CN113423957A

CN113423957A - Extractor assembly to be installed inside an air duct

Info

Publication number: CN113423957A
Application number: CN201980091410.2A
Authority: CN
Inventors: A·巴赫-埃斯蒂夫伯奇
Original assignee: Soler and Palau Research SL
Current assignee: Soler and Palau Research SL
Priority date: 2019-02-06
Filing date: 2019-12-30
Publication date: 2021-09-21
Also published as: EP3922857A1; IL285199B2; AU2019428668B2; SG11202107911RA; RU2767859C1; CL2021002040A1; AU2019428668A1; EP3922857B1; NZ778318A; IL285199A; MX2021009141A; ES2777923B2; PE20220101A1; IL285199B1; WO2020161369A1; ES2777923A1; CO2021009398A2; EP3922857A4; PL3922857T3

Abstract

The invention relates to an extractor assembly to be installed inside an air duct, comprising an impeller (1); an actuating element (2) for imparting rotational momentum to the impeller (1); a support (3); A housing (4) surrounding the impeller (1), the actuating element (2) and the support (3). The support (3) comprises an inner wall (3.3), which with the first face (3.1) defines a housing (6) for accommodating the actuating element (2), and an outer wall (3.4), which is opposite to the inner wall (3.3) Disposed radially and externally, so that the walls (3.3, 3.4) define passages (7) for air movement. When the extractor assembly is installed in the use position, the outer wall (3.3) radially covers a portion of the interior of the housing (4) so that the housing (4) along the outer wall (3.4) is not in contact with the air driven by the impeller (4) .

Description

Extractor assembly to be installed inside an air duct

Technical Field

The present invention relates to the sector dedicated to extractor assemblies to be installed inside air ducts.

Background

Currently, extractor assemblies to be installed inside air ducts are well known. These extractor assemblies have an impeller with blades, a motor for rotating the impeller so that a flow or movement of air is generated by the blades, a support that provides the motor to be fixed inside the extractor assembly, and a housing as an overall cover.

Due to the flow or movement of the generated air, the extractor assembly generates an annoying noise. This noise is primarily due to the movement of air along the extractor assembly.

This is, in turn, mainly due to the fact that the air does not move in a completely continuous or uniform manner, whereas the noise is generated by discontinuities resulting from point contacts with the casing according to a certain frequency, which are mainly irregular. This disadvantage is seriously aggravated in the case of metal housings.

In view of the noted shortcomings or limitations with currently existing solutions, there is a need for a solution that reduces the noise generated by the passage of air along an extractor assembly.

Disclosure of Invention

In order to achieve this object and to solve the technical problems discussed so far, the present invention provides, in addition to providing additional advantages that may be obtained hereinafter, an extractor assembly to be installed inside an air duct.

In addition to being able to additionally have a face plate to prevent air from contacting the housing along the vanes, the extractor assembly also includes an impeller having a base and vanes that project from the base.

The extractor assembly additionally comprises an actuating element for imparting rotational momentum to the impeller such that the impeller generates an air flow through the blades; a support having a first face for fixedly positioning an actuating element and a second face; and a housing comprising a first portion and a second portion for surrounding the impeller, the actuating element and the support.

The support comprises an inner wall defining, by a first face, a housing for housing the actuating element; and an outer wall disposed radially and externally with respect to the inner wall such that the walls define a passage for air movement.

Thus, when the extractor assembly is mounted in the use position, the outer wall makes radial and internal contact against the first and second portions and against the engagement areas of the first and second portions that engage each other, so that the air outlet along the outer wall remains blocked. In this way, the noise outlet through the joining region is also blocked.

Preferably, the outer wall is arranged to contact the entire joining region. Furthermore, the joining area is preferably formed by an overlap between the first portion and the second portion.

Preferably, the support comprises fins located in the channels to direct the flow of air. The fins are therefore preferably curved to eliminate the tangential component of the air flow generated by the blades, so that the air flow can be directed according to a straight path.

