silencer

Abstract

Silencer (108) comprising: a first pipe (210) defining a first inlet (212) for receiving exhaust gas and a first outlet (214); wherein the first outlet (214) of the first pipe (210) has a diameter (D1); a housing (200) comprising a closed tuning chamber (260); a second pipe (220) which is at least partially received in the first outlet (214) of the first pipe (210), wherein the second pipe (220) has a second inlet (222) which is arranged in the first pipe (210) and defines a first exhaust gas path through the second pipe (220), and wherein the second pipe (220) has a second outlet (224) which is arranged in flow communication with the tuning chamber (260); and a silencer outlet (270) for releasing exhaust gas from the silencer (108); wherein the first pipe (210) and the second pipe (220) define an annular passage (230) between them and a second exhaust gas path;wherein the annular passage (230) defines the first outlet (214) of the first pipe (210) and is arranged in flow communication with the silencer outlet (270); and wherein the first exhaust path leads into the tuning chamber (260) and wherein the second exhaust path leads through the first outlet (214) and the silencer outlet (270).

Description

TECHNICAL FIELDThe present disclosure relates to a vehicle exhaust system. More particularly, the present disclosure relates to a muffler of the vehicle exhaust system.BACKGROUNDA vehicle exhaust system introduces exhaust gas generated by an internal combustion engine into the external environment. The exhaust system may include various components such as piping, catalysts, filters, and the like. During operation of the exhaust system, the components may generate undesirable sound due to resonant frequencies. Various methods have been used in various applications to address this issue.For example, the components such as tuning chambers, valves, and the like have been incorporated into the exhaust system to attenuate certain resonant frequencies generated by the exhaust system. However, such additional components are expensive and add weight to the exhaust system. Moreover, by adding new components to the exhaust system, new undesired sound sources may be introduced.One widely known method of acoustic attenuation is the use of tuning chambers in acoustic absorbers to reduce the exhaust sound level. Such conventional tuning chambers can increase the design complexity and size of the mufflers. Further, conventional tuning chambers may not be able to effectively attenuate sound at certain frequencies, such as low frequency sound.U.S. Pat. No. 4,924,966 A already discloses a silencer of a vehicle exhaust system having a plurality of pipes arranged coaxially or in parallel.Thus, there is a need for an improved muffler for a vehicle exhaust system for such applications. The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.SUMMARYThe object of the present invention is achieved by sound absorbers according to the main claims. The dependent claims relate to preferred embodiments of the invention. In one aspect of the present disclosure, a silencer comprises a first pipe defining a first inlet for receiving exhaust gas and a first outlet. The silencer comprises a housing having a closed tuning chamber. The silencer comprises a second tube received at least partially in the first outlet of the first tube. Further, the second tube has a second inlet disposed in the first tube and defining a first exhaust path through the second tube, and wherein the second tube has a second outlet disposed in flow communication with the tuning chamber. The silencer comprises a silencer outlet for discharging exhaust gas from the silencer. Moreover, the first tube and the second tube define an annular passage therebetween and a second exhaust path. The annular passage defines the first outlet of the first tube and is disposed in flow communication with the muffler outlet. The first exhaust path leads into the tuning chamber and the second exhaust path leads through the first outlet and the muffler outlet.In another aspect of the present disclosure, a silencer includes a housing and a first partition disposed in the housing. The first partition and the housing define a first tuning chamber therebetween. The silencer further comprises a second partition disposed in the housing and spaced from the first partition. The second partition wall and the housing define a second tuning chamber therebetween. The first partition, the second partition, and the housing define an expansion chamber disposed between the first tuning chamber and the second tuning chamber. The silencer comprises a first tube at least partially accommodated in the housing. The first