US20060237168A1

US20060237168A1 - Air mover with thermally coupled guide vanes

Info

Publication number: US20060237168A1
Application number: US11/111,066
Authority: US
Inventors: Christian Belady; Wade Vinson; Eric Peterson; David Moore
Original assignee: Hewlett Packard Development Co LP
Current assignee: Hewlett Packard Development Co LP
Priority date: 2005-04-21
Filing date: 2005-04-21
Publication date: 2006-10-26
Also published as: TW200639628A; US20060237169A1

Abstract

An air mover comprising a housing and a plurality of blades rotatably disposed within the housing. A plurality of guide vanes are fixed within the housing. The guide vanes are thermally coupled to an electronic component such that heat generated by the electronic component is transferred through the guide vanes into an airflow generated by rotating the blades.

Description

BACKGROUND

Computer systems include numerous electrical components that draw electrical current to perform their intended functions. For example, a computer's microprocessor or central processing unit (“CPU”) requires electrical current to perform many functions such as controlling the overall operations of the computer system and performing various numerical calculations. Generally, any electrical device through which electrical current flows produces heat. The amount of heat any one device generates generally is a function of the amount of current flowing through the device.
Typically, an electrical device is designed to operate correctly within a predetermined temperature range. If the temperature exceeds the predetermined range (i.e., the device becomes too hot or too cold), the device may not function correctly, thereby potentially degrading the overall performance of the computer system. Thus, many computer systems include cooling systems to regulate the temperature of their electrical components. One type of cooling system is a forced air system that relies on one or more air movers to blow air over the electronic components in order to cool the components.
In many applications, the air movers are positioned near the front or rear of a server chassis and either push or pull air through the chassis. Although effective, as the amount of heat generated by the electronic devices increases the volume of air that is needed for cooling increases. In certain applications, such as high density servers, there is limited free space within the chassis for large fans or for the flow of large volumes of air. Therefore, cooling systems for these applications need to be compact and capable of generating high rates of flow.

BRIEF SUMMARY

The problems noted above are solved in large part by an air mover comprising a housing and a plurality of blades rotatably disposed within the housing. A plurality of guide vanes are fixed within the housing. The guide vanes are thermally coupled to an electronic component such that heat generated by the electronic component is transferred through the guide vanes into an airflow generated by rotating the blades.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of exemplary embodiments of the invention, reference will now be made to the accompanying drawings in which:
FIG. 1 shows a partial section view of an air mover constructed in accordance with embodiments of the invention;
FIG. 2 shows a cross-sectional view of an air mover constructed in accordance with embodiments of the invention;
FIG. 3 shows a cross-sectional view of a heat source coupled to an air mover constructed in accordance with embodiments of the invention;
FIG. 4 shows a cross-sectional view of heat transfer elements integrated into an air mover constructed in accordance with embodiments of the invention;
FIG. 5 shows a cross-sectional view of a heat source directly coupled to an air mover constructed in accordance with embodiments of the invention;
FIG. 6 shows a cross-sectional view of heat source directly coupled to heat transfer elements integrated into an air mover constructed in accordance with embodiments of the invention;
FIG. 7 shows a cross-sectional view of the air mover of FIG. 6;
FIGS. 8 and 9 show a cross-sectional view of a two-part air mover constructed in accordance with embodiments of the invention;
FIG. 10 shows a cross-sectional view of a heat sink coupled to an air mover constructed in accordance with embodiments of the invention; and
FIG. 11 shows an end view of the heat sink of FIG. 10.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, computer companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices and connections.