The actuating element is arranged to be fixed in the support and the impeller is joined to the actuating element, a separation gap being provided between the base and the inner wall for the entry of air into the actuating element.

The extractor assembly may include a cover disposed along the second face of the support such that it defines a continuation of the channel. Thus, the cover preferably has a concave side for covering the components of the extractor assembly and a convex side for directing air.

The extractor assembly may include a conduit configured to communicate an exterior portion of the housing with the containment. Thus, the conduit preferably has a first section projecting outwardly relative to the outer wall and each portion of the housing has a slot to collectively define a gap for receiving the first section.

The extractor assembly may include a blocking element arranged to prevent air from moving between the housing and the face plate of the impeller such that air entering the housing is directed between the face plate and the base.

Preferably, the housing comprises a metallic material. Additionally or alternatively, the support preferably comprises a plastics material. Additionally or alternatively to any of the above, the impeller preferably comprises a plastics material.

Drawings

Fig. 1 shows, in the upper part, an extractor assembly belonging to the prior art and, in the lower part, an extractor assembly object of the invention.

Fig. 2 shows an exploded schematic view of an extractor assembly to be installed inside an air duct, which is the object of the present invention.

Fig. 3 and 4 show schematic perspective views of the extractor assembly which is the object of the present invention.

Fig. 5 and 7 show schematic side views of the extractor assembly which is the object of the present invention. And figures 6 and 8 show a rear view and a front view, respectively.

Fig. 9 shows a longitudinal cross-sectional schematic view of the extractor assembly in the use position.

Fig. 10A and 10B show a schematic view of an impeller included in an extractor assembly that is the object of the present invention.

Fig. 11 and 12 show a schematic perspective view of the support included in the extractor assembly, object of the present invention.

Figures 13 and 15 show a rear view and a front view, respectively, of the support; while figures 14 and 16 show a schematic side view and a schematic side cross-sectional view, respectively, of the support.

Detailed Description

The invention relates to an extractor assembly to be installed inside an air duct, comprising an impeller (1), an actuating element (2), a support (3) and a casing (4), the casing (4) comprising a first portion (4.1) and a second portion (4.2) for surrounding the impeller (1), the actuating element (2) and the support (3) as a total covering.

The impeller (1) has a base (1.1) and blades (1.2), the blades (1.2) projecting from the base (1.1). The base (1.1) has a contact surface (1.1 '), the contact surface (1.1') being configured to receive contact from a portion of the air entering the impeller (1) and thus the extractor assembly. The impeller (1) is visible in fig. 2, 10A and 10B.

This configuration of the base (1) provides a direction to the inner periphery of the air extractor assembly, in other words towards a portion that is radially and externally further away with respect to the imaginary central longitudinal axis (X) of the extractor assembly, thereby minimizing the impact or obstruction of the air advancing along the casing (4) through its inner portion. Thus, the contact surface (1.1') has a convex shape.

Furthermore, the actuating element (2) is an electric motor which is provided for imparting a rotational momentum to the impeller (1) in order to cause it to generate an air flow by means of the blades (1.2). The actuating element (2) is visible in fig. 2 and 9.

Thus, the impeller (1), more particularly by the base (1.1), is arranged to be mechanically coupled to the actuating element (2) to receive the rotation driven by the actuating element (2). The air flow generated by the rotational movement of the blades (1.2) moves along the extractor assembly.

The support (3) has a first face (3.1) and a second face (3.2), the first face (3.1) being opposite to the second face (3.2). The first surface (3.1) is used for fixedly arranging the actuating element (2). The support (3) is visible in fig. 11 to 16.

The actuating element (2) is arranged to be fixed on said first face (3.1) of the support (3) by means of a threaded engagement. Also, preferably, a vibration absorber or damping element (5) is provided between the actuating element (2) and the above-mentioned first face (3.1). The actuating element (2) is thus fixedly engaged on the first face (3.1) by being fastened to the damper (5), while the damper (5) is in turn arranged to be fastened to said first face (3.1) for the use of the extractor assembly.

