EP2940311B1 - Radial fan with improved leading edge geometry - Google Patents
Radial fan with improved leading edge geometry Download PDFInfo
- Publication number
- EP2940311B1 EP2940311B1 EP15163971.3A EP15163971A EP2940311B1 EP 2940311 B1 EP2940311 B1 EP 2940311B1 EP 15163971 A EP15163971 A EP 15163971A EP 2940311 B1 EP2940311 B1 EP 2940311B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- edge section
- impeller
- radial fan
- overflowed
- opening
- 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.)
- Active
Links
- 240000006829 Ficus sundaica Species 0.000 description 5
- 238000005192 partition Methods 0.000 description 4
- 230000002093 peripheral effect Effects 0.000 description 4
- 238000004804 winding Methods 0.000 description 3
- 238000005352 clarification Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000005553 drilling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000004026 adhesive bonding Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000012447 hatching Effects 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 210000002105 tongue Anatomy 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
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
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/06—Units comprising pumps and their driving means the pump being electrically driven
-
- 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
- F04D29/42—Casings; Connections of working fluid for radial or helico-centrifugal pumps
- F04D29/44—Fluid-guiding means, e.g. diffusers
- F04D29/441—Fluid-guiding means, e.g. diffusers especially adapted for elastic fluid pumps
- F04D29/444—Bladed diffusers
-
- 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
- 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
- F05D2250/00—Geometry
- F05D2250/50—Inlet or outlet
- F05D2250/52—Outlet
Definitions
- the invention relates to a radial blower, in particular a radial blower for a vacuum cleaner, which comprises an impeller which can be rotated about an axis of rotation and can be driven by a motor and which has a plurality of blades for generating an at least partially radially outwardly directed air flow, and a stationary guide device which has a diffuser plate arranged perpendicular to the axis of rotation axially adjacent to the impeller, an annular wall surrounding the latter radially on the outside and a hood at least partially enclosing the impeller, a continuous annular space surrounding the impeller being formed between the hood, the impeller and the diffuser plate.
- the task of a blower is to provide suction power as a product of the vacuum and volume flow.
- Radial blowers are generally used in vacuum cleaners.
- a radial fan comprises a drive motor, in particular an electric motor, and an aerodynamic device, which comprises a radial impeller and a follow-up device.
- the air volume flow to be conveyed usually flows axially into the impeller, which generates an at least partially radially outward air flow, ie an air flow whose flow direction has a radially outward component.
- the direction of flow when leaving the impeller also has a tangential component directed in the direction of rotation of the impeller.
- the guide device serves to deflect the air flow generated in a desired direction.
- the air flow generated is usually deflected such that components of the electric motor flow through and can be cooled.
- the air flow generated by the impeller is deflected in particular from an obliquely outward, at least partially radial direction into an axial direction, the air flow usually being returned from a periphery of the impeller to the vicinity of the drive axis for cooling the motor becomes.
- the air flow usually flows out of the fan in the axial direction.
- the guide device is also used for pressure recovery and is therefore often referred to as a diffuser.
- a follow-up device for a radial fan is designed as a plate diffuser.
- a substantially circular plate which is also referred to as a diffuser plate, is arranged parallel to a disk-shaped base plate of the impeller, which is arranged perpendicular to the axis of rotation, at a short distance from the base plate.
- the impeller is enclosed by a hood which delimits it from the surroundings, with a distance remaining between the hood and the periphery of the impeller.
- the outer diameter of the diffuser plate is larger than the outer diameter of the impeller, so that there is an annular space between the periphery of the impeller, the diffuser plate and the hood, into which the air flow is conveyed through the blades of the stator.
- Guide vanes can be arranged in the annular space, which interrupt the annular space and guide the air emerging from the impeller.
- the annular space can also be empty, a plurality of openings being provided in the diffuser plate through which the air conveyed by the impeller can pass to the side of the diffuser plate opposite the impeller, where means for further guiding the air flow, for example in the axial direction and / or are arranged radially inwards.
- a motor housing which has a circulation fan mounted on the motor shaft and a deflection means in order to guide the air flow emitted by the fan over the motor.
- the deflection means has a deflection plate which has a plurality of openings on its outer edge. The openings are delimited by curved wall parts and open into air inlet openings through which the air flow reaches an air chamber on the other side of the diffuser plate. The air inlet openings have an edge against which the air flow flows and which is directed essentially in the radial direction.
- an essentially disk-shaped diffuser which has openings on its circumference through which the air flow generated by the impeller of the blower can pass to the other side of the diffuser. These openings have a curved edge on their inner side and a flowed edge running essentially in a radial direction.
- a vacuum cleaner with a blower which comprises a diffuser.
- a plurality of blades, which guide the air flow conveyed by the impeller, are arranged in an annular space on an outside of the radial impeller.
- a plate is arranged below the blades and has on its outer edge essentially triangular cutouts through which the air flow reaches the underside of the plate, where it is guided in the direction of the axis of rotation by return blades.
- the JP 2009299636 A describes an electric blower with a partition plate which is arranged on a rear side of a fan, a diffuser which is arranged on a front side of the partition plate and on an outer peripheral side of the fan.
- a return is arranged on a rear side of the partition plate, and a fan housing is provided on an opening side of a housing, which covers the fan, the diffuser and the return.
- the diffuser is provided with a plurality of diffuser wings.
- a through hole extending from the partition plate is formed on the diffuser wing of at least a part of the plurality of diffuser wings.
- the JP S5990799 A discloses a vacuum cleaner with curved suction vanes which form helical chambers which are connected via return channels in an electric fan contained in the main body of the vacuum cleaner.
- the fan has an impeller around which numerous helical chambers are formed.
- the outer wall of the helical chambers is defined by a curve and tongues that are formed along the curve.
- the US 2003108442 A1 describes a blower having a rotor with a shaft, a stator coupled to the rotor, and a fan connected to the shaft. Furthermore, a one-piece diffuser is provided with a fan side opposite the motor side, the fan side being connected to the fan, and the diffuser Has openings for transferring the air flow from the fan side to the motor side.
- a radial fan according to the invention which is designed in particular for use in a vacuum cleaner, preferably in a battery or battery-operated hand-held vacuum cleaner, comprises an impeller which is rotatably mounted about an axis of rotation and can be driven by a motor, in particular an electric motor.
- the impeller has a plurality of blades that are used to generate a radially outward Airflow are arranged.
- the blades are preferably arranged obliquely to a radial direction and, when the impeller rotates in a direction of rotation, are curved backwards as seen from the inside outwards.
- an air flow which is directed at least partially radially outward is thereby generated, which is emitted at a periphery of the impeller into a space adjoining the impeller to the outside.
- the fact that the air flow is at least partially directed radially outwards means that a direction of flow of the air flow generated has an outward component; due to the entrainment of the air by the blades of the impeller, the direction of flow of the air flow generally also has a tangential component which can exceed the radial amount.
- the air flow when leaving the impeller can form an angle of less than 30 ° with a tangential direction of the impeller.
- the air flow generated is in particular formed uniformly along the peripheral surface of the impeller.
- the air conveyed by the impeller is supplied to the impeller in the axial direction near the axis of rotation.
- the air flow supplied can be used with a vacuum cleaner to achieve the suction effect.
- the blades of the impeller can be arranged on a base plate of the impeller or can also be at least partially free.
- peripheral surface or circumferential surface of the impeller it is meant a substantially cylindrical surface which the radially outer edges of the blades of the impeller produce when the impeller rotates.
- the radial fan further comprises a follow-up device which serves to deflect the air flow generated by the rotating impeller in an axial direction and which is non-rotatable.
- the fact that the air flow has an axial direction means that at least one central flow direction of the air flow has an axially directed component;
- radial and / or tangential components of the flow direction can also be present.
- the follow-up device is designed as a plate diffuser, which has a diffuser plate arranged in the axial direction adjacent to the impeller, an annular wall surrounding it radially on the outside and a hood that at least partially surrounds the impeller.
- the diffuser plate is essentially disc-shaped and is preferably arranged in a plane perpendicular to the axis of rotation at a short distance from the impeller, the axis of rotation penetrating the diffuser plate in a central region.
- the ring wall can be connected to the hood or can be formed in one piece with it.
- the hood and / or the Ring wall can be part of a housing of the radial fan.
- the diameter of the diffuser plate is larger than the diameter of the impeller; the ratio of the outer diameter of the impeller to that of the diffuser plate 13 is in particular 0.8 to 0.9.
- a circumferential continuous annular space is formed between the hood, the impeller and the diffuser plate, into which the generated air flow is conveyed by the impeller.
- An air flow arises in the annular space, which has an at least partially radially outward flow direction, which can have a tangential component due to the entrainment of the air by the blades of the impeller.
- the outer edge of the diffuser plate lies at least selectively on the ring wall or is at least selectively connected to it. Between the outer edge of the diffuser plate and the inside of the ring wall, a plurality of openings distributed along the outer circumference of the diffuser plate are formed by recesses in the diffuser plate, which openings allow air to pass from the annular space into a space formed on the side of the diffuser plate opposite the impeller.
- Guide channels can be arranged in the latter space, through which the air flow is guided in the further course; the guide channels can be formed, for example, by ribs arranged on the diffuser plate and guide the generated air flow radially inward to the vicinity of the axis of rotation, where the air flow can be deflected in the axial direction and then used to cool the motor.
