GB2592417A

GB2592417A - Acoustic damper

Info

Publication number: GB2592417A
Application number: GB2002793.4A
Authority: GB
Inventors: O'neill Cody
Original assignee: Mitsubishi Electric Air Conditioning Systems Europe Ltd
Current assignee: Mitsubishi Electric Air Conditioning Systems Europe Ltd
Priority date: 2020-02-27
Filing date: 2020-02-27
Publication date: 2021-09-01
Anticipated expiration: 2040-02-27
Also published as: GB202002793D0; GB2592417B

Abstract

Acoustic damper 100 mounted external of a compressor 500, the damper formed of two dampening parts 200, 250, separated by an impermeable barrier wall 300 to prevent condensate on pipe 520 from seeping through the whole damper (compare fig 18a, 18b). It may have a bore 220 for accommodating the pipe 520 and a slit 210 to aid installation. The bore and slit may instead be a slot (fig 16, 222). A further projection bore 280 may correspond to the compressor projection 580 to ensure interference fit. A sensor void (fig 18b, 230) may accommodate a compressor sensor 530. The dampening parts may be a polymeric foam, a textile, or natural or synthetic felt. The barrier wall may be polymer, or natural or synthetic rubber. Second aspect: compressor unit having acoustic damper 100. Third aspect: refrigerator having a compressor unit with acoustic damper 100.

Description

ACOUSTIC DAMPER

Field of the Invention

The present invention relates to an acoustic damper or noise damper for a compressor, and particularly, although not exclusively, to an acoustic damper having an impermeable barrier wall for protecting a part of the compressor from moisture.

Background

Refrigeration systems such as refrigerators, heat pumps, refrigeration cycle devices and air conditioning systems are widely used as a means for either heating or cooling of space. While exact configurations vary, such systems typically use a vapour-compression cycle, where a refrigerant is circulated through a compressor, two or more heat exchangers, and one or more control valves via connecting pipework. Among these components, the compressor is often a major source of noise and vibration within the system. Noise dampening around the compressor can therefore be critical, both for the comfort of users in the vicinity of the system and to prevent damage caused by vibrations propagating through the different components.

Noise dampening can be achieved with acoustic dampers formed from materials such as foams and/or textiles such as felt. However, such materials are typically porous and/or water permeable. Where they are placed on or around the connecting pipework of the compressor, therefore, they can become saturated with condensate or moisture that forms on such pipes. For example, the inlet or suction pipe of a compressor, due to the low pressure within, can often be at a lower temperature than the surroundings and therefore may cause condensation to occur, and condensate to form on the pipe. In particular, where the suction pipe enters through the compressor through its top surface, condensate can run down the pipe and into the acoustic damper. Moisture absorbed by the acoustic damper may cause damage to components such as sensors located beneath or behind it. Therefore, it would be desirable to provide an acoustic damper which is less prone to allowing moisture to spread in this way.

The present invention has been devised in light of the above considerations.

Summary of the Invention

At its most general, the present invention relates to an acoustic damper for a compressor, having one or more barrier walls arranged between portions of the noise dampening material. The provision of these barrier walls can prevent moisture from one portion of the acoustic damper from spreading to another portion.

According to a first aspect of the present invention, there is provided an acoustic damper for mounting to a compressor of a refrigeration apparatus. The acoustic damper comprises a noise dampening layer having a first part formed of a noise dampening material and a second part separate from the first part and formed of a noise dampening material, and a barrier wall formed of an impermeable material and located between the first part and the second part of said noise dampening layer.

The barrier wall therefore separates the first part and the second part of the noise dampening layer, to prevent moisture from passing from one to the other.

Optionally, the first part of the noise dampening layer may comprise a noise dampening layer bore extending through the noise dampening layer for receiving a pipe of the compressor.

The provision of a bore in the first part of the noise dampening layer enables the acoustic damper to be placed around a pipe of a compressor. In particular, where that pipe is one on which condensate may form, the location of the pipe bore in the first part of the noise dampening layer means that any condensate cannot pass to the second part.

Conveniently, the first part of the noise dampening layer may comprise a noise dampening layer slit extending through the noise dampening layer and from an edge of the noise dampening layer bore to an edge of the noise dampening layer.

The slit enables the acoustic damper to be located about a pipe of a compressor without requiring said pipe to be disconnected. This therefore enables increased ease of fitting and of maintenance of the acoustic damper.

Advantageously, the first part of the noise dampening layer may comprise a noise dampening layer slot extending from an edge of the noise dampening layer and through the noise dampening layer for receiving a pipe of the compressor.

A noise dampening layer slot, having a similar width to a received pipe, provides an alternative means for fulfilling the function of a bore and of the slit, enabling the acoustic damper to be fitted and removed from a pipe of the compressor. Unlike a bore and slit arrangement, a slot can be used even where the acoustic damper is constructed from rigid or substantially rigid materials.