Furthermore, the support (3) additionally has an inner wall (3.3) which is perpendicular or substantially perpendicular to the first face (3.1) for fastening the actuating element (2). Preferably, the inner wall (3.3) extends parallel to an imaginary central longitudinal axis (X) of the extractor assembly. Also, preferably, the inner wall (3.3) describes a geometric shape, preferably a cylindrical shape, such that it defines the shell (6).

The first face (3.1) of the support (3) is peripherally limited by the above-mentioned inner wall (3.3). In this way, the containment shell (6) is radially and externally or peripherally delimited by the inner wall (3.3) and axially or longitudinally delimited by the first face (3.1).

The housing (6) has an opening at a longitudinal end opposite the position of the first face (3.1), through which opening the actuating element (2) protrudes at its engagement with the impeller (1), in other words the inner wall (3.3) and the first face (3.1) define the housing (6), which housing (6) is open.

Furthermore, the support (3) has an outer wall (3.4), which outer wall (3.4) is arranged radially and externally with respect to the inner wall (3.3). Also, preferably, the outer wall (3.4) describes a geometrical shape, preferably a cylindrical shape. Therefore, preferably, the outer wall (3.4) is parallel or substantially parallel to the inner wall (3.3). Thus, the inner wall (3.3) and the outer wall (3.4) are radially spaced from each other such that they define a channel (7) for air movement.

The inner wall (3.3) and the outer wall (3.4) are joined together by means of fins (3.5) included in the support (3). The fins (3.5) serve as guiding elements for the air or the air flow generated by the impeller (1) in addition to the joining elements between the two walls (3.3, 3.4), and at the same time define a channel gap therebetween in accordance with the channel (7).

Preferably, the fins (3.5) are curved. Said air flow generated by the impeller (1) has a helical flow due to the rotation of the impeller (1), in other words a helical path is described. In other words, the air flow has a velocity with a tangential component when leaving the impeller (1). The fins (3.5) are thus arranged to eliminate said tangential component, so that the air is guided in a linear or straight manner, the velocity and pressure of the air increasing.

Preferably, the outer wall (3.4) is smooth, continuous and uniform, in other words free of through holes in the radial direction. Likewise, it is also preferred that the inner wall (3.3) is likewise smooth, continuous and uniform, in other words free of through holes in the radial direction.

When the actuating element (2) is correspondingly fastened on the support (3) along the vessel (6) and the impeller (1) is mechanically coupled to the actuating element (2) to receive the rotational momentum imparted by the actuating element (2) such that the impeller generates an air flow, the construction and arrangement of the impeller (1) and the outer wall (3.4) is such that the air flow leaves the driven impeller (1) such that the air flow is directed partly substantially parallel to the outer wall (3.4) and partly against said outer wall (3.4).

By such a construction and arrangement, which can be derived from fig. 9, it is at least possible to prevent the majority of the air flow generated from coming into contact with the casing (4) at the outlet of the impeller (1) and in the advancement or movement of the air flow in the longitudinal direction of the extractor assembly and parallel to the imaginary central longitudinal axis (X).

Preferably, by this construction and arrangement, the resulting air flow is in contact with the casing (4) at the outlet of the impeller (1) in a proportion of zero, or at least negligible in terms of decibels generated by this air flow. Likewise, the proportion of the generated air flow that comes into contact with the casing (4) during its advance or movement in the longitudinal direction of the extractor assembly and parallel to the imaginary central longitudinal axis (X) is also zero, or at least negligible from the point of view of the generated noise.

The base (1.1) of the impeller (1) has a flange or profile (1.1 ") which remains aligned or substantially aligned with the inner wall (3.3) of the support (3) when the actuating element (2) is correspondingly fastened on the support (3) along the containment vessel (6) and the impeller (1) is mechanically coupled to the actuating element (2) to receive the rotational momentum imparted by the actuating element (2) so that the impeller generates the air flow. Furthermore, the flange or profile (1.1 ") comprises a longitudinal extension aligned with the inner wall (3.3).