tube defines a first inlet for receiving exhaust gas and a first outlet disposed in flow communication with the expansion chamber. The silencer comprises a second tube at least partially received in the first tube. The second tube has a second inlet disposed in the first tube and defining a first exhaust path through the second tube, and has a second outlet disposed in flow communication with the first tuning chamber. The muffler further includes a third pipe defining a third inlet in flow communication with the expansion chamber and having a muffler outlet for exhausting exhaust gas from the housing. The first tube and the second tube define an annular passage therebetween. The annular passage defines the first outlet of the first tube and is disposed in flow communication with the third inlet. The first exhaust path leads into the tuning chamber and the second exhaust path leads through the first outlet and the muffler outlet.In yet another aspect of the present disclosure, a silencer includes a housing and a first partition disposed in the housing. The first partition and the housing define a first tuning chamber therebetween. The silencer further comprises a second partition disposed in the housing and spaced from the first partition. The second partition wall and the housing define a second tuning chamber therebetween. The first partition, the second partition, and the housing define an expansion chamber disposed between the first tuning chamber and the second tuning chamber. The silencer further comprises a first tube at least partially accommodated in the housing. The first tube defines a first inlet for receiving exhaust gas and a first outlet disposed in flow communication with the expansion chamber. The first tube extends through the second partition, and a second tube is at least partially received within the first tube. The second tube defines a second inlet disposed in the first tube and a second outlet disposed in flow communication with the first tuning chamber. The second tube extends through the first partition. The muffler further includes a third pipe defining a third inlet in fluid communication with the expansion chamber and a muffler outlet for exhausting exhaust gas from the housing. The third tube extends through the first partition, the second partition, and the housing. The silencer comprises a fourth pipe establishing a flow connection of the first tuning chamber with the second tuning chamber. The fourth tube extends through the first partition and the second partition. The first tube and the second tube define an annular passage therebetween. The annular passage is disposed in flow communication with the first outlet and permits the flow of exhaust gas therethrough.Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It is to be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic illustration of a vehicle exhaust system according to an aspect of the present disclosure; FIG. 2 is a schematic cross-sectional view of a muffler of the vehicle exhaust system of FIG. 1, in accordance with an aspect of the present disclosure; FIG. 3 is a perspective view of a muffler of the vehicle exhaust system of FIG. 1 according to another aspect of the present disclosure; FIG. 4 is a perspective view of the interior of the muffler of FIG. 3 according to another aspect of the present disclosure; and FIG. 5 is a cross-sectional view of the silencer of FIG. 4 according to an aspect of the present disclosure.DETAILED DESCRIPTIONThe following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Referring now to the drawings, wherein like reference numerals designate like or corresponding parts throughout the several views, and wherein:. Referring to FIG. 1, a schematic illustration of a vehicle exhaust system 100 is shown. The vehicle exhaust system 100 will be referred to interchangeably herein as the "system 100". The system 100 is fluidly coupled to an engine 102. The engine 102 may be any internal combustion engine operated with fuel, such as diesel, gasoline, natural gas, and / or a combination thereof. Accordingly, the system 100 receives exhaust gas generated by the engine 102.The system 100 includes a number of downstream exhaust components 104 fluidly coupled to the engine 102. The exhaust components 104 may include a number of systems / components (not shown) such as a diesel oxidation catalyst (DOC), a diesel exhaust fluid (DEF) unit, a selective catalytic reduction (SCR) unit, a particulate filter, an exhaust pipe, an active valve, a passive valve, an exhaust heat recovery system (EGHR), and the like. The outlet components 104 may be mounted in a variety of different configurations and combinations based on application