WO2010086210A1

WO2010086210A1 - Side channel blower, in particular secondary air blower for an internal combustion engine

Info

Publication number: WO2010086210A1
Application number: PCT/EP2010/050248
Authority: WO
Inventors: Berthold Herrmann; Andreas Bumbel; Jakob Gehlen; Thomas Rösgen; Rainer Peters
Original assignee: Pieburg Gmbh
Priority date: 2009-01-29
Filing date: 2010-01-12
Publication date: 2010-08-05
Also published as: EP2382393A1; DE102009006652A1; EP2382393B1; DE102009006652B4

Abstract

Side channel blowers comprising devices for minimizing noise emissions are known. However, said side channel blowers often are insufficient and limit the volumetric flow to be conveyed. Therefore, a side channel blower is proposed, wherein the at least one conveying channel (12; 14) leads to the outlet (20) substantially in the tangential direction, wherein an outlet opening (58) in the radially bounding wall (33) extends in the direction of rotation of the rotor (4) to an outlet edge (62), which protrudes into the interruption area (28; 30) of the at least one conveying channel (12; 14), wherein an opening (60) is formed on the radially bounding wall (33) directly behind the outlet opening (58) in the direction of rotation of the rotor (4), reducing the extension of the interruption area (32) on the radially bounding wall (33) in the circumferential direction. By means of such an embodiment, a further noise reduction is achieved, and the volumetric flow conveyed is increased.

Description

DESCRIPTION

Seιtenkanalgebläse _f particular SekundärluftgebSäse for a Verbrennungskraftmaschϊne

The invention relates to a Seitenkanalgebiäse, in particular Sekundärluftgebiäse for an internal combustion engine with a multi-part housing in which an axial inlet, which opens into at least one substantially annular extending delivery channel via an inlet region, and an outlet, an impeller, which via a drive unit is driven, is rotatably mounted in the housing and having conveying blades, which cooperate with the opposite conveying channel and an interruption area between the inlet and the outlet, in which the at least one Förderkana! is interrupted in the circumferential direction,

Side channel blowers or pumps are well known and described in a variety of applications. In the motor vehicle, for example, they serve to convey fuel or to inject secondary air into the exhaust system. The drive is usually via an electric motor that drives the impeller. The impeller is formed at its periphery substantially such that it with the axially opposite conveying channel a revolving Wirbelkana! forms. From the vortex channel forming part of the impeller projecting blades projecting vertically toward the opposite, formed in the housing part of the conveyor channel, so that pockets are formed between the conveyor blades. The pumped fluid in the pockets undergoes a Beschufunigung in rotation in the circumferential direction and in the radial direction, so that in the conveying channel, a rotating vortex flow is created by rotation of the impeller by the Förderschaufein.

There are Seitenkanalgebiäse known in which only a delivery channel is formed on one axial side of the impeller in a housing part, as well as Seitenkanalgebiäse, where at both axial sides of the impeller Förderkana! is formed, in which case both conveyor channels are fluidly connected to each other. In such a side channel blower one of the Förderkanäie is formed in a serving as a cover Gehäuseteii, while the other Förderkana! in the housing! is formed, is usually attached to the drive unit, at the shaft, the impeller is arranged at least rotationally fixed.

In order to obtain the best possible promotion or pressure increase, it is necessary to use as large a part of the circumference of the conveyor channel. For this reason, inlet and outlet must be as far apart as possible over the circumference in the running direction of the impeller, wherein a short-circuit flow between the inlet and the outlet is to be prevented by a Unterbrecnuπgsbereich. As problematic in such SeJtenkanalgebläsen the high noise has been found, which arises in particular by pulsations that occur due to sudden pressure surges of the extracted air.

