the image.

[0032] Figure 7 As indicated by the attached diagram " Figure 7 "Instructions" Figure 5 A magnified view of a portion of the image.

[0033] Figure 8 This is an exploded view of the fan module in an alternative embodiment. Detailed Implementation

[0034] refer to Figure 1-4 A fan module 1, designed for cooling motor vehicle engines, includes an air guide 2, a first motor 30 connected to the air guide 2 via a first shroud 40, and an axial-flow first fan 20 connected to and driven by the first motor 30. Additionally, the fan module 1 includes a second motor 60 connected to the air guide 2 via a second shroud 80, and an axial-flow second fan 50 connected to and driven by the second motor 60. In the illustrated embodiment, the first and second motors may be, for example, brushless DC motors. Each of the first and second motors drives a corresponding fan about a fan rotation axis 12, which is substantially common to both fans. In the fan module 1, the second fan 50 is positioned downstream of the first fan 20 relative to the airflow direction through the fan module 1, indicated by an arrow with reference numeral 10. The first and second fans rotate in opposite directions, such that the first fan 20 and the second fan 50 rotate in opposite directions. As described below, the first and second shrouds include features that improve the efficiency of the fan module 1.

[0035] Air guide 2 is configured to be connected to a heat exchanger (not shown) in a "draw through" configuration, such that the first and second fans draw airflow through the heat exchanger. Alternatively, fan module 1 may be connected to the heat exchanger in a "push through" configuration (not shown), such that the first and second fans exhaust airflow through the heat exchanger.

[0036] In the illustrated embodiment, the air guide 2 is a molded one-piece tube that provides an airflow passage between the heat exchanger and the first and second fans. The air guide 2 includes a frame portion 4 and a tapered portion 6 projecting from the frame portion 4. The frame portion 4 has a rectangular profile and is configured to be secured to the heat exchanger via known connection techniques and / or using any of several different connectors. The tapered portion 6 is generally tapered in shape and includes a first end 8 connected to the frame portion 4 and a second end 9 spaced apart from the first end 8. The diameter of the second end 9 of the tapered portion is smaller than the diameter of the first end 8 of the tapered portion, thereby making the tapered portion 6 at an angle relative to the airflow direction 10 through the air guide 2. In the illustrated suction-through configuration, the second end 9 of the tapered portion is located downstream of the first end 8 of the tapered portion relative to the airflow direction 10 through the fan module 1.

[0037] The first fan 20 is an axial flow fan, comprising a first central hub 22 and first blades 24 extending radially outward from the hub 22. In some embodiments, the first central hub 22 and the first blades 24 are formed as a single piece, for example by injection molding. Each first blade 24 includes a first root 26 coupled to the first central hub 22 and a first tip 28 spaced apart from the first root 26. The surface of each first blade 24 has a complex three-dimensional curvature determined by the requirements of a particular application. The direction of the airflow exhausted from the first fan 20 depends at least in part on the blade curvature and includes axial flow components and tangential flow components. As used herein, the term “axial flow component” refers to the component of airflow flowing parallel to the airflow direction 10 through the fan module 1. In the illustrated embodiment, the axial flow component is also parallel to the fan rotation axis 12. As used herein, the term “tangential flow component” refers to the component of airflow flowing in a direction tangential to the circle defined by the rotating first tip 28, and may also be referred to as a “vortex.”

[0038] The first central hub 22 is mechanically connected to the first motor 30 in such a way that the first fan 20 is driven by the first motor 30 to rotate about the fan rotation axis 12 and is supported by the first motor 30 relative to the air guide 2. The first fan 20 rotates about the fan rotation axis 12 in a first direction (indicated by the arrow with reference numeral 14), for example, in a clockwise direction when viewed along the airflow direction 10 parallel to the airflow through the fan module 1.

