FORM-2
THE PATENT ACT,1970
(39 OF 1970)
AND
THE PATENT RULES, 2003
(As Amended)
COMPLETE SPECIFICATION (See section 10;rule 13)
"MECHANISM OF HYDRO TOP MOUNT WITH DOUBLE FLUID RESONANCE FOR ROAD NOISE"
Sujan Contitech AVS Pvt. Ltd., a corporation organized and existing under the laws of India, of F-11, Phase 3, MIDC Chakan, Taluka Khed, Pune –410 501, Maharashtra, India.
The following specification particularly describes the invention and the manner in which it is to be performed:

MECHANISM OF HYDRO TOP MOUNT WITH DOUBLE FLUID RESONANCE
FOR ROAD NOISE
FIELD OF INVENTION
Embodiments of the present application illustrates hydro top mount to reduce road noise, more specifically, relates to a structure and associated mechanism of hydro top mount with double fluid resonance to effectively counter and reduce road noise.
BACKGROUND OF THE INVENTION
Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently disclosed invention, or that any publication specifically or implicitly referenced is prior art.
Engine mounts are generally used to address the harsh effects of vibrations caused by the weight of the engine as the vehicle traverses across varied surfaces ranging from smooth, rough, and to pure offroad conditions. Generally, users tend to use vehicles along either rough or smooth roads and the effects of the vibrations and eventual noises caused due to each surface varies considerably owing to the nature of the surface involved. Rough road surfaces itself can be of variable conditions depending on multiple factors. It was important to address this issue of road noise and different methods and devices were adopted to address this issue. In the current scenario, the most common method is the usage of hydro top mounts that are available with single frequency low dynamic stiffness. However, in the case of frequencies ranging from 80Hz to 150Hz in two peaks in above range, the current hydro top mounts were ineffective as these are designed for single frequency low dynamic stiffness.
Therefore, there is a need for an improved hydro top mount that overcomes road noise even when the frequencies due to the road noise range from 80Hz to 150Hz in two peaks in above range, where the improved hydro top mount addresses two frequencies of low dynamic stiffness, or in other words, a hydro top mount that exists in Bi-state top mount in terms of countering and resolving two frequencies, for example, 80Hz to 150Hz. In effect, the modified hydro top mount should provide the low dynamic stiffness in particular frequencies so that road noise due to

range of frequencies between 80 Hz to 150 Hz due to structural nature is overcome. The improved hydro top mount characteristics should improve vehicle ride comfort against harsh road conditions.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the subject matter in order to provide a basic understanding of some of the aspects of subject matter embodiments. This summary is not an extensive overview of the subject matter. It is not intended to identify key/critical elements of the embodiments or to delineate the scope of the subject matter. Its sole purpose to present some concepts of the subject matter in a simplified form as a prelude to the more detailed description that is presented later.
Disclosed here is an improved hydro top mount that exists as a ‘Bi-state top mount’ in terms of countering and resolving two frequencies, for example, 80Hz to 150Hz. In effect, the modified hydro top mount provides low dynamic stiffness in particular frequencies so that road noise due to range of frequency between 80 Hz to 150 Hz due to structural nature is overcome. As used herein, the phrase “dynamic stiffness” refers to a frequency dependant ratio between a dynamic force and the resulting dynamic displacement. The improved hydro top mount characteristics should improve vehicle ride comfort against harsh road conditions. The Hydro top mount comprises an inner tube, an outer tube, a bush, and at least two orifices. The outer tube encloses the inner tube, and the bush comprises an upper rubber foot that is enclosed within the outer tube and a lower rubber foot that is attached around the inner tube. The upper rubber foot and the lower rubber feet are of different lengths, respectively to maintain flow of a fluid. The two orifices are formed by the upper rubber foot and the lower rubber foot, wherein the orifices comprise different volumes of the fluid so that dynamic stiffness is lower at two different corresponding frequencies to reduce road noise.
In an embodiment, the Hydro top mount further comprises at least two chambers and of different dimensions formed by the upper rubber foot and the lower rubber foot to generate two fluid resonances based on difference in volume of flow of the fluid in the chambers. The dynamic stiffness at one or more different frequencies within an upper range and a lower range of frequencies is addressed and reduced by the at least two chambers or 3 or more chambers, resulting in reduced road noise. In an embodiment, the dynamic stiffness peaks is reduced by coupling the two fluid resonances, and where coupling the two fluid resonances broadens the

resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
In an embodiment, difference in the lengths of the upper rubber foot and the lower rubber feet maintains the flow of the fluid, and the difference in the dimensions of the two chambers counters and reduces the dynamic stiffness at the one or more different frequencies within the upper range and the lower range of frequencies, resulting in the reduced road noise. In an embodiment, difference in the lengths of the upper rubber foot and the lower rubber feet maintains the flow of the fluid, the difference in volumes of the orifices lowers the dynamic stiffness at two different corresponding frequencies to reduce road noise, and wherein the coupling of the two fluid resonances broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
In an embodiment, difference in the lengths of the upper rubber foot and the lower rubber feet maintains the flow of the fluid. The difference in the dimensions of the two chambers counters and reduces the dynamic stiffness at the one or more different frequencies within the upper range and the lower range of frequencies, resulting in reduced road noise. The dynamic stiffness peaks are reduced by coupling the two fluid resonances, which broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling systems and methods of the present disclosure, are descriptive of some of the methods and mechanism, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
FIGURE 1A exemplarily illustrates a top view of the hydro top mount with a section line AA, as an example embodiment of the present disclosure.
FIGURE 1B exemplarily illustrates a side sectional view of the hydro top mount along the section line AA in FIGURE 1A, as an example embodiment of the present disclosure.

FIGURE 1C exemplarily illustrates another side sectional view of the hydro top mount along the section line KK in FIGURE 1B, as an example embodiment of the present disclosure.
FIGURES 2A-2D exemplarily illustrate different perspective views (isometric view in Figure 2A and top view in Figure 2B) and sectional views (Figures 2C and 2D) of the bush assembly hydro top mount, as an example embodiment of the present disclosure.
FIGURES 3A-3D exemplarily illustrate different perspective views (isometric view in Figure 3A and top view in Figure 3B) and sectional views (Figure 3C and 3D) of the hydro top mount, as an example embodiment of the present disclosure.
FIGURES 4A-4C exemplarily illustrate different perspective views of the orifice of the hydro top mount, as an example embodiment of the present disclosure.
FIGURES 5 exemplarily illustrates dynamic stiffness prediction during usage of the modified hydro top mount based on the road noise frequency range between 80Hz to 150Hz, as an example embodiment of the present disclosure.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may represent both hardware and software components of the system. Further, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments now will be described. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. The terminology used in the detailed description of the particular exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting. In the drawings, like numbers refer to like elements.

It is to be noted, however, that the reference numerals used herein illustrate only typical embodiments of the present subject matter, and are therefore, not to be considered for limiting of its scope, for the subject matter may admit to other equally effective embodiments.
The specification may refer to “an”, “one” or “some” embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and/or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Furthermore, “connected” or “coupled” as used herein may include operatively connected or coupled. As used herein, the term “and/or” includes any and all combinations and arrangements of one or more of the associated listed items.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Referring to FIGURES 1A-1C, FIGURE 1A exemplarily illustrates a top view of the Hydro top mount (10) with a section line AA, FIGURE 1B exemplarily illustrates a side sectional view of the Hydro top mount (10) along the section line AA in FIGURE 1A, FIGURE 1C exemplarily illustrates another side sectional view of the Hydro top mount (10) along the section line KK in FIGURE 1B, as an example embodiment of the present disclosure.

