U.S. patent application number 15/415282 was filed with the patent office on 2017-08-03 for side-channel blower / aspirator with an improved impeller.
The applicant listed for this patent is ESAM S.P.A.. Invention is credited to Pietro BIANCHI.
Application Number | 20170218971 15/415282 |
Document ID | / |
Family ID | 55521354 |
Filed Date | 2017-08-03 |
United States Patent
Application |
20170218971 |
Kind Code |
A1 |
BIANCHI; Pietro |
August 3, 2017 |
SIDE-CHANNEL BLOWER / ASPIRATOR WITH AN IMPROVED IMPELLER
Abstract
The side-channel blower/aspirator (1), comprises an impeller (2)
equipped with a plurality of blades (21) and a casing (13, 14), in
which the impeller (2) is enclosed and within which an annular
conduit (C) is defined in which the blades (21) rotate. The blades
(21) comprise at least one longitudinally curved portion, defining
a concavity (23) facing the advancement direction of the blades
(21) within the conduit.
Inventors: |
BIANCHI; Pietro; (Parma,
IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ESAM S.P.A. |
43122 Parma (PR) |
|
IT |
|
|
Family ID: |
55521354 |
Appl. No.: |
15/415282 |
Filed: |
January 25, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/30 20130101;
F04D 29/281 20130101; F04D 17/16 20130101; F04D 23/008
20130101 |
International
Class: |
F04D 29/30 20060101
F04D029/30; F04D 17/16 20060101 F04D017/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 29, 2016 |
EP |
16153453.2 |
Claims
1. Side-channel blower/aspirator (1), comprising at least one
impeller (2) equipped with a plurality of blades (21) and a casing
(13, 14), in which said impeller (2) is enclosed and within which
an annular conduit (C) is defined in which said blades (21) rotate,
characterised in that the blades (21) comprise at least one
longitudinally curved portion, defining a concavity (23) facing the
advancement direction of the blades (21) within said conduit.
2. The machine (1) according to claim 1, wherein said blades (21)
have a longitudinal curvature along their entire longitudinal
extension.
3. The machine (1) according to claim 1, wherein the impeller (2)
comprises a central body (24) from which said blades (21) extend,
which are arranged tangentially to a circumferential portion (25)
of the central body (24).
4. The machine according to claim 3, wherein the impeller (2)
comprises a central body (24) from which said blades (21) extend,
each blade (21) being provided with a proximal portion (210) joined
to a circumferential portion (25) of the central body (24), said
proximal portion (210) of the blade (21) being curved so as to be
tangential to said circumferential portion (25) of the central body
(24).
5. The machine (1) according to claim 1, wherein the impeller (2)
comprises a central body (24) axial symmetric to which said blades
(21) are joined at respective joining zones, each blade (21) being
completely contained within one of the two semi-spaces defined by
an ideal diametral plane which joins the axis of the central body
(24) to the joining zone between the blade (21) and the central
body (24).
6. The machine (1) according to claim 1, wherein each of said
blades comprises at least one transversally curved portion.
7. The machine (1) according to claim 6, wherein each of said
blades is equipped with a transversal curvature along its whole
longitudinal extension.
Description
[0001] The present invention relates to a side-channel
blower/aspirator with an improved impeller.
[0002] Side-channel (or even air ring) blowers/aspirators provided
with an impeller that has a central body from which a plurality of
peripheral blades extend are known.
[0003] The impeller is enclosed into a casing in which an annular
conduit is defined, in which the impeller blades rotate.
[0004] The annular conduit has a suction mouth, through which a
fluid (normally air) is aspirated and a delivery mouth through
which the fluid is expelled.
[0005] These machines can operate both as vacuum pumps and as
compressors.
[0006] The operation of this type of machines is based on the
principle of the fluid flow caused by the thrust developed by the
impeller blades within the annular conduit, during rotation.
[0007] In detail, during rotation, the blades push the fluid
forwards and, due to the mentioned centrifugal thrust, also
outwards.
[0008] The walls of the annular conduit then deviate the fluid
again between one blade and another.
[0009] The joint action of the blades and the walls of the annular
conduit define a helical motion in the fluid itself.
[0010] Currently, the impellers used in side-channel machines are
provided with rectilinear radial blades.
[0011] The Applicant, following research and experimentation
activities, has observed that the shape of known impeller blades
does not allow the operating principle described above to be
exploited with full efficiency.
[0012] The technical task underpinning the present invention is
therefore to propose a side-channel blower/aspirator with an
improved impeller that makes it able to offer better performance
levels with respect to the known art.
[0013] Such technical task is reached by the side-channel
blower/aspirator obtained according to claim 1.