requirements and / or available packaging space. The exhaust components 104 are configured to receive the exhaust gas from the engine 102 and direct the exhaust gas to the outside atmosphere via a tailpipe 106. The exhaust components 104 are configured to reduce emissions and control sound and may also be used for thermal management.In another embodiment, the engine 102 may be part of a hybrid system, i.e., the engine 102 may be operatively coupled to an electric motor and a battery. Further, the exhaust components 104 of the system 100 may be operating only when the engine 102 is combusting fuel and not operating when the engine 102 is not running.The system 100 further includes an acoustic attenuator, such as an attenuator 108. The muffler 108 is provided in flow communication with the outlet components 104 and the tailpipe 106. In the illustrated embodiment, the muffler 108 is disposed downstream of the outlet components 104 and upstream of the tail pipe 106. In further embodiments, the muffler 108 may be arranged in any sequence with respect to each of the outlet components 104 and / or the tail pipe 106 based on application requirements. The silencer 108 is configured to dampen resonant frequencies generated during operation of the engine 102 and the system 100.FIG. 2 illustrates a first pipe 210 and a second pipe 220 of the muffler 108 according to an aspect of the present disclosure. The muffler 108 includes the first pipe 210 defining a first inlet 212 for receiving exhaust gas and a first outlet 214. The first inlet 212 is fluidly coupled to the outlet components 104 (shown in FIG. 1 ). The silencer 108 includes a housing 200 defining a tuning chamber 260 (alternatively, a first tuning chamber 260). According to the invention, the tuning chamber 260 is a closed chamber. The silencer 108 includes the second tube 220 at least partially received in the first tube 210. The first pipe 210 and the second pipe 220 overlap each other over an overlap distance D. Further, the second tube 220 defines a second inlet 222 disposed in the first tube 210 and a second outlet 224 disposed in flow communication with the tuning chamber 260. The muffler 108 includes a muffler outlet 270 (alternatively, a third outlet 270) for discharging exhaust gas from the muffler 108. FIG. 2 merely illustrates a schematic illustration of the muffler outlet 270, while FIG. 4 illustrates a preferred illustration of the muffler outlet 270. The muffler outlet 270 is fluidly coupled to the tail pipe 106 (shown in FIG. 1 ) for discharging a stream of exhaust gases 240. Moreover, the first tube 210 and the second tube 220 define an annular passage 230 therebetween. The annular passage 230 is disposed in flow communication with the first outlet 214 of the first tube 210 and the muffler outlet 270.As shown in FIG. 2, the first tube 210 has a diameter D 1 and the second tube 220 has a diameter D 2. The diameter D 1 of the first tube 210 is greater than the diameter D 2 of the second tube 220 such that there is a desired flow of the exhaust gases 240 passing through the annular passage 230 between the first tube 210 and the second tube 220. The difference between the diameters D 1, D 2 of the first and second pipes 210, 220 may depend on various factors, such as desired backpressure reduction, frequency domain attenuation level, mikatability, packaging space, durability requirements, modal requirements, or any other factor associated with the system 100 (shown in FIG. 1 ). Backpressure may be a function of the mass flow rate of exhaust gases 240 flowing through the muffler 108. In various cases, the mass flow rate may be 100% of engine flow or a percentage of engine flow, such as 50%. In some embodiments, the diameter D 1 of the first tube 210 may be about 55 mm. Further, the diameter D 2 of the second tube 220 may be about 45 mm. Further, a thickness and a length of the second tube 220 may be about 1.2 mm and 145 mm, respectively.The first tube 210 and the second tube 220 are generally illustrated as cylindrical straight tubes, however, the first tube 210 and the second tube 220 may have a different shape or arrangement in some embodiments. More specifically, the first tube 210 and the second tube 220 may have a non-linear shape, such as curved, a combination of linear and curved portions, and the like. Further, there may be one or more indentations (not shown) disposed between the first tube 210 and the second tube 220 such that the first tube 210 and the second tube 220 are in contact due to the indentations. This may ensure proper alignment and prevent any unintentional movement of the second tube 220 within the first tube 210, particularly when the muffler 108 is in