- the outer edge of the diffuser plate has at least one edge section against which the air flow flows and at least one edge section over which the air flow flows due to the direction of flow of the air flow in the annular space.
- the flow direction which generally has a radial and a tangential component, is directed toward the edge in a flowed-over edge section, and is directed away from the edge in a flowed over edge section.
- the outer edge of the diffuser plate can have further edge sections, for example a tangential edge section, which can rest against the ring wall.
- the side of the diffuser plate facing the impeller is essentially flat, so that the flowed over and the overflowed edge section lie in one plane, namely in the plane of the diffuser plate.
- the outer edge of the diffuser plate is designed in such a way that at least one, preferably each, flowed edge section at an angle of runs at least 50 ° and at most 65 ° to a radial direction related to the axis of rotation.
- the at least one flowed-on edge section can in particular form an obtuse angle with an edge section adjoining the inner end of the flowed-on edge section.
- At least one, preferably each, flowed-in edge section encloses an angle of at least 50 ° and at most 65 ° to a radial direction ensures, in particular, that the flowed-in edge section in no area is perpendicular, even not approximately perpendicular, to the flow direction of the air in the annulus stands. In this way it is achievable that the air is braked to a lesser extent when the flow flows towards the edge section, and thus a higher air volume flow is made possible.
- the oscillation amplitude of pressure fluctuations which arise when the edge flows against the air volume flow pulsating due to the blading of the impeller and which contribute significantly to the sound level generated by the blower can be reduced if the mentioned angular range of the inflow edge is maintained.
- the design according to the invention thus creates a radial fan, in which an improved aerodynamic efficiency and / or a reduction in noise emission is made possible, in particular in a work area of a vacuum cleaner.
- the at least one or each flowed edge section forms an angle of at least 50 ° and at most 60 °, particularly preferably of approximately 55 °, with a radial direction. This enables a particularly high efficiency and / or a particularly low sound level.
- the at least one flowed-on edge section is curved and encloses an angle of at least 50 ° and at most 65 ° with a radial direction related to the axis of rotation.
- Exactly one flowed edge section is preferably provided, and this is concavely curved, a straight connecting line between a radially outer and a radially inner end point of the flowed edge section forming an angle of approximately 65 ° with a radial direction.
- the flow toward the edge section is designed to be concavely curved in such a way that the surface of the area delimited by it.
- the opening of the diffuser plate is equal to the area of such an opening, which is delimited by an edge section that has just been flown against and has the same outer end point and encloses an angle of 55 ° with a radial direction.
- each opening has only a flowed-on edge section, each opening being assigned a guide channel formed on the side of the diffuser plate opposite the impeller, which is formed by an inner wall and an outer wall, and which has an inner wall at an inner end point and an outer wall adjoins an outer end point of one of the flowed edge sections.
- the edge section against which flow flows covers the guide channel.
- the inner wall and the outer wall can be designed as ribs of the diffuser plate, one rib being the outer wall of one guide channel and the inner wall of an adjacent guide channel.
- the guide channels can be open on the side facing away from the diffuser plate or at least partially closed off by a base.
- the guide channels serve to guide the air flow generated, in particular in an obliquely inward direction, ie with a flow direction with a radially inward and a tangential component. Characterized in that the guide channel assigned to an opening in each case adjoins the flow of the edge section, a maximum cross-sectional area of the guide channel and thereby a particularly high efficiency of the fan is made possible.
- each opening has only one edge section overflowed, the inner end point of the flowed edge section coinciding with the inner endpoint of the overflowed edge section.
- a continuation of the inner wall of the guide channel and from the outer end point of the overflowed edge section to the entry opening into the guide channel is preferably arranged along the overflowed edge section an inclined descending ramp.
- the end of the inclined ramp can define an entry opening into the guide channel together with the adjoining regions of the inner wall and the outer wall of the guide channel, as well as with the flowed-on edge section.
- the direction of flow of the air flow entering through the inlet opening also has an axial component. This enables a particularly efficient guidance of the air flow.
- the inlet opening extends in the direction of the axis of rotation beyond the radius of the impeller; in other words, the inlet opening and the impeller overlap when the radial fan is viewed in the direction of the axis of rotation.
- This can be achieved in that the inner wall of the guide channel at the location of the inlet opening has a smaller distance from the axis of rotation than the outer edge of the impeller.
- the ratio between the distance of the limit of the inlet opening on the axis of rotation from the axis of rotation and the radius of the impeller is preferably less than 0.95, particularly preferably less than 0.9.
- the ratio between the distance of the inlet opening from the axis of rotation from the axis of rotation and the radius of the impeller is preferably more than 0.75, particularly preferably more than 0.8, for example 0.83.
- a not too small distance between the boundary of the inlet opening on the axis of rotation and the axis of rotation can ensure pressure recovery in the region of the radial fan downstream of the inlet opening.
- the at least one overflowed edge section is arranged at least in sections obliquely to a radial direction related to the axis of rotation, in particular at an angle of at least 50 ° to the radial direction.
- an edge vortex can arise on an overflowed edge, which can also represent a sound source.
- the edge vortex can hinder the free flow out of the impeller and thus also adversely affect the efficiency of the fan. Due to the fact that the overflowed edge section is oriented obliquely to the radial direction, the formation of such an edge vortex is reduced or suppressed, as a result of which the efficiency can be further increased and the sound power level can be further reduced.
- the overflowed edge section is advantageously at least sectionally arched, in particular in such a way that the center of curvature of the curvature of the overflowed edge section is arranged radially within, but offset from the axis of rotation.
- the overflowed edge section can also be straight in sections. In both cases, it is advantageous that the overflowed edge section forms an angle of at least 50 ° and at most 90 ° to a radial direction in each section. If the overflowed edge section comprises a section in the form of a circular arc with the axis of rotation as the center, it is advantageous that one or each further section of the overflowed edge section encloses an angle of at least 50 ° and at most 90 ° to a radial direction. This enables a particularly loss-free and low-noise overflow.
- the outer edge of the diffuser plate is designed in such a way that the at least one overflowed edge section has a section which is designed as an arc, the center of which lies on the axis of rotation, and thus as a tangential section.
- One or more further sections of the overflowed edge section can run at an angle to a tangential direction. Due to the fact that the at least one edge section overflowed has a partial section shaped as a circular arc with the axis of rotation as the center, a particularly large cross section of the passage openings through which the air flow flows and thus a high aerodynamic efficiency can be achieved, while a generated sound power level remains at a low level.
- the plurality of openings are distributed uniformly around the circumference of the diffuser plate and in particular each have the same shape and size. This enables a simplification of the production as well as a particularly uniform air flow.
- the outer end point of the flowed edge section of a first opening is adjacent to or corresponds to the outer end point of the flowed edge section of a second opening.
- This preferably applies to each opening, so that the openings connect to one another almost without gaps and occupy practically the entire outer circumference of the diffuser plate; a contact with the ring wall, which delimits the opening to the outside, is therefore only selective, namely at the outer end points of the flowed or overflowed edge sections.
- the openings are arranged outside the surface of the diffuser plate which is swept by the blades of the impeller.
- the overflowed edge section has a partial section designed as a circular arc with a center lying on the axis of rotation, it is particularly advantageous that the circular arc has a radius which corresponds approximately to the outer radius of the impeller. This not only enables maximum use of the passage area of the openings, but also more efficient guidance of the air flow.
- the diffuser plate is formed in one piece with the ring wall or the diffuser plate and the ring wall are connected using a suitable joining method, for example ultrasound welding or adhesive bonding.
- the diffuser plate together with the Ring wall thus represents a deflecting body, which deflects the air flow from the annular space for further use in the axial direction and, if appropriate, radially inwards.
- the deflection body, such as the impeller and the hood, are preferably made of plastic. This enables particularly simple manufacture and / or assembly.
- FIG. 1 A radial blower 1 is shown in an axial longitudinal section, for example suitable for a battery-operated hand-held vacuum cleaner, which comprises an impeller 2, a follow-up device 3 and an electric motor 4.
- the impeller 2 consists of a disk-shaped base plate 5 and a likewise disk-shaped cover plate 6, which is slightly curved in the central area, between which a plurality of blades 7 are arranged.
- the impeller 2 is rotatably supported and is driven by the electric motor 4 via a shaft 8.
- the axis of rotation of the shaft 8 or the impeller 2 is in Fig. 1 marked with the reference number 9.
- the engine includes, as in Fig. 1 is shown symbolically, a stator 10 and a rotor 11 connected to the shaft 8 and has a plurality of windings 12 through which the drive current of the electric motor flows.
- the follow-up device 3 is designed as a plate diffuser and comprises a circular diffuser plate 13 which has a substantially flat upper side and is arranged parallel to the base plate 5 of the impeller 2 at a short distance below it.
- the outer diameter of the diffuser plate 13 is larger than the outer diameter of the impeller 2.
- the diffuser plate 13 is connected to a short cylindrical ring wall 14.
- the diffuser plate 13 has on its underside a plurality of ribs 15, which form downwardly open guide channels 16 through which one through in Fig. 1 Air passage openings, not shown, are guided radially inward through the diffuser plate 13.
- inclined ramps 43 are arranged below the air passage openings, which guide the air passing through the openings into the guide channels 16.
- the diffuser plate 13 has a bevel 18 for further deflecting the air flow in a radial direction.
- the Radial fan also has a housing 19, which consists of a lower housing part 20, a hood 21 and a suction flange 22 and, if appropriate, further, in Fig. 1 components not shown.
