Patent Application
20220372714
Embodiments relate to a resonator, and more particularly to a noise-reducing resonator in a surface compaction machine.
Surface compaction machines are used to compact a variety of substrates including soil, asphalt, or other materials. Surface compaction machines are provided with one or more compacting surfaces for this purpose. For example, a surface compaction machine, such as a roller compactor, may be provided with one or more cylindrical drums that provide compacting surfaces for compacting substrates.
Roller compactors use the weight of the compactor applied through rolling drums to compress a surface of the substrate being rolled. In addition, one or more of the drums of some roller compactors may be vibrated by a vibration system to induce additional mechanical compaction of the substrate being rolled. The vibration system of these surface compaction machines can include an eccentric vibration system that includes an eccentric mass that is rotated to generate a vibration force which increases the compacting force exerted by the drum.
These and other vibration systems may produce undesirable noise during operation of the surface compaction machine. For example, known surface compaction machines typically produce noise at frequencies ranging between about 30 Hz to about 80 Hz for eccentric vibration systems, about 60 Hz to about 400 Hz for engine noise, about 300 Hz to about 2000 Hz for fan noise (airborne), and about 200 Hz to about 3000 Hz for hydraulic noise (fluid-borne), with the specific frequencies varying based on machine size, the type of material being compacted, and other factors. While this noise may be reduced by reducing the amplitude and/or speed of the vibration system, this is undesirable because the compaction efficiency of the surface compaction machine would also be reduced.
According to an embodiment, a resonator assembly for a surface compaction machine is disclosed. The resonator assembly includes a resonator housing defining an internal cavity, the resonator housing having a first head plate comprising a plurality of first cutouts. The resonator assembly further includes a plurality of first extension tubes. Each first extension tube of the plurality of first extension tubes is coupled to the first head plate around a corresponding first cutout. Each first cutout forms an acoustic passage between the internal cavity and an exterior of the resonator housing to attenuate sound around the internal cavity.
According to an embodiment, a drum assembly for a surface compaction machine is disclosed. The drum assembly includes a substantially cylindrical drum housing comprising an external compaction surface and an internal surface opposite the external compaction surface. The drum assembly further includes a first head plate coupled to the internal surface of the drum housing. The drum assembly further includes a second head plate coupled to the internal surface of the drum housing. The drum assembly further includes an eccentric vibration system housing coupled between the first head plate and the second head plate. The compaction surface, the first head plate, the second head plate, and the eccentric vibration system housing form a substantially annular internal resonator cavity. The drum assembly further includes a plurality of cutouts in the first head plate and the second head plate. The drum assembly further includes a plurality of extension tubes coupled to the first head plate and the second head plate, wherein each extension tube is coupled around a corresponding cutout to form an acoustic passage between the internal resonator cavity to attenuate sound around the internal resonator cavity.
Other devices, methods, and systems according to embodiments will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such additional surface compaction machines, methods, and control systems be included within this description and protected by the accompanying claims. Moreover, it is intended that all embodiments disclosed herein can be implemented separately or combined in any way and/or combination.
According to an aspect, a resonator assembly for a surface compaction machine is disclosed. The resonator assembly includes a resonator housing defining an internal cavity, the resonator housing having a first head plate comprising a plurality of first cutouts. The resonator assembly further includes a plurality of first extension tubes. Each first extension tube of the plurality of first extension tubes is coupled to the first head plate around a corresponding first cutout. Each first cutout forms an acoustic passage between the internal cavity and an exterior of the resonator housing to attenuate sound around the internal cavity.
According to an aspect, the resonator housing further includes a second head plate opposite the first head plate, wherein the second head plate includes a plurality of second cutouts. The resonator housing further includes a plurality of second extension tubes, wherein each second extension tube of the plurality of second extension tubes is coupled to the second head plate around a corresponding second cutout. The resonator housing further includes a drum housing including a substantially cylindrical compaction surface surrounding the first head plate and the second head plate. The internal cavity includes a substantially cylindrical cavity defined by the first head plate, the second head plate, and the drum housing.
According to an aspect, the resonator assembly further includes an eccentric vibration system housing for enclosing an eccentric vibration system, wherein the internal cavity surrounds the eccentric vibration system.
According to an aspect, at least two first cutouts of the plurality of first cutouts have different sizes.
According to an aspect, each first extension tube of the plurality of first extension tubes has a cross-sectional area substantially equal to the size of the first cutout corresponding to the first extension tube.
According to an aspect, at least two first extension tubes of the plurality of first extension tubes have different lengths.
According to an aspect, a first subset of the plurality of first extension tubes extends into the internal cavity in a first direction. A second subset of the plurality of first extension tubes extends away from the internal cavity in a second direction.
According to an aspect, the first head plate includes a non-removable structural plate coupled to the resonator housing and a removable cover plate removably coupled to the structural plate.