Correspondingly, between the aforementioned profile (1.1') and the longitudinal end of the inner wall (3.3), a separation gap (S) is provided, which defines a controlled air inlet for entering the containment vessel (6). The separation gap (S) is thus configured to provide cooling of the actuating element (2) by a controlled and reduced portion of the air flow generated by the impeller (1).

The second face (3.2) of the support (3) is configured to provide additional components (8) which interfere with the operation of the extractor assembly. In fig. 2 and 9, one of these components (8), which is a capacitor, is shown.

The extractor assembly comprises a cover (9) to be arranged along the second face (3.2) of the support (3) in the position of use, so that it determines the continuity of the channel (7). Preferably, the cover (9) is arranged to be engaged to the support (3) by means of a threaded engagement, but alternatively it may be engaged by means of a clamping or snap engagement point.

Furthermore, a cover (9) is defined such that it has a concave side for covering a component (8) of the extractor assembly arranged along the second face (3.2) and a convex side for guiding air. The covering (9) thus has a peripheral edge (9.1) which is dimensioned such that it is equal to or smaller than the geometry of the inner wall (3.3) in terms of radial measurement. See fig. 9.

Preferably, the cover (9) is joined to the support (3) so that the peripheral edge (9.1) is arranged so that it determines the continuity of the inner wall (3.3) according to a direction longitudinal and parallel to an imaginary central longitudinal axis (X) of the extractor assembly. Thus, turbulence is prevented from being generated in the air flow generated by the impeller (1) when the air flow moves along the end of the inner wall (3.3) according to the movement or advancing direction of said air flow. This arrangement or configuration is clearly visible in fig. 9.

Furthermore, the cover (9) is defined such that it has a convex side to guide air. In other words, the cover smoothes the direction of the air flow after it has advanced through the channel (7) towards a more radial and inner region to exit the extractor assembly.

The cover (9) therefore has on the convex side a curved edge (9.2) which is dimensioned such that it is determined, on a radial measurement of the cover (9) or relative to the imaginary central longitudinal axis (X), to decrease in a progressive manner, in other words not abruptly. In this way, the cover (9) prevents the formation of turbulence or pressure variations that could impede or reduce the fluidity of the air as it exits the extractor assembly or at least in directing it towards a more radial and internal region after it has advanced through the passage (7) to exit the extractor assembly.

As mentioned before, the housing (4) comprises a first part (4.1) and a second part (4.2). Preferably, the portions (4.1,4.2) may be joined together, each defining a longitudinal end of the extractor assembly, as can be clearly seen in fig. 2 for example, although alternatively the portions may be joined together, each defining a longitudinal half of the assembly.

The first portion (4.1) and the second portion (4.2) are joined together according to a joining zone (J) located along the outer wall (3.4). More specifically, the outer wall (3.4) is arranged in contact with a first portion (4.1) and a second portion (4.2), both close to and along the junction area (J) between them, which is formed by the overlap between said portions (4.1, 4.2).

According to the aforementioned preferred option, according to which each portion (4.1,4.2) determines one of the longitudinal ends of the extractor assembly, the joining zone (J) is located completely along the outer wall (3.4) and in contact with the outer wall (3.4), in other words, as a whole, as can be derived from fig. 2 and 9. In this way, it contributes to an airtight joint or seal between the aforementioned portions (4.1,4.2) of the casing (4), so that air is prevented from leaking or exhausting through said joint area (J).

The first portion (4.1) and the second portion (4.2) have a first step (4.1 ', 4.2') in a longitudinal portion for the longitudinal adjustment arrangement of the outer wall (3.4), which longitudinal portion is parallel or substantially parallel to the imaginary central longitudinal axis (X). Furthermore, the first step (4.1 ', 4.2') is defined such that the inner face of the outer wall (3.4) in contact with the housing (4) is aligned with or imparts continuity with the inner surface of the housing (4), in other words of the portion (4.1, 4.2). See fig. 9.