Optionally, the barrier wall may extend between a first position on an outer edge of the noise dampening layer and a second position on an outer edge of the noise dampening layer.

This provides an arrangement where the first and second parts of the noise dampening layer are arranged adjacent to each other, with the barrier wall located between the two parts.

Conveniently, the barrier wall may extend along a substantially straight line. Advantageously, the barrier wall may extend along a curved line.

Providing the barrier wall along a straight or a curved line enables the barrier wall to be configured according to the configuration of the compressor, and of the components to be located behind or beneath the acoustic damper.

Optionally, the second part of the noise dampening layer may be located within the first part of the noise dampening layer, and the barrier wall may extend along an edge of the second part.

This provides an arrangement where the second part of the noise dampening layer (the part that is expected to remain drier or dry in use) can be located as required to protect a particular part or component of the compressor.

Conveniently, the barrier wall may comprise a plurality of barrier wall portions.

Providing a barrier wall comprising a plurality of barrier wall portions allows more complex configurations of the barrier wall for positioning around or otherwise relative to any components to be located behind or beneath the acoustic damper.

Advantageously, the noise dampening layer may comprise a projection bore for receiving a projection of the compressor.

Providing a projection bore or socket in the noise dampening layer, and a corresponding projection, pin, peg, protrusion or bump on the compressor can enable the acoustic damper to be more readily located and retained in position when mounted on the compressor.

Optionally, the projection bore may be located in the first part of the noise dampening layer. Conveniently, the projection bore may be located in the second part of the noise dampening layer.

Advantageously, the projection bore may be located at or on an interface between the first and second noise dampening layer parts.

The location of the projection bore can be chosen according to the configuration of the compressor. It may be preferred, for example, to minimise the number of components located behind or beneath the second part of the noise dampening layer by locating the projection and corresponding projection bore in the first portion. Alternatively, it may be preferable for the first part of the noise dampening layer to be as small in size as possible, meaning that no space is available for the projection bore in this first part.

Optionally, a first portion of the barrier wall may extend from a first position on an edge of the noise dampening layer to a first position on an edge of the projection bore, and a second portion of the barrier wall may extend from a second position on the edge of the noise dampening layer to a second position on the edge of the projection bore.

Where the projection bore is located on or at the interface of the first and second parts of the noise dampening layer, the parts are partially separated by the projection bore. Therefore a barrier wall may not be required within or around the projection bore.

Conveniently, a third portion of the barrier wall may extend along a portion of the edge of the projection bore within the second noise dampening layer part, from the first position on the edge of the projection bore to the second position on the edge of the projection bore.

The third portion of the barrier wall can enable improved protection of the second part of the noise dampening layer by preventing any condensate from moving past or around the projection bore to enter the second part.

Advantageously, the second part of the noise dampening layer may comprise a sensor void for receiving a sensor of the compressor.

Where a sensor of the compressor projects from the surface of the compressor, providing a void in the acoustic damper to receive it can ensure that the sensor is not affected by being in direct contact with the noise dampening material. The void may be precisely shaped to match that of the sensor, or may allow for an additional gap around the sensor, Optionally, the acoustic damper may comprise a barrier layer formed of an impermeable material.

Such a barrier layer can improve the resistance of the acoustic damper to condensate, by preventing at least some of any condensate from the pipe of the compressor from entering into the first part of the noise dampening layer.

Conveniently, the barrier layer may comprise a barrier layer bore at least partially superimposed with the noise dampening layer bore or the noise dampening layer slot and extending through the barrier layer.

A barrier layer bore superimposed with the bore or slot of the noise dampening layer can receive a pipe of the compressor.

Advantageously, the barrier layer may comprise a barrier layer slit extending through the barrier layer and from an edge of the barrier layer bore to an edge of the barrier layer.

As described above with reference to the noise dampening layer slit, this can enable the acoustic damper to be fitted or removed from the compressor without requiring disconnection of the pipe, allowing for increased ease of maintenance.

Optionally, the barrier layer slit may be superimposed with the noise dampening layer slit.

This can allow for easier fitting or removal of the acoustic damper, since both of the slots are aligned.

Conveniently, the barrier layer may comprise a barrier layer slot at least partially superimposed with the noise dampening layer bore or the noise dampening layer slot and extending through the barrier layer.

As with the noise dampening layer slot described above, this provides an alternative to the bore and slot configuration.

It is not necessary that both the noise dampening layer and the barrier layer use the same configuration. For example, it may be preferable to use a bore and slot arrangement in the barrier layer for improved moisture resistance, even if the noise dampening layer uses a slot arrangement for reduced contact with the pipe. Conversely, where the barrier layer is constructed of a rigid or substantially rigid material, it may be necessary to provide a slot as opposed to a bore and slit, since it will not be possible to bend such a barrier layer when fitting to allow the pipe to pass through the slot and into the bore.