These pressure surges occur, inter alia, immediately after sweeping each bucket at the beginning of the interruption area, since in the pockets between the FörderschaufeJn still compressed air is present, which was not completely expelled over the Ausiass, which are accelerated when reaching the interruption area suddenly against the walls , This leads to significantly increased noise emissions,

In order to avoid this, DE 100 24 741 B4 proposes a pump for conveying fluids, in which the outlet axia! is arranged to the impeller and the Förderkanai opens into a Ausiassöffnung whose width is initially smaller in the direction of rotation of the impeller and then in the radially outer region has a small constant width.

Although the noises occurring can be reduced by such an embodiment, the conveyed fluid flow is still accelerated behind the outlet opening towards the breaker area, so that pressure surges occur which lead to an increased noise emission, because of the piötzüche Cross-sectional changes occur behind the interruption range for Teiivolumina the funded volume in the pockets when reaching the Stoppuπgsbereiches.

It therefore raises the task of creating a side channel bubble, with which the noise can be further reduced.

This object is achieved by the characterizing part of the main claim. In the radially inner area of the impeller, the fluid flows between the blades and leaves the pockets between the impeller blades in the radia! outside area. Due to the tangentially outflowing conveyor channel, the inner sides of the conveyor pockets first strike the interruption region of the conveyor channel so that the inlet cross section steadily reduces as the impeller rotates. The compressed fluid can leave the conveyor pockets in the region of the outlet without flow obstacles, Also the Fiuid, which is still in the pockets and is accelerated in these and possibly by VerwirbeJungen still in the more outer area has flowed into the pockets, on the in the direction of rotation Leave behind the conveyor channel lying region of the outlet opening the pockets and flow without flow obstacles. This prevents pressure surges on the housing and reduces noise emissions. Characterized in that in the direction of rotation of the impeller behind the Ausiassöffnung on the radiai delimiting wall is formed a recess which reduces the extent of the interruption area at radialer radially delimiting wall in the circumferential direction, an additional Entspannungsberesch is created for the funded Fiuid behind the Ausfassöffnung, in which the still existing pressure increase can be removed from the bag, whereby the occurring DruckpuSsationen be further reduced.

Preferably, the extent of the Ausiassöffnung increases in the direction of rotation of the impeller towards the Gehäuseteii the secondary air blower, in which the inlet is formed. By this embodiment, the flow vector of an eddy is simulated in the region of the outlet, whereby an additional emptying of the pockets is achieved An additional improvement is achieved in that the length of the projection of the Ausiassöffnung limiting in the direction of rotation of the impeller Ausiasskante is at least as large as or greater than the distance between two blades of the impeller. This will ensure that most of the pressurized fluid is drained from the entire bag to the outlet.

Preferably, the extent of the recess in the direction of rotation of the impeller grows in the direction of the Gehäuseteii the Sekundäriuftgebläses, in which the Einiass is formed. In this way, additional pressure pulsations are reduced because the relaxation path is increased,

In a further embodiment, the extension of the outlet opening in the direction of rotation of the impeller axia grows! in the direction of Einiass the SekundativuftgebSäses stronger than the extent of the recess in the direction of rotation, so that an angle between the AusJasskante the outlet opening and a breaker edge is formed. The air flowing out when passing the recess changes the pressure of the fluid in the pocket and thus the size of the velocity vector in the circumferential direction. Thus, the direction of the velocity vector of the WirstreSsträhne changes, which is used here for the best possible emptying of the pockets behind the inlet opening to reduce the pressure surges,

In a particularly advantageous embodiment of the invention, the housing has two axia! opposite conveyor channels, wherein the impeller blades of the impeller on both axial sides of the impeller facing the conveying channels and the extension of the outlet opening in the direction of rotation of the impeller grows axially from a peripheral ring of the impeller toward the axial ends of the Förderschaufein. In this way, the vortex formation of both conveyor channels or both impeller sides is taken into account in the formation of the outlet opening, in order to achieve the best possible emptying of the pockets and thus a large flow rate, the noise emissions by avoiding pressure surges on both axia! continue to sink on opposite sides of the ejection area.

Preferably, the extension of the recess increases in the direction of rotation of the impeller axially from the peripheral ring of the impeller towards the axial ends of the Förderschaufefn, whereby the relaxation of the funded fluid is used behind the outlet opening with respect to both Förderkanäfe for noise reduction.