Thus, turbulence is prevented from being generated in the air flow generated by the impeller (1) when the air flow moves along both the beginning of the outer wall (3.3) and the end of said wall (3.4) according to the movement or advancing direction of said air flow.

Furthermore, one of the portions (4.1,4.2) has a second step (10) to overlap with the corresponding longitudinal end of the other portion (4.2, 4.1) to improve the tightness, in other words to prevent air and noise from escaping. In this case, the one junction area (J) is determined or defined according to the overlap, also as described previously.

The housing (4) has an inlet opening (11) and an outlet opening (12). Preferably, the inlet opening (11) is located entirely in the first section (4.1) and the outlet opening (12) is located entirely in the second section (4.2). Likewise, the inlet port (11) defines an inlet for air drawn into the extractor assembly by the impeller (1), and the outlet port (12) defines an outlet for air flow driven or generated by the impeller (1) of the extractor assembly.

These ports (11, 12) are configured to be connected to an air duct, which is not an object of the present invention. Likewise, the portions (4.1,4.2) of the housing (4) have a smaller dimension, in other words a smaller inner diameter, in the ports (11, 12).

In this way, the housing (4) therefore has a diameter-changing section (4'). The housing (4) therefore has one of the diameter-changing sections (4 ') immediately after the inlet opening (10) and the other of the diameter-changing sections (4') immediately before the outlet opening (11), depending on the direction of advance or movement of the air flow that can be generated by the impeller (1).

Optionally, the outer wall (3.4) of the support (3) extends such that it covers the housing (4) radially and internally also along the diameter variation section (4') located immediately before the outlet (12).

Along each port (11, 12), radially and externally to these ports (11, 12), the extractor assembly comprises a gasket (13) to provide tightness so that leakage of air with respect to the air duct and the extractor assembly itself is prevented.

When mounting the extractor assembly or at least the portions (4.1,4.2) of the casing (4) are joined together along the outer wall (3.4) of the support (3) according to a joining region (J), the mouths (11, 12) are arranged in a concentric manner with respect to the imaginary central longitudinal axis (X) and are arranged according to a smaller diameter with respect to said outer wall (3.4) in addition to preferably with respect to the inner wall (3.3). In this way, both the air inlet into the extractor assembly and the air outlet from the extractor assembly are advantageous.

Preferably, and as can be clearly observed in fig. 10A and 10B, the impeller (1) has in addition a face plate (1.3). The panel (1.3) has an extension in the longitudinal direction such that the extension is measured corresponding to different diameters at each point along the extension. In other words, the panels (1.3) have open longitudinal ends, each of these longitudinal ends having a diameter different from each other according to a preferably progressive variation.

The diameter of the open longitudinal end arranged facing the inlet opening (11) is smaller than the diameter of the open longitudinal end arranged facing the actuating element (2). According to a gradual and preferably linear change of the diameter of the panel (1.3), the panel (1.3) is configured to be arranged parallel or substantially parallel to the housing (4) along a corresponding diameter change section (4').

When the extractor assembly is installed, for example according to the condition visible in fig. 9, said panel (1.3) prevents or blocks air from coming into contact with the casing (4), more specifically with the diameter variation section (4') located immediately after the inlet opening (11).

Due to the fact that the panel (1.3) can prevent air from coming into contact with the casing (4) in critical areas, the panel (1.3) is highly effective in reducing the noise generated by the extractor assembly in operation, since the critical area is the actuation area of the impeller (1), which is the area in which on the one hand the suction of air is generated and on the other hand the air flow moving or driven along the extractor assembly is generated.