Advantageously, the barrier layer and the barrier wall may be formed of the same impermeable material. Optionally, the barrier layer and the barrier wall may be formed integrally as a unitary component.

This can allow increased ease of manufacture by reducing the number of components or parts in the acoustic damper.

Conveniently, the unitary component may be formed by a moulding process. Moulding provides a quick and repeatable means for producing the required part.

Advantageously, at least one said impermeable material may be a deformable material A deformable material can be bent or shaped to allow, for example, manipulation during fitting to the compressor.

Optionally, at least one said impermeable material may be a polymer. Conveniently, the polymer may be a natural or synthetic rubber.

Advantageously, the first part and the second part of the noise dampening layer may formed of the same noise dampening material.

This can allow improved manufacturing by enabling each part of the noise dampening layer to be handled in the same way.

Optionally, at least one said noise dampening material may be a deformable material.

Conveniently, at least one said noise dampening material may be a foamed material.

Advantageously, the foamed material may be a polymeric foam.

Optionally, at least one said noise dampening material may be a textile.

Conveniently, the textile may be a natural or synthetic felt.

According to a second aspect of the present invention, there is provided a compressor unit of a refrigeration apparatus, the compressor unit comprising a compressor and an acoustic damper according to the first aspect, wherein the damper is mounted to an external surface of the compressor.

A compressor mounted with an acoustic damper of the first aspect can have improved condensate resistance while still ensuring suitable noise damping.

Optionally, the compressor may comprise a pipe extending outwardly from said external surface of the compressor. The damper may be mounted to said external surface of the compressor such that said pipe extends through the noise dampening layer bore or the noise dampening layer slot.

The pipe of a compressor may be a source of noise requiring damping. Providing an acoustic damper that can receive a pipe can therefore improve noise damping for the compressor.

Conveniently, the compressor may comprise a sensor located on said external surface of the compressor, the sensor being located behind the second part of the noise dampening layer of the damper.

Locating a sensor behind the second part of the noise dampening layer enables the sensor to be protected from condensate formed on the pipe of the compressor.

Advantageously, the sensor may be a thermistor.

Optionally, the compressor may comprise a projection from said external surface of the compressor for positioning the acoustic damper, said projection being located behind at least part of the acoustic damper.

A projection on the compressor can enable improved positioning and retention of the acoustic damper, even where a corresponding projection void or socket is not provided on the acoustic damper.

Conveniently, the compressor unit may further comprise a cover formed of an impermeable material.

This cover may have a cover bore extending through the cover and a cover slit extending from an edge of the cover bore to an edge of the cover. The cover may be mounted above or in front of the damper such that the suction pipe extends through the cover bore. The cover slit may not be not coincident with the noise dampening layer slit.

A cover of this type can provide improved protection from condensate for the acoustic damper by further limiting an amount of condensate which may impinge upon the acoustic damper. Providing a slit that is not aligned or coincident with the slit or slits of the acoustic nose damper can further improve moisture protection by causing any moisture to have to follow a tortuous path in order to arrive at or impinge upon the noise dampening layer of the acoustic damper.

Advantageously, the cover slit may be aligned perpendicularly to the noise dampening layer slit.

A perpendicular alignment maximises the distance between the slits for improved moisture resistance.

According to a third aspect of the invention, there is provided a refrigeration apparatus having a refrigerant circuit comprising a first heat exchanger, an expansion valve, a second heat exchanger, and a compressor unit according to the second aspect.

The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

Summary of the Figures

Embodiments and experiments illustrating the principles of the invention will now be discussed with reference to the accompanying figures in which: Figures 1A and 1B are a perspective and top-down view respectively of a part of an acoustic damper according to a first embodiment of the present invention; Figures 2A and 2B are a perspective and top-down view respectively of a part of an acoustic damper according to a first embodiment of the present invention; Figures 3A and 38 are a perspective and top-down view respectively of an acoustic damper according to a first embodiment of the present invention; Figures 4A and 4B are a perspective and top-down view respectively of a part of an acoustic damper according to a second embodiment of the present invention; Figures 5A and 5B are a perspective and top-down view respectively of a part of an acoustic damper according to a second embodiment of the present invention; Figures 6A and 65 are a perspective and top-down view respectively of a part of an acoustic damper according to a second embodiment of the present invention; Figures 7A and 7B are a perspective and top-down view respectively of an acoustic damper according to a second embodiment of the present invention; Figure 8 is a top down view of an acoustic damper according to a third embodiment of the present invention; Figure 9 is a top down view of an acoustic damper according to a fourth embodiment of the present invention; Figure 10 is a top down view of an acoustic damper according to a fifth embodiment of the present invention; Figure 11 is a top down view of an acoustic damper according to a sixth embodiment of the present invention; Figure 12 is a top down view of an acoustic damper according to a seventh embodiment of the present invention; Figure 13 is a top down view of an acoustic damper according to an eighth embodiment of the present invention; Figure 14 is a top down view of an acoustic damper according to a ninth embodiment of the present invention; Figure 15 is a top down view of an acoustic damper according to a tenth embodiment of the present invention; Figure 16 is a top down view of an acoustic damper according to an eleventh embodiment of the present invention; Figure 17 is a compressor on which an acoustic damper according to the present invention may be mounted; Figures 18A and 18B illustrate the effect of the barrier walls on condensate flow in and around the acoustic damper; Figure 19 is an arrangement of the compressor and acoustic damper of the present invention further comprising a cover; and Figure 20 is a refrigeration apparatus which may be utilised in conjunction with acoustic damper of the present invention.

