AU2017100423A4 - Sound Attenuation Device & Associated Methods - Google Patents

Abstract

-15 Abstract There are disclosed examples of a sound attenuation device (10) for a track shoe (11), the device (10) includes a housing (14) with a base (12) adapted to be coupled to the track shoe (11) in a coupled condition. The housing (14) including a cavity (16) that is substantially filled with a visco-elastic material (18) so as to damp vibration of the track shoe (11) in the coupled condition. A track shoe (11) including such a sound attenuation device (10) a method of forming a sound attenuation device (10) and a method of fitting such a sound attenuation device (10) to a track shoe (11) for sound attenuation is also disclosed. Figure 1 Figure 2

Description

Sound Attenuation Device & Associated Methods

Technical Field [001] The invention relates to a sound attenuation device, in particular, a sound attenuation device for tracks of a vehicle or machine, and associated methods of manufacture and sound attenuation.

Background [002] Track-type machines typically include tracks located at either side of the machine. The tracks include a chain formed from a series of links that are coupled end-to-end to form a loop that is driven by drive components such as sprockets. The links are fitted with track shoes that are arranged to engage a ground surface during operation of the machines.

[003] During operation, the tracks that are typically metallic emit noise as the tracks are driven and impact with the drive components. One of the principal sites of noise emission is from the shoes of the track. Sound waves readily travel outwardly from the surfaces of the shoes. The emitted noise is undesirable, especially, when the track-type machine is utilised near to residential or other noise sensitive areas.

[004] US 2014/0306516 A1 discloses a vibration-damping coating, such as polyurethane, applied or bonded directly to a base plate of a track shoe. Whilst such a vibration-damping coating may assist to reduce vibration and associated noise from the track shoe, such a coating is relatively susceptible to wear and may become dislodged from the track shoe in service.

[005] The invention disclosed herein seeks to overcome one or more of the above identified problems or at least provide a useful alternative.

Summary [006] In accordance with a first broad aspect there is provided, a sound attenuation device for a track shoe, the device including housing with a base adapted to be coupled by at least one fastener to the track shoe in a coupled condition, the housing defining or including a cavity that is substantially filled or tillable with a damping or visco-elastic material so as to damp vibration of the track shoe in the coupled condition.

[007] In an aspect, the device includes threaded sockets extending from apertures at the base into the cavity of the housing, wherein the at least one fastener is provided in the form of threaded fasteners arranged to engage with the threaded sockets.

[008] In another aspect, the threaded sockets have blinded ends within the cavity.

[009] In yet another aspect, the base has a substantially square or rectangular plan form shape, and wherein the threaded sockets are each provided toward diagonal opposing comers thereof.

[0010] In yet another aspect, the device includes an entry aperture into which a viscoelastic material is receivable into the cavity and an exhaust aperture arranged to allow displaced gas to escape from the cavity.

[0011] In yet another aspect, the entry and exit apertures are located at the base.

[0012] In yet another aspect, the device includes plugs adapted to seal the entry and exit apertures.

[0013] In yet another aspect, the base has a substantially square or rectangular plan form shape, and wherein the entry and exit apertures are each provided toward diagonal opposing comers thereof.

[0014] In yet another aspect, the base is provided by a plate and the housing is provided by a cap that is coupled at an open side thereof to the plate [0015] In yet another aspect, the base and the housing are integrally formed and/or are formed as a single part.

[0016] In yet another aspect, the cap includes side walls extending from the plate and an outer wall supported by the side walls that is arranged substantially parallel to the plate.

[0017] In yet another aspect, comers between the side walls of the cap and the outer wall are rounded.

[0018] In yet another aspect, the side walls are inwardly angled such that the cap has a trapezoidal side profile shape.

[0019] In yet another aspect, the base and housing are substantially formed from a metal material.

[0020] In yet another aspect, the housing includes an angled wall arranged toward outer free ends of the track shoe.

[0021] In yet another aspect, the housing includes an angled side wall fitted toward an outer free end of the track shoe the coupled condition with a slope of the angled side wall sloping away from the outer free end.

[0022] In yet another aspect, the housing includes a side wall arrangement having three side walls arranged to extend perpendicular to the base and a top arrangement that provides the angled wall between free ends of the three side walls and a cap between the three side walls.