In order to optimize the air intake into the impeller (1) through an open longitudinal end arranged facing the inlet opening (11), the diameter of said open longitudinal end is equal to or preferably greater than the diameter of the inlet opening (11).

In order to further optimize the air intake into the impeller (1) through the open longitudinal end arranged facing the inlet opening (11), the extractor assembly preferably comprises a blocking element (14). The blocking element (14), visible in fig. 9, is arranged to block the passage of air between the casing (4) and the face plate (1.3) of the impeller (1) at the inlet of said air into the extractor assembly and more specifically into the impeller (1).

Thus, said blocking element (14) is arranged to be joined to the housing (4) by its inner portion, as can be seen in said fig. 9. Thus, the blocking element (14) forces air entering the extractor assembly through the inlet port (11) into the impeller (1). The blocking element (14) is arranged to be stationary, which is advantageous for not generating noise.

Furthermore and preferably, the blocking element (14) is fixed in the housing (4) in addition to being partially inserted into the impeller (1) through an open longitudinal end arranged facing the inlet opening (11). See again figure 9 above.

The diameter of the open longitudinal end of the panel (1.3) with the greater diameter (the end disposed facing the actuation element (2)) is greater than the diameter of the flange (1.1 ") of the base (1.1) and greater than the diameter of the longitudinal extension aligned with the inner wall (3.3). These diameters are considered based on the radius relative to the imaginary central longitudinal axis (X) of the extractor assembly.

In this way, by providing a separation between the base (1.1) of the impeller (1) and the face plate (1.3) according to said difference in diameter, a smoother fluid path is provided at the outlet of the blades (1.2) for the air driven by the blades (1.2). Thus, the path is more parallel to the imaginary central longitudinal axis (X) of the extractor assembly, with fewer changes in direction, and less abrupt with existing changes in direction. Please refer to the arrows included in the extractor assembly of fig. 1.

This configuration, in addition to providing less noise, also provides a smaller diameter size of the extractor assembly for certain characteristics of the impeller (1), such as flow and pressure. This makes it possible to fit the extractor assembly in a smaller space than would otherwise be the case, according to the described characteristics of the impeller (1). For example, referring to fig. 1, there is shown a longitudinal cross-sectional view of the present assembly (lower portion) and a view of a conventional extractor assembly (upper portion) according to the same flow and pressure performance.

The extractor assembly comprises a duct (15), the duct (15) being arranged to place an outer portion of the casing (4), and thus of the extractor assembly, in communication with the containment casing (6). In this way, the duct (15) acts as a passage element for wiring in order to electrically connect the electrical box (16), the electrical box (16) being included in the extractor assembly and being arranged in the outer portion of the casing (4) with the actuating element (2) to access it. This duct (15) is visible in fig. 16.

The duct (15) has a first portion (15.1) projecting outwardly with respect to the outer wall (3.4). Furthermore, the conduit (15) has a second portion (15.2) which extends through the passage (7) so that it reaches the housing (6).

Thus, each of said portions (4.1,4.2) of the housing (4) has a slot (17) open at one end to receive said first section (15.1) of the conduit (15) such that said two portions (4.1,4.2) and more particularly said two slots (17) cover or surround the first section (15.1). In this way, the first section (15.1) serves as a positive locating element for the parts (4.1,4.2) of the housing (4) relative to each other.

According to a preferred embodiment of the invention, the present extractor assembly is intended to be installed in aggressive environments which, according to regulations, require the casing (4) to be made of metal. These environments require extractor assemblies that are resistant to impacts, fires, etc., as required. Thus, the elements, construction and arrangement thereof are of particular relevance in order to effectively and significantly reduce the noise generated by the use of the extractor assembly.

According to this described preferred embodiment, the support (3) is preferably made of plastic material to reduce the overall weight of the extractor assembly.