- the diffuser plate 13 with the ring wall 14 is arranged in a fixed manner in the housing 19.
- the hood 21 encloses the impeller 2 and partially the diffuser plate 13 and the ring wall 14, an annular space 23 being formed between the periphery, ie the outer peripheral surface of the impeller 2, the top of the diffuser plate 13 and the inside of the hood 21.
- the annular space 23 is continuous along the circumference of the impeller 2 and does not itself contain any flow-guiding elements.
- the impeller 2 If the impeller 2 is rotated by the electric motor 4 via the shaft 8 in a predetermined direction of rotation indicated by the arrow 24, the impeller 2 generates an at least partially radially outward air flow with the help of the blades 7, as in FIG Fig. 1 is indicated by the arrows.
- air is sucked in along the axis of rotation 9 through the suction flange 22, which in a vacuum cleaner can be connected, for example, to a suction hose.
- the air conveyed to the outside first enters the annular space 23, where, due to the entrainment by the blades 7, it also executes a movement directed tangentially to the axis of rotation 9.
- the air flow generated passes via the ramp 43 into the space below the diffuser plate 13 and into the guide channels 16, through which it is guided radially inward while maintaining a tangential component.
- the air flow is deflected further in the axial direction by the bevel 18 and reaches the electric motor 4, where it can be used for cooling the windings 12.
- the air flow finally reaches the outer region of the blower 1 through outlet openings 25.
- the radial and the axial components of the flow direction of the air flow generated are in FIG Fig. 1 to recognize the sectional view shown with the arrows.
- FIGs 2 and 3rd are in a perspective view of the impeller 2 according Fig. 1 and a follow-up device 31 designed according to the invention is shown in a perspective view, the hood 21 having been omitted for reasons of illustration.
- the impeller 2 has a base plate 5 and a cover plate 6, between which several, for example 13, standing vertically, arcuately curved blades 7 are arranged.
- the blades 7 are arranged at the same angular distance from one another and overlap one another, with each blade covering an angle of approximately 50 ° as seen from the axis of rotation.
- the cover plate 6 has a central cutout 26, which allows air to flow axially into the central region of the impeller 2.
- a bore 27 is made in the base plate 5, into which the shaft 8 connected to the rotor 11 of the electric motor 4 can be inserted for driving the impeller 2 and connected to the impeller 2 (see FIG. Fig. 1 ). If the impeller 2 is moved in the predetermined direction of rotation, the obliquely positioned, backward-curved blades 7 generate an obliquely outwardly directed air flow.
- the diffuser plate 32 is arranged below the base plate 5 and parallel to it, the outer edge of which defines a plurality of openings 33 with the annular wall 14. The air flow exits through the openings 33 from the annular space adjoining the impeller 2 on the outside Fig. 2 Hood 21, not shown, is limited (s. Fig. 1 ) in the space below the diffuser plate 32. There the air flow becomes like Fig. 1 explained, guided radially inwards and finally deflected again in the axial direction.
- each opening 33 is delimited by the inner wall of the short cylindrical ring wall 14.
- Each opening 33 is delimited on the inside by an edge section 34 and an overflow edge section 35 of the outer edge of the diffuser plate 32. Neither the flowed edge section 34 nor the flowed over edge section 35 run in the radial direction.
- the opening 33 has approximately the shape of an obtuse-angled isosceles triangle, the side which is defined by the annular wall 14 and the side which is formed by the overflowed edge section 35 each being curved in an arc shape with an outwardly directed bulge.
- the flow toward the edge section 34 is essentially straight.
- the radial fan according to the first embodiment of the invention is the same as before Figures 1 and 2nd explained.
- the impeller 2 is configured as described above and is arranged adjacent to the upper side of the diffuser plate 32.
- the diffuser plate 32 has a central bore 36 for the passage of the shaft 8 for driving the impeller 2.
- the diffuser plate 32 according to Fig. 3 is in Fig. 4 together with the impeller 2 again shown schematically in plan view.
- the shaft 8 is fastened to drive the impeller 2.
- the oblique, backward-curved blades 7 are on the base plate 5.
- the base plate 5 covers the central region of the diffuser plate 32.
- the ratio of the outer diameter D of the base plate 5 or of the impeller 2 to the outer diameter D 'of the diffuser plate 32 is approximately 0.88 .
- By arrows 37 is in Fig. 4 the direction of flow of the air conveyed by the impeller 2 is indicated relative to the impeller 2.
- the cover plate 6 of the impeller 2 (s. Fig. 1 and 2nd ) is in Fig. 4 not shown.
- the diffuser plate 32 has recesses on the edge which, together with the ring wall 14, form a plurality of openings 33; for clarification, one of the openings 33 in Fig. 4 indicated by hatching.
- the openings 33 are delimited by the ring wall 14.
- the openings 33 are delimited by the outer edge of the diffuser plate, which in the area of the openings has an edge section 34 and an overflowed edge section 35.
- the openings 33 are not covered by the impeller 2, that is to say the distance of the openings 33 from the axis of rotation is at least as large as the radius of the impeller 2.
- the edge section 34 that is flown against is straight, while the edge section 35 that is overflowed is curved in a convex shape.
- the overflowed edge section 35 forms an angle ⁇ of more than 50 ° and less than 90 ° in each point with a radial direction; in Fig. 4 the angle ⁇ is entered between a respective tangent to the overflowed edge section 35 and a respective radial direction in the inner end point 39 and in the outer endpoint 40 of the overflowed edge section 35.
- the arrows 38 show the direction of flow of the air flow conveyed by the impeller 2 in the annular space outside the impeller 2 and above the diffuser plate 32 relative to the latter. When leaving the impeller 2, the direction of flow of the air has an angle of less than 30 ° to a tangential direction.
- the outer end point 40 of the flow edge of an adjacent opening 33 and the flow edge 35 coincide.
- a diffuser plate 48 according to a second embodiment of the invention is shown together with the impeller 2 in a simplified plan view.
- This diffuser plate 48 like that in FIGS Figures 3 and 4th shown diffuser plate 32 in the radial fan according to Fig. 1 are used, so that a radial fan equipped with the diffuser plate 48 corresponds to the second exemplary embodiment of the invention.
- the overflowed edge section 49 is formed with two sections 46, 47.
- a first section 46 of the overflowed edge section 49 adjoins the flowed-over edge section 29, the first section 46 having the shape of an arc, the center of which lies in the center of the diffuser plate 48, ie on the axis of rotation of the impeller 2 or in the center of the central bore 36 (s. Fig. 3 ).
- the radius of the circular arc corresponds to the radius of the impeller 2, so that the first section 46 comes to lie approximately in an extension of the peripheral surface of the impeller 2.
- a second section 47 of the overflowed edge section 30 is arc-shaped and forms an angle ⁇ of between 50 ° and 90 ° with a radial direction, in the illustrated example of approximately 80 °, ie with an tangential direction an angle of approximately 10 °.
- a radial direction in the illustrated example of approximately 80 °, ie with an tangential direction an angle of approximately 10 °.
- the diffuser plate 48 is like that with respect to the flow against the edge section 34 and for the rest Fig. 3 and 4th Diffuser plate 32 described formed, the reference numerals have the same meaning.
- the direction of flow of an air flow guided in a guide channel 16 below the diffuser plate 48 is shown in FIG Fig. 5 indicated by the dashed arrows 41.
- FIG Fig. 6 The passage of the air flow through the diffuser plate 32 is shown in FIG Fig. 6 shown, partially sectioned side view.
- the air flow indicated by the arrows 42 passes from the annular space 23 through the in Fig. 6 not shown opening 33 (s. Fig. 3 , 4th ) in the space below the diffuser plate 32.
- the air flow is guided through an inclined ramp 43, which begins at the outer end point 40 of the overflowed edge 35 (see. Fig. 4 ). Laterally, the air flow in this area is guided on the one hand through the ring wall 14 and on the other hand through a vertical side wall 44 which runs along the overflowed edge 35 or is slightly offset inwards.
- the air flow then passes through the inlet opening 45, which is formed between the diffuser plate 32 in the area of the flowed edge section 34 and the end of the ramp 43 and is at a slight angle to an axial direction, into the space below the diffuser plate 32, where a guide channel 16 for further guiding the air serves (in Fig. 6 Not shown).
- a guide channel 16 for further guiding the air serves (in Fig. 6 Not shown).
- Fig. 6 there are two entry openings in Fig. 6 shown hatched.
- the air flow passes through the diffuser plate 48 in a corresponding manner as in FIG Fig. 6 for the first embodiment (see Fig. 3 , 4th ).
- the outer side wall 44 of the rib 15 has a smaller distance from the axis of rotation than the outer edge of the impeller 2.
- the inlet opening 45 extends in the direction of the axis of rotation 9 beyond the radius of the impeller 2, so that inlet opening 45 and Cover impeller 2.