operation. In the illustrated embodiment, the second tube 220 is concentrically disposed within the first tube 210. However, in some other embodiments, the second tube 220 may be eccentrically disposed in the first tube 210.As shown, the exhaust gases 240 pass through the annular passage 230 between the first tube 210 and the second tube 220, while propagating sound waves 250 through the second tube 220 for desired attenuation in the tuning chamber 260. Depending on the design, there may be a small portion of the exhaust gases 240 flowing through the second tube 220 while allowing the sound waves 250 to propagate through the second tube 220. This flow of exhaust gases 240 may result from leakage from tuning chamber 260. Leakage from tuning chamber 260 may occur due to condensate holes / condensate channel or due to holes in a partition. The exhaust gases 240 flowing through the second tube 220 may be a fraction (less than 50%) of the total exhaust gas flow 240. This results in a "Helmholtz effect" as would be apparent to one of ordinary skill in the art. As used herein, the "Helmholtz effect" as used in the present disclosure is produced by a combination of a tuning device and / or an enclosed volume / chamber for tuning the sound waves 250 in the sound attenuator 108. The present disclosure includes two conduits (i.e., the first tube 210 and the second tube 220) concentrically disposed therebetween with the annular passage 230 to allow the flow of the exhaust gases 240 while the sound waves 250 are tuned by the combination of the tuning device (i.e., the second tube 220) and the enclosed volume / chamber (i.e., the tuning chamber 260).In some embodiments, the first tube 210 and the second tube 220 may have depressions (not shown) on the overlay line D. The recesses may have a diameter which depends on the performance requirements, while the number of recesses on the superposition line D may be any suitable number. Further, the overlap distance D between the first tube 210 and the second tube 220 may be about 50 mm. Moreover, the first tube 210 and the second tube 220 may be mechanically joined together by welding and / or fasteners and / or bonding. Further, the length of the second lower frequency sound tuning tube 220 may be increased, e.g., the length of the second tube 220 may be increased by 80 mm or by any other amount as required.FIG. 3 illustrates another embodiment of the muffler 108. As shown in FIG. 3, the muffler 108 includes a housing 300. The silencer 108 comprises a first partition wall 400 arranged in the housing 300. The first partition wall 400 and the housing 300 define a first tuning chamber 360 therebetween. The silencer 108 includes a second partition 410 disposed in the housing 300 and spaced from the first partition 400. The second partition 410 and the housing 300 define a second tuning chamber 430 (alternatively, another tuning chamber 430) therebetween. The first partition 400, the second partition 410, and the housing 300 define an expansion chamber 420 disposed between the first tuning chamber 360 and the second tuning chamber 430.The housing 300 may have a two-part arrangement, wherein a part of the two-part housing 300 may be removed to access the interior of the housing 300 as shown in FIG. 4. FIG. 5 illustrates a sectional view of the muffler 108 shown in FIG. 4. Referring to FIGS. 3, 4, and 5, the housing 300 includes a first inlet 312 for receiving exhaust gas from the engine 102 (shown in FIG. 1 ) and a third outlet 370 for exhausting the exhaust gas from the housing 300. The third outlet 370 is interchangeably referred to as "the muffler outlet 370.". As shown in FIG. 4, the housing 300 defines the expansion chamber 420 and the first tuning chamber 360 different from the expansion chamber 420. The first tuning chamber 360 is synonymous with "the tuning chamber 360". The silencer 108 comprises a first pipe 310 which is at least partially accommodated in the housing 300, in particular in the second tuning chamber 430. The first tube 310 defines the first inlet 312 and a first outlet 314. The first tube 310 defines the first inlet 312 for receiving exhaust gas and the first outlet 314 disposed in flow communication with the expansion chamber 420. The first tube 310 extends through the second partition 410. The silencer 108 includes a second tube 320 at least partially received in the first tube 310.The second tube 320 includes a curved portion 321 adjacent to the first inlet 312. The silencer 108 further comprises a second tube 320. The second tube 320 defines a second inlet 322 and a second outlet 324. The second inlet 322 is disposed in the first pipe 310. The second outlet 324 is disposed in fluid