EP1106837B1 - Fan casing - Google Patents

Description

The subject of the present invention is a heating and / or air-conditioning installation comprising at least one centrifugal blower comprising at least one annular turbine provided with fins, which is driven in rotation about an axis of rotation by a motor. annular being surrounded by a volute defining a space for the transmission of air out, by centrifugal effect, from the periphery of the annular turbine, to direct it to an output region of the blower.

pour θ compris entre 0° et θ_M, θ_M désignant la valeur maximum de l'angle θ intéressé par ladite évolution angulaire, et correspondant en général à un bord de sortie de la région de sortie ;
et Io désignant la constante d'évolution radiale exponentielle.In such installations, it has been planned to confer on the inner wall, of radius r, of the volute, a radial evolution as a function of an angle θ taken in a plane perpendicular to the axis of rotation so as to form a spiral, especially exponential, and consistent with the relation: $$\mathrm{r}={\mathrm{r}}_{\mathrm{o}}\exp \left({\mathrm{I}}_{\mathrm{o}}\mathrm{\pi }\mathrm{\theta }/180°\right)$$

for θ between 0 ° and θ _M , where θ _M denotes the maximum value of the angle θ concerned by said angular change, and generally corresponds to an output edge of the output region;
and Io designating the exponential radial evolution constant.

Such a pulser having a spiral-forming radial evolution is for example described in Japanese Patent Application JP-9-242,696 (DENSO Corp. Ltd) filed March 11, 1996 and published September 16, 1997.

Furthermore, the application of Japanese Patent JP-9-158 898 (DENSO Corp. Ltd) filed December 5, 1995 and published June 17, 1997 describes a blower which associates a radial evolution of aforementioned type to an evolution axial depending on the same angle so as to define a ring-shaped sector whose height taken parallel to the axis of the blower varies substantially linearly depending on the angle. This ring shaped sector has an inclined inner wall to reduce the noise generated in the sector thus created.

Such a pulser has optimized performance, but it occupies a large space, which goes against the current requirements of manufacturers to reduce the space occupied by the components.

To limit the radial bulk of the blowers while retaining a major part of the advantages related to the existence of a radial evolution of the radius r of the inner wall of the volute as a function of the angle θ, the value of the coefficient Io d The exponential evolution is, in some blowers, lowered to values ensuring a compromise between the radial dimension and the performances.

Pulsers with reduced radial dimensions are thus known for which the value of Io is close to 7.2 × ^{2 -2} .

As indicated above, this reduced size does not allow to take full advantage of the possibilities of the blower. This results in a yield and an output pressure which are noticeably lower than those obtained with a "normal" size blower which has not been the subject of such a compromise, which leads to unsatisfactory performance.

The present invention relates to a blower having a reduced radial size, while maintaining satisfactory performance.

pour θ compris entre 0° et θ_M
r_o = rayon de la paroi interne pour θ = 0°
I_o = constante,
caractérisée en ce que : $$6,{5.10}^{-2}\le \mathrm{I}\mathrm{o}\le {8.10}^{-2}$$

et en ce que la paroi interne de la volute présente une hauteur croissante en fonction de l'angle θ depuis une valeur H'_o pour θ = 0 jusqu'à une valeur H'_M pour θ = θ_M, avec $$0,67\le {\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\prime }}_{\mathrm{M}}\le 0,8$$

The invention thus relates to a heating-air-conditioning installation having at least one centrifugal blower comprising at least one annular turbine provided with fins, which is driven by a motor, this annular turbine being surrounded by a volute defining a space for transmission of air exiting by centrifugal effect from the periphery of the annular turbine, to direct it towards an outlet region of the blower, the volute having an inner wall of radius r presenting an exponential angular evolution as a function of an angle θ taken in a plane perpendicular to the axis of rotation of the blower, in accordance with the relation: $$\mathrm{r}={\mathrm{r}}_{\mathrm{o}}\exp \left({\mathrm{I}}_{\mathrm{o}}\mathrm{\pi }\mathrm{\theta }/180°\right)$$

for θ between 0 ° and θ _M
r _o = radius of the inner wall for θ = 0 °
I _o = constant,
characterized in that $$6,{5.10}^{-\mathrm{two}}\le \mathrm{I}\mathrm{o}\le {8.10}^{-\mathrm{two}}$$

and in that the inner wall of the volute has an increasing height as a function of the angle θ from a value H ' _o for θ = 0 to a value H' _M for θ = θ _M , with $$0,67\le {\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\text{'}}}_{\mathrm{M}}\le 0,8$$

In particular, one can have Io ≃ 7.210 ^-2 .