Detailed Description of the Invention

Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

A first embodiment of an acoustic damper 100 according to the present invention is illustrated in Figures 1 -3. The acoustic damper 100a comprises a noise dampening layer having a first part 200, a second part 250, and portions of barrier wall 300 separating the first part 200 and second part 250. In this arrangement, the first part 200 of the noise dampening layer comprises a slit 210 and a bore 220 for receiving a pipe 520 of a compressor 500. In some configurations, the slit 210 and/or the bore 220 may be omitted. A slit 210 may enable the acoustic damper to be fitted, removed or replaced from the compressor 500 without requiring the pipe 520 to be disconnected, and can therefore enable easier maintenance of the system.

In the illustrated embodiment, the acoustic damper 100 is substantially circular in shape, with the barrier wall portions 300 being radially aligned and at an acute angle to each other, so as to define two separate sectors of the noise dampening layer as the first part 200 and second part 250. This arrangement is non-limiting, and the acoustic damper 100 may be configured as required to correspond to the dimension and configuration of the compressor to which acoustic damper 100 is to be mounted. It is preferred that the first part 200 of the noise dampening layer is smaller than the second part 250 of the noise dampening layer. This minimises the proportion of the noise dampening layer that may absorb condensate or moisture (the "wet" part), for example from a pipe 520 in the pipe bore 220, and maximises the proportion of compressor 500 located beneath or behind the acoustic damper 100 that is protected from moisture (the "dry" part).

The first part 200 and second part 250 of the noise dampening layer are formed of a noise dampening material. This may be, for example, a foamed material such as a polymer foam. Alternatively, the noise dampening material may be a textile such as wool, felt, artificial or natural textile fibres, or fiberglass. The first part 200 and second part 250 may be formed of the same or of different materials. The barrier walls 300 are formed of an impermeable material, which may be, for example, a polymer such as a plastic or vinyl or a natural or synthetic rubber. The noise dampening material and the impermeable material may be rigid, or may be deformable or flexible. In particular, in configurations where the slit 210 is present, the noise dampening material may be flexible or bendable such that the acoustic damper 100 can be deformed or flexed or manipulated to be fitted to a pipe 520, as is required since the slit 210 can be narrower than the width of the pipe 520.

Further, in this arrangement, the noise dampening layer comprises a further bore 280. This further bore 280 may alternatively be a void, socket, or cut-out not extending fully through the noise dampening layer.

In this arrangement, the further bore 280 is illustrated as being located on or at the interface of the first part 200 and second part 250 of the noise dampening layer. As illustrated in Figures 12 and 13, however, this bore 280 may alternatively be located fully within the first part 200 or fully within the second part 250 of the noise dampening layer. This further bore 280 is a locating bore for receiving a corresponding projection 580 of a compressor 500, and may therefore be referred to as a projection bore 280. The projection 580, as illustrated in Figure 17, may be a locator pin or peg for retaining or locating the acoustic damper 100a on an external surface of the compressor 500. The projection bore 280 may be sized to match the size of a corresponding projection 580 so as to create an interference fit between the two components. Alternatively, the projection bore 280 may instead be larger than the size of any corresponding projection 580, which may allow, for example, for expansion or contraction of the compressor 500 without resulting deformation of the noise dampening layer. The projection bore 280 may comprise a fixing means such as a socket of a snap-fit fastener for improved retention of the acoustic damper 100 to the compressor 500. The projection bore 280 may be omitted in some configurations of the acoustic damper 100.

Although not illustrated, the second part 250 of the noise dampening layer may additionally comprise a further bore 230 or void for receiving a sensing element 530 or other component of a compressor 500.

While the sequence of images in Figures 1-3 illustrates a possible method of construction for the acoustic damper, this is not intended to be limiting, and a different sequence may be used instead. For example, bores 220 and 280 and slit 210 may be added by cutting or punching the noise dampening layer after the separate components are assembled. Furthermore, while the barrier walls 300 are illustrated as being bonded to an end face of the first part 200 of the noise dampening layer, they may instead be bonded first to an end face of the second part 250 of the noise dampening layer. Alternatively, the barrier walls 300 may comprise a socket for receiving the first part 200 and/or the second part 250 of the noise dampening layer (not illustrated). In this way, the noise dampening material may be inserted into the socket, thereby avoiding a requirement for bonding the first part 200 and/or second part 250 of the noise dampening layer to the barrier wall 300.