- the ratio between the distance between the boundary of the inlet opening 45 on the axis of rotation and the axis of rotation 9 and the radius of the impeller 2 is 0.83.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Description
Die Erfindung betrifft ein Radialgebläse, insbesondere ein Radialgebläse für einen Staubsauger, das ein um eine Drehachse drehbares, durch einen Motor antreibbares Laufrad, das eine Mehrzahl von Schaufeln zur Erzeugung eines zumindest teilweise radial nach außen gerichteten Luftstroms aufweist, und eine feststehende Nachleiteinrichtung umfasst, die eine senkrecht zur Drehachse axial benachbart zum Laufrad angeordnete Diffusorplatte, eine diese radial außen umgebende Ringwand und eine das Laufrad zumindest teilweise umschließende Haube aufweist, wobei zwischen der Haube, dem Laufrad und der Diffusorplatte ein das Laufrad radial außen umgebender, durchgehender Ringraum gebildet ist.The invention relates to a radial blower, in particular a radial blower for a vacuum cleaner, which comprises an impeller which can be rotated about an axis of rotation and can be driven by a motor and which has a plurality of blades for generating an at least partially radially outwardly directed air flow, and a stationary guide device which has a diffuser plate arranged perpendicular to the axis of rotation axially adjacent to the impeller, an annular wall surrounding the latter radially on the outside and a hood at least partially enclosing the impeller, a continuous annular space surrounding the impeller being formed between the hood, the impeller and the diffuser plate.
Die Aufgabe eines Gebläses, insbesondere in Staubsaugern, ist es, eine Saugleistung als Produkt von Unterdruck und Volumenstrom zur Verfügung zu stellen. In Staubsaugern kommen in der Regel Radialgebläse zum Einsatz. Ein solches Radialgebläse umfasst einen Antriebsmotor, insbesondere einen Elektromotor, und eine Aerodynamikeinrichtung, die ein Radiallaufrad und eine Nachleiteinrichtung umfasst. Der zu fördernde Luftvolumenstrom strömt in der Regel axial in das Laufrad ein, das einen zumindest teilweise radial nach außen gerichteten Luftstrom erzeugt, d.h. einen Luftstrom, dessen Strömungsrichtung eine radial nach außen gerichtete Komponente aufweist. In der Regel hat die Strömungsrichtung beim Verlassen des Laufrads auch eine in Drehrichtung des Laufrads gerichtete tangentiale Komponente. Die Nachleiteinrichtung dient der Umlenkung des erzeugten Luftstroms in eine gewünschte Richtung. Da der elektrische Antriebsmotor in der Regel gekühlt werden muss, wird der erzeugte Luftstrom üblicherweise derart umgelenkt, dass Komponenten des Elektromotors durchströmt und gekühlt werden können. In der Nachleiteinrichtung erfolgt daher insbesondere eine Umlenkung des vom Laufrad erzeugten Luftstroms von einer schräg nach außen gerichteten, zumindest teilweise radialen Richtung in eine axiale Richtung, wobei in der Regel zur Kühlung des Motors der Luftstrom von einer Peripherie der Laufrads in die Nähe der Antriebsachse zurückgeführt wird. Im weiteren Verlauf strömt der Luftstrom üblicherweise in axialer Richtung aus dem Gebläse aus. Die Nachleiteinrichtung dient ferner auch der Druckrückgewinnung und wird daher oft als Diffusor bezeichnet.The task of a blower, particularly in vacuum cleaners, is to provide suction power as a product of the vacuum and volume flow. Radial blowers are generally used in vacuum cleaners. Such a radial fan comprises a drive motor, in particular an electric motor, and an aerodynamic device, which comprises a radial impeller and a follow-up device. The air volume flow to be conveyed usually flows axially into the impeller, which generates an at least partially radially outward air flow, ie an air flow whose flow direction has a radially outward component. As a rule, the direction of flow when leaving the impeller also has a tangential component directed in the direction of rotation of the impeller. The guide device serves to deflect the air flow generated in a desired direction. Since the electric drive motor generally has to be cooled, the air flow generated is usually deflected such that components of the electric motor flow through and can be cooled. In the after-guiding device, therefore, the air flow generated by the impeller is deflected in particular from an obliquely outward, at least partially radial direction into an axial direction, the air flow usually being returned from a periphery of the impeller to the vicinity of the drive axis for cooling the motor becomes. In the further course, the air flow usually flows out of the fan in the axial direction. The guide device is also used for pressure recovery and is therefore often referred to as a diffuser.
Es ist bekannt, dass eine Nachleiteinrichtung für ein Radialgebläse als Plattendiffusor ausgebildet ist. Dabei ist parallel zu einer scheibenförmigen Grundplatte des Laufrads, welche senkrecht zur Drehachse angeordnet ist, in einem geringen Abstand zur Grundplatte eine im Wesentlichen kreisförmige Platte angeordnet, die auch als Diffusorplatte bezeichnet wird. Das Laufrad ist von einer Haube umschlossen, die diese gegen die Umgebung abgrenzt, wobei zwischen der Haube und der Peripherie des Laufrads ein Abstand verbleibt. Der Außendurchmesser der Diffusorplatte ist größer als der Außendurchmesser des Laufrads, so dass sich zwischen der Peripherie des Laufrads, der Diffusorplatte und der Haube ein Ringraum ergibt, in den der Luftstrom durch die Schaufeln des Leitrads gefördert wird. In dem Ringraum können Leitschaufeln angeordnet sein, die den Ringraum unterbrechen und die aus dem Laufrad austretende Luft führen. Der Ringraum kann aber auch leer sein, wobei in der Diffusorplatte eine Mehrzahl von Öffnungen vorgesehen ist, durch die die vom Laufrad geförderte Luft auf die dem Laufrad entgegengesetzte Seite der Diffusorplatte hindurchtreten kann, wo Mittel zur weiteren Führung des Luftstroms, beispielsweise in axialer Richtung und/oder radial nach innen angeordnet sind.It is known that a follow-up device for a radial fan is designed as a plate diffuser. A substantially circular plate, which is also referred to as a diffuser plate, is arranged parallel to a disk-shaped base plate of the impeller, which is arranged perpendicular to the axis of rotation, at a short distance from the base plate. The impeller is enclosed by a hood which delimits it from the surroundings, with a distance remaining between the hood and the periphery of the impeller. The outer diameter of the diffuser plate is larger than the outer diameter of the impeller, so that there is an annular space between the periphery of the impeller, the diffuser plate and the hood, into which the air flow is conveyed through the blades of the stator. Guide vanes can be arranged in the annular space, which interrupt the annular space and guide the air emerging from the impeller. However, the annular space can also be empty, a plurality of openings being provided in the diffuser plate through which the air conveyed by the impeller can pass to the side of the diffuser plate opposite the impeller, where means for further guiding the air flow, for example in the axial direction and / or are arranged radially inwards.
Aus
Gemäß
Aus
Die
Die
Die
Es ist Aufgabe der vorliegenden Erfindung, ein gattungsgemäßes Radialgebläse, insbesondere ein Radialgebläse für einen Staubsauger, anzugeben, bei dem der erzeugte Schallleistungspegel reduziert und/oder der aerodynamische Wirkungsgrad erhöht ist.It is an object of the present invention to provide a generic radial fan, in particular a radial fan for a vacuum cleaner, in which the sound power level generated is reduced and / or the aerodynamic efficiency is increased.
Die Bezugszeichen in sämtlichen Ansprüchen haben keine einschränkende Wirkung, sondern sollen lediglich deren Lesbarkeit verbessern.The reference symbols in all claims have no restrictive effect, but are merely intended to improve their legibility.
Die Lösung der gestellten Aufgabe gelingt durch ein Radialgebläse mit den Merkmalen des Anspruchs 1.The problem is solved by a radial fan with the features of claim 1.
Ein erfindungsgemäßes Radialgebläse, das insbesondere zur Verwendung in einem Staubsauger ausgebildet ist, vorzugsweise in einem batterie- bzw. akkubetriebenen Handstaubsauger, umfasst ein Laufrad, das um eine Drehachse drehbar gelagert und durch einen Motor, insbesondere einen Elektromotor, antreibbar ist. Das Laufrad weist eine Mehrzahl von Schaufeln auf, die zur Erzeugung eines radial nach außen gerichteten Luftstroms angeordnet sind. Die Schaufeln sind vorzugsweise schräg zu einer radialen Richtung angeordnet und bei einer Drehung des Laufrads in einer Drehrichtung von innen nach außen gesehen rückwärts gekrümmt. Wird das Laufrad durch den Motor in Rotation versetzt, so wird hierdurch ein zumindest teilweise radial nach außen gerichteter Luftstrom erzeugt, der an einer Peripherie des Laufrads in einen nach außen an das Laufrad anschließenden Raum abgegeben wird. Dass der Luftstrom zumindest teilweise radial nach außen gerichtet ist, bedeutet hier, dass eine Strömungsrichtung des erzeugten Luftstroms eine nach außen gerichtete Komponente aufweist; die Strömungsrichtung des Luftstroms weist aufgrund der Mitnahme der Luft durch die Schaufeln des Laufrads in der Regel auch eine tangentiale Komponente auf, die die radiale betragsmäßig übersteigen kann. So kann der Luftstrom beim Verlassen des Laufrads mit einer tangentialen Richtung des Laufrads einen Winkel von weniger als 30° bilden. Der erzeugte Luftstrom ist insbesondere entlang der Umfangsfläche des Laufrads gleichmäßig ausgebildet. Die vom Laufrad geförderte Luft wird in der Nähe der Drehachse in axialer Richtung dem Laufrad zugeführt. Der zugeführte Luftstrom kann bei einem Staubsauger zum Erzielen der Saugwirkung genutzt werden. Die Schaufeln des Laufrads können an einer Grundscheibe des Laufrads angeordnet sein oder auch zumindest teilweise frei stehen. Wenn im vorliegenden Zusammenhang von "Peripherie" oder "Umfangsfläche" des Laufrads die Rede ist, so ist damit eine im Wesentlichen zylindrische Fläche gemeint, die die radial äußeren Kanten der Schaufeln des Laufrads bei einer Drehung des Laufrads erzeugen.A radial fan according to the invention, which is designed in particular for use in a vacuum cleaner, preferably in a battery or battery-operated hand-held vacuum cleaner, comprises an impeller which is rotatably mounted about an axis of rotation and can be driven by a motor, in particular an electric motor. The impeller has a plurality of blades that are used to generate a radially outward Airflow are arranged. The blades are preferably arranged obliquely to a radial direction and, when the impeller rotates in a direction of rotation, are curved backwards as seen from the inside outwards. If the impeller is set in rotation by the motor, an air flow which is directed at least partially radially outward is thereby generated, which is emitted at a periphery of the impeller into a space adjoining the impeller to the outside. The fact that the air flow is at least partially directed radially outwards means that a direction of flow of the air flow generated has an outward component; due to the entrainment of the air by the blades of the impeller, the direction of flow of the air flow generally also has a tangential component which can exceed the radial amount. For example, the air flow when leaving the impeller can form an angle of less than 30 ° with a tangential direction of the impeller. The air flow generated is in particular formed uniformly along the peripheral surface of the impeller. The air conveyed by the impeller is supplied to the impeller in the axial direction near the axis of rotation. The air flow supplied can be used with a vacuum cleaner to achieve the suction effect. The blades of the impeller can be arranged on a base plate of the impeller or can also be at least partially free. When the term "periphery" or "circumferential surface" of the impeller is used in the present context, it is meant a substantially cylindrical surface which the radially outer edges of the blades of the impeller produce when the impeller rotates.