communication with the first tuning chamber 360. The second tube 320 extends through the first partition 400. In the illustrated embodiment, the first tube 310 and the second tube 320 are concentrically arranged with respect to each other. The silencer 108 further comprises the first partition wall 400 arranged in the housing 300. The first partition wall 400 separates the tuning chamber 360 from the expansion chamber 420. Further, the first outlet 314 of the first pipe 310 is in fluid communication with the expansion chamber 420, and the expansion chamber 420 is in fluid communication with the muffler outlet 370. The silencer 108 further comprises a second partition 410 arranged in the housing 300. The second partition wall 410 separates the expansion chamber 420 from the other tuning chamber 430 so that the expansion chamber 420 is disposed between the tuning chamber 360 and the other tuning chamber 430. Moreover, the first tube 310 extends through the second partition 410. The present disclosure illustrates the first partition wall 400 and the second partition wall 410 partitioning the housing 300 into the first tuning chamber 360, the expansion chamber 420, and the second tuning chamber 430, however, the present disclosure may be implemented with any other arrangement or number of partitions and / or chambers.The first tube 310 and the second tube 320 define an annular passage 330 therebetween. The annular passage 330 is disposed in flow communication with the first outlet 314 and permits the flow of exhaust gas therethrough.As shown, in the present disclosure, the second tube 320 extends into the tuning chamber 360. However, in other embodiments, the second tube 320 may be substantially flush with the first partition 400. Various arrangements of the second pipe 320 may depend on acoustic requirements, expected exhaust flow through the first pipe 310 and the second pipe 320, or any other factor associated with the muffler 108.The muffler 108 further includes a third pipe 440 defining a third inlet 442 in flow communication with the expansion chamber 420 and the muffler outlet 370. The third tube 440 extends through the first partition 400, the second partition 410, and the housing 300. In addition, the muffler outlet 370 is disposed adjacent to the housing 300. As shown, a fourth tube 460 fluidly connects the first tuning chamber 360 to the second tuning chamber 430. The fourth tube 460 extends through the first partition 400 and the second partition 410. In some embodiments, a length of the first tuning chamber 360 may be about 149 mm, while the lengths of the expansion chamber 420 and the second tuning chamber 430 may be about 136 mm and 144.7 mm, respectively. A volume of the fourth tube 460 may affect the tuning frequencies of the first tuning chamber 360 and the second tuning chamber 430. For example, if the volume of the fourth pipe 460 is small compared to the tuning chamber volume, the fourth pipe 460 may reduce the tuning frequency of the first tuning chamber 360 and increase the tuning frequency of the second tuning chamber 430. However, when the volume of the fourth tube 460 is large (e.g., greater than 50% of the tuning chamber volume), the first and second tuning chambers 360, 430 may effectively function as a single tuning chamber having an effective tuning frequency that is less than the individual tuning frequencies of the first and second tuning chambers 360, 430.During operation, a flow of exhaust gases 540 occurs through the first inlet 312 of the housing 300 and flows through the first tube 310 before moving through the annular passage 330 between the first tube 310 and the second tube 320. Propagation of sound waves 550 through the second tube 320 and then through the expansion chamber 420 may result in acoustic attenuation. The exhaust gases 540 then travel within the expansion chamber 420 before entering the third tube 440 through the third inlet 442. The third tube 440 conveys the exhaust gases 540 to the third outlet 370 for exhausting the exhaust gases 540 from the housing 300. In some cases, a portion of the exhaust gases 540 may enter the first tuning chamber 360, from where the exhaust gases 540 may move to the second tuning chamber 430 through the fourth tube 460. In particular, the fourth tube 460 may allow any exhaust gases 540 to flow from the first tuning chamber 360 to the second tuning chamber 430. Then, the exhaust gases 540 in the second tuning chamber 430 may enter the third tube 440 through one or more openings 446 of the third tube 440. Preferably, two apertures 446 are provided at diametrically opposite ends of the third tube 440. The number of openings 446 may vary based on factors such as exhaust