DETAILED DESCRIPTION

The following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
Referring now to FIG. 1, air mover 10 comprises cylindrical housing 12 surrounding rotating blades 14, stationary guide vanes 16, and motor 18. Motor 18 rotates blades 14 to draw air from inlet 13. The airflow generated by rotating blades 14 is straightened as it moves over stationary guide vanes 16 and travels through exhaust 15 as a primarily axial airflow. Stationary guide vanes 16 reduce disturbances in the airflow as it leaves rotating blades 14. This reduction in disturbances results in higher pressures, increased efficiency, and lower noise levels.
Referring now to FIG. 2, a cross-sectional view of an air mover 20 comprising cylindrical housing 22 surrounding rotating blades 24, stationary guide vanes 26, and motor 28. Stationary guide vanes 26 are constructed from a heat-conductive material so as to act as a heat sink when thermally coupled to a heat source. Stationary guide vanes 26 may be constructed from a highly conductive metal, such as copper, or from some other highly conductive material.
As the highly turbulent airflow generated by rotating blades 24 passes over stationary guide vanes 26, heat is transferred between the stationary guide vanes and the airflow. The amount of heat that can be transferred into the airflow is dependent on properties of the air and the velocity of the airflow. The highly turbulent airflow that passes over stationary guide vanes 26 has a high heat transfer coefficient. Therefore, the airflow can effectively remove large amounts of heat from stationary guide vanes 26. Air mover 20 may comprise a large number of stationary guide vanes 26 having a considerable surface area. In some applications, the heat transfer provided by stationary guide vanes 26 may be used to supplement or eliminate other heat transfer components.
In order to improve performance, the stationary guide vanes of the air mover are thermally coupled to a heat source, such as an electronic device. For example, FIG. 3 illustrates an air mover 30 comprising stationary guide vanes 32 constructed from a heat-conductive material. Air mover 30 also comprises one or more heat pipes 34 that thermally couple stationary guide vanes 32 to a heat-generating electronic component 36. Heat produced by electronic component 36 is transferred through heat pipes 34 to the portion of air mover 30 comprising stationary guide vanes 32. Heat pipes 34 may circumferentially surround the outer surface of air mover 30. Multiple heat pipes 34 may thermally couple air mover 30 to a plurality of electronic components 36, and other heat sources, located throughout an electronic system.
In certain embodiments, the portion of an air mover containing the stationary guide vanes, known as a stator section, may be a molded component including heat transfer elements, such as heat pipes or a coolant loop. The heat transfer elements can be positioned and the stator section molded over them. The mold compound may be a material with a high thermal conductivity, such as a graphite, or carbon fiber, filled plastic molding compound, or a powder metallurgy metallic material. By molding the stator section directly onto heat transfer elements, a very good thermally conductive path to the stationary guide vanes can be achieved. In other embodiments, a metal sleeve may be placed directly over housing. A highly conductive grease or other material may enhance the heat transfer between the housing and an external sleeve. FIG. 4 illustrates an air mover 40 comprising stationary guide vanes 42 constructed from a heat-conductive material. Air mover 40 also comprises integrated heat transfer elements 44 that thermally couple stationary guide vanes 42 to one or more heat-generating electronic components 46.
In some embodiments, a heat-conductive air mover may be directly coupled to an electronic component. FIG. 5 illustrates an air mover 50 comprising stationary guide vanes 52 constructed from a heat-conductive material. Air mover 50 is directly coupled to a heat-generating electronic component 54. Heat generated by electronic component 54 is directly transferred into air mover 50 and dissipated to the airflow through stationary guide vanes 52 as the highly turbulent airflow passes over the stationary guide vanes. In certain embodiments, stationary guide vanes 52 may comprise sufficient surface area to provide all of the cooling needed for the electronic component. A highly conductive grease, or other material, may be disposed between and enhance the heat transfer between air mover 50 and electronic component 54.
To more evenly distribute the heat generated by a directly-coupled electronic component, an air mover may further comprise integral heat transfer elements to distribute the heat around the air mover. FIGS. 6 and 7 illustrate an air mover 60 comprising stationary guide vanes 62 constructed from a heat-conductive material. Air mover 60 is directly coupled to a heat-generating electronic component 64. Heat transfer elements 66 are provided to further increase overall heat transfer by distributing heat from electronic component 64 circumferentially around stationary guide vanes 62. Heat transfer elements 66 may be heat pipes, liquid-filled loops, or other heat transfer systems.
In selected applications, it may be desirable to be able to remove and maintain certain components of an air mover without interrupting the thermal coupling between an electronic component and the air mover. The components of an air mover that require the most routine maintenance are the moving parts, namely the rotating blades and the motor. FIGS. 8 and 9 show an air mover 80 comprising a removable rotor housing 82 and a fixed stator housing 84. Rotor housing 82 comprises intake housing 86, rotating blades 88, and motor 90. Stator housing 84 comprises exhaust housing 92, stationary guide vanes 94, and receptacle 96. Receptacle 96 is operable to receive motor 90 and provide for alignment between the rotor housing 82 and stator housing 84. Quick disconnect electrical and mechanical connectors provide attachment between rotor housing 82 and stator housing 84 while allowing easy removal and replacement of rotor housing 82. In certain embodiments, stator housing 84 may comprise a damper assembly to prevent reverse flow when rotor housing 82 is removed.
In some applications, the heat transfer capacity of the stationary fins may not be sufficient for all of the cooling needs of a system. In these applications, the airflow into or out of the air mover can be further utilized as a heat transfer medium. FIGS. 10 and 11 show an air mover 100 comprising an external, radial heat sink 110. Air mover 100 comprises cylindrical housing 102 surrounding rotating blades 104, stationary guide vanes 106, and motor 108. Radial heat sink 110 comprises center portion 112 and radial fins 114. Radial heat sink 110 is disposed adjacent to the exhaust end of housing 102. A heat pipe or liquid cooling radiator tube may be disposed within center portion 112.
Heat enters center portion 112 through the heat pipe or liquid cooling system that is thermally coupled to a heat source, such as a microprocessor or other electronic device. Heat is rejected from fins 114 into the air moving through air mover 100. Heat sink 110 can be placed at either the inlet or exhaust of an air mover. In certain embodiments, heat sink 110 can be combined with ductwork that improves the flow of air over the radial-finned heat sink. In other embodiments, heat may be transferred to fins 114 from their outer diameter in addition to, or alternatively to, heat from center portion 112.
The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. For example, air movers of different sizes, shapes, and configurations may utilize the principles of the present invention. It is intended that the following claims be interpreted to embrace all such variations and modifications.