It is thus a Seitenkanalgebiase created in which compared to known side channel blowers the expelled volume flow is increased with the same size of the pump and at the same time outwardly urgent noise due to pressure surges occurring in the region of the outlet and the interruption range are significantly reduced.

An embodiment of a Seitenkanalgebiäses invention is shown in the drawings and will be described below.

Figure 1 shows a side view of a Seitenkanalgebiäses in a sectional view.

FIG. 2 shows a perspective view of a housing nozzle of the side channel pump of FIG. 1.

FIG. 3 shows a perspective view of the cover part of the side channel pump of FIG. 1.

The side channel blower shown in Figure 1 consists of a two-part housing 2 and a rotatably mounted in the housing 2 and driven by a drive unit 3 impeller 4, for example for the promotion of air. The air passes through an axial inlet 6 in an inlet region 8 of a first housing part 10, soft in the present embodiment as Deckeltei! of the side channel blower is used. From Einiassbereich 8 from the air then flows into two substantially annularly extending conveyor channels 12, 14, of in which the first conveying channel 12 is formed in the cover part 10 and the second conveying channel 14 is formed in a second housing part 16, in whose central opening 17 also a bearing 18 of a drive shaft 19 of the drive unit 3 is arranged, on which the impeller 4 is fixed. The outlet of the air via a tangential Ausiass 20, the second Gehäusetei! 16 is arranged.

The impeller 4 is disposed between the cover part 10 and the second housing part 16 and has at its periphery conveying blades 22 which are curved and extend radially, wherein the conveying blades 22 by a radially extending peripheral ring 24 in a first row axially opposite to the first Delivery channel 12 and a second row axially opposite to the second conveying channel 14 are divided, so that two Wirbeikanäie are formed, each formed by one of the conveying channels 12, 14 with the facing part of the impeller 4. The outer diameter of the conveying channels 12, 14 is slightly larger than the outer diameter of the impeller 4, so that a fluidic connection between the two conveying channels 12, 14 outside the outer periphery of the impeller 4, so that an exchange of air between the two conveying channels 12, 14th can take place. Between the extending from the peripheral ring 24 Förderschaufefn 22 are thus formed radially outwardly open pockets 26, in which the air is promoted or accelerated so that the pressure over the length of the conveyor channels 12, 14 is increased.

In order to obtain the best possible delivery rate and pressure increase, the axial inlet 6 in the direction of rotation of the impeller 4 as far as possible away from the tangential Ausiass 20. In order reliably to prevent a short-circuit flow against the direction of rotation of the impeller 4 from the inlet 6 to the outlet 20, interruption regions 28, 30 are arranged between the inlet 6 and the outlet 20 on the cover part 10 and on the housing part 16, which interrupt the delivery channels 12, 14 that in the interruption regions 28, 30 axially opposite to the conveying blades 22 of the impeller 4 as small as possible gap is present. An interruption region 32 is formed on a radially delimiting wall 33 of the second housing part 16 and interrupts a radially outer connection region 35 between the two Förderkanäien 12, 14th

In FIGS. 2 and 3 it can be seen that the conveying channels 12, 14 arranged in the cover side 10 and in the second housing part 16 have a substantially constant width and, with the exception of the interruption areas

28, 30 extend over the circumference of the cover egg 10 and the housing part 16.

In the view selected in FIG. 2, therefore, the impeller 4 rotates counterclockwise from the inlet region 8 to the end of the conveying channel 12 and then back to the inlet region 8 via the interruption region 28.

The cover part 10 is screwed on the second Gehäusetei! 16 fastened, which are inserted through corresponding bores 34, which are formed on radially outwardly extending projections 36 on Deckelteii 10. At two of these projections 36 are additionally small, axially extending bolts 38, which for prefixing the Deckeiteiis 10 on the second Gehäusetei! Serve 16, are formed on the corresponding holes 40,

Radially behind a wall 42 of the conveying channel 12, an IMut 44 is formed, in the sealing between the cover part 10 and the second Gehäusetei! 16, a sealing ring 46 is inserted, which is held in the groove 44 via lugs 48.