[0023] In accordance with a second broad aspect there is provided, a track shoe including a sound attenuation device as described above and herein.

[0024] In accordance with a third broad aspect there is provided, a track shoe for coupling with a chain of a track-type machine, the track shoe including an elongate body having opposing ends, front and back edges, and outer and inner surfaces, wherein the inner surface includes an intermediate portion adapted to couple with the chain and outer portions located on each side of the intermediate portion, wherein sound attenuation devices as described above and herein are respectively coupled to each of the outer portions.

[0025] In accordance with a fourth broad aspect there is provided, a method of forming or manufacturing a sound attenuation device for a track shoe, the method including the steps of: Providing the device including a base and a housing that defines a cavity, the base being adapted to be coupled to the track shoe with at least one fastener; and Introducing a damping or visco-elastic material into the cavity via an entry aperture in communication therewith and allowing displaced air from the cavity to exhaust via an associated exhaust aperture; and Fitting plugs to the entry and exhaust apertures.

[0026] In accordance with a fifth broad aspect there is provided, a method of fitting a sound attenuation device for a track shoe, the method including the steps of: Providing the device including a base and a housing that defines a cavity, the base being adapted to be coupled to the track shoe with at least one fastener and the cavity being filled with a damping or visco-elastic material; and Securing the sound attenuation device to the track shoe by fitting or securing the at least one fastener between the track shoe and the base.

[0027] In accordance with a sixth broad aspect there is provided, a method of attenuating noise from a track shoe, the method including providing a device including a base and a housing that defines a cavity, the base being adapted to be coupled to the track shoe with at least one fastener and the cavity being filled with a damping or visco-elastic material; and Securing the sound attenuation device to the track shoe by fitting or securing the at least one fastener between the track shoe and the base such that the device attenuates noise emitted from the track shoe.

[0028] In accordance with a seventh broad aspect there is provided, a sound attenuation device for a track shoe, the device including a housing adapted to be coupled to the track shoe in a coupled condition, the housing defining a cavity that is substantially filled with a visco-elastic material so as to damp vibration of the track shoe in the coupled condition.

Brief Description of the Figures [0029] The invention is described, by way of non-limiting example only, by reference to the accompanying figures, in which; [0030] Figure 1 is an underside perspective view illustrating a sound attenuation device for a track shoe; [0031] Figure 2 is an underside view illustrating the device; [0032] Figure 3 is a top hidden detail view illustrating the device; [0033] Figure 4 is a side view illustrating the device; [0034] Figure 5 is a cross sectional view illustrating the device; [0035] Figure 6 is a perspective view illustrating the track shoe fitted with the device coupled to a representative chain link; [0036] Figure 7 is a perspective exploded parts view illustrating a second example of the device; [0037] Figure 8 is a perspective part hidden detail view illustrating the second example of the device; [0038] Figure 9 is a perspective view illustrating two of the devices being aligned to be fitted to a track shoe; and [0039] Figure 10 is a perspective view illustrating two of the devices fitted to the track shoe.

Detailed Description [0040] Referring to Figures 1 to 6 there is shown a first example of a sound attenuation device 10 (also known as a “damper”) for a track shoe 11. The device 10 includes a housing 14 with a base 12 adapted to be coupled by one or more fasteners 15 (shown in relation to the second example in Figure 9) to the track shoe 11 in a coupled condition as shown in Figure 6. The housing 14 is supported by the base 12 and including, more specially defines, a cavity 16 that is substantially filled or Tillable with a visco-elastic or “damping” material 18 so as to damp vibration of the track shoe 11 in the coupled condition.

[0041] The device 10 includes threaded sockets 20 extending from apertures 22 at the base 12 into the cavity 16 of the housing 14. The fastener 15 is preferably a mechanical fastener such as threaded fasteners arranged to engage with the threaded sockets 20. The threaded sockets 20 have blinded ends 23 within the cavity 16 so as to be sealed from the cavity 16. The fasteners 15 may be high tensile Ml6 countersunk socket head screws. These can be fitted with an adhesive such as Loctite™ to give additional security to avoid coming loose due to vibration. Of course, other suitable fasteners may also be used, and in some examples the fasteners may be omitted and/or provided in other forms such as fastening by welding.