[0039] Similarly, the second fan 50 is an axial fan, comprising a second central hub 52 and second blades 54 extending radially outward from the second central hub 52. In some embodiments, the second central hub 52 and the second blades 54 are formed as a single piece, for example by injection molding. Each second blade 54 includes a second root 56 coupled to the second central hub 52 and a second tip 58 spaced apart from the second root 56. The surface of each second blade 54 has a complex three-dimensional curvature, which is determined by the requirements of a specific application. The direction of the airflow exhausted from the second fan 50 depends at least in part on the blade curvature. In this counter-rotating arrangement, the second blades 54 are shaped to remove the tangential flow component or vortex imparted by the first fan 20 to the airflow passing through the fan module 1.

[0040] The second center hub 52 is mechanically connected to the second motor 60 in such a way that the second fan 50 is driven by the second motor 60 to rotate about the fan rotation axis 12 and is supported by the second motor 60 relative to the air guide 2. The second fan 50 rotates about the fan rotation axis 12 in a second direction (indicated by the arrow with reference numeral 16), for example, in a counterclockwise direction when viewed in a direction parallel to the airflow direction 10 through the fan module 1.

[0041] refer to Figure 4-7 The first shield 40 supports the first motor 30 relative to the air guide 2. The first shield 40 includes a first cylinder 41, a first motor bracket 42 spaced apart from and disposed inward relative to the first cylinder 41, and a first guide vane 43 extending radially between the first cylinder 41 and the first motor bracket 42.

[0042] The first cylindrical body 41 is an annular belt and is configured to connect to the air guide 2. For example, in some embodiments, the outer surface of the first cylindrical body 41 may include a mounting feature 49 having a through hole (not shown) axially aligned with a corresponding opening (not shown) in the second end 9 of the tapered portion. A fastener (not shown) may extend through the through hole of the mounting feature 49 and engage with the opening in the tapered portion 6, thereby securing the first cylindrical body 41 to the second end 9 of the tapered portion. The first cylindrical body 41 may have a double-walled structure including an inner wall 32 and an outer wall 33. In some embodiments, the downstream end 34 of the outer wall 33 of the first cylindrical body may be fan-shaped. The fan-shaped portion 35 is formed by removing material between the first guide vanes 43 to reduce the weight of the fan module.

[0043] The first motor bracket 42 is a generally annular structure with an outer diameter smaller than that of the first cylinder 41. The first motor bracket 42 is concentric with the first cylinder 41 and supports the first motor 30. Although in the illustrated embodiment the first motor bracket 42 is surrounded by the first cylinder 41, it is not limited to this configuration. For example, in some embodiments, the first motor bracket 42 may be positioned slightly upstream or downstream of the first cylinder 41 relative to the airflow direction 10 through the fan module 1. The first motor 30 is supported by the first motor bracket 42 in such a way that the first fan 20 is positioned upstream of the first motor bracket 42 relative to the airflow direction 10 through the fan module 1.

[0044] The first guide vane 43 supports the first motor bracket 42 relative to the first cylinder 41. For this purpose, each first guide vane 43 includes a rounded front end or nose 44 facing or upstream of the airflow direction 10 through the fan module 1, and a rounded rear end or tail 45 opposite the nose 44 (e.g., away from or downstream of the airflow direction 10 through the fan module 1). Each first guide vane 43 includes opposing airflow surfaces 47, 48 extending between the nose 44 and the tail 45. When viewed in a cross-section obtained by cutting a cylindrical section of the first shroud 40, wherein the cylinder forming the section is concentric with the axis of rotation of the first fan 20 and passes through the first guide vane 43 (see, for example...). Figure 6 The airflow surfaces 47 and 48 are linear and parallel to each other. Each first guide vane is a thin beam because the distance between the airflow surfaces 47 and 48 is smaller than the distance between the nose 44 and the tail 45.

[0045] Each first guide vane 43 is at an angle θ1 (e.g., a non-zero angle) relative to the fan rotation axis 12. In particular, a first line 46 extending between the nose 44 and the tail 45 and parallel to the airflow surfaces 47, 48 is at an angle θ1 (e.g., a non-zero angle) relative to the fan rotation axis 12. More specifically, the first line 46 corresponds to the longest straight line that can be drawn through the cylindrical cross-section of the first guide vane 43.

