EP3702620A1 - Axial fan with noise reducing fan impeller vanes having bores - Google Patents

Axial fan with noise reducing fan impeller vanes having bores Download PDF

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Publication number
EP3702620A1
EP3702620A1 EP20155642.0A EP20155642A EP3702620A1 EP 3702620 A1 EP3702620 A1 EP 3702620A1 EP 20155642 A EP20155642 A EP 20155642A EP 3702620 A1 EP3702620 A1 EP 3702620A1
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EP
European Patent Office
Prior art keywords
bores
fan
blade tip
axial
fan wheel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP20155642.0A
Other languages
German (de)
French (fr)
Other versions
EP3702620B1 (en
Inventor
Roland Keber
Tobias SIEGER
Wolfgang Laufer
Jürgen Herr
Arnold Schulde
Georg Eimer
Martin Müller
Dominik Haas
Simon HOPPE
Julien GRILLIAT
Johannes DANNECKER
Clemens GÜNTER
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ebm Papst St Georgen GmbH and Co KG
Original Assignee
Ebm Papst St Georgen GmbH and Co KG
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Publication date
Application filed by Ebm Papst St Georgen GmbH and Co KG filed Critical Ebm Papst St Georgen GmbH and Co KG
Priority to EP21215518.8A priority Critical patent/EP3988797B1/en
Publication of EP3702620A1 publication Critical patent/EP3702620A1/en
Application granted granted Critical
Publication of EP3702620B1 publication Critical patent/EP3702620B1/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D19/00—Axial-flow pumps
    • F04D19/002—Axial flow fans
    • F04D19/005—Axial flow fans reversible fans
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D19/00—Axial-flow pumps
    • F04D19/002—Axial flow fans
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/68—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers
    • F04D29/681—Combating cavitation, whirls, noise, vibration or the like; Balancing by influencing boundary layers especially adapted for elastic fluid pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/32—Rotors specially for elastic fluids for axial flow pumps
    • F04D29/38—Blades
    • F04D29/388—Blades characterised by construction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/52—Casings; Connections of working fluid for axial pumps
    • F04D29/522—Casings; Connections of working fluid for axial pumps especially adapted for elastic fluid pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/663—Sound attenuation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/666—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by means of rotor construction or layout, e.g. unequal distribution of blades or vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/667—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by influencing the flow pattern, e.g. suppression of turbulence
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2210/00—Working fluids
    • F05D2210/10—Kind or type
    • F05D2210/12—Kind or type gaseous, i.e. compressible
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/20—Rotors
    • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05D2240/307—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor related to the tip of a rotor blade
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00—Function
    • F05D2260/96—Preventing, counteracting or reducing vibration or noise
    • F05D2260/962—Preventing, counteracting or reducing vibration or noise by means of "anti-noise"