[0042] The base 12 also includes an entry aperture 24 into which a visco-elastic material 18 is receivable into the cavity 16 and an exhaust aperture 26 arranged to allow displaced gas to escape from the cavity 16. Tapered plugs 28 may be fitted to each of the apertures 24, 26 to seal or plug the apertures 24, 26 once filled with the visco-elastic material 18.

[0043] The base 12 has a substantially square or rectangular plan form shape. The threaded sockets 20 are each provided toward diagonal opposing corners thereof and the entry and exit apertures 24, 26 are provide toward the other of the diagonal opposing comers.

[0044] In this example, the base 12 is provided in the form of a metal plate 30 and the housing 14 is defined by a metal cap 32 that is coupled, preferably by welding, a rim 34 of the metal cap 32 to the plate 30. The cap 32 includes side walls 36 extending from the metal plate 30 that support an outer or cap wall 38 that is arranged substantially parallel to the plate 30. The corners 40 between the side walls 36 of the cap 32 and the outer wall 38 are rounded. The side walls 36 are inwardly angled such that the cap 32 has a trapezoidal side profde. It is noted that in some examples, the housing 14 and the base 12 may be provided as a single part. In other examples, the base 12 may be part of the housing 14, and in further examples the base 12 and the housing 14 may be separate parts that are coupled or joined together during formation of the device 10.

[0045] A method of forming or manufacturing the sound attenuation device 10 for the track shoe 11 may include the steps of: providing the plate 30 and forming apertures therein for the threaded sockets 20 and the entry and exit apertures 24, 26. The threaded sockets 20 are then be secured to the plate 30 and the metal cap 32 is secured, preferably by welding, to the plate 30 with the threaded sockets 20 extending therein. The metal cap 32 thereby providing the housing 14 and the cavity 16 therein. The metal cap 32 may be a single piece that is pressed to shape.

[0046] In this example, the plan form dimensions of the base 12 may be about 150 mm by 150 mm and the height of the housing 14 is about 40mm. However, any suitable dimensions may be applied.

[0047] The visco-elastic material 18, that is preferably at least initially a pourable liquid, is then introduced into the entry aperture 24 and the fdling continues until the visco-elastic material fdls the cavity 16 and is viewable beginning to overflow from the exhaust aperture 26. The displaced air escapes from the exit aperture 26. The tapered plugs 28 are then fitted to the entry and exit apertures 24, 26. The viscoelastic material is then allowed to set within the cavity 16.

[0048] It is noted that various types of visco-elastic materials may be utilised including one or more of Bitumen, polyurethane and a super-polymer acoustic material. These materials may be both hot and cold pourable and adapted to set or rigidify once within the cavity 16. Accordingly, it may be appreciated that the device 10 including the base 12 and housing 14 serves to encapsulate and protect the viscoelastic material received thereby.

[0049] Referring to Figures 7 to 10 there is shown a second example of a sound attenuation device 10 for the track shoe 11. The second example of the device 10 is similar to the first example and as such like numerals are used to denote like parts. However, in this second example, the structural arrangement of the housing 14 is different. The remaining parts are substantially the same such as the base 12 and the visco-elastic material 18 housed by the housing 14, and the remaining parts are not again described.

[0050] Turning then to the housing 14, in this example, the housing 14 includes a side wall arrangement 70 and a top or cap arrangement 74 that are supported by the base 12. The side wall arrangement 70 includes three sides 72 and the top or cap arrangement 74 provides a cap 76 between the three sides 72 and provides a fourth angled side 78 that extends from the cap 76 to the base 12. The side wall arrangement 70 and the top arrangement 74 define the cavity 16 in which the visco-elastic or damping material 18 is received.

[0051] The three sides 72 extend outwardly perpendicularly from the base 12 and may be formed from a 5mm piece of folded wear resistant steel. The top arrangement 74 may be formed from 3mm wear resistance steel and the angled side 78 may be angled at about 45 to 65 degrees relative to a plane of the base 12. The top arrangement 74 may be welded to the side wall arrangement 70 so as to be slightly recessed relative to outer edges 80 of the side wall arrangement 70. The base 12 may be 8mm carbon steel and the sockets 20 may also be carbon steel. Of course, other arrangements, sizes and materials may be used.

