Quiet active fan for servers chassis

Abstract

An Active Muffler in the form of a duct having two open ends for conveying air from a within a cabinet to outside the cabinet. A fan or blower is incorporated in the duct. An Automatic Noise Control (ANC) unit is associated with the duct, and at least one microphone and at least one speaker are incorporated in to the duct for noise-reduction. An outer portion of the duct may be sound-absorbing material. the ANC unit may cause noise to be shifted to a frequency that can be absorbed by the sound-absorbing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made in detail to embodiments of the disclosure, examples of which may be illustrated in the accompanying drawing figures (FIGs.). The figures are intended to be illustrative, not limiting. Although the disclosure is generally described in the context of these embodiments, it should be understood that it is not intended to limit the disclosure to these particular embodiments.

Certain elements in selected ones of the figures may be illustrated not-to-scale for illustrative clarity. Certain ones of the drawings may be stylized for illustrative clarity. For example, an element which is hidden (such as in a perspective view) may be illustrated with solid lines, rather than dashed lines.

FIG. 1 is a diagram illustrating an ANC system, generally.

FIG. 2 is a block diagram of an ANC controller, generally, such as for the ANC system of FIG. 1.

FIG. 3 is a flow chart of a method for reducing the effects of a noise source, such as may be implemented in the ANC controller of FIG. 2.

FIG. 4 is a diagram of a cabinet for mounting electronic equipment (referred to herein as “blade chassis”), with an active muffler installed to control noise generated within the blade chassis.

FIG. 5 is a perspective view of an embodiment of an active linear muffler (ALM).

FIG. 6 is a perspective view of an embodiment of an active angular muffler (AAM).

Claims

1. An active muffler for a server chassis, comprising: a duct having an overall form of a rectangular prism comprising an inner portion for being disposed within the interior of a server chassis and an outer portion for protruding from the server chassis;the inner portion and the outer portion are contiguous with one another and together comprise the duct for moving air from within the server chassis to without the server chassis.

2. The active muffler of claim 1, further comprising: a blower disposed within the inner portion for drawing air from within the chassis into the inner portion, and for moving the air through the outer portion to the atmosphere.

3. The active muffler of claim 1, further comprising: passive materials to treat noise, especially at or above 1000 Hz; andan active noise control (ANC) system to reduce noise, especially at or below 1000 Hz.

4. The active muffler of claim 1, further comprising: a microphone for monitoring noise within the muffler; anda speaker for emitting anti-noise.

5. The active muffler of claim 1, wherein: the microphone is mounted within the outer portion of the muffler.

6. The active muffler of claim 1, wherein: the microphone is mounted within the inner portion of the muffler.

7. The active muffler of claim 1, wherein: the speaker is mounted within the outer portion of the muffler.

8. The active muffler of claim 1, wherein: the speaker is mounted within the inner portion of the muffler.

9. The active muffler of claim 1, wherein: the inner and outer portions are arranged in a linear configuration, thereby forming an active linear muffler (ALM).

10. The active muffler of claim 1, wherein: the inner and outer portions are arranged in an angular configuration, thereby forming an active angular muffler (AAM).

11. The active muffler of claim 1, wherein: the inner portion is formed of sheet metal.

12. The active muffler of claim 1, wherein: the outer portion is formed of a sound-absorbing material.

13. The active muffler of claim 12, wherein: the outer portion is covered with sheet metal to give it rigidity.

14. The active muffler of claim 1, wherein: the inner portion is generally in the overall form of a rectangular prism and has the following dimensions: length (L1), approximately 250 mm,width (W), approximately 205 mm,height (H), approximately 100 mm,the outer portion is generally in the overall form of a rectangular prism and has the following dimensions: length (L2), approximately 150 mm,width (W), approximately 205 mm,height (H), approximately 100 mm.

15. The active muffler of claim 1, wherein: the inner portion and the outer portion have approximately the same width (W) and height (H), and are aligned lengthwise.

16. The active muffler of claim 1, wherein: a front side of the inner portion is open and contiguous with a corresponding open rear side of the outer portion.

17. The active muffler of claim 1, wherein: a front end of the outer portion has an exhaust opening for exhausting air to the atmosphere.

18. The active muffler of claim 1, wherein: a side surface of the outer portion has an exhaust opening for exhausting air to the atmosphere.

19. The active muffler of claim 1, wherein: a rear side of the inner portion has an “intake” opening for receiving air from within the chassis.

20. Method of reducing noise from a server chassis, comprising: providing a duct comprising an inner portion disposed within the chassis and an outer portion extending outside of the chassis;providing a blower within the inner portion for drawing air from within the chassis into the inner portion, and for moving the air through the outer portion to the atmosphere;forming the duct at least partially of passive materials to treat noise, especially at or above 1000 Hz; andproviding an active noise control (ANC) system to reduce noise, especially at or below 1000 Hz.

21. The method of claim 20, wherein the ANC system comprises: at least one microphone for monitoring noise within the muffler; andat least one speaker for emitting anti-noise.

22. The method of claim 21 wherein; a selected on of the at least one microphones the microphone is mounted within the outer portion of the muffler.

23. The method of claim 21 wherein; a selected on of the at least one microphones the microphone is mounted within the inner portion of the muffler.

24. The method of claim 21 wherein; a selected one of the at least one speakers is mounted within the outer portion of the muffler.

25. The method of claim 21 wherein; a selected on of the at least one speakers is mounted within the inner portion of the muffler.

26. The method of claim 20, wherein: the inner portion is formed of sheet metal.

27. The method of claim 20, wherein: the outer portion is formed of a sound-absorbing material.

28. The active muffler of claim 27, wherein: the outer portion is covered with sheet metal to give it rigidity.

29. The method of claim 20, wherein: the active noise control (ANC) system is capable of shifting noise to a frequency which can be absorbed by the passive materials.