A second embodiment of an acoustic damper 100b according to the present invention is as illustrated in Figures 4-7. The second embodiment differs from the first in that it includes a barrier layer 400 in addition to the noise dampening layer. Components already described in reference to the first embodiment are shown with the same reference numerals, and are not described further.

The barrier layer 400 is formed of an impermeable material. It is arranged on one face of the noise dampening layer. When the acoustic damper 100b is mounted to the compressor 500, the barrier layer 400 is located on the outer side of the acoustic damper 100b such that the noise dampening layer is located between an outer surface of the compressor and the barrier layer 400. As with the noise dampening layer, the barrier layer may comprise a slit 410 and/or a bore 420 for receiving a pipe 520 of the compressor in a similar manner. The bore 420 is coincident or superimposed with the bore 220 of the noise dampening layer. While the slit 410 is illustrated as being coincident with the slit 210 of the noise dampening layer, the slit 410 may instead be configured such that it is not coincident with the slit 210.

The barrier layer may also comprise a locating bore (not illustrated) coincident with the projection bore 280 of the noise dampening layer, which may extend fully or partially through the barrier layer 400.

In the illustrated embodiment, the barrier layer 400 has substantially the same cross-sectional area as that of the noise dampening layer. In other embodiments, the barrier layer 400 may be larger or smaller than the noise dampening layer. Where the barrier layer 400 is larger, it may extend beyond the noise dampening layer equally in all directions. Alternatively, the barrier layer 400 may extend more in a single direction. In this way, the barrier layer 400 may provide a run-off route for incident condensate to an area beyond the acoustic damper 100b. Such a barrier layer 400 may additionally be provided with one or more grooves, corrugations or other contouring to direct moisture towards this run-off route.

The barrier layer 400 may be bonded to the noise dampening layer across the entire face of the noise dampening layer. Alternatively the barrier layer 400 may be bonded to the noise dampening layer at a portion of the noise dampening layer. In still further configurations, the barrier layer 400 may be shaped to receive the noise dampening layer. For example, the barrier layer 400 may be wholly or partially dish-or bowl-shaped, with a lip (not illustrated) at an outer edge, and the noise dampening layer may be received in this dish or bowl.

The barrier layer 400 may be formed of the same impermeable material as the barrier wall 300. The barrier wall 300 and barrier layer 400 may be formed as a unitary component. This may be formed, for example, by a moulding process.

As discussed in view of the first embodiment, the construction or assembly of the acoustic damper 100b may not follow the sequence indicated in Figures 4-7. For example, bores 220,420 and 280 and slits 210 and 410 may be added by cutting or punching of the noise dampening layer after the separate components are assembled.

The relative arrangement of the first part 200, second part 250 of the noise dampening layer and barrier wall 300 may be different from that illustrated for the first or second embodiment. Figures 8-16 illustrate altemative and exemplary arrangements for the components. While each of these further examples illustrates the acoustic damper 100 as being substantially circular in shape, this is not limiting. The acoustic damper 100 can be shaped as required to correspond to the compressor 500 on which the acoustic damper 100 is to be mounted. For example, the acoustic damper 100 may instead be square, rectangular, ovoid or elliptical, in addition to other shapes.

Figure 8 illustrates an acoustic damper 100c, wherein the barrier wall 300 follows a straight line between two points at the outer edge of the noise dampening layer.

Figure 9 illustrates an acoustic damper 100d, wherein the barrier wall 300 follows a curved line between two points at the outer edge of the noise dampening layer.

The curved or straight barrier walls 300 depicted here are not limiting. The barrier wall 300 may be shaped as required to conform to the configuration of the compressor 500 to which the acoustic damper is to be mounted. For example, the barrier wall 300 may instead follow a path that has both straight and curved portions, or that may follow a winding or serpentine path. The barrier wall 300 may be arranged to closely surround the pipe bore 220 of the acoustic damper 100. In this way, the first part 200 of the noise dampening layer may preferably be substantially smaller than the second part of the noise dampening layer 250, such that the proportion of the noise dampening layer that is most likely to be exposed to moisture is minimised.

Figure 10 illustrates an acoustic damper 100e, wherein the barrier wall 300 is composed of two barrier wall portions 300a, 300b meeting at an acute angle to define a sector of the noise dampening layer. The angle and arrangement of the barrier wall portions 300a, 300b to define a sector in this way can minimise the area of the first part 200 of the noise dampening layer to best match the area required for the pipe bore 220.