Definitions

  • the invention relates to an axial fan with a housing and a fan wheel arranged in the housing for generating an axial air flow through the housing.
  • the invention is based on the object of improving the noise behavior of an axial fan.
  • an axial fan with a housing and a fan wheel arranged in the housing for generating an axial air flow through the housing is proposed.
  • the fan wheel has a plurality of fan wheel blades extending radially outward from a hub to the respective blade tip, which run spaced apart from an inner wall of the housing via a head gap.
  • the blade tip is the extension of the fan impeller blades along the inner wall of the housing, which in particular surrounds the fan impeller as a housing ring.
  • the fan wheel blades have bores along the respective blade tip.
  • the bores along the respective blade tip interact directly with the head gap vortex and reduce the noise emissions of the fan wheel during operation.
  • the shape and spread of the flow vortex along the blade tips of the fan impeller blades is favorably influenced.
  • axial fans which only differ in terms of the impeller blades with and without holes provided along the blade tip, it was possible to achieve reductions in noise development of over 20% during measurements.
  • the bores have a particularly advantageous effect in axial fans in which the fan wheel blades have a very flat angle of incidence with respect to the axial plane running perpendicular to the direction of flow, which is in the range of 5-25 °, preferably 10-20 °.
  • a further development of the axial fan is characterized in that the bores are formed on both axial sides of the fan wheel blades.
  • the bores are designed as through bores through the fan wheel blades.
  • the bores per fan wheel blade are provided along the respective blade tip.
  • the number of bores is at least two, but in particular at least three, preferably at least five, more preferably at least seven.
  • the bores run along a line parallel to the blade tip. Their arrangement is thus determined by the course of the blade tip along the head gap with respect to the inner wall of the housing.
  • the bores with a circular cross-section has proven to be particularly favorable.
  • the size of the holes is determined by their diameter.
  • the bores have a maximum diameter DBmax, which corresponds to 0.7-1.5%, preferably 1% of a maximum fan wheel diameter of the fan wheel.
  • a special arrangement of the holes in relation to one another also favors noise reduction.
  • An embodiment variant is favorable in which the bores have a distance A from one another along the respective blade tip which corresponds to twice the maximum diameter DBmax of the bores. The distance A is measured at the center of each hole. The distance A between the holes is related to the maximum fan wheel diameter D of the fan wheel along the respective blade tip to one another when it corresponds to 2% of the maximum fan wheel diameter D.
  • the bores are somewhat spaced radially inward from the respective blade tip of the respective fan wheel blade, but are nevertheless adjacent, so that the radially outer blade tip of the respective fan wheel blade runs continuously and uninterrupted.
  • the bores are preferably offset radially inward by 1.5 times the bore diameter from the blade tip.
  • measurements are always taken in the center of the holes.
  • the length LS with which the bores are spaced apart from the respective blade tip corresponds to preferably 1.5% of the maximum fan wheel diameter D of the fan wheel.
  • all of the bores of the fan wheel are identical in shape and size.
  • the bores are arranged over an extension along the blade tip of the respective fan wheel blade which corresponds to 10-40% of a maximum extension of the blade tip along the head gap. This means that there is a predominant section along the blade tip in which no bores are provided, but a minimum amount and a minimum extent must not be exceeded. It is also favorable to have the bores particularly in a region of the blade tip to be arranged, which is adjacent to the respective blade leading edge and / or respective blade trailing edge.
  • the axial fan also provides that each of the fan wheel blades along the blade tip has a central section which is free of bores and adjoins a radial center line of the fan wheel blades on both sides.
  • the bores are thus provided in a region of the front edge and / or rear edge of the fan wheel blades.
  • the central section preferably determines 20-90%, more preferably 40-80% of the maximum extent of the respective fan wheel blade in the circumferential direction.
  • the bores are additionally provided along a front edge and / or a rear edge of the fan impeller blades.
  • the distances to one another or to the front edge and / or a rear edge preferably correspond to those of the bores along the blade tip or to the blade tip.
  • an embodiment is favorable in which, in the axial fan, the respective number of bores along the front edge and / or the rear edge of the fan impeller blades is smaller than or equal to the number of bores along the blade tip. This means that the number of holes on the leading edge and on the trailing edge is always not greater than the number of holes on the blade tip.
  • the axial fan is further characterized in that the fan wheel is designed to be reversible and its generated during operation Direction of flow depends on its direction of rotation.
  • the bores are then preferably provided both on the front edge and on the rear edge as well as on both axial sides of the respective fan wheel blades.
  • a first variant of the axial fan 1 is shown.
  • This comprises a ring-shaped closed housing 2 in which the reversible fan wheel 3 is arranged for generating the axial air flow, the direction of flow of which depends on the direction of rotation of the fan wheel 4.
  • the fan wheel 3 has the hub 5 with several ventilation openings 25 which are arranged in a circle and in which the drive motor is received, which is electrically powered via the connections 14 is supplied.
  • the drive motor is held by the holder 20, which is connected to the housing 2 via webs 11 distributed in the circumferential direction.
  • the webs 11 run in a straight line, but are inclined with respect to a radial plane.
  • the fan impeller blades 4 extend radially outward as far as their respective blade tip 8, which forms the blade edge adjoining the inner wall of the housing 2.
  • the head gap 12 is provided between the blade tips 8 and the inner wall of the housing 2, so that the fan wheel 3 can rotate relative to the housing 2.
  • the fan wheel blades 4 are each shaped identically. Adjacent to the blade tip 8, viewed in the circumferential direction, they each have a radially retracted section 9 on both sides, in which the blade edge still points radially outward, but is spaced from the inner wall of the housing 2.
  • the blade edge then merges into the front edge 17 and rear edge 18, which each point in the circumferential direction, but are each designed to be drawn in in the circumferential direction with respect to the radially outermost section of the fan wheel blade 4.
  • An axial step 24 is formed on each of the fan impeller blades 4 along their central axis, viewed in the circumferential direction, which increases in size in the radial direction and tapers towards the blade tip 8, so that the impeller blade 4 has a stepless profile in the area of the blade tip 8.
  • a plurality of bores 7 with a circular cross section are provided along the respective blade tip 8 on both axial sides.
  • the bores 7 are formed on both axial sides at the respectively identical position and thus have the respectively identical central axis. Provision is preferably made for the bores 7 to be designed as through bores.
  • eight holes 7, ie A total of 16 bores 7 are provided per fan wheel blade 4, of which there are six bores 7 per area with bores 7 along the blade tip 8 along the head gap 12 and two bores 7 in each case in the drawn-in section 9.
  • Each of the fan impeller blades 4 comprises, along the blade tip 8, in each case a central section 15 which adjoins a radial center line of the fan impeller blades 4 on both sides and is free of bores 7.
  • the middle section 15 without holes 7 determined in both embodiments according to FIG Figures 1 and 5 In the comparatively larger area, ie over a greater extent of the respective fan wheel blade 4, no bores 7 are provided, since these are essentially located in the peripheral edge sections.
  • the fan wheel blades 4 have a very small angle of incidence of less than 25 ° with respect to the axial plane extending through the housing 2, which is well in Figure 3 can be seen. With such low angles of attack, the bores 7 particularly effective.
  • the size, shape and arrangement of the bores 7 clearly influence the noise-reducing effect.
  • Advantageous dimensions are entered, which are identical for the embodiment of Figures 1-4 are applicable.
  • the holes 7 have a maximum diameter DBmax, which corresponds to 1% of the maximum fan wheel diameter D of the fan wheel 4, measured in each case in the center of the holes 7.
  • the distance A of the holes 7 to one another along the respective blade tip 8 corresponds to twice the maximum diameter DBmax and 2 % of the maximum fan wheel diameter D of the fan wheel 4.
  • the bores 7 are spaced from the blade tip 8 over the length LS, which makes up 1.5% of the impeller diameter D and 1.5 times the maximum diameter DBmax.
  • the radially outer blade tip 8 of the respective fan wheel blade 4 runs continuously and without interruption.
  • the bores 7 are distributed along the blade tip 8 over a length which corresponds to 10% of the blade tip length L along which the head gap 12 is formed. In the execution according to the Figures 1 - 4 it's 20%.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

Die Erfindung betrifft einen Axialventilator (1) mit einem Gehäuse (2) und einem in dem Gehäuse (2) angeordneten Lüfterrad (3) zur Erzeugung eines Axialluftstromes durch das Gehäuse (2), wobei das Lüfterrad (3) mehrere sich von einer Nabe (5) nach radial außen bis zur jeweiligen Schaufelspitze (8) erstreckende Lüfterradschaufeln (4) aufweist, welche über einen Kopfspalt (12) beanstandet zu einer Innenwand des Gehäuses (2) verlaufen, und wobei die Lüfterradschaufeln (4) entlang der jeweiligen Schaufelspitze (8) Bohrungen (7) aufweisen.The invention relates to an axial fan (1) with a housing (2) and a fan wheel (3) arranged in the housing (2) for generating an axial air flow through the housing (2), the fan wheel (3) being several from a hub ( 5) has fan impeller blades (4) extending radially outwards to the respective blade tip (8), which run over a head gap (12) spaced apart from an inner wall of the housing (2), and wherein the fan wheel blades (4) along the respective blade tip (8 ) Have bores (7).

Description

Die Erfindung betrifft einen Axialventilator mit einem Gehäuse und einem in dem Gehäuse angeordneten Lüfterrad zur Erzeugung eines Axialluftstromes durch das Gehäuse.The invention relates to an axial fan with a housing and a fan wheel arranged in the housing for generating an axial air flow through the housing.

