Noise attenuation assembly

• US 6,913,112 B2
• Filed: 02/05/2003
• Issued: 07/05/2005
• Est. Priority Date: 02/05/2003
• Status: Expired due to Term

• Current Assignee: ET US Holdings LLC
• Original Assignee: Arvin Technologies, Inc. (Meritor, Inc. (Nevada))
• Inventors: Bogard, Joseph T.
• Primary Examiner(s): HSIEH, SHIH YUNG
• Application Number:
  US10/358,511
• Publication Number:
  US 20040149514A1
• Time in Patent Office: 881 Days
• Field of Search: 181/252, 181/247, 181/248, 181/258
• US Class Current: 181/252
• CPC Class Codes: F01N 1/003 by using dead chambers communicating with gas flow passages resonance chambers F01N1/02; chambers containing sound-absorbing materials F01N1/24
• CPC Class Codes: F01N 1/04 having sound-absorbing materials in resonance chambers
• CPC Class Codes: F01N 1/10 in combination with sound-absorbing materials F01N1/125 takes precedence

Abstract

The present invention provides a noise attenuation assembly having at least one noise prevention pad disposed within an annular gap formed between a gas passage tube and an overlap tube. The noise prevention pad prevents the two tubes from coming in contact during thermal expansion of the tubes, and allows the tubes to contract without causing “tick and ping” noise, during a cool down.

Claims

1. A noise attenuation assembly comprising:

a shell defining an interior chamber;

a passage tube having an inlet end coupled to a first end of said shell and an outlet end coupled to a second end of said shell;

an overlap tube concentric to and surrounding an overlap portion of said passage tube, said overlap tube forming an annular gap with said overlap portion of said passage tube, said overlap portion of said passage tube defining at least one opening in communication with said annular gap, said annular gap having a closed end and on open end in communication with said interior chamber; and

at least one noise prevention pad disposed within said annular gap, said at least one noise prevention pad having a first surface in contact with said overlap portion of said passage tube, and a second surface in contact with said overlap tube wherein said passage tube has an inner wall defining a gas passage and an outer wall having said at least one noise prevention pad attached thereon, said at least one noise prevention pad being spot welded to said outer wall of said passage tube.

2. The noise attenuation assembly of claim 1, wherein said at least one noise prevention pad comprises a plurality of noise prevention pads with each noise prevention pad being spaced along a circumference of said outer wall at said passage tube, forming a plurality of channels between said plurality of noise prevention pads.

3. The noise attenuation assembly of claim 1, wherein said at least one noise prevention pad is made of a heat resistant material.

4. The noise attenuation assembly of claim 3, wherein said at least one noise prevention pad includes a steel wool pad.

5. The noise attenuation assembly of claim 3 wherein said at least one noise prevention pad includes a stainless steel wool pad.

6. The noises attenuation assembly of claim 5, wherein said stainless steel wool pad defines fine needles protruding from said first surface.

7. The noise attenuation assembly of claim 3, wherein said at least one noise prevention pad is a ceramic material.

8. A pipe assembly comprising:

an inner pipe defining a first gas passage;

an outer pipe defining a second gas passage, said outer pipe having an overlap portion surrounding an overlap portion of said inner pipe, said second gas passage in communication with said first gas passage of said inner pipe, said overlap portion of said inner and said outer pipes forming an annular gap open at an overlap end of said outer pipe; and

at least one noise prevention pad disposed within said annular gap keeping said overlap portions of said inner and said outer pipes from coming in contact wherein said inner pipe has an outer wall and said at least one noise prevention pad is attached thereon.

9. The pipe assembly of claim 8, wherein said at least one noise prevention pad is spot welded said outer wall said inner pipe.

10. The pipe assembly of claim 8, wherein said at least one noise prevention pad comprises a plurality of noise prevention that are each disposed along a circumference of said outer wall of said inner pipe, leaving a plurality of channels therebetween for sound communication.

11. A noise attenuation assembly comprising:

a first rigid tube defining a first gas passage;

a second rigid tube defining a second gas passage in fluid communication with said first gas passage, said second rigid tube surrounding at least a portion of said first rigid tube to define an overlap portion;

wherein said second rigid tube is spaced apart from said first rigid tube at said overlap portion to form an annular gap; and

at least one noise prevention pad disposed within said annular gap wherein said at least one noise prevention pad is mounted to an external surface of said first rigid tube.

12. The noise attenuation assembly of claim 11 wherein said at least one noise prevention pad includes a first surface in direct contact with said first rigid tube and a second surface in direct contact with said second rigid tube.

13. The noise attenuation assembly of claim 11 wherein said at least one noise prevention pad is mounted to an internal surface of said second rigid tube.

14. The noise attenuation assembly of claim 11 wherein said at least one noise prevention pad includes a heat resistant material.

15. The noise attenuation assembly of claim 11 wherein said first and said second rigid tubes move relative to one another in response to changes in temperature.

16. The noise attenuation assembly of claim 15 wherein said second rigid tube has at least one tube end portion spaced apart from said first rigid tube and wherein said at least one noise prevention pad engages said first and said second rigid tubes to prevent contact between said first and second rigid tubes at said at least one tube end portion during relative movement between said first and said second rigid tubes resulting from changes in temperature.