Continuing with the preferred embodiment of the description, the impeller (1) is preferably made of plastic material, so as to reduce, among other things, the overall weight of the extractor assembly, reduce the noise generated in generating the air flow to be driven towards the outlet (12) and improve the performance of the extractor assembly, on the one hand due to the reduction in weight made of plastic material instead of metal material, and on the other hand due to the specific geometric proportions with respect to the blades (1.2), which are obviously within limited manufacturing times and costs, due to its being made of plastic instead of metal.

Claims

1. An extractor assembly to be installed inside an air duct, the extractor assembly comprising:

-an impeller (1) having a base (1.1) and blades (1.2), the blades (1.2) protruding from the base (1.1);

-an actuating element (2) for imparting a rotational momentum to the impeller (1) such that the impeller (1) generates an air flow by means of the blades (1.2);

-a support (3) having a first face (3.1) and a second face (3.2), said first face (3.1) being intended for the fixed arrangement of said actuating element (2);

-a housing (4) comprising a first portion (4.1) and a second portion (4.2) for surrounding the impeller (1), the actuating element (2) and a support (3);

characterized in that said support (3) comprises:

-an inner wall (3.3) defining, through said first face (3.1), a housing (6) for housing said actuating element (2); and

-an outer wall (3.4) arranged radially and externally with respect to the inner wall (3.3) so that the walls (3.3, 3.4) define a passage (7) for air movement;

wherein, when the extractor assembly is mounted in the use position, the outer wall (3.4) makes radial and internal contact against the first portion (4.1) and the second portion (4.2) and against a joining region (J) in which the first portion (4.1) and the second portion (4.2) join each other, so that the air outlet along the outer wall (3.4) remains blocked.

2. The extractor assembly according to claim 1, characterized in that said outer wall (3.4) is arranged to be in contact against the entire engagement area (J).

3. The extractor assembly according to claim 1 or 2, characterized in that said joining region (J) is formed by an overlap between said first portion (4.1) and said second portion (4.2).

4. The extractor assembly according to any one of claims 1 to 3, wherein the support (3) comprises fins (3.5) in the channel (7) to guide the air flow.

5. The extractor assembly according to claim 4, characterized in that said fins (3.5) are curved to eliminate the tangential component of the air flow generated by said blades (1.2), so that said air flow can be directed according to a rectilinear path.

6. The extractor assembly according to any one of claims 1 to 4, wherein, when the actuating element (2) is arranged to be fixed in the support (3) and the impeller (1) is coupled to the actuating element (2), a separation gap (S) is provided between the base (1.1) and the inner wall (3.3) for the air inlet into the actuating element (2).

7. The extractor assembly according to any one of claims 1 to 5, further comprising a cover (9) arranged along the second face (3.2) of the support (3), so that it determines the continuity of the channel (7).

8. The extractor assembly according to claim 7, characterized in that said cover (9) has a concave side for covering the parts (8) of the extractor assembly and a convex side for guiding the air.

9. The extractor assembly according to any one of claims 1 to 8, characterized in that it additionally comprises a duct (15) arranged to communicate an external portion of the casing (4) with the containment shell (6).

10. The extractor assembly according to claim 9, characterized in that said duct (15) has a first section (15.1) externally projecting with respect to said outer wall (3.4) and in that each of said portions (4.1,4.2) of said casing (4) has a slot (17) to define together a gap for receiving said first section (15.1).

11. The extractor assembly according to any one of claims 1 to 10, wherein the impeller (1) further has a face plate (1.3) to prevent the air from coming into contact with the casing (4) along the blades (1.2).

12. The extractor assembly according to claim 11, characterized in that it further comprises a blocking element (14) arranged to prevent air from moving between the casing (4) and the panel (1.3), so that the air entering the casing (4) is guided between the panel (1.3) and the base (1.1).

13. The extractor assembly according to any one of claims 1 to 12, wherein the casing (4) comprises a metallic material.

14. The extractor assembly according to any one of claims 1 to 13, wherein the support (3) comprises a plastic material.

15. The extractor assembly according to any one of claims 1 to 14, wherein the impeller (1) comprises a plastic material.