US20140161602A1

US20140161602A1 - Structural assembly for centrifugal fan rotor housing

Info

Publication number: US20140161602A1
Application number: US14/103,029
Authority: US
Inventors: Julio Cesar Schmidt; Luiz Alfranio Alves Ferreira; Ederson Adriano dos Santos
Original assignee: Whirlpool SA
Current assignee: Whirlpool SA
Priority date: 2012-12-11
Filing date: 2013-12-11
Publication date: 2014-06-12
Also published as: BR102012031576A2

Abstract

The present invention refers to a structural assembly for centrifugal fan rotor housing capable of optimizing the air flow in its interior. Such optimization is due to the existence of a pneumatic circuit (5) which disposed inside said structural assembly for centrifugal fan rotor housing comprises at least one essentially spiraled virtual orientation (53).

Description

FIELD OF THE INVENTION

The present invention refers to a structural assembly for centrifugal fan rotor housing and, more specifically, to a centrifugal fan used in refrigeration equipment such as household appliances, industrial refrigerators, etc.
More particularly, the invention refers to a structural assembly for centrifugal fan rotor housing capable of optimizing the air flow in its interior, in addition to reducing eventual shocks between its inner surfaces and said centrifugal rotor.

BACKGROUND OF THE INVENTION

As it is already known by those skilled in the art, refrigeration equipment are usually integrated by a refrigeration system and at least an air-conditioned chamber. In this context, it is known that conventional refrigeration systems are essentially comprised of at least a compressor, at least a condenser, at least an expansion device and at least an evaporator. Generally speaking, said evaporator is disposed near said air-conditioned chamber.
In the specific case of household refrigerators, it is known by those skilled in the art that an evaporator is usually disposed outside the air-conditioned chamber and, more particularly, between the air-conditioned chamber and the structural housing of said household refrigerator.
In those cases, said evaporator is capable of cooling the air also disposed between the air-conditioned chamber and said structural housing of said household refrigerator. Consequently, the air-conditioning (or cooling) of the air-conditioned chamber is carried out by insufflating cooled air from the evaporator to the interior of said air-conditioned chamber.
To this effect, and as disclosed in technical and teaching material pertaining to the present state of the art, a ventilation system capable of forcing air circulation between the interior of the air-conditioned chamber and a region near the evaporator is used.
Conventionally, and also concerning refrigeration household appliances, an axial fan disposed between the air-conditioned chamber and the region near the evaporator is used. Such fan is mainly intended to constantly carry out air exchange between said too rooms, Consequently, a suction zone disposed at the region near the evaporator and a discharge zone disposed within the air-conditioned chamber are created.
It is worth to mention that the functional capacity of a ventilation system of a refrigeration household appliance directly influence the efficiency of said refrigeration household appliance.
Therefore, it is also known by those skilled in the art that high performance refrigeration household applicant (composed of high volume air-conditioned chambers) are integrated by high capacity ventilation systems.
In conventional embodiments of the present state of the art, high capacity of a ventilation system can be obtained by using high proportion axial fans. Nevertheless, said high proportion axial fans also generate high intensity noise (inherent in their operation), in addition to occupying (not event existing) large rooms.
Optional embodiments of ventilation systems, which are based on centrifugal fans are also known from the state of the art. Documents EP1980806 and U.S. Pat. No. 6,299,409 discloses examples of household appliances provided with ventilation systems based on centrifugal fans.
High capacity of a centrifugal fan-based ventilation system is more related to rotation speed of the fan rotor than to the size of said rotor.
This means that refrigeration household appliance of high performance and small sized tend to use centrifugal fan-based ventilation systems to solve problems of lack of room.
However, centrifugal fans, when at high speed, present drawbacks relative of radials and axial clearances that their centrifugal rotors comprises in relation to their structural housing assembly and, more particularly radial and axial clearances, which at high speed may cause collisions between said centrifugal rotor and its structural housing assembly. Such collisions, in addition to being harmful to the maintenance of high speed of said centrifugal fan, they are also undesirable because they produce a high level of acoustic noise.
In view of the foregoing, the present invention has been developed.

OBJECTS OF THE INVENTION

By this way, one object of the present invention is to provide a structural assembly for centrifugal fan rotor housing capable of defining a virtual orientation, in its interior, which is capable of optimizing air flow flowing in its interior.
Another object of the invention is to provide a structural assembly for centrifugal fan rotor housing presenting a construction capable of reducing damaging effects of eventual radial and axial clearances that a rotor may have when at high speed.

