US20140102675A1

US20140102675A1 - Fan shroud

Info

Publication number: US20140102675A1
Application number: US13/652,144
Authority: US
Inventors: Abram M. Ingold
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2012-10-15
Filing date: 2012-10-15
Publication date: 2014-04-17

Abstract

A cooling system is provided for use in a machine. The cooling system includes a fan having a hub and a plurality of evenly spaced blades connected with the hub, and a shroud partially surrounding the fan. The shroud includes a flat surface having an opening of a predetermined diameter is centrally disposed on the flat surface. Further, the shroud includes a circular sidewall having of a predetermined width extending in a substantially perpendicular direction from the flat surface and encompasses the opening.

Description

TECHNICAL FIELD

The present disclosure relates generally to a fan shroud adapted for use within a cooling system in a machine and more particularly related to a design of the fan shroud for attaining low noise and maximum air flow.

BACKGROUND

A cooling system is provided for cooling an engine of a machine. The fan induces cooling air flow to pass through the core of the radiator for engine cooling purposes. EP Patent Number 645,543 discloses a cooling system for use with an internal combustion engine, the cooling system including a fan defining a central axis, a radiator asymmetrical in shape about the central axis, and a fan shroud disposed about the fan and defining a flow path for directing cooling flow across the radiator. The fan shroud includes a radially converging inlet portion, a radially diverging outlet portion and a cylindrical transition portion there between. The radially converging inlet portion and the radially diverging outlet portion are axisymmetrical in shape about the central axis and are substantially symmetric with one another about an imaginary plane constructed normal to the central axis. The geometry of the fan shroud, the alignment of the fan shroud relative to the fan, and the fan spacing relative to the radiator are determined according to dimensionless numbers relating the various geometries to the fan diameter and the projected axial fan chord. However, there is still room for improvement in the art.

SUMMARY

In an aspect, a cooling system is provided for use in a machine. The cooling system includes a fan having a hub and a plurality of evenly spaced blades connected with the hub, and a shroud partially surrounding the fan. The shroud includes a flat surface having an opening of a predetermined diameter is centrally disposed on the flat surface. Further, the shroud includes a circular sidewall having of a predetermined width extending in a substantially perpendicular direction from the flat surface and encompasses the opening, such that the circular sidewall partially covers the blades.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side cross-sectional view of a cooling system in a machine;

FIG. 2 illustrates an exploded view of the cooling system of FIG. 1, according to an aspect of the present disclosure;

FIG. 3 illustrates a perspective assembled view of the cooling system of FIG. 2; and

FIG. 4 illustrates a side assembled view of the cooling system of FIG. 2.