Das Radialgebläse umfasst weiterhin eine Nachleiteinrichtung, die zum Umlenken des von dem rotierenden Laufrad erzeugten Luftstroms in eine axiale Richtung dient und die nicht drehbar ausgebildet ist. Dass der Luftstrom eine axiale Richtung aufweist, bedeutet in diesem Fall, dass zumindest eine mittlere Strömungsrichtung des Luftstroms eine axial gerichtete Komponente aufweist; zusätzlich können auch radiale und/oder tangentiale Komponenten der Strömungsrichtung vorhanden sein. Die Nachleiteinrichtung ist dabei als Plattendiffusor ausgebildet, der eine in axialer Richtung benachbart zum Laufrad angeordnete Diffusorplatte, eine diese radial außenseitig umgebende Ringwand und eine das Laufrad zumindest teilweise umschließende Haube aufweist. Die Diffusorplatte ist im Wesentlichen scheibenförmig ausgebildet und in einer zur Drehachse senkrechten Ebene vorzugsweise in einem geringen Abstand zum Laufrad angeordnet, wobei die Drehachse die Diffusorplatte in einem zentralen Bereich durchstößt. Die Ringwand kann mit der Haube verbunden oder einstückig mit dieser ausgebildet sein. Die Haube und/oder die Ringwand können Teil eines Gehäuses des Radialgebläses sein. Der Durchmesser der Diffusorplatte ist größer als der Durchmesser des Laufrads; das Verhältnis des Außendurchmessers des Laufrads zu dem der Diffusorplatte 13 beträgt insbesondere 0,8 bis 0,9. Dadurch wird zwischen der Haube, dem Laufrad und der Diffusorplatte ein umfangsmäßig durchgehender Ringraum gebildet, in den der erzeugte Luftstrom vom Laufrad gefördert wird. In dem Ringraum entsteht eine Luftströmung, die eine zumindest teilweise radial nach außen gerichtete Strömungsrichtung hat, die aufgrund der Mitnahme der Luft durch die Schaufeln des Laufrads eine tangentiale Komponente aufweisen kann.The radial fan further comprises a follow-up device which serves to deflect the air flow generated by the rotating impeller in an axial direction and which is non-rotatable. In this case, the fact that the air flow has an axial direction means that at least one central flow direction of the air flow has an axially directed component; In addition, radial and / or tangential components of the flow direction can also be present. The follow-up device is designed as a plate diffuser, which has a diffuser plate arranged in the axial direction adjacent to the impeller, an annular wall surrounding it radially on the outside and a hood that at least partially surrounds the impeller. The diffuser plate is essentially disc-shaped and is preferably arranged in a plane perpendicular to the axis of rotation at a short distance from the impeller, the axis of rotation penetrating the diffuser plate in a central region. The ring wall can be connected to the hood or can be formed in one piece with it. The hood and / or the Ring wall can be part of a housing of the radial fan. The diameter of the diffuser plate is larger than the diameter of the impeller; the ratio of the outer diameter of the impeller to that of the
Die Diffusorplatte liegt mit ihrer Außenkante zumindest punktuell an der Ringwand an oder ist zumindest punktuell mit dieser verbunden. Zwischen der Außenkante der Diffusorplatte und der Innenseite der Ringwand wird durch Ausnehmungen der Diffusorplatte eine Mehrzahl von entlang des Außenumfangs der Diffusorplatte verteilten Öffnungen gebildet, die einen Luftdurchtritt von dem Ringraum in einen auf der dem Laufrad gegenüberliegenden Seite der Diffusorplatte gebildeten Raum ermöglichen. In dem letzteren Raum können Führungskanäle angeordnet sein, durch die der Luftstrom im weiteren Verlauf geführt wird; die Führungskanäle können beispielsweise durch an der Diffusorplatte angeordnete Rippen gebildet werden und den erzeugten Luftstrom radial einwärts bis in die Nähe der Drehachse führen, wo der Luftstrom in axialer Richtung umgelenkt und sodann zur Kühlung des Motors genutzt werden kann. Im Bereich einer jeden Öffnung weist die Außenkante der Diffusorplatte aufgrund der im Ringraum herrschenden Strömungsrichtung des Luftstroms mindestens einen vom Luftstrom angeströmten und mindestens einen vom Luftstrom überströmten Kantenabschnitt auf. In einem angeströmten Kantenabschnitt ist die Strömungsrichtung, die in der Regel eine radiale und eine tangentiale Komponente aufweist, gegen die Kante gerichtet, und in einem überströmten Kantenabschnitt von der Kante fortgerichtet. Die Außenkante der Diffusorplatte kann weitere Kantenabschnitte aufweisen, beispielsweise einen tangential verlaufenden Kantenabschnitt, der an der Ringwand anliegen kann. Vorzugsweise ist die dem Laufrad zugewandte Seite der Diffusorplatte im Wesentlichen eben ausgebildet, so dass der angeströmte und der überströmte Kantenabschnitt in einer Ebene, nämlich in der Ebene der Diffusorplatte, liegen.The outer edge of the diffuser plate lies at least selectively on the ring wall or is at least selectively connected to it. Between the outer edge of the diffuser plate and the inside of the ring wall, a plurality of openings distributed along the outer circumference of the diffuser plate are formed by recesses in the diffuser plate, which openings allow air to pass from the annular space into a space formed on the side of the diffuser plate opposite the impeller. Guide channels can be arranged in the latter space, through which the air flow is guided in the further course; the guide channels can be formed, for example, by ribs arranged on the diffuser plate and guide the generated air flow radially inward to the vicinity of the axis of rotation, where the air flow can be deflected in the axial direction and then used to cool the motor. In the region of each opening, the outer edge of the diffuser plate has at least one edge section against which the air flow flows and at least one edge section over which the air flow flows due to the direction of flow of the air flow in the annular space. The flow direction, which generally has a radial and a tangential component, is directed toward the edge in a flowed-over edge section, and is directed away from the edge in a flowed over edge section. The outer edge of the diffuser plate can have further edge sections, for example a tangential edge section, which can rest against the ring wall. Preferably, the side of the diffuser plate facing the impeller is essentially flat, so that the flowed over and the overflowed edge section lie in one plane, namely in the plane of the diffuser plate.
Erfindungsgemäß ist die Außenkante der Diffusorplatte derart ausgebildet, dass mindestens ein, vorzugsweise jeder angeströmte Kantenabschnitt in einem Winkel von mindestens 50° und höchstens 65° zu einer auf die Drehachse bezogen radialen Richtung verläuft. Der mindestens eine angeströmte Kantenabschnitt kann insbesondere mit einem am inneren Ende des angeströmten Kantenabschnitts anschließenden Kantenabschnitt einen stumpfen Winkel bilden.According to the invention, the outer edge of the diffuser plate is designed in such a way that at least one, preferably each, flowed edge section at an angle of runs at least 50 ° and at most 65 ° to a radial direction related to the axis of rotation. The at least one flowed-on edge section can in particular form an obtuse angle with an edge section adjoining the inner end of the flowed-on edge section.