[0014] Further characteristics and advantages of the present
invention will become more apparent from the following indicative,
and hence non-limiting, description of a preferred, but not
exclusive, embodiment of the machine according to the invention, as
illustrated in the accompanying drawings, in which:
[0015] FIG. 1 is an axonometric view of the machine according to
the invention;
[0016] FIG. 2 is an exploded view of the machine of FIG. 1;
[0017] FIG. 3 is a front view of the machine, wherein the
containment casing of the improved impeller has been uncovered;
[0018] FIG. 4 is an enlarged detail of the previous figure, wherein
an upper zone of the casing, the impeller and the annular conduit
afforded in the casing itself are shown;
[0019] FIG. 5 is an axonometric view of the impeller;
[0020] FIG. 6 is a front view of the impeller; and
[0021] FIG. 7 is a diametral sectional view of the impeller.
[0022] With reference to the mentioned figures, 1 indicates the
side-channel blower/aspirator according to the invention.
[0023] The proposed machine 1 comprises an impeller 2 improved with
respect to machines of the prior art.
[0024] The impeller 2 is provided with a plurality of peripheral
blades 21 and is equipped with a central hub 22, fitted onto a
shaft 11 (see in particular FIG. 2), which is placed in rotation by
motor means of the known type, for example the electric motor 12
represented in FIGS. 1 and 2.
[0025] As will be explained in detail below and as can be seen from
the appended figures, the blades 21 of the impeller 2 are not
rectilinear like those of the prior art but, on the contrary, have
a particular curvature.
[0026] The advantages offered by such a special conformation of the
blades 21 will be better understood following the description of
some general aspects of the machine 1 in which such an impeller 2
is used.
[0027] The impeller 2 according to the invention is enclosed in a
casing 13, 14 which internally defines an annular conduit C within
which the blades 21 rotate, in the direction indicated by the arrow
in FIG. 3.
[0028] In more detail, the two parts of the channel C which are
ideally separated by the plane orthogonal to the axis of rotation
of the impeller 2 coinciding with the plane of symmetry of the
machine 1, are called "side channels".
[0029] As shown in FIG. 2, the casing is preferably made of two
half-shells 13, 14, sealingly fixed, one of which is connected to
the electric motor 12, while the other one constitutes a front
cover.
[0030] According to an aspect of the prior art, the aforementioned
annular conduit C has a suction mouth 3 for aspirating fluid (in
particular air) taken externally to the machine 1 and a delivery
mouth 4 for allowing the fluid to exit from the machine 1 itself
(see FIG. 3).
[0031] In practice, through the action of the blades 21 of the
impeller 2, the fluid is aspirated by the suction mouth 3 and,
after crossing the annular conduit C, is expelled through the
delivery mouth 4.
[0032] The annular conduit C has a first section which, with
respect to the advancement direction of the blades 21 in the
conduit, goes from the suction mouth 3 to the delivery mouth 4.
[0033] In this first section, there is a free space between the
blades 21 in rotation and the internal wall of the annular conduit
C, to allow, during use, the formation, within the fluid, of the
main motion internal to the machine 1 mentioned during the
discussion of the prior art.
[0034] The annular conduit C further has a second section, which
goes from the delivery mouth 4 to the suction mouth 3, within
which, preferably, the blades 21 skim the internal walls of the
section itself so as to limit the passage of fluid from the
delivery mouth 4 to the suction mouth 3.
[0035] As shown in the appended figures, the impeller 2 according
to the invention is equipped with blades 21 comprising at least one
longitudinally curved portion, defining a substantially curved
profile.
[0036] In detail, such blades 21 each define a concavity 23 facing
the advancement direction of the blades 21 within the conduit
C.
[0037] In practice, the blades 21 of the impeller 2 according to
the invention, rather than being rectilinear, are bent or curved,
hence having a concave front surface 23, at least at the respective
aforementioned curved portion. In other words, the section (or
intersection) of the blades 21 of the impeller 2 taken along an
ideal plane perpendicular to the axis of rotation of the impeller 2
defines, at the front surface 23, a curved and not rectilinear
line. More precisely, the impeller 2 may comprise a central body
24, preferably axial symmetric, for example discoidal, at the
centre of which the aforementioned hub 22 is afforded and from
which the blades 21 extend.
[0038] The blades 21 originate from a circumferential portion 25 of
the central body 24 and extend outwards, substantially lying in the
plane of the central body 24 itself.
[0039] In more detail, each blade 21 includes a proximal portion
210 (i.e. more internal) joined to the central body 24 at its
circumferential portion 25.
[0040] In the preferential embodiment of the invention, shown in
the appended figures, the blades 21 have a curvature along their
whole longitudinal extension; in this case, the whole side profile
of the individual blade 21 has a continuous curvature, without
rectilinear sections (see in particular FIGS. 3 and 4).
[0041] Alternatively, the blades may each be provided with one
rectilinear portion and at least one curved portion, the latter
being for example a longitudinal distal portion comprising the free
end of the relative blade 21.