[0046] The specific angle θ1 used is determined by the requirements of the specific application. In some embodiments, each first guide vane 43 is designed to align with the airflow leaving the first fan 20 at all radii. In other words, the angle θ1 is set such that the first line 46 aligns with the airflow leaving the first fan 20. By aligning the first line 46 with the tangential component of the airflow leaving the first fan 20, the destructive effects of the presence of the first guide vane 43 in the airflow path are minimized (e.g., airflow loss is minimized). Since the airflow leaves the first fan 20 at an angle varying from the first root 26 to the first tip 28, the angle θ1 varies from the inner end 37 to the outer end 39 of the first guide vane for each guide vane 43. In the illustrated embodiment, for a given radius, the first line 46 forms an acute angle, such as 45 degrees, relative to the fan rotation axis 12.

[0047] The second shield 80 supports the second motor 60 relative to the air guide 2. The second shield 80 includes a second cylinder 81, a second motor bracket 82 spaced apart from and disposed inward relative to the second cylinder 81, and a second guide vane 83 extending radially between the second cylinder 81 and the second motor bracket 82.

[0048] The second cylindrical body 81 is an annular band and is configured to connect to the downstream end of the first cylindrical body 41. For example, in some embodiments, the outer surface of the second cylindrical body 81 may include a mounting feature 89 that aligns with a corresponding mounting feature 49 disposed on the outer surface of the first cylindrical body 41. The mounting feature 89 of the second cylindrical body 81 includes a through hole, and a fastener may extend through the through holes of the mounting features 49, 89 of both the first and second cylindrical bodies and engage with an opening in the tapered portion 6, thereby securing the first cylindrical body 41 to the second end 9 of the tapered portion.

[0049] The second cylinder 81 may have a double-wall structure including an inner wall 62 and an outer wall 63. In some embodiments, the downstream end 64 of the inner wall 62 and the outer wall 63 of the second cylinder may be fan-shaped. By removing the material between the second guide vanes 83, a fan-shaped portion 65 is formed to reduce the weight of the fan module.

[0050] The upstream end 66 of the second cylinder 81 may include a collar 68 projecting axially toward the first cylinder 41. The collar 68 is sized to correspond to the outer diameter of the inner wall 32 of the first cylinder, and when the second cylinder 81 is assembled with the first cylinder 41, the collar 68 is accommodated in the space between the inner wall 32 and the outer wall 33 of the first cylinder. The collar 68 is used to position the second cylinder 81 relative to the first cylinder 41 and also facilitates an airtight connection between the first and second cylinders.

[0051] The second motor bracket 82 is a generally annular structure with an outer diameter smaller than that of the second cylinder 81. The second motor bracket 82 is concentric with the second cylinder 81 and supports the second motor 60. In the illustrated embodiment, the second motor bracket 82 is surrounded by the second cylinder 81, but this configuration is not limited to. For example, in some embodiments, the second motor bracket 82 may be positioned slightly upstream or downstream of the second cylinder 81 relative to the airflow direction 10 through the fan module 1. The second motor 60 is supported by the second motor bracket 82 in such a way that the second fan 50 is positioned upstream of the second motor bracket 82 relative to the airflow direction 10 through the fan module 1.

[0052] The second guide vane 83 supports the second motor bracket 82 relative to the second cylinder 81. For this purpose, each second guide vane 83 includes a rounded front end or nose 84 facing or upstream of the airflow direction 10 through the fan module 1, and a rounded rear end or tail 85 opposite the nose 84 (e.g., away from or downstream of the airflow direction 10 through the fan module 1). Each second guide vane 83 includes opposing airflow surfaces 87, 88 extending between the nose 84 and the tail 85. When viewed in a cross-section obtained by cutting a cylindrical section of the second shroud 80, wherein the cylinder forming this section is concentric with the axis of rotation of the second fan 50 and passes through the second guide vane 83 (see, for example...). Figure 7 The airflow surfaces 87 and 88 are linear and parallel to each other. Each second guide vane 83 is a thin beam because the distance between the airflow surfaces 87 and 88 is small relative to the distance between the nose 84 and the tail 85.