Bei Axialventilatoren mit ringförmigen, das Lüfterrad umschließenden Gehäusen entstehen am Kopfspalt zwischen den Lüfterradschaufeln und der Gehäuseinnenwand Kopfspaltwirbel, die in Praxis zu einer erheblichen Geräuschentwicklung führen. Zu deren Reduzierung gibt es im Stand der Technik bereits mehrere Ansätze, die jedoch nicht für jeden Einsatz geeignet sind. Beispielsweise kann der Durchmesser des Axialventilators vergrößert werden. Dies ist jedoch kontraproduktiv hinsichtlich seines Wirkungsgrads und Windlastverhaltens. Alternativ gibt es die Möglichkeit, die Zuströmung oder Abströmung zu beeinflussen, jedoch sind hierfür zusätzliche Bauteile und meist ein erhöhter Bauraumbedarf nötig.In the case of axial fans with ring-shaped housings that surround the fan wheel, head gap vortices occur at the head gap between the fan wheel blades and the inner wall of the housing, which in practice lead to considerable noise generation. To reduce them there are in the state of Technology already has several approaches, but they are not suitable for every application. For example, the diameter of the axial fan can be increased. However, this is counterproductive in terms of its efficiency and wind load behavior. Alternatively, there is the possibility of influencing the inflow or outflow, but this requires additional components and usually an increased space requirement.

Der Erfindung liegt die Aufgabe zugrunde, das Geräuschverhalten eines Axialventilators zu verbessern.The invention is based on the object of improving the noise behavior of an axial fan.

Diese Aufgabe wird durch die Merkmalskombination gemäß Patentanspruch 1 gelöst.This object is achieved by the combination of features according to patent claim 1.

Erfindungsgemäß wird ein Axialventilator mit einem Gehäuse und einem in dem Gehäuse angeordneten Lüfterrad zur Erzeugung eines Axialluftstromes durch das Gehäuse vorgeschlagen. Das Lüfterrad weist mehrere sich von einer Nabe nach radial außen bis zur jeweiligen Schaufelspitze erstreckende Lüfterradschaufeln auf, welche über einen Kopfspalt beanstandet zu einer Innenwand des Gehäuses verlaufen. Die Schaufelspitze ist die Erstreckung der Lüfterradschaufeln entlang der Innenwand des Gehäuses, das insbesondere als Gehäusering das Lüfterrad umgibt. Die Lüfterradschaufeln weisen entlang der jeweiligen Schaufelspitze Bohrungen auf.According to the invention, an axial fan with a housing and a fan wheel arranged in the housing for generating an axial air flow through the housing is proposed. The fan wheel has a plurality of fan wheel blades extending radially outward from a hub to the respective blade tip, which run spaced apart from an inner wall of the housing via a head gap. The blade tip is the extension of the fan impeller blades along the inner wall of the housing, which in particular surrounds the fan impeller as a housing ring. The fan wheel blades have bores along the respective blade tip.

Die Bohrungen entlang der jeweiligen Schaufelspitze interagieren unmittelbar mit dem Kopfspaltwirbel und reduzieren die Geräuschemission des Lüfterrads im Betrieb. Insbesondere wird die Form und Ausbreitung des Strömungswirbels entlang der Schaufelspitzen der Lüfterradschaufeln günstig beeinflusst. Bei Axialventilatoren, die sich ausschließlich durch die Laufradschaufeln mit und ohne entlang der Schaufelspitze vorgesehene Bohrungen unterschieden, konnten bei Messungen Reduzierungen der Geräuschentwicklung von über 20% erreicht werden.The bores along the respective blade tip interact directly with the head gap vortex and reduce the noise emissions of the fan wheel during operation. In particular, the shape and spread of the flow vortex along the blade tips of the fan impeller blades is favorably influenced. In the case of axial fans, which only differ in terms of the impeller blades with and without holes provided along the blade tip, it was possible to achieve reductions in noise development of over 20% during measurements.

Besonders vorteilhaft wirken die Bohrungen bei Axialventilatoren, bei denen die Lüfterradschaufeln einen sehr flachen Anstellwinkel gegenüber der senkrecht zur Strömungsrichtung verlaufenden Axialebene aufweisen, der insbesondere im Bereich von 5-25°, vorzugsweise 10-20° liegt.The bores have a particularly advantageous effect in axial fans in which the fan wheel blades have a very flat angle of incidence with respect to the axial plane running perpendicular to the direction of flow, which is in the range of 5-25 °, preferably 10-20 °.

Eine Weiterbildung des Axialventilators ist dadurch gekennzeichnet, dass die Bohrungen auf beiden axialen Seiten der Lüfterradschaufeln ausgebildet sind. In einer bevorzugten Ausführung sind die Bohrungen als Durchgangsbohrungen durch die Lüfterradschaufeln ausgebildet.A further development of the axial fan is characterized in that the bores are formed on both axial sides of the fan wheel blades. In a preferred embodiment, the bores are designed as through bores through the fan wheel blades.

Vorzugsweise werden mehrere der Bohrungen je Lüfterradschaufel entlang der jeweiligen Schaufelspitze vorgesehen. Die Anzahl der Bohrungen beträgt mindestens zwei, insbesondere jedoch mindestens drei, vorzugsweise mindestens fünf, weiter bevorzugt mindestens sieben. Die Bohrungen verlaufen dabei entlang einer Linie parallel zur Schaufelspitze. Ihre Anordnung ist somit über den Verlauf der Schaufelspitze entlang des Kopfspalts gegenüber der Innenwand des Gehäuses festgelegt.Preferably, several of the bores per fan wheel blade are provided along the respective blade tip. The number of bores is at least two, but in particular at least three, preferably at least five, more preferably at least seven. The bores run along a line parallel to the blade tip. Their arrangement is thus determined by the course of the blade tip along the head gap with respect to the inner wall of the housing.

Als besonders günstig hat sich eine Ausführung der Bohrungen mit einem kreisförmigen Querschnitt erwiesen. Die Größe der Bohrungen wird über ihren Durchmesser bestimmt. In einer vorteilhaften Ausführung des Axialventilators weisen die Bohrungen einen maximalen Durchmesser DBmax auf, der 0,7-1,5%, vorzugsweise 1% eines maximalen Lüfterraddurchmessers des Lüfterrads entspricht.A design of the bores with a circular cross-section has proven to be particularly favorable. The size of the holes is determined by their diameter. In an advantageous embodiment of the axial fan, the bores have a maximum diameter DBmax, which corresponds to 0.7-1.5%, preferably 1% of a maximum fan wheel diameter of the fan wheel.