According to an aspect, each first cutout includes a structural plate cutout and a corresponding cover plate cutout that is smaller than the structural plate cutout. Each first extension tube has a cross sectional area that is substantially coincident with the cover plate cutout corresponding to the first extension tube.
According to an aspect, each first extension tube of the plurality of first extension tubes is coupled to the cover plate around the cover plate cutout corresponding to first extension tube.
According to an aspect, the removable cover plate includes a plurality of removable cover plates. Each removable cover plate is removably coupled to the structural plate around a corresponding structural plate cutout.
According to an aspect, the internal cavity, the first cutouts and the first extension tubes are sized to attenuate sound in one or more predetermined frequency ranges.
According to an aspect, the predetermined frequency range is between about 30 Hz and 80 Hz.
According to an embodiment, a drum assembly for a surface compaction machine is disclosed. The drum assembly includes a substantially cylindrical drum housing comprising an external compaction surface and an internal surface opposite the external compaction surface. The drum assembly further includes a first head plate coupled to the internal surface of the drum housing. The drum assembly further includes a second head plate coupled to the internal surface of the drum housing. The drum assembly further includes an eccentric vibration system housing coupled between the first head plate and the second head plate. The compaction surface, the first head plate, the second head plate, and the eccentric vibration system housing form a substantially annular internal resonator cavity. The drum assembly further includes a plurality of cutouts in the first head plate and the second head plate. The drum assembly further includes a plurality of extension tubes coupled to the first head plate and the second head plate, wherein each extension tube is coupled around a corresponding cutout to form an acoustic passage between the internal resonator cavity to attenuate sound around the internal resonator cavity.
According to an aspect, at least two cutouts of the plurality of cutouts have different sizes.
According to an aspect, each extension tube of the plurality of extension tubes has a cross-sectional area substantially equal to the size of the cutout corresponding to the extension tube.
According to an aspect, at least two extension tubes of the plurality of extension tubes have different lengths.
According to an aspect, a first subset of the plurality of extension tubes extends into the internal cavity. A second subset of the plurality of extension tubes extends away from the internal cavity.
According to an aspect, the first head plate includes a non-removable first structural plate coupled to the drum housing and the eccentric vibration system housing and a removable first cover plate removably coupled to the first structural plate. The second head plate includes a non-removable second structural plate coupled to the drum housing and the eccentric vibration system housing a removable second cover plate removably coupled to the second structural plate.
According to an aspect, the internal resonator cavity, the cutouts and the extension tubes are sized to attenuate sound in one or more predetermined frequency ranges.
The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate certain non-limiting embodiments of inventive concepts. In the drawings:
Those of ordinary skill in the art will appreciate that one or both of the drums 18 may include an eccentric vibration system 32 that rotates to generate vibration energy. The generated vibration energy causes the compaction surface 40 of the drum 18 to vibrate against the substrate 30 to aid in compacting the substrate 30. Other types of vibration systems may be used within the drum 18 and/or at other locations of the surface compaction machine 10, as well. The eccentric vibration system 32, and other vibration systems, are a significant source of unwanted noise. In many typical applications, this unwanted noise from the eccentric vibration system is in the 30-80 Hz range. Those of ordinary skill in the art will also appreciate that surface compaction machines 10 may have additional sources of unwanted noise, as well, such as the engine, cooling fans, hydraulic systems, or other sources (not shown).
In some embodiments, a resonator assembly 34 is formed in the drum 18 to reduce unwanted noise generated by the eccentric vibration system 32 and/or other components of the surface compaction machine 10. The resonator assembly 34 includes a resonator housing 36 that defines an internal cavity (shown in
Referring now to
Referring again to
Each head plate 242 also includes a removable cover plate 260 removably coupled to the respective structural plate 258. As shown in greater detail by
Referring again to
In this example, each cover plate cutout 264 is smaller than the corresponding structural plate cutout 262, with the cover plate cutouts 264 having different sizes. Each extension tube has a cross sectional area that is substantially equal to the size of the corresponding cover plate cutout 264 (i.e., coincident with the corresponding cover plate cutout 264) so that the corresponding acoustic passage 248 has a substantially uniform cross-sectional area along its entire length. In some embodiments, the extension tubes 246 have different lengths as well. These different cross-sectional areas and/or lengths cause different frequencies and/or frequency ranges to be attenuated, and “tune” the resonator assembly 234 to reduce different types of noise.
By varying the cross-sectional areas and/or lengths of the different acoustic passages 248, the acoustic profile of the resonator assembly 234 may be selectively tuned to attenuate sound having predetermined frequencies or frequency ranges. As sound waves pass by the different extension tubes 246 and cutouts 264, the acoustic passages 248 generate a change in acoustic impedance, with the acoustic pressure of the sound waves causing certain frequencies to be drawn into the acoustic passages 248 and attenuated. The specific frequencies that are attenuated are dependent on the lengths, sizes, and/or shapes of the extension tubes 246 and cutouts 264, which allows the resonator assembly 234 to be tuned to attenuate specific frequencies. For example, the resonator assembly 234 may be tuned to attenuate noise generated by the eccentric vibration system (e.g., in the 30 Hz-80 Hz range), engine (e.g., in the 60 Hz-400 Hz range), fan (e.g., in the 300 Hz-2000 Hz range), hydraulic system (e.g., in the 200 Hz to 3000 Hz range), etc. In some embodiments, by using different cross-sectional area/length/tube combinations, the resonator assembly 234 may be tuned to attenuate broad band and/or narrow band noise frequencies more effectively.