Referring to FIGURES 1B-1C, the Hydro top mount (10) comprises an inner tube (1), an outer tube (4), a bush (2), and at least two orifices (5). The outer tube (4) encloses the inner tube (1) and the bush (2) comprises an upper rubber foot (L1) that is enclosed within the outer tube (4) and a lower rubber foot (L2) that is attached around the inner tube (1). The upper rubber foot (L1) and the lower rubber feet (L2) are of different lengths (L1) and (L2) respectively to maintain flow of a fluid. The two orifices (5) are formed by the upper rubber foot (L1) and the lower rubber foot (L2), wherein the orifices (5) comprise different volumes of the fluid so that dynamic stiffness is lower at two different corresponding frequencies to reduce road noise.
The Hydro top mount (10) further comprises at least two chambers (LQ-A) and (LQ-B) of different dimensions formed by the upper rubber foot (L1) and the lower rubber foot (L2) to generate two fluid resonances based on difference in volume of flow of the fluid in the chambers (LQ-A) and (LQ-B). The dynamic stiffness at one or more different frequencies within an upper range and a lower range of frequencies is addressed and reduced by the at least two chambers (LQ-A) and (LQ-B) or 3 or more chambers, resulting in reduced road noise. The dynamic stiffness peaks are reduced by coupling the two fluid resonances, and wherein coupling the two fluid resonances broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
The difference in the lengths (L1) and (L2) of the upper rubber foot (L1) and the lower rubber feet (L2) maintains the flow of the fluid, and the difference in the dimensions of the two chambers (LQ-A) and (LQ-B) counters and reduces the dynamic stiffness at the one or more different frequencies within the upper range and the lower range of frequencies, resulting in the reduced road noise. In an embodiment, difference in the lengths (L1) and (L2) of the upper rubber foot (L1) and the lower rubber feet (L2) maintains the flow of the fluid, the difference in volumes of the orifices (5) lowers the dynamic stiffness at two different corresponding frequencies to reduce road noise, and wherein the coupling of the two fluid resonances broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance. The difference in the lengths (L1) and (L2) of the upper rubber foot (L1) and the lower rubber feet (L2) maintains the flow of the fluid. The difference in the dimensions of the two chambers (LQ-A) and (LQ-B) counters and reduces the dynamic stiffness at the one or more different frequencies within the upper range and the lower range of frequencies, resulting in reduced road noise. The dynamic stiffness peaks are reduced by

coupling the two fluid resonances, which broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
To summarize the above:
1) Generate dual-frequency fluid resonance in the Z direction.
2) Top and bottom rubber feet are of different lengths (L1 & L2) to ensure fluid flow.
3) There are Two Chambers (LQ-A) and (LQ-B) with different geometry size to attain the different liquid volume.
4)Stiffness Ratio (Kz:Kx:Ky) is maintained from 1:2:3 to 1:3:3 to have better ride and handling.
5) The above effect of 1) + 2) + 3) provides low dynamic stiffness at two different frequencies to avoid road noise.
6) Road noise in the 80 to 125 Hz frequency band can be reduced by the above 1) + 2) + 3).
7) These two different frequencies can be changed by change the Liquid Volume geometry.
As a working example scenario, during the vehicle ride on the road in range of low amplitude and 80~150 Hz frequency there is noise amplification. To reduce noise level, we need the hydro top mount (10) which create low dynamic stiffness in same range. Therefore, the Hydro top mount (10) has a different length of rubber feet and rubber volume which affect the liquid flow during low amplitude movement. This above scenario creates resonance in the hydro top mount (10) in the frequency range of 80~150 Hz, which further helps the hydro top mount (10) to achieve the low dynamic stiffness two or multiple frequencies.
Referring to FIGURES 2A-3D, FIGURES 2A-2D exemplarily illustrate different perspective views (isometric view in Figure 2A and top view in Figure 2B) and sectional views (Figures 2C and 2D) of the bush assembly hydro top mount (10), as an example embodiment of the present disclosure. FIGURES 3A-3D exemplarily illustrate different perspective views (isometric view in Figure 3A and top view in Figure 3B) and sectional views (Figure 3C and 3D) of the hydro top mount (10), as an example embodiment of the present disclosure. As described before, the outer tube (4) enfolds the inner tube (1) and the bush (2) includes an upper rubber foot (L1) that is enfolded within the outer tube (4) and a lower rubber foot (L2) that is connected around the inner tube (1). The outer frame (3) that is positioned between the upper