Eine spezielle Anordnung der Bohrungen zueinander begünstigt die Geräuschreduzierung ebenfalls. Günstig ist eine Ausführungsvariante, bei der die Bohrungen zueinander einen Abstand A entlang der jeweiligen Schaufelspitze aufweisen, der dem doppelten maximalen Durchmesser DBmax der Bohrungen entspricht. Der Abstand A wird dabei jeweils am Mittelpunkt der jeweiligen Bohrung gemessen. Bezogen auf den maximalen Lüfterraddurchmesser D des Lüfterrads ist der Abstand A der Bohrungen entlang der jeweiligen Schaufelspitze zueinander dann vorteilhaft, wenn er 2% des maximalen Lüfterraddurchmessers D entspricht.A special arrangement of the holes in relation to one another also favors noise reduction. An embodiment variant is favorable in which the bores have a distance A from one another along the respective blade tip which corresponds to twice the maximum diameter DBmax of the bores. The distance A is measured at the center of each hole. The distance A between the holes is related to the maximum fan wheel diameter D of the fan wheel along the respective blade tip to one another when it corresponds to 2% of the maximum fan wheel diameter D.

Ferner ist vorteilhaft, dass die Bohrungen von der jeweiligen Schaufelspitze der jeweiligen Lüfterradschaufel nach radial innen etwas beabstandet gleichwohl angrenzend sind, so dass die radial außen liegende Schaufelspitze der jeweiligen Lüfterradschaufel durchgängig und ununterbrochen verläuft. Eine bezüglich der Geräuscherzeugung vorteilhafte Ausführung ist dadurch gekennzeichnet, dass die Bohrungen einen maximalen Durchmesser DBmax aufweisen und von der jeweiligen Schaufelspitze über eine radiale Länge LS beanstandet sind, so dass gilt: DBmax ≤ LS ≤ 2,5 x DBmax. Besonders bevorzugt ist LS=1,5 x DBmax. In anderen Worten sind die Bohrungen vorzugsweise um den 1,5-fachen Bohrungsdurchmesser von der Schaufelspitze nach radial innen versetzt. Gemessen wird auch hier stets im Mittelpunkt der Bohrungen.It is also advantageous that the bores are somewhat spaced radially inward from the respective blade tip of the respective fan wheel blade, but are nevertheless adjacent, so that the radially outer blade tip of the respective fan wheel blade runs continuously and uninterrupted. An embodiment that is advantageous in terms of noise generation is characterized in that the bores have a maximum diameter DBmax and are spaced from the respective blade tip over a radial length LS, so that the following applies: DBmax ≤ LS ≤ 2.5 x DBmax. LS = 1.5 x DBmax is particularly preferred. In other words, the bores are preferably offset radially inward by 1.5 times the bore diameter from the blade tip. Here, too, measurements are always taken in the center of the holes.

Bezogen auf den maximalen Lüfterraddurchmesser D des Lüfterrads entspricht die Länge LS, mit welcher die Bohrungen von der jeweiligen Schaufelspitze über beanstandet sind, vorzugsweise 1,5% des maximalen Lüfterraddurchmessers D des Lüfterrads.In relation to the maximum fan wheel diameter D of the fan wheel, the length LS with which the bores are spaced apart from the respective blade tip corresponds to preferably 1.5% of the maximum fan wheel diameter D of the fan wheel.

Vorzugsweise sind alle Bohrungen des Lüfterrads bezüglich Form und Größe jeweils identisch ausgebildet.Preferably, all of the bores of the fan wheel are identical in shape and size.

In einer vorteilhaften Ausführungsvariante des Axialventilators ist vorgesehen, dass die Bohrungen über eine Erstreckung entlang der Schaufelspitze der jeweiligen Lüfterradschaufel angeordnet sind, welche 10-40% einer maximalen Erstreckung der Schaufelspitze entlang des Kopfspalts entspricht. Das bedeutet, dass es entlang der Schaufelspitze einen überwiegenden Abschnitt gibt, in dem keine Bohrungen vorgesehen sind, jedoch eine Mindestmenge und eine Mindesterstreckung nicht zu unterschreiten sind. Ferner ist günstig, die Bohrungen insbesondere in einem Bereich der Schaufelspitze anzuordnen, der an die jeweilige Schaufelvorderkante und/oder jeweilige Schaufelhinterkante angrenzt. Soweit die Lüfterradschaufeln im Übergangsbereich von der Schaufelspitze zur Schaufelvorderkante oder jeweilige Schaufelhinterkante radial eingezogen verlaufen und in diesem Abschnitt kein Kopfspalt zu dem Gehäuse mehr besteht, können Bohrungen gleichwohl auch in diesem Abschnitt entlang der Schaufelspitze vorgesehen werden.In an advantageous embodiment of the axial fan, it is provided that the bores are arranged over an extension along the blade tip of the respective fan wheel blade which corresponds to 10-40% of a maximum extension of the blade tip along the head gap. This means that there is a predominant section along the blade tip in which no bores are provided, but a minimum amount and a minimum extent must not be exceeded. It is also favorable to have the bores particularly in a region of the blade tip to be arranged, which is adjacent to the respective blade leading edge and / or respective blade trailing edge. If the fan impeller blades in the transition area from the blade tip to the blade leading edge or the respective blade trailing edge are radially retracted and there is no longer a head gap to the housing in this section, bores can nevertheless also be provided in this section along the blade tip.

Der Axialventilator sieht in einer vorteilhaften Ausführungsvariante zudem vor, dass jede der Lüfterradschaufeln entlang der Schaufelspitze jeweils einen sich an eine radiale Mittellinie der Lüfterradschaufeln beidseitig angrenzenden Mittelabschnitt aufweist, der frei von Bohrungen ist. Die Bohrungen werden somit in einem Bereich der Vorderkante und/oder Hinterkante der Lüfterradschaufeln vorgesehen. Der Mittelabschnitt bestimmt vorzugsweise 20-90%, weiter bevorzugt 40-80% der maximalen Erstreckung der jeweiligen Lüfterradschaufel in Umfangsrichtung.In an advantageous embodiment variant, the axial fan also provides that each of the fan wheel blades along the blade tip has a central section which is free of bores and adjoins a radial center line of the fan wheel blades on both sides. The bores are thus provided in a region of the front edge and / or rear edge of the fan wheel blades. The central section preferably determines 20-90%, more preferably 40-80% of the maximum extent of the respective fan wheel blade in the circumferential direction.