[0042] According to a further, non-preferential, variation, the
blades may be formed by a plurality of curved sections, defining
cuspidal joining zones. The curved or partially curved conformation
of the blades 21 allows the machine 1 to operate more efficiently
with respect to the prior art, for the reasons illustrated
below.
[0043] As explained above, during the use of this type of machines,
the air found inside the annular channel receives, from the
impeller 2, both a thrust forwards (see arrow A of FIG. 4) and a
centrifugal thrust (see arrow B), i.e. away from the centre of
rotation of the impeller 2 itself.
[0044] Thanks to the curvature of the blades 21 according to the
invention, the part of air thrust in the centrifugal direction,
which would tend to move radially away from the blades 21, is
instead intercepted by the blades 21 themselves and projected
forwards.
[0045] More precisely, the radial component of the fluid's motion
field is in part deviated in the circumferential direction already
by the actual blade before the fluid is subject to the action of
the closing walls of the annular conduit C.
[0046] In this way, a prevailing part of the volume of air included
in the annular channel is thrust forwards by the blades 21,
allowing the machine 1 according to the invention to obtain
improved performance levels with respect to known machines.
[0047] Note that known impeller blades, being rectilinear, are not
able to "capture" air flows moving in the centrifugal direction
within the annular conduit.
[0048] Even known impellers equipped with blades formed by angular
segments cannot obtain the efficiency provided by the proposed
impeller 2, since at the most they will be able to partially
deviate centrifugal flows whereas the blades 21 according to the
invention retain them much more and thrust them in the rotation
direction.
[0049] In the preferred embodiment of the invention, the blades 21
of the impeller 2 are placed tangentially to the aforementioned
circumferential portion 25 of the central body 24 (see in
particular FIG. 4).
[0050] In detail, the mentioned proximal portion 210 of the blade
21 extends from the circumferential portion 25 outwards and along a
tangential direction to the circumferential portion 25 itself.
[0051] In other words, the proximal (or "base") portion 210 of the
blade 21 has a curvature such that it is tangential to the
circumferential portion 25.
[0052] This aspect is particularly advantageous, in terms of
efficiency of use of the proposed machine 1, for the reasons
illustrated below.
[0053] As mentioned above, during the use of the machine 1, within
the annular conduit C swirls of fluid are developed due to the
action of the blades 21 of the impeller 2.
[0054] In detail, part of the fluid contained in the annular
conduit C, furthest from the centre of rotation, tends to move
forwards in the rotation direction along an ascending curve;
instead, part of the fluid closer to the centre of rotation follows
a descending curve until it moves in the retrograde direction upon
reaching the internal area affected by the base of the blades 21
(see arrow D in FIG. 4).
[0055] The blades 21 of the impeller 2 according to the invention,
being equipped at the base 210 of the aforementioned tangential
bend at the joining circumference between blades 21 and central
body 24, are able to intercept the aforementioned retrograde fluid
and push it forwards, increasing the efficiency of the machine
1.
[0056] According to an optional embodiment of the invention (not
depicted in the appended figures), each blade has, in addition to
the longitudinal curvature described above, a second curvature
along its transversal extension.
[0057] Preferably, in this "double curvature" version, each
proposed impeller blade has the transversal curvature along its
extension, particularly along its whole longitudinal extension and
its whole transversal extension.
[0058] In other words, consider a diametral plane of the impeller 2
which passes through a prefixed point of the front surface 23 of a
blade 21 of the impeller 2.
[0059] The section (or intersection) of the blades 21 of the
impeller 2 taken along a plane perpendicular to the diametral plane
and parallel to the axis of rotation of the impeller 2 defines, at
the front surface 23 itself, a curved and not rectilinear line.
[0060] Thanks to the second curvature, the blade is able to
intercept and project forwards the air flows which would tend to
laterally escape from the blade itself.
[0061] Therefore, yet again, the invention allows improved
efficiency of the machine 1 with respect to the prior art.
[0062] Optionally, the blades 21 have a curvature such as to be
tangential to a respective diametral plane which passes through the
axis of the central body; in detail, the tangency point is located
in the rear convex part of the blade 21.
[0063] Preferably, each blade 21 is contained in one of the two
semi-spaces defined by an ideal diametral plane that joins the axis
of the central body 24 to the joining zone between the blade 21 and
the central body 24.
[0064] As shown in the figures, in particular in FIGS. 4 and 5, the
impeller 2 proposed may include a portion with an annular
progression 26, i.e. a geometric surface of revolution about the
axis of rotation.
[0065] Such an annular portion 26 is incorporated into the blades
21 and extends starting from the circumferential portion 25
mentioned various times of the impeller, in a radial direction, and
ends at a shorter distance than the longitudinal extension of the
blades 21, for example, substantially half way along their
length.
[0066] Finally, by way of non-exhaustive example, the impeller 2
proposed may be made of die-cast aluminium or a polymeric material
by injection moulding.
* * * * *