Noise suppression systems

Patent metadata

Field	Value
Publication number	US-10077707-B2
Application number	US-201715623913-A
Country	US
Kind code	B2
Filing date	Jun 15, 2017
Priority date	Mar 15, 2013
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

An apparatus or system includes a component that generates or transfers noise having a frequency within a noise frequency range. The component may include a boundary. The apparatus or system may be an engine in some examples. The engine may additionally include a micro-perforated sheet positioned a distance from the boundary. The micro-perforated sheet may include a plurality of micro-perforated holes, and may be configured to absorb sound within an absorption frequency range based on parameters of the micro-perforated sheet. The parameters may include the distance from the boundary and dimensions of the micro-perforated holes, and may be set such that the absorption frequency range overlaps the noise frequency range.

First claim

What is claimed is:

1. A muffler comprising:
a body including a first end, an opposing second end, and an internal cavity;
a first micro-perforated end cap affixed to the first end and defining a first exterior surface, the first micro-perforated end cap comprising a first micro-perforated sheet having a plurality of micro-perforated holes, the first micro-perforated sheet configured to absorb sound within an absorption frequency range based on parameters of the first micro-perforated sheet; and
a second end cap affixed to the second end and defining a second exterior surface.

2. The muffler according to claim 1 , wherein the first micro-perforated end cap is configured as a micro-perforated panel comprised of the first micro-perforated sheet spaced a first distance from a solid boundary end wall.

3. The muffler according to claim 2 , wherein the first distance is selected to form a panel cavity depth that absorbs sound within the absorption frequency range.

4. The muffler according to claim 1 , wherein the parameters include the diameters and spacing of the micro-perforated holes set such that the absorption frequency range overlaps a noise frequency range experienced by the muffler.

5. The muffler according to claim 4 , wherein the parameters are set such that the absorption frequency range overlaps a portion of the noise frequency range consisting of sound between 200-800 Hz for tonal noise and sound between 800-4000 Hz for flow noise.

6. The muffler according to claim 1 , wherein the second end cap is a micro-perforated end cap, the second micro-perforated end cap comprising a second micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the second micro-perforated sheet.

7. The muffler according to claim 1 , wherein the body comprises cylindrical sidewalls extending between the first and second ends.

8. The muffler according to claim 7 , further comprising a micro-perforated cylindrical wrap extending along a length of the body and conforming in shape to the cylindrical sidewalls.

9. The muffler according to claim 1 , further comprising a first micro-perforated baffle positioned in the internal cavity of the body, the first micro-perforated baffle comprising a micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the micro-perforated sheet.

10. The muffler according to claim 9 , wherein the first micro-perforated baffle is spaced apart from the first micro-perforated end cap forming a first chamber therebetween, the first chamber dimensioned to absorb sound within the absorption frequency range.

11. The muffler according to claim 10 , further comprising a second micro-perforated baffle positioned in the internal cavity of the body and spaced apart from the first micro-perforated baffle forming a second chamber therebetween, the second micro-perforated baffle comprising a micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the micro-perforated sheet.

12. The muffler according to claim 11 , wherein the second micro-perforated baffle is spaced apart from the second micro-perforated end cap forming a third chamber therebetween, the second and third chambers dimensioned to absorb sound within the absorption frequency range.

13. The muffler according to claim 1 , wherein the micro-perforated holes of the first micro-perforated end cap including a first set of holes of a first diameter and first spacing, and a second set of holes a second diameter and second spacing different than the first diameter and first spacing.

14. A muffler comprising:
a body including a first end, an opposite second end, and an internal cavity;
a first end cap affixed to the first end and defining an exterior surface;
a second end cap affixed to the second end and defining an exterior surface; and
a first micro-perforated baffle positioned in the internal cavity of the body between the first and second ends, the first micro-perforated baffle comprising a first micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within an absorption frequency range based on parameters of the micro-perforated sheet;
wherein the first end cap is a micro-perforated end cap, the first micro-perforated end cap comprising a first micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the first micro-perforated sheet.

15. The muffler according to claim 14 , wherein the first micro-perforated baffle is spaced apart from the first end cap forming a first chamber therebetween, the first chamber dimensioned to absorb sound within the absorption frequency range.

16. The muffler according to claim 15 , further comprising a second micro-perforated baffle positioned in the internal cavity of the body and spaced apart from the first micro-perforated baffle and the second end cap, the second micro-perforated baffle comprising a micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the micro-perforated sheet.

17. The muffler according to claim 16 , wherein the second micro-perforated baffle forms a second chamber between the second end cap and the second micro-perforated baffle, and a third chamber between the second micro-perforated baffle and the first micro-perforated baffle, the end cap, wherein the second and third chambers are each dimensioned to absorb sound within the absorption frequency range.

18. A muffler comprising:
a body including a first end, an opposing second end, and an internal cavity;
a first micro-perforated end cap affixed to the first end and defining a first exterior surface, the first micro-perforated end cap comprising a first micro-perforated sheet having a plurality of micro-perforated holes, the first micro-perforated sheet configured to absorb sound within an absorption frequency range based on parameters of the first micro-perforated sheet; and
a second end cap affixed to the second end and defining a second exterior surface;
wherein the second end cap is a micro-perforated end cap, the second micro-perforated end cap comprising a second micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the second micro-perforated sheet.

19. The muffler according to claim 18 , further comprising a first micro-perforated baffle positioned in the internal cavity of the body, the first micro-perforated baffle comprising a micro-perforated sheet having a plurality of micro-perforated holes configured to absorb sound within the absorption frequency range based on parameters of the micro-perforated sheet.

20. The muffler according to claim 19 , wherein the first micro-perforated baffle is spaced apart from the first micro-perforated end cap forming a first chamber therebetween, the first chamber dimensioned to absorb sound within the absorption frequency range.

Assignees

• Kohler Co

Inventors

• Le Roy Tyler W
• Baumann Todd A
• Snyder Dale D
• Adams Amy

Classifications

• F04D29/4213

  suction ports · CPC title

• F04D29/665

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• F04D29/582 Primary

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• F01P11/12 Primary

  Filtering, cooling, or silencing cooling-air · CPC title

• F04D29/424

  Double entry casings · CPC title