Figure 11 illustrates an acoustic damper 100f, wherein the barrier wall 300 comprises portions 300a, 300b along the interface between the first part 200 and second part 250 of the noise dampening layer, and additionally a portion 300c around an outer edge of the projection bore 280. This is a variation of the configuration shown in Figures 3 and 7. In those arrangements, since the projection bore 280 is located on or at the interface of the first part 200 and second part 250 of the noise dampening layer, it intersects the barrier wall portions 300a, 300b, and there is a corresponding gap or opening in the barrier wall 300. In some circumstances, moisture or condensate may be able to cross the projection void 280, particularly if the first part 200 of the noise dampening layer becomes saturated during use. Therefore, the additional portion 300c of the barrier wall surrounds the projection bore 280 so as to close this gap in the barrier wall 300 and thereby prevent moisture from crossing the projection bore 280. A barrier wall 300 arrangement of this type would also be advantageous if the projection bore 280 is a void that does not extend fully through the noise dampening layer, since otherwise the first part 200 and second part 250 of the noise dampening layer would not be fully separated from each other.

Figure 12 illustrates an acoustic damper 100g, wherein the projection bore is located entirely within the first part 200 of the noise dampening layer.

Figure 13 illustrates an acoustic damper 100g, wherein the projection bore 280 is located entirely within the second part 200 of the noise dampening layer.

Locating the projection bore 280 entirely within the first part 200 or the second part 250 of the noise dampening layer can provide a configuration in which fewer or even no gaps are required in the barrier wall 300 when compared to an arrangement where the projection bore 280 is located on or at the interface between the first part 200 and the second part 250. Whether the projection bore 280 is to be located within the first part 200 or the second part 250 of the noise dampening layer may be selected according to design configurations and to the space available in each of the parts.

Figure 14 illustrates an acoustic damper 100h, wherein the second part 250 of the noise dampening layer is located within the first part 200 of the noise dampening layer, so as to be surrounded around its entire periphery by the first part 200. While this does not fulfil the same function of maximising the "dry" area of the acoustic damper 100h, it can instead enable the "dry" area to be more precisely matched to the location of a moisture sensitive component of the compressor 500. Meanwhile, condensate flowing or absorbed by the "wet" part of the acoustic damper 100h can be spread out across a wider area, preventing moisture from concentrating on one side of the compressor 520, which may be considered beneficial for some installations.

Figure 15 illustrates an acoustic damper 100i, wherein the first part 200 of the noise dampening layer is located within the second part 250 of the noise dampening layer so as to be surrounded around its entire periphery by the second part 250, and no slit 210 is present. This can provide good matching between the area of the first part 200 of the noise dampening layer and the pipe bore 280. However, it precludes the use of a slit 210, since this would necessarily have to pass through the second part 250 of the noise dampening layer, and could therefore allow moisture to pass into the second part 250 via the slit 210.

Figure 16 illustrates a acoustic damper 100j, wherein the pipe bore 220 is replaced by a slot 222 located at an outer edge of the noise dampening layer, and no slit 210 is present. Instead, the slot, which is approximately equal in width to the external diameter of the pipe 520 to be received therein, provides an alternative means for fulfilling the function of both the slit 210 and pipe bore 220. This can enable the acoustic damper 100] to be constructed from rigid materials, since no bending or flexing of the acoustic damper 100] is required to fit a pipe 520 through the slot 222 when locating the acoustic damper 100] about the pipe 520.

The acoustic damper 100 is mountable on a compressor 500. An exemplary compressor 500 is shown in Figure 17, illustrating the elements that may be present on a surface to which the acoustic damper is to be mounted. These can include one or more pipes 520, a projection 580 (which may be, for example, a peg, pin or otherwise shaped protrusion), and one or more sensor elements 530, which may include, for example, a thermistor. The pipe 520 may be received in a pipe bore 220 or pipe slot 222 of the acoustic damper 100 of the present invention.

The projection 580 may be received in a projection bore 280 of the acoustic damper 100. The projection 580 therefore acts as a means to locate or retain the acoustic damper 100 on the compressor 500. This may be beneficial, for example, in ensuring that the acoustic damper 100 is correctly oriented on the compressor 500 such that the first and second parts of the noise dampening layer are correctly positioned. A pipe 520 and the projection 580 can act as two fixed points and thereby orient the acoustic damper 100. Additionally or alternatively, the projection 580 can prevent the acoustic damper 100 from being moved or displaced by vibrations of the compressor.

The function of the barrier walls 300 of the acoustic dampers 100a-100j is now explained with reference to Figures 18A and 18B. Figure 18A illustrates a cross sectional view of an acoustic damper without barrier walls mounted on a compressor 500. Figure 18B illustrates a cross sectional view of an acoustic damper 100 in accordance with the present invention mounted on a compressor 500. A pipe 520 extends through the noise damper 100. When the compressor 500 operates, condensate may form on the pipe 520. This condensate can flow or run along the pipe 520 under the influence of gravity, as indicated by the arrows. While a barrier layer 400 provided in an acoustic damper 100 can prevent some of the condensate from passing into the noise dampening layer, some condensate may nevertheless still pass through the barrier layer 400 via either the pipe bore 420 or the slit 410. In the absence of a barrier wall 300, this condensate can then migrate through the noise dampening material via, for example, capillary flow and the wicking effect of the noise dampening material. The moisture can then impinge upon other components of the compressor 500 such as a sensor 530. Such components may be moisture sensitive, and may therefore fail to function correctly when wet, or may be damaged or destroyed by moisture.