rubber foot (L1) and the lower rubber foot (L2) to stabilize the upper rubber foot (L1) and the lower rubber foot (L2) during working.
FIGURES 4A-4C exemplarily illustrate different perspective views of the orifice of the hydro top mount (10), as an example embodiment of the present disclosure. The Hydro top mount (10) further comprises a dust cover (9) that is positioned and fastened below the top mount to prevent entry of dust within the orifices (5) and the at least two chambers (LQ-A) and (LQ-B). The Hydro top mount (10) also comprises a bolt (6) and an upper bracket (7), wherein the Hydro top mount is attached to a chassis of a vehicle using the bolt (6) that in fastened on the upper bracket (7) that is attached to the chassis of the vehicle. The Hydro top mount (10) also comprises a bearing (8) that provides a housing for the Hydro top mount (10). FIGURES 5 exemplarily illustrates dynamic stiffness prediction during usage of the modified hydro top mount (10) based on the road noise frequency range between 80Hz to 150Hz, as an example embodiment of the present disclosure.
Current invention has been discussed specifically with full disclosure. However, numerous changes can be made in the detail of structures, combinations, and part arrangement along with technical advancements that will be implemented in near future without changing the spirit and scope of the invention.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore, contemplated that such modifications can be made without departing from the scope of the present invention as defined.

We Claim:
1. A Hydro top mount (10) comprising:
an inner tube (1);
an outer tube (4) that encloses the inner tube (1);
a bush (2) comprising an upper rubber foot (L1) that is enclosed within the outer tube (4) and a lower rubber foot (L2) that is attached around the inner tube (1), wherein the upper rubber foot (L1) and the lower rubber feet (L2) are of different lengths (L1) and (L2) respectively to maintain flow of a fluid; and
at least two orifices (5) formed by the upper rubber foot (L1) and the lower rubber foot (L2), wherein the orifices (5) comprise different volumes of the fluid so that dynamic stiffness is lower at two different corresponding frequencies to reduce road noise.
2. The Hydro top mount (10) as claimed in claim 1, further comprising at least two chambers (LQ-A) and (LQ-B) of different dimensions formed by the upper rubber foot (L1) and the lower rubber foot (L2) to generate two fluid resonances based on difference in volume of flow of the fluid in the chambers (LQ-A) and (LQ-B), wherein the dynamic stiffness at one or more different frequencies within an upper range and a lower range of frequencies is addressed and reduced by the at least two chambers (LQ-A) and (LQ-B) or 3 or more chambers, resulting in reduced road noise.
3. The Hydro top mount (10) as claimed in claim 1, wherein the dynamic stiffness peaks is reduced by coupling the two fluid resonances, and wherein coupling the two fluid resonances broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
4. The Hydro top mount (10) as claimed in claim 2, wherein difference in the lengths (L1) and (L2) of the upper rubber foot (L1) and the lower rubber feet (L2) maintains the flow of the fluid, and the difference in the dimensions of the two chambers (LQ-A) and (LQ-B) counters and reduces the dynamic stiffness at the one or more different frequencies within the upper range and the lower range of frequencies, resulting in the reduced road noise.

5. The Hydro top mount (10) as claimed in claim 2, wherein difference in the lengths (L1) and (L2) of the upper rubber foot (L1) and the lower rubber feet (L2) maintains the flow of the fluid, the difference in volumes of the orifices (5) lowers the dynamic stiffness at two different corresponding frequencies to reduce road noise, and wherein the coupling of the two fluid resonances broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.
6. The Hydro top mount(10) as claimed in claim 2, wherein difference in the lengths (L1) and (L2) of the upper rubber foot (L1) and the lower rubber feet (L2) maintains the flow of the fluid, wherein the difference in the dimensions of the two chambers (LQ-A) and (LQ-B) counters and reduces the dynamic stiffness at the one or more different frequencies within the upper range and the lower range of frequencies, resulting in reduced road noise, and wherein the dynamic stiffness peaks are reduced by coupling the two fluid resonances, which broadens the resonance and widens the range of frequencies where the dynamic stiffness drops during resonance.