Radiai in front of a wall 50 of the conveying channel 12, an annular web 52 is formed, which engages after assembly of the fan in a corresponding groove 54 of the impeller 4, whereby a seal from Förderkanai 12 toward the interior of the impeller 4 takes place, in addition, the cover part 10, a cylindrical recess 56 into which the driving path 19 of the drive unit 3 protrudes,

Erfϊndungsgemäß are the delivery channels 12, 14 in Deckeiteü 10 and Gehäusetei! 16 are formed so that they extend in the area in front of the outlet 20 instead of as before in Umfangsrϊchtung from here towards the outlet 20 as the outlet 20 in the tangential direction. At the same time the width of the Delivery channels 12, 14 smaller than the width of the outlet 20, so that it is initially flowed by the delivery channels 12, 14 only over its radially outer region. An outlet opening 58, which leads through the radially delimiting wall 33 of the second housing part 16 and connects the interior of the fan with the outlet 20, is formed such that in the direction of rotation of the impeller 4 the outlet opening 58 into the interruption areas 28, 30 of the housing parts 10 , 16 extends, as can be seen in Figure 2.

In the embodiment shown here, an exit edge 62, which delimits the exit opening 58 in the direction of rotation of the impeller 4, extends from an inner edge 64 of the delivery channel 14 in the second housing part 16 to the wall

33 obliquely upward, so with an axial component in the direction of

Lid part 10 and a component in the direction of rotation of the impeller 4. The

Angle of this slope should be chosen so that the component corresponds in Umfangsrϊchtung at least the distance between two blades 22.

In addition to this particular configuration of the outlet opening 58, a recess 60 is formed directly behind the outlet opening 58 at the discontinuity region 32 of the radially delimiting wall 33. This recess 60 is bounded by a breaker edge 66 in the direction of rotation of the impeller 4, which also extends obliquely from the bottom of the housing part 16, afso having an axial component in the direction of the cover part 10 and a component in the direction of rotation of the impeller. However, the interrupt edge 66 and the outlet edge 62 are not parallel but are at an angle to each other, wherein for the outlet edge 62, the component in the direction of rotation is greater than for the interrupt edge 66, It should be noted that with a larger distance between the blades 22 of the Impeller 4, the included angle between the breaker edge 66 and the outlet edge 62 should be selected larger.

Looking now at the movement of a single to the liddle! 10 facing pocket 26 in the outlet of the impeller 4, which due to the arrangement of the inlet 6 has a higher filling than the axially opposite

Bag 26, so this first passes with its radially inner edge of the interruption region 28 of the cover part 10. Upon further rotation of the

Impeller 4, the bag 26 is covered from the inside out through the interruption area 28, so that only a significantly reduced Anteii the air can flow back into the bag. Before the bag 26 is completely covered by the interruption area 28, the bag reaches the

Outlet opening 58, so that the compressed air can flow out. With the

However, compressed air is still present in the pocket 26 of the impeller 4 reaching the end of the delivery channel 12, which pocket 26 at its radial

Outside edge leaves. The velocity vector of this residual air has a

Component radially outward, a component in the direction of rotation of the impeller

4 as well as a component towards the lid! 10. This corresponds to the

It follows that, due to the selected maximum extent of the outlet opening 58 in the direction of rotation, the air flowing out of the pocket 28 does not bear against the outlet edge 62 of the airflow in the circumferential direction

Ausiassöffnung 58 abuts in the form of a pressure surge, but in the outlet

20 flows.