In einer Weiterbildung des Axialventilators sind die Bohrungen zusätzlich entlang einer Vorderkante und/oder einer Hinterkante der Lüfterradschaufeln vorgesehen. Die Abstände zueinander bzw. zur Vorderkante und/oder einer Hinterkante entsprechen dabei vorzugsweise denjenigen der Bohrungen entlang der Schaufelspitze bzw. zu der Schaufelspitze.In a further development of the axial fan, the bores are additionally provided along a front edge and / or a rear edge of the fan impeller blades. The distances to one another or to the front edge and / or a rear edge preferably correspond to those of the bores along the blade tip or to the blade tip.

Ferner ist eine Ausführung günstig, bei welcher bei dem Axialventilator die jeweilige Anzahl der Bohrungen zusätzlich entlang der Vorderkante und/oder der Hinterkante der Lüfterradschaufeln kleiner oder gleich der Anzahl an Bohrungen entlang der Schaufelspitze ist. Das bedeutet, dass die Anzahl der Bohrungen an der Vorderkante und an der Hinterkante jeweils stets nicht größer ist, als die Anzahl der Bohrungen an der Schaufelspitze.Furthermore, an embodiment is favorable in which, in the axial fan, the respective number of bores along the front edge and / or the rear edge of the fan impeller blades is smaller than or equal to the number of bores along the blade tip. This means that the number of holes on the leading edge and on the trailing edge is always not greater than the number of holes on the blade tip.

Der Axialventilator ist in einer Ausführung ferner dadurch gekennzeichnet, dass das Lüfterrad reversierbar ausgebildet und seine im Betrieb erzeugte Strömungsrichtung von seiner Rotationsrichtung abhängt. Dann werden die Bohrungen vorzugsweise sowohl an der Vorderkante als auch der Hinterkante sowie an beiden axialen Seiten der jeweiligen Lüfterradschaufeln vorgesehen.In one embodiment, the axial fan is further characterized in that the fan wheel is designed to be reversible and its generated during operation Direction of flow depends on its direction of rotation. The bores are then preferably provided both on the front edge and on the rear edge as well as on both axial sides of the respective fan wheel blades.

Andere vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen gekennzeichnet bzw. werden nachstehend zusammen mit der Beschreibung der bevorzugten Ausführung der Erfindung anhand der Figuren näher dargestellt. Es zeigen:

Fig. 1
eine Draufsicht auf einen Axialventilator in einer ersten Ausführung;
Fig. 2
eine Detailansicht des Axialventilators aus Figur 1;
Fig. 3
eine perspektivische Vorderansicht des Axialventilators aus Figur 1;
Fig. 4
eine perspektivische Rückansicht des Axialventilators aus Figur 1;
Fig. 5
eine Draufsicht auf einen Axialventilator in einer zweiten Ausführung.
Other advantageous developments of the invention are characterized in the subclaims or are shown in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:
Fig. 1
a plan view of an axial fan in a first embodiment;
Fig. 2
a detailed view of the axial fan Figure 1 ;
Fig. 3
a perspective front view of the axial fan Figure 1 ;
Fig. 4
a perspective rear view of the axial fan from Figure 1;
Fig. 5
a plan view of an axial fan in a second embodiment.

In den Figuren 1 - 4 ist eine erste Ausführungsvariante des Axialventilators 1 gezeigt. Dieser umfasst ein ringförmig geschlossenes Gehäuse 2, in dem das reversierbare ausgebildete Lüfterrad 3 zur Erzeugung des Axialluftstromes angeordnet ist, dessen Strömungsrichtung von der Rotationsrichtung des Lüfterrads 4 abhängt. Das Lüfterrad 3 weist die Nabe 5 mit mehreren in Kreisform angeordneten Belüftungsöffnungen 25 auf, in der der Antriebsmotor aufgenommen ist, welcher über die Anschlüsse 14 elektrisch versorgt wird. Rückseitig ist der Antriebsmotor von der Halterung 20 gehalten, welche über in Umfangsrichtung verteilt angeordnete Stege 11 mit dem Gehäuse 2 verbunden ist. Die Stege 11 verlaufen geradlinig, sind jedoch gegenüber einer Radialebene geneigt. Von der Nabe 5 aus erstrecken sich die Lüfterradschaufeln 4 nach radial außen bis zu ihrer jeweiligen Schaufelspitze 8, welche die an die Innenwand des Gehäuses 2 angrenzende Schaufelkante bildet. Zwischen den Schaufelspitzen 8 und der Innenwand des Gehäuses 2 ist der Kopfspalt 12 vorgesehen, so dass das Lüfterrad 3 gegenüber dem Gehäuse 2 rotieren kann. Die Lüfterradschaufeln 4 sind jeweils identisch geformt. Angrenzend zur Schaufelspitze 8 weisen sie in Umfangsrichtung gesehen beidseitig jeweils einen radial eingezogenen Abschnitt 9 auf, in dem die Schaufelkante zwar noch nach radial außen weist, jedoch von der Innenwand des Gehäuses 2 beabstandet ist. Anschließend geht die Schaufelkante in die Vorderkante 17 und Hinterkante 18 über, welche jeweils in Umfangsrichtung weisen, jedoch gegenüber dem radial äußersten Abschnitt der Lüfterradschaufel 4 jeweils in Umfangsrichtung eingezogen gestaltet sind. Entlang ihrer jeweils in Umfangsrichtung gesehenen Mittelachse ist an den Lüfterradschaufeln 4 jeweils eine axiale Stufe 24 ausgebildet, die sich nach radial innen gesehen vergrößert und zur Schaufelspitze 8 hin ausläuft, so dass im Bereich der Schaufelspitze 8 ein stufenloser Verlauf der Laufradschaufel 4 gegeben ist.In the Figures 1 - 4 a first variant of the axial fan 1 is shown. This comprises a ring-shaped closed housing 2 in which the reversible fan wheel 3 is arranged for generating the axial air flow, the direction of flow of which depends on the direction of rotation of the fan wheel 4. The fan wheel 3 has the hub 5 with several ventilation openings 25 which are arranged in a circle and in which the drive motor is received, which is electrically powered via the connections 14 is supplied. At the rear, the drive motor is held by the holder 20, which is connected to the housing 2 via webs 11 distributed in the circumferential direction. The webs 11 run in a straight line, but are inclined with respect to a radial plane. From the hub 5, the fan impeller blades 4 extend radially outward as far as their respective blade tip 8, which forms the blade edge adjoining the inner wall of the housing 2. The head gap 12 is provided between the blade tips 8 and the inner wall of the housing 2, so that the fan wheel 3 can rotate relative to the housing 2. The fan wheel blades 4 are each shaped identically. Adjacent to the blade tip 8, viewed in the circumferential direction, they each have a radially retracted section 9 on both sides, in which the blade edge still points radially outward, but is spaced from the inner wall of the housing 2. The blade edge then merges into the front edge 17 and rear edge 18, which each point in the circumferential direction, but are each designed to be drawn in in the circumferential direction with respect to the radially outermost section of the fan wheel blade 4. An axial step 24 is formed on each of the fan impeller blades 4 along their central axis, viewed in the circumferential direction, which increases in size in the radial direction and tapers towards the blade tip 8, so that the impeller blade 4 has a stepless profile in the area of the blade tip 8.