Dadurch, dass mindestens ein, bevorzugt jeder angeströmte Kantenabschnitt einen Winkel von mindestens 50° und höchstens 65° zu einer radialen Richtung einschließt, kann insbesondere gewährleistet werden, dass der angeströmte Kantenabschnitt in keinem Bereich senkrecht, auch nicht näherungsweise senkrecht, zur Strömungsrichtung der Luft in dem Ringraum steht. Hierdurch ist es erreichbar, dass beim Anströmen des angeströmten Kantenabschnitts die Luft weniger stark abgebremst wird und somit ein höherer Luftvolumenstrom ermöglicht wird. Ferner ist erfindungsgemäß erkannt worden, dass die Schwingungsamplitude von Druckschwankungen, die beim Anströmen der Kante durch den aufgrund der Beschaufelung des Laufrades pulsierenden Luftvolumenstrom entstehen und die wesentlich zu dem vom Gebläse erzeugten Schallpegel beitragen, bei Einhalten des genannten Winkelbereichs der angeströmten Kante reduziert werden kann. Durch die erfindungsgemäße Ausbildung wird somit ein Radialgebläse geschaffen, bei dem insbesondere in einem Arbeitsbereich eines Staubsaugers ein verbesserter aerodynamischer Wirkungsgrad und/oder eine Reduzierung der Geräuschemission ermöglicht wird.The fact that at least one, preferably each, flowed-in edge section encloses an angle of at least 50 ° and at most 65 ° to a radial direction ensures, in particular, that the flowed-in edge section in no area is perpendicular, even not approximately perpendicular, to the flow direction of the air in the annulus stands. In this way it is achievable that the air is braked to a lesser extent when the flow flows towards the edge section, and thus a higher air volume flow is made possible. Furthermore, it has been recognized according to the invention that the oscillation amplitude of pressure fluctuations which arise when the edge flows against the air volume flow pulsating due to the blading of the impeller and which contribute significantly to the sound level generated by the blower, can be reduced if the mentioned angular range of the inflow edge is maintained. The design according to the invention thus creates a radial fan, in which an improved aerodynamic efficiency and / or a reduction in noise emission is made possible, in particular in a work area of a vacuum cleaner.
Vorteilhafte Aus- und Weiterbildungen, welche einzeln oder in Kombination miteinander eingesetzt werden können, sind Gegenstand der abhängigen Ansprüche.Advantageous training and further developments, which can be used individually or in combination with one another, are the subject of the dependent claims.
Erfindungsgemäss bildet der mindestens eine bzw. jeder angeströmte Kantenabschnitt einen Winkel von mindestens 50° und höchstens 60°, besonders bevorzugt von etwa 55° mit einer radialen Richtung. Hierdurch werden ein besonders hoher Wirkungsgrad und/oder ein besonders niedriger Schallpegel ermöglicht.According to the invention, the at least one or each flowed edge section forms an angle of at least 50 ° and at most 60 °, particularly preferably of approximately 55 °, with a radial direction. This enables a particularly high efficiency and / or a particularly low sound level.
Erfindungsgemäß ist der mindestens eine angeströmte Kantenabschnitt gekrümmt ausgebildet und schließt mit einer auf die Drehachse bezogen radialen Richtung einen Winkel von mindestens 50° und höchstens 65° ein. Vorzugsweise ist genau ein angeströmter Kantenabschnitt vorgesehen, und dieser ist konkav gekrümmt ausgebildet, wobei eine gerade Verbindungslinie zwischen einem radial äußeren und einem radial inneren Endpunkt des angeströmten Kantenabschnitts einen Winkel von etwa 65° mit einer radialen Richtung bildet. In besonders vorteilhafter Weise ist der angeströmte Kantenabschnitt derart konkav gekrümmt ausgebildet, dass die Fläche der von diesem begrenzter. Öffnung der Diffusorplatte gleich der Fläche einer solchen Öffnung ist, die durch einen gerade ausgebildeten angeströmten Kantenabschnitt, der denselben äußeren Endpunkt hat und mit einer radialen Richtung einen Winkel von 55° einschließt, begrenzt wird. Hierdurch ist ebenfalls ein besonders hoher Wirkungsgrad und/oder ein besonders niedriger Schallpegel erzielbar.According to the invention, the at least one flowed-on edge section is curved and encloses an angle of at least 50 ° and at most 65 ° with a radial direction related to the axis of rotation. Exactly one flowed edge section is preferably provided, and this is concavely curved, a straight connecting line between a radially outer and a radially inner end point of the flowed edge section forming an angle of approximately 65 ° with a radial direction. In a particularly advantageous manner, the flow toward the edge section is designed to be concavely curved in such a way that the surface of the area delimited by it. The opening of the diffuser plate is equal to the area of such an opening, which is delimited by an edge section that has just been flown against and has the same outer end point and encloses an angle of 55 ° with a radial direction. As a result, a particularly high efficiency and / or a particularly low sound level can also be achieved.
Vorzugsweise weist jede Öffnung nur einen angeströmten Kantenabschnitt auf, wobei jeder Öffnung ein auf der dem Laufrad gegenüberliegenden Seite der Diffusorplatte ausgebildeter Führungskanal zugeordnet ist, der durch eine Innenwand und eine Außenwand gebildet wird, und der mit seiner Innenwand an einen inneren Endpunkt und mit seiner Außenwand an einen äußeren Endpunkt des einen angeströmten Kantenabschnitts anschließt. Der angeströmte Kantenabschnitt überdeckt somit den Führungskanal. Die Innenwand und die Außenwand können als Rippen der Diffusorplatte ausgebildet sein, wobei jeweils eine Rippe gleichzeitig die Außenwand eines Führungskanals und die Innenwand eines benachbarten Führungskanals ist. Die Führungskanäle können auf der der Diffusorplatte abgewandten Seite offen oder zumindest abschnittsweise durch einen Boden abgeschlossen sein. Die Führungskanäle dienen zu einer Führung des erzeugten Luftstroms insbesondere in einer schräg nach innen gerichteten Richtung, d.h. mit einer Strömungsrichtung mit einer radial nach innen gerichteten und einer tangentialen Komponente. Dadurch, dass der einer Öffnung zugeordnete Führungskanal jeweils an den angeströmten Kantenabschnitt anschließt, wird eine maximale Querschnittsfläche des Führungskanals und dadurch ein besonders hoher Wirkungsgrad des Gebläses ermöglicht.Preferably, each opening has only a flowed-on edge section, each opening being assigned a guide channel formed on the side of the diffuser plate opposite the impeller, which is formed by an inner wall and an outer wall, and which has an inner wall at an inner end point and an outer wall adjoins an outer end point of one of the flowed edge sections. The edge section against which flow flows covers the guide channel. The inner wall and the outer wall can be designed as ribs of the diffuser plate, one rib being the outer wall of one guide channel and the inner wall of an adjacent guide channel. The guide channels can be open on the side facing away from the diffuser plate or at least partially closed off by a base. The guide channels serve to guide the air flow generated, in particular in an obliquely inward direction, ie with a flow direction with a radially inward and a tangential component. Characterized in that the guide channel assigned to an opening in each case adjoins the flow of the edge section, a maximum cross-sectional area of the guide channel and thereby a particularly high efficiency of the fan is made possible.
In vorteilhafter Weise kann es weiter vorgesehen sein, dass jede Öffnung nur einen überströmten Kantenabschnitt aufweist, wobei der innere Endpunkt des angeströmten Kantenabschnitts mit dem inneren Endpunkt des überströmten Kantenabschnitts zusammenfällt. Vorzugsweise ist entlang dem überströmten Kantenabschnitt eine Fortsetzung der Innenwand des Führungskanals und vom äußeren Endpunkt des überströmten Kantenabschnitts bis zur Eintrittsöffnung in den Führungskanal eine in den Führungskanal mündende, schräg absteigende Rampe angeordnet. Das Ende der schrägen Rampe kann gemeinsam mit den anschließenden Bereichen der Innenwand und der Außenwand des Führungskanals sowie mit dem angeströmten Kantenabschnitt eine Eintrittsöffnung in den Führungskanal definieren. Im Bereich der schrägen Rampe bzw. der Eintrittsöffnung weist die Strömungsrichtung des durch die Eintrittsöffnung eintretenden Luftstroms auch eine axiale Komponente auf. Hierdurch wird eine besonders effiziente Führung des Luftstroms ermöglicht.In an advantageous manner, it can further be provided that each opening has only one edge section overflowed, the inner end point of the flowed edge section coinciding with the inner endpoint of the overflowed edge section. A continuation of the inner wall of the guide channel and from the outer end point of the overflowed edge section to the entry opening into the guide channel is preferably arranged along the overflowed edge section an inclined descending ramp. The end of the inclined ramp can define an entry opening into the guide channel together with the adjoining regions of the inner wall and the outer wall of the guide channel, as well as with the flowed-on edge section. In the area of the inclined ramp or the inlet opening, the direction of flow of the air flow entering through the inlet opening also has an axial component. This enables a particularly efficient guidance of the air flow.