The barrier wall 300 of the present invention provides an impermeable separation between the first part and the second part 250 of the noise dampening layer, thereby preventing moisture from passing from the first part 200 to the second part 250, as shown in Figure 18B. The compressor 500 is configured such that moisture sensitive components such as a sensor 530 are located beneath or behind the second part 250 of the acoustic damper 100 when it is mounted to the compressor. In this way, since moisture is confined within the first part 200 of the acoustic damper 100, the barrier wall 300 can protect the sensor 530 or other moisture sensitive components from being either damaged or from giving false or incorrect readings due to the presence of moisture. It may be preferable to configure the compressor such that the moisture-sensitive components are spaced from or remote from both the barrier wall 300 and the "wet" first part 200 of the noise dampening layer, as this can better ensure that even moisture that passes through the acoustic damper and onto a surface of the compressor is still distant from any moisture sensitive components. Providing an acoustic damper 100 wherein the first part 200 of the noise dampening layer is smaller than the second part 250 of the noise dampening layer, and preferably significantly smaller, can enable this separation to be maximised.

The acoustic damper 100 may further be supplemented with an additional cover 600, as illustrated in Figure 19. This cover 600 is formed of an impermeable material, which may be the same or a different impermeable material than that of the barrier walls 300 or the barrier layer 400 of the acoustic damper 100. The cover comprises a slit 610 and a pipe bore 620. In other embodiments, one or both of these features may be omitted. Where a slit 610 is present, the slit 610 may be aligned so as to not be coincident with the slits 210, 410 of the acoustic damper 100, and to thereby create a tortuous path for condensate to follow before reaching the noise dampening layer of the acoustic damper 100. In some embodiments, the slit 610 may be perpendicular to the slits 210, 410 of the acoustic damper 100. Figure 19 illustrates the assembly in a semi-exploded manner, such that the relative orientation of these slits 210, 410, 610 can be seen. Once assembled, the acoustic damper 100 and cover 600 would instead sit directly on the compressor.

The cover 600 may, for example, be larger than the acoustic damper 100. In this way, the cover 600 may divert at least some of the condensate away from the acoustic damper, providing a run-off route to an area beyond the acoustic damper 100. The cover 600 may additionally be provided with one or more grooves, corrugations or other contouring to direct moisture towards this run-off route.

The compressor 500 on which the acoustic damper 100 is to be mounted may form part of a refrigeration apparatus 1000 such as a refrigerator, heat pump, refrigeration cycle device or air conditioning system. A schematic arrangement of such an apparatus 1000 is illustrated in Figure 20. The apparatus 1000 comprises a compressor 500 equipped with an acoustic damper 100, two or more heat exchangers 1010, functioning either as an evaporator or a condenser, and an expansion valve 1020. These components are connected by connecting pipework to enable refrigerant to flow around the apparatus. Other configurations of a refrigeration apparatus may also be used without affecting the functionality of the present invention.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the word "comprise" and "include", and variations such as "comprises", "comprising", and "including" 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.