An jeder der Lüfterradschaufeln 4 sind entlang der jeweiligen Schaufelspitze 8 auf beiden axialen Seiten mehrere Bohrungen 7 mit kreisförmigem Querschnitt vorgesehen. Die Bohrungen 7 sind auf beiden axialen Seiten an der jeweils identischen Position ausgebildet und weisen somit die jeweils identische Mittelachse auf. Bevorzugt wird vorgesehen, die Bohrungen 7 als Durchgangsbohrungen zu gestalten. In der Ausführung gemäß der Figuren 1 - 4 sind auf beiden zur Vorderkante 17 und zur Hinterkante 18 weisenden Endabschnitten entlang der Schaufelspitze 8 jeweils acht Bohrungen 7, d.h. pro Lüfterradschaufel 4 insgesamt 16 Bohrungen 7 vorgesehen, von denen sich pro Bereich mit Bohrungen 7 jeweils sechs Bohrungen 7 entlang der Schaufelspitze 8 entlang des Kopfspalts 12 und jeweils zwei Bohrungen 7 im eingezogenen Abschnitt 9 befinden. In der Ausführung gemäß Figur 5 sind an den jeweiligen Endabschnitten entlang der Schaufelspitze 8 jeweils nur sieben Bohrungen 7, d.h. pro Lüfterradschaufel 4 insgesamt 14 Bohrungen 7 vorgesehen. Gegenüber der Ausführung gemäß Figur 1 - 4 sind bei der Ausführung gemäß Figur 5 die Bohrungen 7 in Umfangsrichtung gesehen weiter nach außen verlagert, so dass sich vier der sieben Bohrungen 7 jeweils entlang der Schaufelspitze 8 entlang des Kopfspalts 12 und jeweils drei Bohrungen 7 im eingezogenen Abschnitt 9 befinden. Im Übrigen sind die Ausführungen gemäß Figur 1-4 und Figur 5 identisch. In beiden Ausführungen nicht gezeigt, gleichwohl ebenfalls vorsehbar sind entsprechende Bohrungen 7 im Bereich der Vorderkante 17 oder der Hinterkante 18 sowie sowohl an der Vorderkante 17 als auch der Hinterkante 18 der jeweiligen Lüfterradschaufeln 4. Die Anzahl der Bohrungen jeweils entlang der Vorderkante 17 bzw. der Hinterkante 18 wird jedoch geringer festgelegt als diejenige der radialen Außenkante. Jede der Lüfterradschaufeln 4 umfasst entlang der Schaufelspitze 8 jeweils einen sich an eine radiale Mittellinie der Lüfterradschaufeln 4 beidseitig angrenzenden Mittelabschnitt 15 auf, der frei von Bohrungen 7 ist. Der Mittelabschnitt 15 ohne Bohrungen 7 bestimmt in beiden Ausführungen gemäß der Figuren 1 und 5 den vergleichsweise größeren Bereich, d.h. über eine größere Erstreckung der jeweiligen Lüfterradschaufel 4 sind keine Bohrungen 7 vorgesehen, da sich diese im Wesentlichen in den Umfangsrandabschnitten befinden.On each of the fan impeller blades 4, a plurality of bores 7 with a circular cross section are provided along the respective blade tip 8 on both axial sides. The bores 7 are formed on both axial sides at the respectively identical position and thus have the respectively identical central axis. Provision is preferably made for the bores 7 to be designed as through bores. In the execution according to the Figures 1 - 4 are on both of the leading edge 17 and the trailing edge 18 facing end sections along the blade tip 8 in each case eight holes 7, ie A total of 16 bores 7 are provided per fan wheel blade 4, of which there are six bores 7 per area with bores 7 along the blade tip 8 along the head gap 12 and two bores 7 in each case in the drawn-in section 9. In the execution according to Figure 5 For example, only seven bores 7, ie a total of 14 bores 7 per fan wheel blade 4, are provided on the respective end sections along the blade tip 8. Compared to the execution according to Figure 1 - 4 are in accordance with Figure 5 the bores 7 are displaced further outwards, seen in the circumferential direction, so that four of the seven bores 7 are each located along the blade tip 8 along the head gap 12 and three bores 7 are each located in the retracted section 9. Otherwise, the statements are in accordance with Figure 1-4 and Figure 5 identical. In both versions, not shown, but can also be provided corresponding bores 7 in the area of the front edge 17 or the rear edge 18 as well as both the front edge 17 and the rear edge 18 of the respective fan blades 4. The number of holes along the front edge 17 or the However, the rear edge 18 is set lower than that of the radial outer edge. Each of the fan impeller blades 4 comprises, along the blade tip 8, in each case a central section 15 which adjoins a radial center line of the fan impeller blades 4 on both sides and is free of bores 7. The middle section 15 without holes 7 determined in both embodiments according to FIG Figures 1 and 5 In the comparatively larger area, ie over a greater extent of the respective fan wheel blade 4, no bores 7 are provided, since these are essentially located in the peripheral edge sections.