Claims

1. An air mover comprising:

a housing;

a plurality of blades rotatably disposed within said housing; and

a plurality of guide vanes fixed within said housing, wherein said guide vanes are thermally coupled to an electronic component such that heat generated by the electronic component is transferred through said guide vanes into an airflow generated by rotating said plurality of blades.

2. The air mover of claim 1 further comprising a heat transfer element that thermally couples said guide vanes to the electronic component.

3. The air mover of claim 2 wherein said heat transfer element comprises a heat pipe.

4. The air mover of claim 2 wherein said heat transfer element comprises a fluid loop.

5. The air mover of claim 2 wherein said heat transfer element is integrated into said housing proximate to said plurality of guide vanes.

6. The air mover of claim 1 wherein said housing is directly coupled to the electronic component.

7. The air mover of claim 1 further comprising a heat sink coupled to said housing.

8. The air mover of claim 7 wherein said heat sink comprises a plurality of fins protruding radially from a center portion.

9. The air mover of claim 1 wherein said plurality of blades are removable from said plurality of guide vanes.

10. A computer assembly comprising:

a electronic component that generates heat;

an air mover comprising a stator housing and a rotor housing, wherein the stator housing is thermally coupled to said electronic component;

a plurality of rotating blades disposed within the rotor housing;

a motor coupled to said plurality of rotating blades, wherein said motor is disposed within the rotor housing;

a plurality of stationary guide vanes disposed within the stator housing such that an airflow generated by said rotating blades passes across said guide vanes.

11. The computer assembly of claim 10 wherein the rotor housing of said air mover is detachable from the stator housing of said air mover.

12. The computer assembly of claim 10 further comprising a heat transfer element that thermally couples the stator housing of said air mover to said electronic component.

13. The computer assembly of claim 10 wherein the stator housing of said air mover is directly coupled to said electronic component.

14. The computer assembly of claim 10 wherein the stator housing of said air mover further comprises integral heat transfer elements.

15. The computer assembly of claim 14 wherein said heat transfer elements comprise a fluid loop.

16. The computer assembly of claim 14 wherein said heat transfer elements comprise a heat pipe.

17. A heat transfer method comprising:

thermally coupling a plurality of stationary guide vanes to a heat generating component;

rotating a plurality of blades so as to generate an airflow; and

passing the airflow across the plurality of stationary guide vanes so as to straighten the airflow and transfer heat from the stationary guide vanes into the airflow.

18. The heat transfer method of claim 17 wherein the stationary guide vanes are thermally coupled to the heat generating component by a heat pipe.

19. The heat transfer method of claim 17 further comprising passing the airflow over a heat sink comprising a plurality of fins protruding radially from a center portion that is thermally coupled to a heat source.

20. The heat transfer method of claim 17 wherein the plurality of stationary guide vanes are disposed within a housing that is directly coupled to the heat generating component.