flow volume, noise attenuation requirements. The exhaust gases 540 then move within the third tube 440 to move out of the housing 300 through the third outlet 370, as previously mentioned. In some embodiments, the third tube 440 may include one or more openings 446 as required by the engine 102 or the muffler 108. The openings 446 may be provided to remove the small amounts of exhaust gases 540 that may be present in the second tuning chamber 430. The openings 446 may allow the exhaust gases 540 in the second tuning chamber 430 to enter the third tube 440 through the openings 446 and exit it through the third outlet 370.In some embodiments, the size of the openings 446 may be about 8 mm. The apertures 446 may provide advantages such as preventing or mitigating some standing waves in the third tube 440, or any other advantage as would be apparent to one of ordinary skill in the art.The fourth tube 460 may also transport the sound waves 550 from the first tuning chamber 360 to the second tuning chamber 430. The sound waves 550 can then be attenuated by reflection. In some embodiments, the combination of the tuning chamber 360 and the other tuning chamber 430 increases the tuning efficiency of the silencer 108 and provides flexibility to optimize and balance acoustic performance for a given frequency range. Lengths and diameters of the second and fourth tubes 320, 460 may be optimized to meet an acoustic performance target of the muffler 108. As the acoustic power target changes, these parameters (i.e., lengths and diameters) may be changed accordingly. Moreover, by combining the tuning chamber 360 and the other tuning chamber 430, selecting a desired (e.g., long) length of the tail pipe 106 (shown in FIG. 1 ) that also works better for low frequency is permitted. From a manufacturing point of view, in order to avoid some manufacturing and manufacturing restrictions, such as perforations on the curved portion 321, it is helpful to have the interference and the annular passage 330 between the first tube 310 and the second tube 320.In one embodiment, the third tube 440 further includes a flared portion 448 disposed at least partially within the expansion chamber 420. The flared portion 448 defines the third inlet 442. Further, the flared portion 448 allows the flow of exhaust gases 540 to enter the third tube 440 through the third inlet 442. The flared portion 448 may be funnel-shaped to allow easy admission or aspiration of the flow of exhaust gases 540 through the third inlet 442 during operation of the muffler 108. Additionally or alternatively, there may be one or more perforations (not shown) around the flared portion 448 of the third tube 440 to facilitate the flow of the exhaust gases 540 entering the third tube 440 within the expansion chamber 420. This may help maintain a lower Mach number for the flow velocity at the entrance of the third pipe 440, or even beyond the entrance point, to some length. This generally helps to avoid possible flow noise and increased backpressure.The silencer 108 includes a retaining member 450 connected to the second tube 320 and the third tube 440. The presence of the retaining member 450 may serve to secure the second tube 320 in position, in particular to retain and protect the second tube 320 against any vibration or unintended force during operation of the silencer 108. In some embodiments, the retention member 450 may be a gusset or metal bracket that may be welded to the second tube 320 and the third tube 440, depending on the application.Further, a connector (not shown) may connect the first tube 310 and the second tube 320. The link may include one or more rods connecting the first tube 310 and the second tube 320. When two or more rods are used as the link, the rods may be spaced apart from each other. Alternatively, a single rod may be used as the connector, with the single rod welded at its edges to the first tube 310 and the second tube 320.FIG. 5 is a cross-sectional view of the muffler 108 of FIG. 4 according to an aspect of the present disclosure. As shown, the third tube 440 further includes a curved portion 444 disposed at least partially within the second tuning chamber 430. The curved portion 444 defines the one or more apertures 446. The opening 446 may be positioned about 15 mm away from an end of the curved portion 444 of the third tube 440. The first tube 310 and the second tube 320 overlap each other over an overlap distance E. As shown in FIG. 5, the first tube 310 has a diameter E 1 and the second tube 320 has a diameter E 2. The diameter E 1 of the first tube 310 is greater than the diameter E 2 of the second tube 320 such that there is a desired flow of the exhaust gases 540 