Hinsichtlich ihrer Ausdehnung senkrecht zur axialen Richtung erstreckt sich die Eintrittsöffnung in Richtung der Drehachse über den Radius des Laufrads hinaus; mit anderen Worten, Eintrittsöffnung und Laufrad überdecken sich, wenn man das Radialgebläse in Richtung der Drehachse betrachtet. Das ist dadurch erreichbar, dass die Innenwand des Führungskanals am Ort der Eintrittsöffnung einen geringeren Abstand von der Drehachse aufweist als der äußere Rand des Laufrads. Dadurch ist vorteilhafterweise ein möglichst großer Volumenstrom durch die Eintrittsöffnung erreichbar. Vorzugsweise beträgt das Verhältnis zwischen dem Abstand der drehachsenseitigen Begrenzung der Eintrittsöffnung von der Drehachse und dem Radius des Laufrads weniger als 0,95, besonders vorzugsweise weniger als 0,9. Vorzugsweise beträgt das Verhältnis zwischen dem Abstand der drehachsenseitigen Begrenzung der Eintrittsöffnung von der Drehachse und dem Radius des Laufrads mehr als 0,75, besonders vorzugsweise mehr als 0,8, zum Beispiel 0,83. Ein nicht zu kleiner Abstand der drehachsenseitigen Begrenzung der Eintrittsöffnung von der Drehachse kann eine Druckrückgewinnung im der Eintrittsöffnung nachgelagerten Bereich des Radialgebläses sicherstellen.With regard to its extension perpendicular to the axial direction, the inlet opening extends in the direction of the axis of rotation beyond the radius of the impeller; in other words, the inlet opening and the impeller overlap when the radial fan is viewed in the direction of the axis of rotation. This can be achieved in that the inner wall of the guide channel at the location of the inlet opening has a smaller distance from the axis of rotation than the outer edge of the impeller. As a result, the greatest possible volume flow can be achieved through the inlet opening. The ratio between the distance of the limit of the inlet opening on the axis of rotation from the axis of rotation and the radius of the impeller is preferably less than 0.95, particularly preferably less than 0.9. The ratio between the distance of the inlet opening from the axis of rotation from the axis of rotation and the radius of the impeller is preferably more than 0.75, particularly preferably more than 0.8, for example 0.83. A not too small distance between the boundary of the inlet opening on the axis of rotation and the axis of rotation can ensure pressure recovery in the region of the radial fan downstream of the inlet opening.
Gemäß einer bevorzugten Ausführungsform der Erfindung ist der mindestens eine überströmte Kantenabschnitt zumindest abschnittsweise schräg zu einer auf die Drehachse bezogen radialen Richtung, insbesondere in einem Winkel von mindestens 50° zu der radialen Richtung angeordnet. Gemäß diesem Aspekt der Erfindung ist erkannt worden, dass an einer überströmten Kante ein Kantenwirbel entstehen kann, der ebenfalls eine Schallquelle darstellen kann. Weiterhin kann der Kantenwirbel die freie Ausströmung aus dem Laufrad behindern und somit auch den Wirkungsgrad des Gebläses nachteilig beeinflussen. Dadurch, dass der überströmte Kantenabschnitt schräg zur radialen Richtung orientiert ist, wird die Ausbildung eines solchen Kantenwirbels reduziert bzw. unterdrückt, wodurch der Wirkungsgrad weiter erhöht und der Schallleistungspegel weiter reduziert werden können.According to a preferred embodiment of the invention, the at least one overflowed edge section is arranged at least in sections obliquely to a radial direction related to the axis of rotation, in particular at an angle of at least 50 ° to the radial direction. According to this aspect of the invention, it has been recognized that an edge vortex can arise on an overflowed edge, which can also represent a sound source. Furthermore, the edge vortex can hinder the free flow out of the impeller and thus also adversely affect the efficiency of the fan. Due to the fact that the overflowed edge section is oriented obliquely to the radial direction, the formation of such an edge vortex is reduced or suppressed, as a result of which the efficiency can be further increased and the sound power level can be further reduced.
In vorteilhafter Weise ist der überströmte Kantenabschnitt zumindest abschnittsweise bogenförmig ausgebildet, insbesondere in einer solchen Art bogenförmig, dass der Krümmungsmittelpunkt der Krümmung des überströmten Kantenabschnitts radial innerhalb, jedoch gegen die Drehachse versetzt angeordnet ist. Der überströmte Kantenabschnitt kann auch abschnittsweise gerade ausgebildet sein. In beiden Fällen ist es vorteilhaft, dass der überströmte Kantenabschnitt in jedem Teilabschnitt einen Winkel von mindestens 50° und maximal 90° zu einer radialen Richtung bildet. Sofern der überströmte Kantenabschnitt einen Teilabschnitt in Form eines Kreisbogens mit der Drehachse als Mittelpunkt umfasst, ist es vorteilhaft, dass ein oder jeder weitere Teilabschnitt des überströmten Kantenabschnitts einen Winkel von mindestens 50° und maximal 90° zu einer radialen Richtung einschließt. Hierdurch wird eine besonders verlustfreie und schallarme Überströmung ermöglicht.The overflowed edge section is advantageously at least sectionally arched, in particular in such a way that the center of curvature of the curvature of the overflowed edge section is arranged radially within, but offset from the axis of rotation. The overflowed edge section can also be straight in sections. In both cases, it is advantageous that the overflowed edge section forms an angle of at least 50 ° and at most 90 ° to a radial direction in each section. If the overflowed edge section comprises a section in the form of a circular arc with the axis of rotation as the center, it is advantageous that one or each further section of the overflowed edge section encloses an angle of at least 50 ° and at most 90 ° to a radial direction. This enables a particularly loss-free and low-noise overflow.
Gemäß einer bevorzugten Ausführungsform der Erfindung ist die Außenkante der Diffusorplatte derart ausgebildet, dass der mindestens eine überströmte Kantenabschnitt einen Teilabschnitt aufweist, der als Kreisbogen, dessen Mittelpunkt auf der Drehachse liegt, und somit als tangential verlaufender Teilabschnitt ausgebildet ist. Ein oder mehrere weitere Teilabschnitte des überströmten Kantenabschnitts können in einem Winkel zu einer tangentialen Richtung verlaufen. Dadurch, dass der mindestens eine überströmte Kantenabschnitt einen als Kreisbogen mit der Drehachse als Mittelpunkt geformten Teilabschnitt aufweist, kann ein besonders großer Querschnitt der vom Luftstrom durchströmten Durchtrittsöffnungen und somit ein hoher aerodynamischer Wirkungsgrad erreicht werden, wobei ein erzeugter Schallleistungspegel dennoch auf einem niedrigen Niveau bleibt.According to a preferred embodiment of the invention, the outer edge of the diffuser plate is designed in such a way that the at least one overflowed edge section has a section which is designed as an arc, the center of which lies on the axis of rotation, and thus as a tangential section. One or more further sections of the overflowed edge section can run at an angle to a tangential direction. Due to the fact that the at least one edge section overflowed has a partial section shaped as a circular arc with the axis of rotation as the center, a particularly large cross section of the passage openings through which the air flow flows and thus a high aerodynamic efficiency can be achieved, while a generated sound power level remains at a low level.
Gemäß einer bevorzugten Ausführungsform der Erfindung sind die Mehrzahl von Öffnungen gleichmäßig am Umfang der Diffusorplatte verteilt und weisen insbesondere eine jeweils gleiche Form und Größe auf. Hierdurch werden eine Vereinfachung der Herstellung ebenso wie eine besonders gleichmäßige Luftführung ermöglicht.According to a preferred embodiment of the invention, the plurality of openings are distributed uniformly around the circumference of the diffuser plate and in particular each have the same shape and size. This enables a simplification of the production as well as a particularly uniform air flow.
Weiterhin ist es bevorzugt, dass der äußere Endpunkt des angeströmten Kantenabschnitts einer ersten Öffnung dem äußeren Endpunkt des überströmten Kantenabschnitts einer zweiten Öffnung benachbart ist oder mit diesem übereinstimmt. Vorzugsweise gilt dies für jede Öffnung, so dass die Öffnungen nahezu lückenlos aneinander anschließen und praktisch den gesamten Außenumfang der Diffusorplatte einnehmen; eine Berührung mit der Ringwand, die die Öffnung nach außen begrenzt, erfolgt somit nur punktuell, nämlich an den äußeren Endpunkten der angeströmten bzw. überströmten Kantenabschnitte. Hierdurch wird es ermöglicht, die Öffnungen mit einer maximalen Fläche auszubilden, so dass ein besonders hoher Luftvolumenstrom bzw. ein besonders niedriger Strömungswiderstand ermöglicht wird.Furthermore, it is preferred that the outer end point of the flowed edge section of a first opening is adjacent to or corresponds to the outer end point of the flowed edge section of a second opening. This preferably applies to each opening, so that the openings connect to one another almost without gaps and occupy practically the entire outer circumference of the diffuser plate; a contact with the ring wall, which delimits the opening to the outside, is therefore only selective, namely at the outer end points of the flowed or overflowed edge sections. This makes it possible to form the openings with a maximum area, so that a particularly high air volume flow or a particularly low flow resistance is made possible.
Gemäß einer bevorzugten Ausführungsform der Erfindung sind die Öffnungen außerhalb der von den Schaufeln des Laufrads überstrichenen Fläche der Diffusorplatte angeordnet. Dies bedeutet, dass der innere Endpunkt des angeströmten wie des überströmten Kantenabschnitts sich bei einem größeren oder gleichen Abstand von der Drehachse befinden, als dem auf die Drehachse bezogenen Radius der äußeren Enden der Schaufeln des Laufrads entspricht. Sofern der überströmte Kantenabschnitt einen als Kreisbogen mit einem auf der Drehachse liegenden Mittelpunkt ausgebildeten Teilabschnitt aufweist, ist es besonders vorteilhaft, dass der Kreisbogen einen Radius aufweist, der etwa dem Außenradius des Laufrads entspricht. Hierdurch wird nicht nur eine maximale Nutzung der Durchtrittsfläche der Öffnungen, sondern auch eine effizientere Führung des Luftstroms ermöglicht.According to a preferred embodiment of the invention, the openings are arranged outside the surface of the diffuser plate which is swept by the blades of the impeller. This means that the inner end point of the inflow and overflow edge section are at a greater or equal distance from the axis of rotation than corresponds to the radius of the outer ends of the blades of the impeller relative to the axis of rotation. If the overflowed edge section has a partial section designed as a circular arc with a center lying on the axis of rotation, it is particularly advantageous that the circular arc has a radius which corresponds approximately to the outer radius of the impeller. This not only enables maximum use of the passage area of the openings, but also more efficient guidance of the air flow.