[0053] Each second guide vane 83 is parallel to the fan rotation axis 12. Specifically, a second line 86 extending between the nose and tail portions 84 and parallel to the airflow surfaces 87, 88 is set at an angle θ2 relative to the fan rotation axis 12. More specifically, the second line 86 corresponds to the longest straight line that can be drawn through the cylindrical cross-section of the second guide vane 83. The angle θ2 of the second line 86 is oriented to match the direction of the airflow leaving the second fan 50 at all radii. Since the tangential component of the airflow is removed from the total airflow by the shape of the blades 54 of the second fan 50, the second line 86 is set parallel to the fan rotation axis 12 for all radii (e.g., the angle θ2 is approximately zero). It should be understood that in use, the second line 86 and the fan rotation axis 12 may not be precisely parallel. In some embodiments, the term "approximately zero" is used to indicate that the second line 86 is parallel to the fan rotation axis 12 within twelve degrees. In other embodiments, the term "approximately zero" is used to indicate that the second line 86 is parallel to the fan rotation axis 12 within six degrees. In yet another embodiment, the term "approximately zero" is used herein to indicate that the second line 86 is parallel to the fan rotation axis 12 within three degrees.

[0054] When fan module 1 is in use, air enters the first fan 20 in a direction parallel to the fan rotation axis 12. The first fan 20 introduces vortices within the air guide 2. That is, the airflow leaving the first fan 20 includes a flow component that travels tangentially relative to the fan rotation axis 12. The direction of the vortex is the same as the rotation direction of the first fan 20.

[0055] Air exiting the first fan 20 passes through a first guide vane 43 located downstream of the first fan 20. The first guide vane 43 is set at an angle substantially aligned with the vortex of the passing air so as to present minimal resistance to the airflow at that location.

[0056] After exiting the first fan 20 and the first shroud 40, the airflow, including the vortex introduced by the first fan 20, enters the second fan 50. The second fan 50 applies vortices to this airflow in the opposite direction (e.g., "reverse vortices"). The reverse vortices introduced by the second fan 50 substantially counteract the vortices introduced by the first fan 20. As a result, the airflow exiting the second fan 50 is substantially parallel to the fan's axis of rotation.

[0057] Air leaving the second fan 50 passes through the second guide vane 83. The second guide vane 83 is set at an angle substantially aligned with the axis of rotation of the second fan 50 in order to present minimal resistance to the airflow.

[0058] refer to Figure 8 The alternative embodiment of the fan module 100 is similar to the above reference. Figure 1-4The fan module 1 is described, and common reference numerals are used to refer to common components. Figure 8 The fan module 100 shown is the same as the one referenced above. Figure 1 The difference between fan module 1 described in section -7 is that fan module 100 includes a modified air guide 102. Like the air guide 2 in the previous embodiment, the modified air guide 102 includes a frame portion 4 and a tapered portion 6 extending from the frame portion 4. Additionally, the modified air guide 102 includes a first shroud 140 integrally formed with the tapered portion 6 to protrude from a second end 9 of the tapered portion. By forming the first shroud 140 and the air guide 102 as a single piece, the number of parts and assembly costs are reduced. In fan module 100, a second shroud 80 is fixed to the downstream end 34 of the first cylinder 41.

[0059] Although the first and second covers include motor brackets 42, 82 and a cylinder with generally circular outlines, the motor brackets 42, 82 and the cylinder are not limited to having generally circular outlines. For example, the shape and size of the motor brackets 42, 82 may be configured to accommodate the respective motors, and the shape and size of the cylinder may be configured to accommodate a portion of the inner surface of the air guide 2. Furthermore, in some embodiments, the motor brackets 42, 82 may not have the same shape as the cylinder, and / or the motor brackets 42, 82 may not be concentric with the cylinder.

[0060] Although in the illustrated embodiment, the airflow surfaces 47, 48, 87, 88 of the guide vanes 43, 83 are linear and parallel to each other when viewed in cross-section, the guide vanes 43, 83 are not limited to this configuration. The cross-sectional shape of the guide vanes 43, 83 is determined by the requirements of the specific application.