passing through the annular passage 330 between the first tube 310 and the second tube 320.Further, the third tube 440 may include a region in the first tuning chamber 360 that includes a roving pinch can 470. Pinch can 470 may be generally cylindrical and define a plurality of perforations 472 that may be filled with roving (i.e., any sound absorbing material such as fiberglass insulation). The presence of the roving pinch can 470 may provide high frequency sound attenuation among other advantages. In some embodiments, pinch can 470 may have a length of about 150 mm, although any other length of pinch can 470 may be implemented in the present disclosure.As shown in FIG. 5, the first tube 310, the third tube 440, and the fourth tube 460 are provided with brackets 502 therebetween to provide support and restraint for any unintentional movement due to vibrations during operation of the muffler 108. More specifically, the first tube 310 and the third tube 440 may be provided with the brackets 502, while the third tube 440 may in turn include the brackets 502 supporting it with the fourth tube 460. The brackets 502 may be further supported or supplemented by welding, riveting, or any other coupling means used or known in the art. The number, position, type, and arrangement of the mounts 502 may be consistent with factors such as the vibration dynamics of the first tube 310, the third tube 440, and the fourth tube 460 or the muffler itself.The arrangement of the present disclosure, wherein the second tube 320 is at least partially received within the first tube 310, provides a simple, compact, and efficient construction of the muffler 108. This can be seen by the overlap distance E between the first tube 310 and the second tube 320, thereby saving abundant space in the tuning chamber 360 by reducing the dimensional footprint of the second tube 320 within the required limit. The present disclosure provides the desired acoustic attenuation by combining tuning the tuning chamber 360 and the other tuning chamber 430, which is more efficient than tuning provided by conventional muffler designs.Although aspects of the present disclosure have been specifically shown and described with reference to the above embodiments, it will be appreciated by those skilled in the art that various additional embodiments may be devised by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of the claims. Such embodiments fall within the scope of the present disclosure, which is determined based on the claims and any equivalents thereof.

Claims

A silencer (108) comprising: a first pipe (210) defining a first inlet (212) for receiving exhaust gas and a first outlet (214); wherein the first outlet (214) of the first pipe (210) has a diameter (D1); a housing (200) having a closed tuning chamber (260); a second pipe (220) at least partially received in the first outlet (214) of the first pipe (210), wherein the second pipe (220) has a second inlet (222) disposed in the first pipe (210) and defining a first exhaust path through the second pipe (220), and wherein the second pipe (220) has a second outlet (224) disposed in flow communication with the tuning chamber (260); and a muffler outlet (270) for exhausting exhaust gas from the muffler (108); wherein the first pipe (210) and the second pipe (220) define an annular passage (230) therebetween and a second exhaust path; wherein the annular passage (230) defines the first outlet (214) of the first pipe (210) and is disposed in flow communication with the muffler outlet (270); and wherein the first exhaust path leads into the tuning chamber (260), and wherein the second exhaust path leads through the first outlet (214) and the muffler outlet (270).The silencer (108) of claim 1, wherein the first tube (210) and the second tube (220) are concentrically arranged with respect to each other.A silencer (108) comprising: a housing (300); a first bulkhead (400) disposed in the housing (300), wherein the first bulkhead (400) and the housing (300) define a first tuning chamber (360) therebetween; a second bulkhead (410) disposed in the housing (300) and spaced from the first bulkhead (400), wherein the second bulkhead (410) and the housing (300) define a second tuning chamber (430) therebetween, and wherein the first bulkhead (400), the second bulkhead (410), and the housing (300) define an expansion chamber (420) disposed between the first tuning chamber (360) and the second tuning chamber (430); a first tube (310) at least partially received in the housing (300), the first tube (310) defining a first inlet (312) for receiving exhaust gas and a first outlet (314) disposed in flow communication with the expansion chamber (420); wherein