In beiden Ausführungen der Figuren 1 und 5 weisen die Lüfterradschaufeln 4 gegenüber der sich durch das Gehäuse 2 erstreckenden Axialebene einen sehr geringen Anstellwinkel weniger als 25° auf, der gut in Figur 3 zu erkennen ist. Bei derartig geringen Anstellwinkeln sind die Bohrungen 7 besonders wirkungsvoll.In both versions of the Figures 1 and 5 the fan wheel blades 4 have a very small angle of incidence of less than 25 ° with respect to the axial plane extending through the housing 2, which is well in Figure 3 can be seen. With such low angles of attack, the bores 7 particularly effective.

Die Größe, Form und Anordnung der Bohrungen 7 beeinflusst den geräuschmindernden Effekt deutlich. In Figur 5 sind vorteilhafte Dimensionierungen eingetragen, welche identisch auch für das Ausführungsbeispiel der Figuren 1-4 anwendbar sind. Die Bohrungen 7 weisen einen maximalen Durchmesser DBmax auf, der 1% des maximalen Lüfterraddurchmessers D des Lüfterrads 4 entspricht, gemessen jeweils im Mittelpunkt der Bohrungen 7. Der Abstand A der Bohrungen 7 zueinander entlang der jeweiligen Schaufelspitze 8 entspricht dem doppelten maximalen Durchmesser DBmax und 2% des maximalen Lüfterraddurchmessers D des Lüfterrads 4. Von der Schaufelspitze 8 sind die Bohrungen 7 über die Länge LS beabstandet, welche 1,5% des Laufraddurchmessers D und dem 1,5-fachen des maximalen Durchmessers DBmax ausmacht. Die radial außen liegende Schaufelspitze 8 der jeweiligen Lüfterradschaufel 4 verläuft durchgängig und ununterbrochen. Gemäß der Ausführung in Figur 5 erfolgt die Verteilung der Bohrungen 7 entlang der Schaufelspitze 8 über eine Länge, welcher 10% der Schaufelspitzenlänge L entspricht, entlang derer der Kopfspalt 12 gebildet ist. In der Ausführung gemäß der Figuren 1 - 4 sind es 20%.The size, shape and arrangement of the bores 7 clearly influence the noise-reducing effect. In Figure 5 Advantageous dimensions are entered, which are identical for the embodiment of Figures 1-4 are applicable. The holes 7 have a maximum diameter DBmax, which corresponds to 1% of the maximum fan wheel diameter D of the fan wheel 4, measured in each case in the center of the holes 7. The distance A of the holes 7 to one another along the respective blade tip 8 corresponds to twice the maximum diameter DBmax and 2 % of the maximum fan wheel diameter D of the fan wheel 4. The bores 7 are spaced from the blade tip 8 over the length LS, which makes up 1.5% of the impeller diameter D and 1.5 times the maximum diameter DBmax. The radially outer blade tip 8 of the respective fan wheel blade 4 runs continuously and without interruption. As executed in Figure 5 the bores 7 are distributed along the blade tip 8 over a length which corresponds to 10% of the blade tip length L along which the head gap 12 is formed. In the execution according to the Figures 1 - 4 it's 20%.

In beiden Ausführungen gemäß der Figuren 1-4 und 5 sind alle Bohrungen 7 jeweils identisch ausgebildet. Alternativ kann jedoch auch vorgesehen werden, dass sich die Bohrungen 7 zueinander in Form und Größe unterscheiden.In both versions according to the Figures 1-4 and 5 all holes 7 are each formed identically. Alternatively, however, it can also be provided that the bores 7 differ from one another in terms of shape and size.

Claims (16)