[0052] Similarly to the first example, once the housing 14 and the sockets 20 are secured to the base 12, the cavity 16 provided by the housing 14 is substantially filled with the visco-elastic material 18 via the entry aperture 24 and the filling continues until the visco-elastic material 18 fills the cavity 16 and is viewable beginning to overflow from the exhaust aperture 26. The displaced air escapes from the exit aperture 26. The tapered plugs 28 (shown in Figures 1 and 2 in relation to the first example) are then fitted to the entry and exit apertures 24, 26. The visco-elastic material is then allowed to set within the cavity 16.

[0053] In comparison to the first example, the structural shape and configuration changes of the second example generally seek to provide improved operational impact resistance and acoustic performance. For example, the side wall arrangement 70 seeks to improve wear resistance and is positioned for greater operational impact resistance. In relation to the top arrangement 74, the single piece with the integrated external angled side 78 allow for self-clearing of impacting debris and seeks to provided greater operational impact resistance. In relation to acoustic performance, the straighter three sides 72 of the side wall arrangement 70 allow for increased volume of the internal cavity 16 and hence greater volume of the damping material 18 fill that assist to further improve sound attenuation qualities.

[0054] Once the device 10 is formed, it may be fitted to the track shoe 11 as shown in Figure 6 in relation to the first example, or Figures 9 and 10 in relation to the second example. The track shoe 11 is shown coupled with a chain link 50 that forms parts of a chain of a track-type machine such as a dozer.

[0055] Referring more specifically to Figures 6, 9 and 10, the track shoes 11 include an elongate body 52 having opposing ends 54, 55, front and back edges 56, 58, and outer and inner surfaces 60, 62. The outer surface 60 is the ground-engaging surface and includes a ground-engaging ridge 61.

[0056] The elongate body 52 includes an intermediate portion 64 adapted to couple with the chain link 50 and flanking outer portions 66 located on each side of the intermediate portion 64. The flanking outer portions 66 may include or may be drilled to include apertures 65 to allow the fasteners 15 to extend there-through and fasten with the threaded sockets 20 in the coupled condition. Accordingly, the sound attenuation device 10 may be pre-installed or retrofitted to the track shoes 11 so as to be mechanically coupled thereto.

[0057] It is noted that the flanking outer portions 66 are cantilevered from the intermediate portion 64 and typically are responsible for vibration and the generation of noise. Accordingly, as shown in Figures 6 and 10, the sound attenuation devices 10 are typically coupled to both of the flanking outer portions 66. The sound attenuation devices 10 may be coupled to either the outer and inner surfaces 60, 62 of the outer portions 66. However, in this example, the sound attenuation devices 10 are preferably coupled to the inner surface 62.

[0058] In use, the devices 10 are fixed to the track shoes 11 and reduce reverberation of the body 52 of the track shoes 11 by changing the natural frequency of the track shoes 11 and by absorbing sound energy in the visco-elastic material 18 and converting it to heat. In more detail, reverberation of the track shoe 11 in service creates a shearing effect in the visco-elastic material 18 inside the device 10. This shearing energy is absorbed by the visco-elastic material and converted to heat energy. It is noted that preliminary testing via an impact test on a Komatsu™ dozer track shoe showed a reduction of about 5 to 6 dBa.

[0059] Advantageously, there has been described a sound attenuation device for a track shoe that has a robust housing enclosing the damping or visco-elastic material and a base to mechanically couple the sound attenuation device to the track shoe. The coupling via fasteners provides a robust coupling to ensure the sound attenuation device does not become easily dislodged in service.

[0060] The devices may be retro-fitted to any track shoes where there is sufficient area extending out the sides of the chain link to allow the fixing of the devices. The devices have the effect of reducing the noise generated by the impact of the track shoes at generally every point of impact in the drive train. This includes noise generated by the impact of the track shoes with the drive sprockets, idler wheels and carry rollers where applicable.

[0061] It is noted the application of the device disclosed herein relates to track shoes. However, the device may find use in other applications and may be fitted to other vibration parts and is not to be construed to be limited to use only with track shoes.

[0062] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

[0063] The reference in this specification to any known matter or any prior publication is not, and should not be taken to be, an acknowledgment or admission or suggestion that the known matter or prior art publication forms part of the common general knowledge in the field to which this specification relates.

[0064] While specific examples of the invention have been described, it will be understood that the invention extends to alternative combinations of the features disclosed or evident from the disclosure provided herein.

[0065] Many and various modifications will be apparent to those skilled in the art without departing from the scope of the invention disclosed or evident from the disclosure provided herein.