SUMMARY OF THE INVENTION

These and other objects of presently disclosed invention are totally achieved by means of the structural assembly for centrifugal fan rotor housing, comprising at least a cap, at least a base and at least a rotor, and defines at least a pneumatic circuit provided with at least an air inlet and at least an air outlet.
Generally speaking, said cap comprises, in its posterior surface, at least an essentially sinuous wall and defined in accordance with the pneumatic circuit, wherein the base comprises, in its frontal surface, an essentially spiraled recess and defined in accordance with the pneumatic circuit. Consequently, said pneumatic circuit comprises at least an essentially spiraled virtual orientation.
Preferably, said base comprises, in its frontal surface, at least a essentially sinuous wall and defined in accordance with the pneumatic circuit, and, at least a mechanical reinforcing rib in its posterior surface, which can be disposed at the essential spiraled recess.
In addition, said cap preferably comprises, in this frontal surface, a mechanical reinforcing rib, and can be secured to the base by means of fixation elements.
According to the present invention, said essentially spiraled virtual orientation of the pneumatic circuit can be essentially based on logarithmic function, in Fibonacci sequence, or even, on golden function.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be particularly detailed on the basis of figures listed below, wherein:

FIG. 1 is an isometric perspective view of the structural assembly for centrifugal fan rotor housing in accordance with the present invention;

FIG. 2 is an exploded view of the structural assembly for centrifugal fan rotor housing in accordance with the present invention;

FIG. 3A illustrates the outer surface of the cap integrating said structural assembly for centrifugal fan rotor housing in accordance with the present invention;

FIG. 3B illustrates the inner surface of the cap integrating said structural assembly for centrifugal fan rotor housing in accordance with the present invention;

FIG. 4A illustrates the outer surface of the base integrating said structural assembly for centrifugal fan rotor housing in accordance with the present invention;

FIG. 4B illustrates the inner surface of the base integrating said structural assembly for centrifugal fan rotor housing in accordance with the present invention; and