The air flowing out behind the outlet opening 58 also does not strike immediately against the interruption area 32 on the radial wall 33 but flows into the recess 6Q ₁ where at least a slight relaxation takes place by turbulence of the air reaching into the recess. The angle is chosen so that neither the simultaneously over the entire height of the pocket 26 ejected air flow reaches the breaker edge 66 at the same time still reaches the same width over the entire air stream expelled. At the same time, the expansion path for the existing residual air increases. So pressure surges can be additionally reduced. The described side channel blower is characterized by a significant reduction in noise emissions compared to known Seitenπkanalgebläsen. At the same time, a high delivery rate is achieved. However, it should be clear that various modifications of the Ausführungsbeiispie! In particular, it may be a pump with only one side channel or the outlet opening and breaker shape may be configured correspondingly with respect to the larger flow leading to the inlet facing channel as well as to the opposite channel be. In this case, it would be necessary to design the outlet opening with two bevels, which expand the outlet opening from the height of the peripheral ring upwards and downwards accordingly.

Claims

1. Seitenkanafgebläse, in particular Sekundärfuftgebiäse for an internal combustion engine with a multi-part housing, in which an axial Einiass, via an inlet region in at least one substantially annularly extending Förderkana! an outlet, an impeller which is drivable via a drive unit, is rotatably mounted in the housing and has Förderschaufein, which cooperate with the opposite Förderkanai, and an interruption area between the enclosure and the outlet, in which the at least one conveying channel is interrupted in the circumferential direction, characterized in _/ that the at least one conveying channel (12; 14) performs substantially in the tangential direction to the outlet (20), wherein an outlet opening (58) in the radial limiting wall (33) (in the direction of rotation of the impeller 4) to an outlet edge (62) extending into the interruption area

(28; 30) of the at least one delivery channel (12; 14) protrudes, wherein in

Direction of rotation of the impeller (4) immediately behind the outlet opening (58) on the radia! limiting wall (33) has a recess (60) is formed, which reduces the extension of the interruption region (32) on the radially delimiting wall (33) in the circumferential direction.

2. Seitenkanalgebiäse, in particular secondary air blower for an internal combustion engine according to claim 1, characterized in that the extension of the outlet opening (58) in the direction of rotation of the impeller (4) towards the housing part (10) of the secondary air blower, in which the Einiass (6) is, grows.

3. Side channel blower, in particular Sekundärfuftgebläse for an internal combustion engine according to any one of claims 1 or 2, characterized in that the length of the projection in the direction of rotation of the impeller (4)

Outlet edge (58) bordering Austrasskante (62) at least as large as or greater than the distance between two conveyor blades (22) of the impeller (4),

4, side channel blower, in particular Sekundärluftgebfäse for an internal combustion engine according to claim 1, characterized in that the extension of the recess (60) in the direction of rotation of the impeller (4) in the direction of the housing part (1O) _{7 formed} in the Einiass (6) of the Sekundäriuftgebläses is, grows.

5, Seitenkanafgebläse, in particular secondary air blower for an internal combustion engine according to claim 4, characterized in that the extension of the Ausfassöffnung (58) in the direction of rotation of the impeller (4) axially towards Einiass (6) of the Sekundäriuftgebläses grows stronger than the extension of the recess (60 ) in the direction of rotation, so that an angle between the outlet edge (62) of the Ausiassöffnung (58) and a breaker edge (66) is formed,

6. Seitenkanaägebläse, in particular Sekuπdärluftgebläse for an internal combustion engine according to any one of the preceding claims, characterized in that the housing (2) has two axially opposite conveying channels (12, 14), wherein the Förderschaufein (22) of the impeller (4) on both axial sides of the impeller (4) facing the delivery channels (12, 14) and the extension of the outlet opening (58) in the direction of rotation of the Impeller (4) axially from a Umfangsriπg (24) of the impeller (4) towards the axial ends of the Förderschaufein (22) grows.

Seϊtenkanalgebiase, in particular secondary air blower for an internal combustion engine according to claim 6, characterized cfass the extent of the recess (60) on the housing (2) in the direction of rotation of the impeller (4) axially from the peripheral ring (24) of the impeller (4) in the direction of the axiaien Ends of Förderschaufein (22) grows.