According to a preferred embodiment, r _o / H ' _M ≃ 0.7.

The invention makes it possible to obtain particularly remarkable results, in particular with r _o / H ' _o ≃ 1.

• les figures 1a et 1b représentent en perspective et en coupe partielle, un pulseur de l'art antérieur selon la demande JP-9-158 898 précitée :
• les figures 2a et 2b représentent une vue éclatée d'un pulseur selon l'invention, respectivement en perspective et de côté ;
• la figure 3a représente en coupe axiale un pulseur assemblé selon les figures 2a et 2b ;
• la figure 3b illustre l'évolution radiale du pulseur de la figure 3a, en fonction de l'angle θ ;
• la figure 4 illustre les performances d'un pulseur selon l'invention ;
• les figures 5a et 5b sont respectivement des détails des ailettes du pulseur de la figure 3a (figure 5a), et d'une variante de celle-ci (figure 5b).

The features and advantages of the invention will become apparent on reading the following description, given by way of non-limiting example, in conjunction with the drawings in which:

• FIGS. 1a and 1b show in perspective and in partial section, a blower of the prior art according to the above-mentioned application JP-9-158 898:
• Figures 2a and 2b show an exploded view of a blower according to the invention, respectively in perspective and side;
• Figure 3a shows in axial section an assembled blower according to Figures 2a and 2b;
• FIG. 3b illustrates the radial evolution of the blower of FIG. 3a, as a function of the angle θ;
• FIG. 4 illustrates the performance of a blower according to the invention;
• Figures 5a and 5b are respectively details of the blades of the blower of Figure 3a (Figure 5a), and a variant thereof (Figure 5b).

The blower represented in FIGS. 1a and 1b has a turbine 1 in the form of an annular ring, provided with blades 2 and surrounded by a volute 3 whose outer wall 6 has a radial evolution forming a spiral which flares toward the outlet 14 of the blower . This radial evolution is accompanied by an axial evolution to define an annular corridor of gradually increasing height towards the exit 14 and which is delimited inside by an inner wall 10 which forms an angle θ ₂ (increasing or not) with a plane normal to the axis of the blower, this angle substantially corresponding to the angle θ _f of ejection of the air flow outside the turbine 1.

As indicated above, such a blower has the disadvantage of a large footprint.

The device according to the invention illustrated by FIGS. 2a, 2b, 3a and 3b, has a motor 28 whose axis 30 drives an annular turbine 25 provided with blades 26 and which is surrounded by a volute 20 delimited at its upper part by a ring region 21, at its lower part by a bottom 22, as well as by a wall 35 which defines an annular passage 36 having a radial evolution as a function of the angle θ and finally a wall 23 located substantially in the extension of the periphery 34 of the turbine 25, and which defines together with an extension 35 'of the wall 35, an annular passage 38 having an axial evolution corresponding to an increasing height towards the output 40 of the blower.

avec 6,5.10^-2 ≤ Io ≤ 8.10^-2 et notamment Io = 7,2.10^-2
pour θ compris entre 0° et θ_M.
θ = 0° correspond au début de l'expansion radiale, au voisinage du bord 43 de la sortie 40, et θ_M correspond à la fin de l'expansion radiale, au voisinage du bord 44 de la sortie 40.As shown more particularly in FIG. 3b, the spiral formed by the wall 35 (and its extension 35 ') has a radial expansion as a function of the angle θ (taken in a plane perpendicular to the axis of rotation of the turbine 25 ). This radial expansion is relatively small in order to limit the size of the blower and is given by the formula $$\mathrm{r}={\mathrm{r}}_{\mathrm{o}}\exp \left({\mathrm{I}}_{\mathrm{o}}\mathrm{\pi }\mathrm{\theta }/180°\right)$$

with 6.5.10 ^-2 ≤ Io ≤ 8.10 ^-2 and in particular Io = 7.2.10 ^-2
for θ between 0 ° and θ _M.
θ = 0 ° corresponds to the beginning of the radial expansion, in the vicinity of the edge 43 of the outlet 40, and θ _M corresponds to the end of the radial expansion, in the vicinity of the edge 44 of the outlet 40.