DETAILED DESCRIPTION

The present disclosure relates to a fan shroud adapted for use within a cooling system of a machine. FIG. 1 illustrates a side cross-sectional view of a cooling system 100 in a machine 102, such as an articulated truck, in which various embodiments of the present disclosure may be implemented. In an exemplary embodiment, the machine 102 may include a front section 104 and a body 106 connected by an articulation joint 108. The front section 104 of the machine 102 may include an operator cab 110 and an engine enclosure 112. As illustrated in FIG. 1, a portion of the engine enclosure 112 is removed to show a partial cross-sectional view of the cooling system 100 and an associated engine 114. The engine enclosure 112 may include a frame 116 for supporting various components, primarily including the engine 114 and the cooling system 100. The engine 114 may include an engine block 118 and is connected to the frame 116 by engine mounts 120 (only one is shown). The engine mounts 120, of a conventional type, may resiliently connect the engine block 118 to the frame 116 and enables limited movement of the engine 114 relative to the frame 116.
According to an aspect of the present disclosure, the cooling system 100 may include a fan 122, a shroud 124, and a heat exchanger 126 adjacently positioned along an axial direction XX′. The fan 122 may include, for example, but not limited to, an axial flow fan. The fan 122 may include a hub 128 and a plurality of evenly spaced blades 130 connected with the hub 128. In an embodiment, the blades 130 may include about 4 to 12 aerodynamically contoured blades. Further, the blades 130 of the fan 122 may have a predetermined width W1.
In an embodiment of the present disclosure, the hub 128 is connected to a fan drive pulley 132. The fan drive pulley 132 is driven in a conventional manner by a drive belt 134 rotated by an engine driven drive pulley 136 as illustrated in FIG. 1. In an alternative embodiment, the hub 128 is configured to be rotatably driven by a motor or any other suitable source known in the art. The fan 122 may be driven hydraulically or electrically by the motor, which may derive power from the engine 114. In an embodiment of the present disclosure, the heat exchanger 126 may include at least one of a radiator, a condenser, an oil-cooler, an exhaust gas recirculation (EGR) cooler or an intercooler/charge air cooler. The heat exchanger 126 may include a core of rectangular cross-section. In the illustrated embodiment, the heat exchanger 126, for example, the radiator, is positioned adjacent the shroud 124 and the fan 122 is rotatably mounted within the shroud 124 which is further discussed in detail in conjunction with FIG. 2.
FIG. 2 illustrates an exploded view of the cooling system 100, according to an embodiment of the present disclosure. As illustrated, the shroud 124 may have a substantially rectangular shape with a major dimension L1 and a minor dimension L2 and be configured to surround the fan 122. In an embodiment, the ratio of minor and major dimensions L2:L1 may be about 0.67. In various other aspects of the present disclosure, the ratio of minor and major dimensions L2:L1 may be in a range of about 0.5 to 0.8. Further, based on the application and size of cooling system 100, the shroud 124 may have a square, circular, oval or any other suitable shape to surround the fan 122. According to an aspect of the present disclosure, the shroud 124 may include a flat surface 138 with a centrally disposed opening 140 with a predetermined diameter D1. The opening 140 provided on the flat surface 138 having the predetermined diameter D1 is configured to receive the fan 122 within expected clearances. Further, the fan 122 may have an outer diameter D2, such that the predetermined diameter D1 is greater than the outer diameter D2 by about 16 mm. In various other aspects of the present disclosure, the predetermined diameter D1 of the opening 140 is greater than fan outer diameter D2 by about 14 mm to 18 mm. It will be apparent to a person having ordinary skill in the art that, the expected clearances between the blades 130 and the opening 140 permits a predetermined amount of movement of the fan 122 in a transverse direction with respect to the axial direction XX′. Moreover, the clearance is preferably kept at a minimum in order to maximize efficiency of the cooling system 100.
Furthermore, the shroud 124 includes a circular sidewall 142 having a predetermined width W2, which extends in a substantially perpendicular direction, along the axial direction XX′, from the flat surface 138 and encompasses the opening 140. In an aspect of the present disclosure, the circular sidewall 142 is configured to partially cover the blades 130 in the axial direction XX′, such that a ratio of circular sidewall of predetermined width W2 and the fan blade of predetermined width W1 may be about 0.67. In various other aspects of the present disclosure, ratio of circular sidewall of predetermined width W2 and the fan blade of predetermined width W1 may be in a range of about 0.5 to 0.8. Further, the flat surface 138 and the circular sidewall 142 may be connected by a curved surface 144. In an embodiment, the circular sidewall 142 may be connected to the flat surface 138 by welding or alternatively manufactured integrally with the flat surface 138 by casting. Moreover, the shroud 124 may be made of a glass reinforced polymer, which may impart high impact toughness in addition to high strength.
A plurality of first fastening means 146 are configured to connect the shroud 124 to the heat exchanger 126. In an embodiment, the first fastening means 146 may include, for example, but not limited to, threaded fasteners, to releasably connects first mounting flange portions 148, of the shroud 124, to the second mounting flange portions 150, of the heat exchanger 126. As illustrated, the first fastening means 146 are configured to pass through a set of apertures 152 provided in the first mounting flange portions 148 and securely attach within a set of threaded holes 154, substantially aligned with the set of apertures 152, provided in the second mounting flange portions 150, to releasably connect the shroud 124 with the heat exchanger 126. Likewise, a plurality of second set of fastening means 156 are configured to connect a protective shield 158 to the shroud 124. The protective shield 158 may be fabricated of a spaced wire formed into a domed configuration, and is positioned to substantially cover the fan 122. The protective shield 158 is configured to allow airflow and block entrance of objects of a substantial size. In various other embodiments, various other possible methods including, welding, riveting may be used to connect the shroud 124 and the protective shield 158.
FIGS. 3 and 4 illustrate an assembled view of the cooling system 100. During operation, a cooling air flow A induced by the fan 122 is configured to pass through radiator 126 and facilitate heat transfer between the air and coolant flowing through a radiator core, in a conventional manner. As illustrated in FIG. 4, the fan 122 may extend by a predetermined distance P from the circular sidewall 142. In an embodiment, a ratio of the predetermined distance P and the fan blade of predetermined width W1 may be about 0.33. In various other aspects of the present disclosure, the ratio of the predetermined distance P and the fan blade of predetermined width W1 may be in a range of about 0.2 to 0.4.