Axialventilator (1) mit einem Gehäuse (2) und einem in dem Gehäuse (2) angeordneten Lüfterrad (3) zur Erzeugung eines Axialluftstromes durch das Gehäuse (2), wobei das Lüfterrad (3) mehrere sich von einer Nabe (5) nach radial außen bis zur jeweiligen Schaufelspitze (8) erstreckende Lüfterradschaufeln (4) aufweist, welche über einen Kopfspalt (12) beanstandet zu einer Innenwand des Gehäuses (2) verlaufen, und wobei die Lüfterradschaufeln (4) entlang der jeweiligen Schaufelspitze (8) Bohrungen (7) aufweisen.Axial fan (1) with a housing (2) and a fan wheel (3) arranged in the housing (2) for generating an axial air flow through the housing (2), the fan wheel (3) extending radially from a hub (5) has fan impeller blades (4) extending externally to the respective blade tip (8), which run spaced apart from an inner wall of the housing (2) via a head gap (12), and wherein the fan impeller blades (4) along the respective blade tip (8) have bores (7 ) exhibit. Axialventilator nach Anspruch 1, dadurch gekennzeichnet, dass die Lüfterradschaufeln (4) einen geringen Anstellwinkel gegenüber einer Axialebene im Bereich von 5-25°, insbesondere 10-20° aufweist.Axial fan according to Claim 1, characterized in that the fan wheel blades (4) have a small angle of incidence with respect to an axial plane in the range of 5-25 °, in particular 10-20 °. Axialventilator nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Bohrungen (7) auf beiden axialen Seiten der Lüfterradschaufeln (4) ausgebildet sind.Axial fan according to Claim 1 or 2, characterized in that the bores (7) are formed on both axial sides of the fan wheel blades (4). Axialventilator nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Bohrungen (7) als Durchgangsbohrungen durch die Lüfterradschaufeln (4) ausgebildet sind.Axial fan according to claim 1 or 2, characterized in that the bores (7) are designed as through bores through the fan wheel blades (4). Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass eine Anzahl der Bohrungen (7) je Lüfterradschaufel (4) entlang der jeweiligen Schaufelspitze (8) mindestens zwei, insbesondere mindestens drei, insbesondere mindestens fünf beträgt, und wobei die Bohrungen (7) entlang einer Linie parallel zur Schaufelspitze (8) angeordnet sind.Axial fan according to one of the preceding claims, characterized in that the number of bores (7) per fan wheel blade (4) along the respective blade tip (8) is at least two, in particular at least three, in particular at least five, and the bores (7) along are arranged in a line parallel to the blade tip (8). Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass die Bohrungen (7) einen kreisförmigen Querschnitt aufweisen.Axial fan according to one of the preceding claims, characterized in that the bores (7) have a circular cross-section exhibit. Axialventilator nach dem vorigen Anspruch, dadurch gekennzeichnet, dass die Bohrungen (7) einen maximalen Durchmesser DBmax aufweisen, der 1% eines maximalen Lüfterraddurchmessers D des Lüfterrads (3) entspricht.Axial fan according to the preceding claim, characterized in that the bores (7) have a maximum diameter DBmax which corresponds to 1% of a maximum fan wheel diameter D of the fan wheel (3). Axialventilator nach dem vorigen Anspruch, dadurch gekennzeichnet, dass die Bohrungen (7) zueinander einen Abstand A entlang der jeweiligen Schaufelspitze (8) aufweisen, der dem doppelten maximalen Durchmesser DBmax entspricht, wobei der Abstand jeweils am Mittelpunkt der jeweiligen Bohrung (7) gemessen wird.Axial fan according to the preceding claim, characterized in that the bores (7) have a distance A from one another along the respective blade tip (8) which corresponds to twice the maximum diameter DBmax, the distance being measured at the center of the respective bore (7) . Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass die Bohrungen (7) zueinander einen Abstand A entlang der jeweiligen Schaufelspitze (8) aufweisen, der 2% eines maximalen Lüfterraddurchmessers D des Lüfterrads (3) entsprichtAxial fan according to one of the preceding claims, characterized in that the bores (7) have a distance A from one another along the respective blade tip (8), which corresponds to 2% of a maximum fan wheel diameter D of the fan wheel (3) Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass die Bohrungen (7) einen maximalen Durchmesser DBmax aufweisen und von der jeweiligen Schaufelspitze (8) über eine Länge LS beanstandet sind, so dass gilt: DBmax ≤ LS ≤ 2,5 x DBmax, insbesondere LS=1,5 x DBmax.Axial fan according to one of the preceding claims, characterized in that the bores (7) have a maximum diameter DBmax and are spaced from the respective blade tip (8) over a length LS, so that the following applies: DBmax ≤ LS ≤ 2.5 x DBmax, especially LS = 1.5 x DBmax. Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass die Bohrungen (7) von der jeweiligen Schaufelspitze (8) über eine Länge LS beanstandet sind, die 1,5% eines maximalen Lüfterraddurchmessers D des Lüfterrads entspricht.Axial fan according to one of the preceding claims, characterized in that the bores (7) are spaced apart from the respective blade tip (8) over a length LS which corresponds to 1.5% of a maximum fan wheel diameter D of the fan wheel. Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass die Bohrungen (7) über eine Erstreckung entlang der Schaufelspitze (8) der jeweiligen Lüfterradschaufel (4) vorgesehen sind, welche 10-40% einer maximalen Erstreckung der Schaufelspitze (8) entlang des Kopfspalts entspricht.Axial fan according to one of the preceding claims, characterized in that the bores (7) are provided over an extension along the blade tip (8) of the respective fan wheel blade (4) which corresponds to 10-40% of a maximum extension of the blade tip (8) along the head gap. Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass die Bohrungen (7) zusätzlich entlang einer Vorderkante (17) und/oder einer Hinterkante (18) der Lüfterradschaufeln (4) vorgesehen sind.Axial fan according to one of the preceding claims, characterized in that the bores (7) are additionally provided along a front edge (17) and / or a rear edge (18) of the fan wheel blades (4). Axialventilator nach dem vorigen Anspruch, dadurch gekennzeichnet, dass eine jeweilige Anzahl der Bohrungen (7) zusätzlich entlang der Vorderkante (17) und/oder der Hinterkante (18) der Lüfterradschaufeln kleiner oder gleich einer Anzahl an Bohrungen (7) entlang der Schaufelspitze (8) ist.Axial fan according to the preceding claim, characterized in that a respective number of the bores (7) along the front edge (17) and / or the rear edge (18) of the fan impeller blades is smaller than or equal to a number of bores (7) along the blade tip (8 ) is. Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass jede der Lüfterradschaufeln (4) entlang der Schaufelspitze (8) jeweils einen sich an eine radiale Mittellinie der Lüfterradschaufeln (4) beidseitig angrenzenden Mittelabschnitt (15) aufweist, der frei von Bohrungen (7) ist, wobei der Mittelabschnitt 20-90% einer Erstreckung der jeweiligen Lüfterradschaufel (4) in Umfangsrichtung bestimmt.Axial fan according to one of the preceding claims, characterized in that each of the fan impeller blades (4) along the blade tip (8) has in each case a central section (15) adjoining a radial center line of the fan impeller blades (4) on both sides and which is free of bores (7). is, wherein the middle section 20-90% of an extension of the respective fan wheel blade (4) determined in the circumferential direction. Axialventilator nach einem der vorigen Ansprüche, dadurch gekennzeichnet, dass das Lüfterrad (3) reversierbar ausgebildet und seine im Betrieb erzeugte Strömungsrichtung von seiner Rotationsrichtung abhängt.Axial fan according to one of the preceding claims, characterized in that the fan wheel (3) is designed to be reversible and its direction of flow generated during operation depends on its direction of rotation.
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US (1) US11391282B2 (en)
EP (2) EP3702620B1 (en)
KR (1) KR102320943B1 (en)
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USD972707S1 (en) * 2019-04-29 2022-12-13 Ebm-Papst Mulfingen Gmbh & Co. Kg Ventilating fan
DE102021116749A1 (en) 2021-06-29 2022-12-29 Stiebel Eltron Gmbh & Co. Kg Decentralized ventilation unit and flow straightener
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US11391282B2 (en) 2022-07-19
PL3702620T3 (en) 2022-08-16
KR20200105627A (en) 2020-09-08
KR102320943B1 (en) 2021-11-04
EP3988797B1 (en) 2022-11-23
PL3988797T3 (en) 2023-03-06
EP3988797A1 (en) 2022-04-27
CN210050072U (en) 2020-02-11
US20200277962A1 (en) 2020-09-03
EP3702620B1 (en) 2022-04-27

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