the first outlet (314) of the first tube (310) has a diameter (E1); a second tube (320) at least partially received in the first tube (310), wherein the second tube (320) has a second inlet (322) disposed in the first tube (310) and defining a first exhaust path through the second tube (320), and wherein the second tube (320) has a second outlet (324) disposed in flow communication with the first tuning chamber (360); and a third pipe (440) defining a third inlet (442) in flow communication with the expansion chamber (420) and having a muffler outlet (370) for discharging exhaust gas from the housing (300); wherein the first pipe (310) and the second pipe (320) define an annular passage (330) therebetween and a second exhaust path; wherein the annular passage (330) defines the first outlet (314) of the first pipe (310) and is disposed in flow communication with the third inlet (442); wherein the first exhaust path leads into the tuning chamber (360) and wherein the second exhaust path leads through the first outlet (314) and the muffler outlet (370).The silencer (108) of claim 3, wherein the first tube (310) and the second tube (320) are concentrically arranged with respect to each other.The silencer (108) of claim 3, wherein the third tube (440) further comprises a curved portion (444) disposed at least partially within the second tuning chamber (430), the curved portion (444) defining one or more openings (446) therethrough.The silencer (108) of claim 3, wherein the third tube (440) further comprises a flared portion (448) disposed at least partially within the expansion chamber (420), the flared portion (448) defining the third inlet (442).The silencer (108) of claim 3, wherein the third tube (440) extends through the first partition (400), the second partition (410), and the housing (300), wherein the silencer outlet (370) is disposed in the housing (300).The silencer (108) of claim 3, further comprising a fourth pipe (460) fluidly connecting the first tuning chamber (360) to the second tuning chamber (430), the fourth pipe (460) extending through the first partition (400) and the second partition (410).The silencer (108) of claim 3, further comprising a retaining member (450) connected to the second tube (320) and the third tube (440).A silencer (108) comprising: a housing (300); a first bulkhead (400) disposed in the housing (300), wherein the first bulkhead (400) and the housing (300) define a first tuning chamber (360) therebetween; a second bulkhead (410) disposed in the housing (300) and spaced from the first bulkhead (400), wherein the second bulkhead (410) and the housing (300) define a second tuning chamber (430) therebetween, and wherein the first bulkhead (400), the second bulkhead (410), and the housing (300) define an expansion chamber (420) disposed between the first tuning chamber (360) and the second tuning chamber (430); a first tube (310) at least partially received in the housing (300), the first tube (310) defining a first inlet (312) for receiving exhaust gas and a first outlet (314) disposed in flow communication with the expansion chamber (420), the first tube (310) extending through the second baffle (410); a second tube (320) at least partially received in the first tube (310), the second tube (320) defining a second inlet (322) disposed in the first tube (310) and a second outlet (324) disposed in flow communication with the first tuning chamber (360), the second tube (320) extending through the first baffle (400); and a third tube (440) defining a third inlet (442) in flow communication with the expansion chamber (420) and a muffler outlet (370) for exhausting exhaust gas from the housing (300), the third tube (440) extending through the first partition (400), the second partition (410) and the housing (300); a fourth tube (460) providing flow communication of the first tuning chamber (360) with the second tuning chamber (430), the fourth tube (460) extending through the first partition (400) and the second partition (410); wherein the first tube (310) and the second tube (320) define an annular passage (230, 330) therebetween, and wherein the annular passage (330) is disposed in flow communication with the first outlet (314) and permits the flow of exhaust gas therethrough.The silencer (108) of claim 10, wherein the third tube (440) further comprises a curved portion (444) disposed at least partially within the second tuning chamber (430), the curved portion (444) defining one or more openings (446) therethrough.The silencer (108) of claim 10, further comprising a retaining member (450) connected to the second tube (320) and the third tube (440).

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