In some embodiments, the cover plates 260 may be removed from the structural plates 258 and replaced with different cover plates (not shown) that are tuned to attenuate different frequencies or frequency ranges, e.g., by using different cover plates cutouts and/or extension tube arrangements. For example, the cover plates 260 may be coupled to the structural plates 258 using bolts (not shown) or other suitable fasteners. Alternatively, the cover plates 260 may be permanently coupled to the structural plates 258 (e.g., by welding, brazing, etc.) after they are selected, as desired.
In some embodiments, the internal cavity 250 may be empty or may include additional material for noise attenuation within the internal cavity 250. For example, acoustic absorption material may be arranged on internal surfaces within the internal cavity 250 or within individual acoustic passages 248, as desired, to increase noise attenuation further.
Advantages of the modular design of
In another embodiment, the head plate may be formed as a unitary structure during assembly of the drum. In this regard,
In another embodiment, each head plate may include a plurality of cover plates to individually cover different structural plate cutouts. In this regard,
In this example, each removable cover plate 560 includes one or more extension tubes 546 coupled thereto around respective cover plate cutouts 564. Each removable cover plate 560 is removably coupled to the structural plate 558 around a corresponding structural plate cutout 562. In this embodiment, the structural plate cutouts 562 and acoustic passages 548 are circular and are arranged coaxially in a regular pattern around the structural plate 558, but those of ordinary skill in the art will appreciate that different symmetric or non-symmetric shapes (e.g., oval, regular or irregular polygon, etc.) may be used and that the structural plate cutouts 562 and/or acoustic passages 548 may be arranged parallel or non-parallel to the axis of rotation, and/or in different regular or irregular patterns, as desired. As with other embodiments, the removable cover plates 560 may be removably coupled to the structural plate 558 (e.g., with bolts or other removable fasteners), or may be permanently attached after assembly (e.g., by welding, glue, etc.), as desired.
As discussed above, the cover plate cutouts 564 and extension tubes 546 may be customized in many different ways, such as by varying the size, cross-sectional area, length, shape, and other aspects to provide different acoustic properties. In this regard,
These and other embodiments may have several advantages. For example, by reducing unwanted noise, an eccentric vibration system can operate at higher vibration amplitudes and speeds allowing for a more efficient compaction process, including in markets that have stricter noise regulations, such as urban markets. This reduction in noise exposure to machine operators and jobsite workers may reduce the danger to workers and lessen the hearing protection requirements to safely operate these machines. Other components, such as engine and hydraulic system fans, may also be operated at higher speeds, which may enable operation in more extreme environments (e.g., high altitude, extreme temperature, etc.).
When an element is referred to as being “connected”, “coupled”, “responsive”, “mounted”, or variants thereof to another element, it can be directly connected, coupled, responsive, or mounted to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected”, “directly coupled”, “directly responsive”, “directly mounted” or variants thereof to another element, there are no intervening elements present. Like numbers refer to like elements throughout. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Well-known functions or constructions may not be described in detail for brevity and/or clarity. The term “and/or” and its abbreviation “/” include any and all combinations of one or more of the associated listed items.
It will be understood that although the terms first, second, third, etc. may be used herein to describe various elements/operations, these elements/operations should not be limited by these terms. These terms are only used to distinguish one element/operation from another element/operation. Thus, a first element/operation in some embodiments could be termed a second element/operation in other embodiments without departing from the teachings of present inventive concepts. The same reference numerals or the same reference designators denote the same or similar elements throughout the specification.
As used herein, the terms “comprise”, “comprising”, “comprises”, “include”, “including”, “includes”, “have”, “has”, “having”, or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions but do not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof. Furthermore, as used herein, the common abbreviation “e.g.”, which derives from the Latin phrase “exempli gratia,” may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. The common abbreviation “i.e.”, which derives from the Latin phrase “id est,” may be used to specify a particular item from a more general recitation.
Persons skilled in the art will recognize that certain elements of the above-described embodiments may variously be combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of inventive concepts. It will also be apparent to those of ordinary skill in the art that the above-described embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of inventive concepts. Thus, although specific embodiments of, and examples for, inventive concepts are described herein for illustrative purposes, various equivalent modifications are possible within the scope of inventive concepts, as those skilled in the relevant art will recognize. Accordingly, the scope of inventive concepts is determined from the appended claims and equivalents thereof.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2019/059028 | 10/22/2019 | WO |