INDUSTRIAL APPLICABILITY

The industrial applicability of the shroud 124 for attaining low noise and maximizing air flow described herein will be readily appreciated from the foregoing discussion. Although the machine 102 shown as the articulated truck, any type of machine that performs at least one operation associated with, for example, mining, construction, and other industrial applications may embody the disclosed fan shroud 124. The machine 102 may also be associated with non-industrial uses and environments, such as, for example, but not limited to, an off-highway truck, on-highway truck, a backhoe loader, an industrial loader, a skidder, a wheel tractor, an excavator, a wheel dozer, an wheel loader, a asphalt paver, a cold planer, a compactor, a feller buncher, a forest machine, a forwarder, a harvester, a motor grader, a hydraulic shovel, a road reclaimer, a tele-handler, a mining machine or the like.
With reference to the above-described FIGS. 1 to 4, the circular sidewall 142 of the shroud 124 protruding the flat surface 138 partially covers the blades 130. In an aspect, the blades 130 which extend by the predetermined distance P may reduce any possible for interference between the blades 130 and the shroud 124 in both static applications and dynamic machine applications. The predetermined distance P may be based on design and application of the fan 122, and it is optimally calculated to avoid pulling any air from around the blades 130, when the fan 122 is placed too far from the opening 140. Further, it also avoids turbulence and noise, in case the fan 122 is placed deep into the opening 140 of the shroud 124.
In an aspect of the present disclosure, the flat surfaces 138 provided in the shroud 124 may direct airflow through a transition of the rectangular cross section of the core of the heat exchanger 126 to a circular cross section of the fan 122. Further, the flat surfaces 138 are parallel to the core of the heat exchanger 126, which may prevent excess restriction of the airflow coming from corners of the core of the heat exchanger 138, thereby noise may be reduced attaining maximum airflow. These factors of low noise and maximum airflow may increase efficiency of the shroud 124.
As described above, the shroud 124 may be made of a glass-reinforced polymer, which may provide a highly smooth surface finish even when glass or mineral reinforcement is added. This smooth surface finish helps reduce the frictional loss while air passing through the fan 122, thereby increasing the overall efficiency of the cooling system 100.
It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

What is claimed is:

1. A cooling system adapted for use in a machine comprising:

a fan having a hub and a plurality of evenly spaced blades connected with the hub; and

a shroud partially surrounding the fan, the shroud includes:

a flat surface;

an opening of a predetermined diameter is centrally disposed on the flat surface; and

a circular sidewall having of a predetermined width extending in a substantially perpendicular direction from the flat surface and encompasses the opening.

2. The cooling system of claim 1, wherein the shroud has a rectangular shape.

3. The cooling system of claim 2, wherein the shroud having a major dimension and a minor dimension, a ratio of the minor dimension to the major dimension is in a range of about 0.5 to 0.8.

4. The cooling system of claim 3, wherein the ratio of the minor dimension to the major dimension is about 0.67.

5. The cooling system of claim 1, wherein the flat surface and the circular sidewall are connected by a curved surface.

6. The cooling system of claim 1, wherein the circular sidewall partially covers the fan blades.

7. The cooling system of claim 6, wherein the plurality of fan blades having a predetermined width, a ratio of the circular sidewall width to the fan blade of predetermined width is in a range of about 0.5 to 0.8.

8. The cooling system of claim 7, wherein the ratio of the circular sidewall of predetermined width to the fan blade of predetermined width is about 0.67.

9. The cooling system of claim 7, wherein the fan extends by a predetermined distance beyond the shroud, a ratio of the predetermined distance to the fan blade of predetermined width is in a range of about 0.2 to 0.4.

10. The cooling system of claim 9, wherein the ratio of the predetermined distance to the fan blade of predetermined width is about 0.33.

11. The cooling system of claim 1 further includes a heat exchanger releasably connected with the shroud.

12. The cooling system of claim 11, the heat exchanger includes a core, wherein the flat surfaces are parallel with the core of the heat exchanger.

13. The cooling system of claim 1 further includes a protective shield releasably connected with the shroud and is positioned to substantially cover the fan.

14. A shroud configured to partially surround a fan adapted in a cooling system comprising:

a flat surface;

15. The shroud of claim 14, wherein the shroud has a rectangular shape.

16. The shroud of claim 15, wherein the shroud having a major dimension and a minor dimension, a ratio of the minor dimension to the major dimension is in a range of about 0.5 to 0.8.

17. The shroud of claim 16, wherein the ratio of the minor dimension to the major dimension is about 0.67.

18. The shroud of claim 14, wherein the flat surface and the circular sidewall are connected by a curved surface.

19. The shroud of claim 14, wherein the shroud is configured to be releasably connected with a heat exchanger.

20. The cooling system of claim 19, the heat exchanger includes a core, wherein the flat surfaces are parallel with the core of the heat exchanger.