[0061] Selective illustrative embodiments of the fan module have been described in more detail above. It should be understood that only structures deemed necessary for clarifying the fan module have been described herein. Other conventional structures, as well as the structures of auxiliary and auxiliary components of the fan module, are considered to be known and understood by those skilled in the art. Furthermore, while working examples of the fan module have been described above, the fan module is not limited to the working examples described above, but various design changes can be implemented without departing from the fan module set forth in the claims.

Claims

1. A fan module for an automotive cooling system, the fan module comprising: The first fan is configured to rotate about the fan rotation axis; A second fan is configured to rotate about a second axis, which is positioned downstream of the first fan relative to the airflow direction through the fan module, and the second axis is substantially the same as the fan rotation axis. A first motor is configured to drive the first fan to rotate about the fan's rotation axis in a first direction; A second motor is configured to drive the second fan to rotate about the second axis in a second direction, which is opposite to the first direction; A first protective cover supporting the first motor, the first protective cover including a first cylindrical body about the rotation axis of the fan, a first motor bracket disposed inward relative to the first cylindrical body, and a first guide vane extending between the first cylindrical body and the first motor bracket. and A second protective cover supports the second motor. The second protective cover includes a second cylindrical body surrounding the fan's rotation axis, a second motor bracket disposed inwardly relative to the second cylindrical body, and a second guide vane extending between the second cylindrical body and the second motor bracket. in, The first motor is supported by the first motor bracket. The second motor is supported by the second motor bracket. The first motor bracket is positioned downstream of the first fan relative to the direction of airflow through the fan module. The second motor bracket is positioned downstream of the second fan relative to the direction of airflow through the fan module. Each first guide vane has a first nose facing the direction of airflow through the fan module and a first tail opposite the first nose, and a first line extending between the first nose and the first tail forms a first angle with respect to the fan's axis of rotation. Each second guide vane has a second nose facing the direction of airflow through the fan module and a second tail opposite the second nose, and a second line extending between the second nose and the second tail forms a second angle with respect to a second axis. The second angle is different from the first angle. The first angle is aligned with the airflow exhausted from the first fan, and The second angle is approximately zero.

2. The fan module according to claim 1, wherein, The first angle is a non-zero angle.

3. The fan module according to claim 1, wherein, The second line is parallel to the second axis.

4. The fan module of claim 1, comprising an air guide that supports the first shroud and is configured to provide an airflow passage between the first fan and the heat exchanger, wherein the second shroud is supported on the first shroud.

5. The fan module according to claim 4, wherein, The first protective cover is integrated with the air guide.

6. The fan module according to claim 1, wherein The first guide vane includes opposing first airflow surfaces extending between the first nose and the first tail, and the distance between the respective first airflow surfaces is small relative to the distance between the first nose and the first tail. The second guide vane includes opposing second airflow surfaces extending between the second nose and the second tail, and the distance between the respective second airflow surfaces is small relative to the distance between the second nose and the second tail.

7. An automotive cooling system comprising a heat exchanger and a fan module configured to draw in air through said heat exchanger, wherein, The fan module includes: The first fan is configured to rotate about the fan rotation axis; A second fan is configured to rotate about a second axis, and the second fan is positioned downstream of the first fan relative to the airflow direction through the fan module. The second axis is substantially the same as the fan's axis of rotation. A first motor is configured to drive the first fan to rotate about the fan's rotation axis in a first direction; A second motor is configured to drive the second fan to rotate about the second axis in a second direction, wherein the second direction is opposite to the first direction; A first protective cover supporting the first motor, the first protective cover including a first cylindrical body about the fan's rotation axis, a first motor bracket disposed inwardly relative to the first cylindrical body, and a first guide vane extending between the first cylindrical body and the first motor bracket; and A second protective cover supports the second motor. The second protective cover includes a second cylindrical body surrounding the fan's rotation axis, a second motor bracket disposed inwardly relative to the second cylindrical body, and a second guide vane extending between the second cylindrical body and the second motor bracket. in, The first motor is supported by the first motor bracket. The second motor is supported by the second motor bracket. The first motor bracket is positioned downstream of the first fan relative to the direction of airflow through the fan module. The second motor bracket is positioned downstream of the second fan relative to the direction of airflow through the fan module. The first guide vane has a first nose facing the direction of airflow through the fan module and a first tail opposite the first nose, and a first line extending between the first nose and the first tail forms a first angle with respect to the fan's axis of rotation. The second guide vane has a second nose facing the direction of airflow through the fan module and a second tail opposite to the second nose, and a second line extending between the second nose and the second tail forms a second angle with respect to a second axis. The second angle is different from the first angle. The first angle is aligned with the airflow exhausted from the first fan, and The second angle is approximately zero.