As shown more particularly in Figures 2a, 2b and 3a, the volute 20 also has an axial expansion, defining an annular passage 28 extending towards the motor 28 the annular passage 36. The annular passage 38 is delimited by the extension 35 'of the spiral wall 35, the bottom 22, and the wall 23.

The annular passage 38 has a height h 'which varies from 0 for θ = 0, up to h' _M for θ = θ _M.

The axial dimension of the volute thus varies from H ' _o for θ = 0 to H' _M for θ = θ _M with H ' _M = H' _o + h ' _M.

et en particulier $${\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\prime }}_{\mathrm{M}}=0,7.$$

The axial evolution is advantageously chosen so that $$0,67\le {\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\text{'}}}_{\mathrm{M}}\le 0,8$$

and especially $${\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\text{'}}}_{\mathrm{M}}=0,7.$$

As can be seen in FIG. 4, these values correspond to quite satisfactory performances as regards both the efficiency (curve I) and the outlet air pressure (curve II), which give the blower remarkable characteristics despite a small footprint.

As shown in Figures 5a and 5b, the fins 26 have at their end located on the side of the air inlet 50 a concave bevel 27 of height h _b which runs along a corresponding curved region 24 forming part of an upper housing of the volute 20. If one designates by the height of the blade 26, it is advantageous that h _b / h _p ≃ 0.1. This improves the aerodynamic performance of the blower (about 10 to 15%) and reduce the noise generated by it (about 2 to 3 dBA).

The ends 27 and 27 'of the blades 26 are interconnected by strips 22 and 32 which occupy part of the width of the blades 26, without overlapping, so as to allow axial demolding of the assembly formed by the blades 26 , the strips 12 and 32 and the conical bowl 29 integral with the strip 32 and which is engaged on the axis 30.

Alternatively (FIG. 5b), the upper strip 37 is disposed on the outer longitudinal face of the blades 26 and the lower strip 39 integral with the bowl 29 occupies a majority or the whole of the end 27 ', which also allows the mold to be unmolded. 'together.

Claims (6)

1. Heating - air conditioning installation with at least one centrifugal blower comprising at least one annular turbine provided with ribs, that is driven in rotation about an axis of rotation by a motor, this annular turbine being surrounded by a volute defining a space for transmission of outlet air by a centrifugal effect, from the periphery of the annular turbine to direct it towards an outlet region from the blower, the volute having an internal wall with a radius r with an exponential angular variation as a function of an angle θ measured in a plane perpendicular to the axis of rotation, complying with the relation: $$\mathrm{r}={\mathrm{r}}_{\mathrm{o}}\exp \left({\mathrm{I}}_{\mathrm{o}}\mathrm{\pi }\mathrm{\theta }/180°\right)$$

   

   
   for θ between 0° and θ_M
   r_o = radius of the internal wall for θ = 0°
   I_o = exponential variation constant, characterised in
   that: $$6.5\times {10}^{-2}\mathrm{\theta }\le \mathrm{I}\mathrm{o}\le 8\times {10}^{-2}$$

   

   
   and in that the height of the internal wall (35) of the volute (20) increases as a function of the angle θ from a value H'_o for θ = 0 to a value H'_M for θ = θ_M, where $$0.67\le {\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\prime }}_{\mathrm{M}}\le 0.8$$

   
2. Installation according to claim 1, characterised in that: $$\mathrm{I}\mathrm{o}\approx 7.2\times {10}^{-2}$$

   
3. Installation according to either of claims 1 and 2, characterised in that: $${\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\prime }}_{\mathrm{M}}\approx 0.7$$

   
4. Installation according to any of the previous claims, characterized in that $${\mathrm{r}}_{\mathrm{o}}/{{\mathrm{H}}^{\prime }}_{\mathrm{o}}\approx 1$$

   
5. Installation according to any of the previous claims, characterised in that the axial end (27) of the ribs (26) on the side of an air inlet (50) to the blower, has concave bevels with height (h_b) running along a complementary curved wall (24).
6. Installation according to claim 5, characterised in that $${\mathrm{h}}_{\mathrm{b}}/{\mathrm{h}}_{\mathrm{p}}\approx 0.1$$

   

   
   where hp denotes the height of a blade.

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