FIG. 5 illustrate, in a schematic form, the virtual orientation defined within said structural assembly for centrifugal fan rotor housing in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As formerly summarized, there are two main objectives in accordance with the present invention, viz.: optimizing air flow inside the structural assembly for centrifugal fan rotor housing; and reducing the contact between the centrifugal rotor (subjected to axial and radial clearances, when at high speed), and the inner surfaces of components which defined the integrating said structural assembly for centrifugal fan rotor housing. As a result of these two objectives, reduction in the noise intensity due to the operation of the ventilation system integrated by said integrating said structural assembly for centrifugal fan rotor housing is obtained.
Generally speaking, the first objective is accomplished by defining within the structural assembly for centrifugal fan rotor housing, comprising a single pneumatic circuit with spiraled (even if virtual) orientation, which is capable of exhibiting more laminar characteristics whereby air direction is facilitated.
Further, generally speaking, the objective of the second invention is achieved by means of centrifugal rotor, which means that, once defined by recess at the base which integrates the structural assembly for centrifugal fan rotor housing, preventing an eventual contact of said centrifugal rotor with the remaining inner surfaces of the components which define the structural assembly for centrifugal fan rotor housing.
Due to coupling between parts, it is necessary to estimate the clearances between the components, as low as possible (tolerance analysis) such that excessive clearance are prevented, which may cause “air leakage” to occur and in some case noise is produced.
The structural assembly for centrifugal fan rotor housing in accordance with the present invention is better understood by means of its preferred embodiment depicted in FIGS. 1, 2, 3A, 3B, 4A, 4B and 5.
From FIGS. 1 and 2, it can be inferred that the preferred embodiment 1 of said structural assembly for centrifugal fan rotor housing is essentially composed of a cap 2, a base 3 and a centrifugal rotor 4.
From these figures, it can further be noted that in a coherent assemblage, said centrifugal rotor 4 is disposed between the base 3 and the cap 2, wherein the last two ones are secured to one another by means of fixation elements 6 defined by bolts and the like.
Moreover, it can also be seen from FIG. 5 that the preferred embodiment 1 of said structural assembly for centrifugal fan rotor housing further comprises a pneumatic circuit 5, which is provided with an air inlet 51 and an air outlet 52.
From FIGS. 3A and 3B, it can be noted that cap 2 comprises a king of rectangular perimeter plate provided with a circular opening 23 which is not necessarily centralized.
The posterior surface of cap 2, as illustrated in FIG. 3B, is essential smooth, and comprises a sinuous wall 21 defining the pneumatic circuit 5.
The frontal surface of cap 2, as illustrated in FIG. 3AS, comprises in turn mechanical reinforcing ribs 22, which are disposed in parallel to one another.
Furth, from FIGS. 4A and 4B, it can be seen that the base 3 comprises a rectangular perimeter body (said perimeter being essential equivalent to the perimeter of cap 2) provided a recess 31 and a semi contour wall 35.
In said preferred embodiment 1, the recess 31 is essentially spiraled and also defines the pneumatic circuit 5. In the center of said recess 32 a through-hole 34 is provided.
The frontal surface of base 3, as illustrated in FIG. 4A, also comprises a sinuous wall which further defines pneumatic circuit 5. Said sinuous wall 32 is analogous to the sinuous wall 21 of the posterior surface of cap 2.
Said posterior surface of base 3, as illustrated in FIG. 4B, comprises mechanical reinforcing ribs 33 disposed at the portion where the semi contour wall 35 is absent, and mechanical reinforcing ribs 36 are disposed at the “bottom” of the recess 31. Preferably, said mechanical reinforcing ribs 33 are parallel to one another, and said mechanical reinforcing ribs 36 define an “H”-shaped arrangement.
Once mounted, said preferred embodiment 1 of the structural assembly for centrifugal fan rotor housing “forms” a pneumatic circuit disposed (also the centrifugal rotor 4) between said cap 2 and base 3.
Inlet 51 of said pneumatic circuit 5 is defined in the portion where the semi contour wall 35 is absent, and the outlet 52 is disposed at the circular opening 23 of cap 2.
Said pneumatic circuit 5, which is defined between its inlet 51 and its outlet 52, has its orientation shaped by the posterior (or inner) surface of cap 2 and the frontal (or inner surface) of base 3, and, more particularly, by the recess 31 of base 3. Consequently, said pneumatic circuit 5 then comprises a virtual orientation 53 of single flow, wherein said virtual orientation 53 is essentially spiraled.
As formerly mentioned, said essentially spiraled virtual orientation 53 of the pneumatic circuit 5 is capable of optimizing the air flow, and, finally, said air flow will be more “laminar”, that is, of easier direction, wherein frictions with the air circulation pipelines can be avoided.
Additionally, the arrangements of said centrifugal rotor 4 inside the recess 31 of base 3, in accordance with the preferred embodiment 1, allow for reduction of contact between said centrifugal rotor 4 and inner surfaces of cap 2 and base 4 since the coupling between cap 2 and base 3 permits optimization of calculations of clearances between components, at the possible minimum value (tolerance analysis) whereby excessive clearances capable of causing “air leakage” can be avoided.
Moreover, it can be noted that ribs 21, 33, ad 36 are capable of, in addition to play a function of mechanical reinforcement, avoiding resonant vibrations at the portions of cap 2 and base 3, where they are arranged. This ensures that the preferred embodiment 1 of the structural assembly for centrifugal fan rotor housing presents low vibration index values.
In view of details given above, one may ascertain that the structural assembly for centrifugal fan rotor housing and more particularly that the preferred embodiment 1 of the structural assembly for centrifugal fan rotor housing achieves all the proposed objects.
Although there has been described only one preferred embodiment of the present invention, it is to be construed that the scope thereof contemplates other possible variations which are only limited by the contents of claims, wherein possible equivalent means are included therein.

Claims

1. Structural assembly for centrifugal fan rotor housing, comprising at least one cap (2), at least one base (3) and at least one rotor (4), and defining at least one pneumatic circuit (5) provided with at least one air inlet (51) and at least an air outlet (52);

said structural assembly for centrifugal fan rotor housing being CHARACTERIZED in that:

the cap (2) comprises in its posterior surface, at least one essentially sinuous wall (21) defined in accordance with said pneumatic circuit (5);

the base (3) comprises in its frontal surface at least one essentially spiraled recess (31) and defined in accordance with the pneumatic circuit (5); and

the pneumatic circuit (5) comprises at least one essentially spiraled virtual orientation (53).

2. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said base (3) comprises, in its frontal surface, at least one essentially sinuous wall (32) defined in accordance with said pneumatic circuit (5).

3. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said base (3) comprises, in its posterior face, at least one mechanical reinforcing rib (33, 36).

4. Structural assembly, in accordance with claim 3, CHARACTERIZED in that at least one mechanical reinforcing rib (36) is disposed at the essentially spiraled recess (31).

5. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said cap (2) comprises, in its frontal surface, at least one mechanical reinforcing rib (22).

6. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said cap (2) is attached to said base (3) by means of fixing elements (6).

7. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said essentially spiraled virtual orientation (53) of the pneumatic circuit (5) is essentially based on logarithmic function.

8. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said essentially spiraled virtual orientation (53) of the pneumatic circuit (5) is essentially based on Fibonacci sequence.

9. Structural assembly, in accordance with claim 1, CHARACTERIZED in that said spiraled virtual orientation (53) of the pneumatic circuit (5) is essentially based on golden function.