It must be noted that, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

Claims

Claims: 1. An acoustic damper for mounting to a compressor of a refrigeration apparatus, the acoustic damper comprising: a noise dampening layer having a first part formed of a noise dampening material and a second part separate from the first part and formed of a noise dampening material; and a barrier wall formed of an impermeable material and located between the first part and the second part of said noise dampening layer.
2. An acoustic damper according to claim 1, wherein the first part of the noise dampening layer comprises: a noise dampening layer bore extending through the noise dampening layer for receiving a pipe of the compressor.
3 An acoustic damper according to claim 2, wherein the first part of the noise dampening layer comprises: a noise dampening layer slit extending through the noise dampening layer and from an edge of the noise dampening layer bore to an edge of the noise dampening layer.
4 An acoustic damper according to claim 1, wherein the first part of the noise dampening layer comprises: a noise dampening layer slot extending from an edge of the noise dampening layer and through the noise dampening layer for receiving a pipe of the compressor.
5. An acoustic damper according to any preceding claim, wherein the barrier wall extends between a first position on an outer edge of the noise dampening layer and a second position on an outer edge of the noise dampening layer.
6. An acoustic damper according to any preceding claim, wherein the barrier wall extends along a substantially straight line. 30
7. An acoustic damper according to any of claims 1 to 5, wherein the barrier wall extends along a curved line.
8. An acoustic damper according to any of claims 1 to 4, wherein the second part of the noise dampening layer is located within the first part of the noise dampening layer, and the barrier wall extends along an edge of the second part.
9. An acoustic damper according to any preceding claim, wherein the barrier wall comprises a plurality of barrier wall portions.
10. An acoustic damper according to any preceding claim, wherein the noise dampening layer comprises a projection bore for receiving a projection of the compressor.
11. An acoustic damper according to claim 10, wherein the projection bore is located in the first part of the noise dampening layer.
12. An acoustic damper according to claim 10, wherein the projection bore is located in the second part of the noise dampening layer.
13. An acoustic damper according to claim 10, wherein the projection bore is located at or on an interface between the first and second noise dampening layer parts.
14 An acoustic damper according to claim 13, wherein a first portion of the barrier wall extends from a first position on an edge of the noise dampening layer to a first position on an edge of the projection bore, and a second portion of the barrier wall extends from a second position on the edge of the noise dampening layer to a second position on the edge of the projection bore.
15. An acoustic damper according to claim 14, wherein a third portion of the barrier wall extends along a portion of the edge of the projection bore within the second noise dampening layer part, from the first position on the edge of the projection bore to the second position on the edge of the projection bore.
16. An acoustic damper according to any preceding claim, wherein the second part of the noise dampening layer comprises a sensor void for receiving a sensor of the compressor.
17. An acoustic damper according to any preceding claim, further comprising a barrier layer formed of an impermeable material.
18. An acoustic damper according to claim 17 as dependent on any of claims 2 to 16, wherein the barrier layer comprises a barrier layer bore at least partially superimposed with the noise dampening layer bore or the noise dampening layer slot and extending through the barrier layer.
19. An acoustic damper according to claim 18 wherein the barrier layer comprises a barrier layer slit extending through the barrier layer and from an edge of the barrier layer bore to an edge of the barrier layer.
20. An acoustic damper according to claim 19, wherein the barrier layer slit is superimposed with the noise dampening layer slit.
21. An acoustic damper according to claim 17 as dependent on any of claims 2 to 16, wherein the barrier layer comprises a barrier layer slot at least partially superimposed with the noise dampening layer bore or the noise dampening layer slot and extending through the barrier layer.
22. An acoustic damper according to any of claims 17 to 21, wherein the barrier layer and the barrier wall are formed of the same impermeable material.
23. An acoustic damper according to claim 22, wherein the barrier layer and the barrier wall are formed as a unitary component.
24. An acoustic damper according to claim 23, wherein the unitary component is formed by a moulding process.
25. An acoustic damper according to any preceding claim, wherein, at least one said impermeable material is a deformable material.
26. An acoustic damper according to any preceding claim, wherein at least one said impermeable material is a polymer.
27. An acoustic damper according to claim 26, wherein the polymer is a natural or synthetic rubber.
28. An acoustic damper according to any preceding claim, wherein the first part and the second part of the noise dampening layer are formed of the same noise dampening material.
29. An acoustic damper according to any preceding claim, wherein, at least one said noise dampening material is a deformable material
30. An acoustic damper according to any preceding claim, wherein at least one said noise dampening material is a foamed material.
31. An acoustic damper according to claim 30, wherein the foamed material is a polymeric foam.
32. An acoustic damper according to any preceding claim, wherein at least one said noise dampening material is a textile.
33. An acoustic damper according to claim 32, wherein the textile is a natural or synthetic felt.
34. A compressor unit of a refrigeration apparatus, the compressor unit comprising a compressor and an acoustic damper according to any preceding claim, wherein the damper is mounted to an external surface of the compressor.
35. A compressor unit according to claim 34 wherein the acoustic damper is in accordance with claim 2 or claim 4 or with any preceding claim as dependent on claim 2 or claim 4, and wherein the compressor comprises a pipe extending outwardly from said external surface of the compressor; said damper being mounted to said external surface of the compressor such that said pipe extends through the noise dampening layer bore or the noise dampening layer slot.
36. A compressor unit according to claim 34 or claim 35, wherein the compressor comprises a sensor located on said external surface of the compressor, the sensor being located behind the second part of the noise dampening layer of the damper.
37. A compressor unit according to claim 36, wherein the sensor is a thermistor.
38. A compressor unit according to any one of claims 34 to 37, wherein the compressor comprises a projection from said external surface of the compressor for positioning the acoustic damper, said projection being located behind at least part of the acoustic damper.
39. A compressor unit according to any one of claims 34 to 38, further comprising a cover formed of an impermeable material, the cover having a cover bore extending through the cover and a cover slit extending from an edge of the cover bore to an edge of the cover, wherein the cover is mounted above the damper such that the suction pipe extends through the cover bore, and wherein the cover slit is not coincident with the noise dampening layer slit.
40. A compressor unit according to claim 39, wherein the cover slit is aligned perpendicularly to the noise dampening layer slit.
41 A refrigeration apparatus having a refrigerant circuit comprising: a first heat exchanger, an expansion valve, a second heat exchanger, and a compressor unit according to any one of claims 34 to 40.