Claims (21)

1. The claims defining the Invention are as follows:

   1. A sound attenuation device for a track shoe, the device including a housing with a base adapted to be coupled by at least one fastener to the track shoe in a coupled condition, the housing including a cavity that is substantially fdlable with a visco-elastic material so as to damp vibration of the track shoe in the coupled condition.
2. 2. The device according to claim 1, wherein the device includes threaded sockets extending from apertures at the base into the cavity of the housing, wherein the at least one fastener is provided in the form of threaded fasteners arranged to engage with the threaded sockets.
3. 3. The device according to claim 2, wherein the threaded sockets have blinded ends within the cavity.
4. 4. The device according to claim 2, wherein the base has a substantially square or rectangular plan form shape, and wherein the threaded sockets are each provided toward diagonal opposing comers thereof.
5. 5. The device according to claim 1, wherein the device includes an entry aperture into which a visco-elastic material is receivable into the cavity and an exhaust aperture arranged to allow displaced gas to escape from the cavity.
6. 6. The device according to claim 5, wherein the entry and exit apertures are located at the base.
7. 7. The device according to claim 5, wherein the device includes plugs adapted to seal the entry and exit apertures.
8. 8. The device according to claim 5, wherein the base has a substantially square or rectangular plan form shape, and wherein the entry and exit apertures are each provided toward diagonal opposing comers thereof.
9. 9. The device according to claim 1, wherein the base is provided by a plate and the housing is provided by a cap that is coupled at an open side thereof to the plate.
10. 10. The device according to claim 9, wherein the base and the housing are integrally formed.
11. 11. The device according to claim 9, wherein the cap includes side walls extending from the plate and an outer wall supported by the side walls that is arranged substantially parallel to the plate.

    11. The device according to claim 10, wherein corners between the side walls of the cap and the outer wall are rounded.
12. 12. The device according to claim 11, wherein the side walls are inwardly angled such that the cap has a trapezoidal side profile shape.
13. 13. The device according to claim 1, wherein the housing includes an angled side wall fitted toward an outer free end of the track shoe the coupled condition with a slope of the angled side wall sloping away from the outer free end.
14. 14. The device according to claim 13, wherein the housing includes a side wall arrangement having three side walls arranged to extend perpendicular to the base and a top arrangement that provides the angled wall between free ends of the three side walls and a cap between the three side walls.
15. 15. The device according to claim 1, wherein the base and housing are substantially formed from a metal material.
16. 16. A track shoe including a sound attenuation device as defined in any one of the previous claims.
17. 17. A track shoe for coupling with a chain of a track-type machine, the track shoe including an elongate body having opposing ends, front and back edges, and outer and inner surfaces, wherein the inner surface includes an intermediate portion adapted to couple with the chain and outer portions located on each side of the intermediate portion, wherein sound attenuation devices as defined in any one of claims 1 to 15 are respectively coupled to each of the outer portions.
18. 18. A method of forming a sound attenuation device for a track shoe, the method including the steps of: Providing the device including a base and a housing that defines a cavity, the base being adapted to be coupled to the track shoe with at least one fastener; and Introducing a visco-elastic material into the cavity via an entry aperture in communication therewith and allowing displaced air from the cavity to exhaust via an associated exhaust aperture; and Fitting plugs to the entry and exhaust apertures.
19. 19. A method of fitting a sound attenuation device for a track shoe, the method including the steps of: Providing the device including a base and a housing that defines a cavity, the base being adapted to be coupled to the track shoe with at least one fastener and the cavity being filled with a visco-elastic material; and Securing the sound attenuation device to the track shoe by fitting the at least one fastener between the track shoe and the base.
20. 20. A method of attenuating noise from a track shoe, the method including providing a device including a base and a housing that defines a cavity, the base being adapted to be coupled to the track shoe with at least one fastener and the cavity being filled with a visco-elastic material; and Securing the sound attenuation device to the track shoe by fitting or securing the at least one fastener between the track shoe and the base such that the device attenuates noise emitted from the track shoe.
21. 21. A sound attenuation device for a track shoe, the device including a housing adapted to be coupled to the track shoe in a coupled condition, the housing defining a cavity that is substantially filled with a visco-elastic material so as to damp vibration of the track shoe in the coupled condition.