8. The cooling system according to claim 7, wherein, The first angle is a non-zero angle.

9. The cooling system according to claim 7, wherein, The second line is parallel to the second axis.

10. The cooling system of claim 7, further comprising an air guide that supports the first shroud and is configured to provide an airflow passage between the first fan and the heat exchanger, wherein the second shroud is supported on the first shroud.

11. The cooling system according to claim 10, wherein, The first protective cover is integrated with the air guide.

12. The cooling system according to claim 7, wherein The first guide vane includes opposing first airflow surfaces extending between the first nose and the first tail, and the distance between the respective first airflow surfaces is smaller than the distance between the first nose and the first tail. The second guide vane includes opposing second airflow surfaces extending between the second nose and the second tail, and the distance between the respective second airflow surfaces is small relative to the distance between the second nose and the second tail.

13. A method for manufacturing a fan module for a vehicle, The fan module includes: First fan; A first motor is configured to drive the first fan to rotate about a fan rotation axis in a first direction; A first protective cover supports the first motor relative to the first fan via a first motor bracket, the first motor bracket being positioned downstream of the first fan relative to the direction of airflow through the fan module; The second fan is positioned downstream of the first fan relative to the airflow direction through the fan module; A second motor is configured to drive the second fan to rotate about a second axis in a second direction, wherein the second direction is opposite to the first direction and the second axis is substantially the same as the fan's rotation axis; The second shield supports the second motor relative to the second fan via a second motor bracket, the second motor bracket being positioned downstream of the second fan relative to the direction of airflow through the fan module; The first protective cover includes a first cylindrical body surrounding the fan's rotation axis, a first motor bracket disposed inwardly relative to the first cylindrical body, and a first guide vane extending between the first cylindrical body and the first motor bracket; and The second shield includes a second cylindrical body surrounding the fan's rotation axis, a second motor bracket disposed inwardly relative to the second cylindrical body, and a second guide vane extending between the second cylindrical body and the second motor bracket. in, Each first guide vane has a first nose facing the direction of airflow through the fan module and a first tail opposite the first nose, and a first line extending between the first nose and the first tail forms a first angle with respect to the fan's axis of rotation. Each second guide vane has a second nose facing the direction of airflow through the fan module and a second tail opposite the second nose, and a second line extending between the second nose and the second tail forms a second angle with respect to the second axis. The second angle is different from the first angle. The first angle is aligned with the airflow exhausted from the first fan, and The second angle is approximately zero. The method includes: The assembly includes the first fan, the first shield, the first motor bracket, and a first sub-assembly of the first motor; The assembly includes the second fan, the second shroud, the second motor bracket, and the second sub-assembly of the second motor, as well as The first sub-component and the second sub-component are assembled to provide a third sub-component, wherein the second fan is positioned downstream of the first fan relative to the direction of airflow through the first fan.

14. The method of claim 13, wherein The fan module includes an air guide, and the method includes: Assemble the third sub-component with the air guide.

15. The method according to claim 13, wherein, The first shield is integrally formed with an air guide, and the method steps of assembling the first sub-assembly and the second sub-assembly to provide a third sub-assembly include securing the second sub-assembly to an end of the first shield.

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