In weiter vorteilhafter Weise ist die Diffusorplatte mit der Ringwand einstückig ausgebildet oder die Diffusorplatte und die Ringwand sind mit einem geeigneten Fügeverfahren, etwa Ultraschallschweißen oder Kleben, verbunden. Die Diffusorplatte stellt gemeinsam mit der Ringwand somit einen Umlenkkörper dar, der den Luftstrom aus dem Ringraum zur weiteren Nutzung in axialer Richtung sowie ggf. radial nach innen umlenkt. Der Umlenkkörper, wie beispielsweise auch das Laufrad und die Haube, bestehen bevorzugt aus Kunststoff. Hierdurch wird eine besonders einfache Herstellung und/oder Montage ermöglicht.In a further advantageous manner, the diffuser plate is formed in one piece with the ring wall or the diffuser plate and the ring wall are connected using a suitable joining method, for example ultrasound welding or adhesive bonding. The diffuser plate together with the Ring wall thus represents a deflecting body, which deflects the air flow from the annular space for further use in the axial direction and, if appropriate, radially inwards. The deflection body, such as the impeller and the hood, are preferably made of plastic. This enables particularly simple manufacture and / or assembly.
Weitere vorteilhafte Ausgestaltungen werden nachfolgend an Hand zweier in den Zeichnungen dargestellten Ausführungsbeispiele, auf welche die Erfindung jedoch nicht beschränkt ist, näher beschrieben.Further advantageous embodiments are described in more detail below with reference to two exemplary embodiments shown in the drawings, to which the invention is not limited, however.
Es zeigen schematisch:
-
Fig. 1 ein Radialgebläse gemäß den beiden nachfolgend beschriebenen Ausführungsbeispielen der Erfindung in einem axialen Längsschnitt; -
Fig. 2 das Laufrad des Radialgebläses gemäßFig. 1 sowie eine Nachleiteinrichtung in einer perspektivischen Ansicht; -
Fig. 3 eine Nachleiteinrichtung gemäß einem ersten Ausführungsbeispiel der Erfindung in einer perspektivischen Ansicht; -
Fig. 4 die Nachleiteinrichtung gemäßFig. 3 mit dem Laufrad in einer schematischen Draufsicht; -
Fig. 5 eine Nachleiteinrichtung gemäß einem zweiten Ausführungsbeispiel der Erfindung mit dem Laufrad in einer schematischen Draufsicht;
und schließlich -
Fig. 6 die Nachleiteinrichtungen gemäßFig. 3 mit dem Laufrad in einer schematischen, teilweise geschnittenen Seitenansicht.bis 5
-
Fig. 1 a radial fan according to the two embodiments of the invention described below in an axial longitudinal section; -
Fig. 2 the impeller of the radial fan according toFig. 1 and a tracking device in a perspective view; -
Fig. 3 a follow-up device according to a first embodiment of the invention in a perspective view; -
Fig. 4 the tracking device according toFig. 3 with the impeller in a schematic top view; -
Fig. 5 a Nachleiteinrichtung according to a second embodiment of the invention with the impeller in a schematic plan view;
and finally -
Fig. 6 the tracking devices according to3 to 5 with the impeller in a schematic, partially sectioned side view.
Bei der nachfolgenden Beschreibung zweier bevorzugter Ausführungsformen der vorliegenden Erfindung bezeichnen gleiche Bezugszeichen gleiche oder vergleichbare Komponenten. Der Übersichtlichkeit halber sind nicht in allen Figuren alle Bezugszeichen dargestellt.In the following description of two preferred embodiments of the present invention, identical reference symbols designate identical or comparable components. For the sake of clarity, not all reference symbols are shown in all figures.
In
Die Nachleiteinrichtung 3 ist als Plattendiffusor ausgebildet und umfasst eine kreisförmige Diffusorplatte 13, die eine im Wesentlichen ebene Oberseite aufweist und parallel zur Grundplatte 5 des Laufrads 2 in einem geringen Abstand unterhalb dieser angeordnet ist. Der Außendurchmesser der Diffusorplatte 13 ist größer als der Außendurchmesser des Laufrads 2. An ihrem äußeren Rand ist die Diffusorplatte 13 mit einer kurzzylindrisch ausgebildeten Ringwand 14 verbunden. Ferner weist die Diffusorplatte 13 an ihrer Unterseite eine Mehrzahl an Rippen 15 auf, die nach unten offene Führungskanäle 16 bilden, durch die eine durch in
Wird das Laufrad 2 von dem Elektromotor 4 über die Welle 8 in einer durch den Pfeil 24 angedeuteten, vorgegebenen Drehrichtung in Drehung versetzt, so erzeugt das Laufrad 2 mit Hilfe der Schaufeln 7 einen zumindest teilweise radial nach außen gerichteten Luftstrom, wie in
In
Auch in
Die Diffusorplatte 32 gemäß
Die Diffusorplatte 32 weist randseitige Ausnehmungen auf, die zusammen mit der Ringwand 14 eine Mehrzahl von Öffnungen 33 bilden; zur Verdeutlichung ist eine der Öffnungen 33 in
Unterhalb der Diffusorplatte 32 wird der Luftstrom durch in
In
Im Unterschied zu der Diffusorplatte 32 gemäß
Der Durchtritt des Luftstroms durch die Diffusorplatte 32 ist in der in
Wie in
- 11
- RadialgebläseRadial blower
- 22nd
- LaufradWheel
- 33rd
- NachleiteinrichtungTracking device
- 44th
- ElektromotorElectric motor
- 55
- GrundplatteBase plate
- 66
- DeckplatteCover plate
- 77
- Schaufelshovel
- 88th
- Wellewave
- 99
- DrehachseAxis of rotation
- 1010th
- Statorstator
- 1111
- Rotorrotor
- 1212th
- WicklungWinding
- 1313
- DiffusorplatteDiffuser plate
- 1414
- RingwandRing wall
- 1515
- Ripperib
- 1616
- FührungskanalGuide channel
- 1717th
- Ramperamp
- 1818th
- SchrägeWeird
- 1919th
- Gehäusecasing
- 2020
- GehäuseunterteilLower part of the housing
- 2121
- HaubeHood
- 2222
- AnsaugflanschIntake flange
- 2323
- RingraumAnnulus
- 2424th
- Pfeilarrow
- 2525th
- AuslassöffnungOutlet opening
- 2626
- AussparungRecess
- 2727
- Bohrungdrilling
- 2929
- Angeströmter KantenabschnittFlushed edge section
- 3030th
- Überströmter KantenabschnittOverflowed edge section
- 3131
- NachleiteinrichtungTracking device
- 3232
- DiffusorplatteDiffuser plate
- 3333
- Öffnungopening
- 3434
- Angeströmter KantenabschnittFlushed edge section
- 3535
- Überströmter KantenabschnittOverflowed edge section
- 3636
- Bohrungdrilling
- 3737
- Pfeilarrow
- 3838
- Pfeilarrow
- 3939
- EndpunktEndpoint
- 4040
- EndpunktEndpoint
- 4141
- Pfeilarrow
- 4242
- Pfeilarrow
- 4343
- Ramperamp
- 4444
- SeitenwandSide wall
- 4545
- EintrittsöffnungEntrance opening
- 4646
- Erster TeilabschnittFirst section
- 4747
- Zweiter TeilabschnittSecond section
- 4848
- DiffusorplatteDiffuser plate
- 4949
- Überströmter KantenabschnittOverflowed edge section
- 5050
- Öffnungopening
- γγ
- Winkel der angeströmten KanteAngle of the flowed edge
- θθ
- Winkel des zweiten Teilabschnitts des überströmten KantenabschnittsAngle of the second section of the overflowed edge section
Claims (12)
- Radial fan, in particular for a vacuum cleaner, comprising an impeller (2) which can rotate about an axis of rotation (9) and can be driven by a motor and has a plurality of blades (7) for generating an air current which is at least partially directed outwards, and a stationary guide facility (31), which has a diffusor plate (13, 32, 48) arranged perpendicularly to the axis of rotation (9) axially adjacent to the impeller (2), and an annular wall (14) surrounding said diffusor plate (13, 32, 48) radially on the outside and a shell (21) at least partially enclosing the impeller (2), wherein a continuous annular space (23) surrounding the impeller (2) radially on the outside is formed between the shell (21), the impeller (2) and the diffusor plate (13, 32, 48), wherein a plurality of openings (33, 50) are embodied between an outer edge of the diffusor plate (13, 32, 48) and the annular wall (14), enabling a passage of air from the annular space (23) to the side of the diffusor plate (13, 32, 48) opposite the impeller (2), and wherein the outer edge of the diffusor plate (13, 32, 48), in the region of each opening (33, 50), has at least one edge section (34) subject to incoming flow and at least one overflowed edge section (35, 49), characterised in that the at least one edge section (34) subject to incoming flow encloses an angle γ of at least 50° and at most 65° with a radial direction and is embodied in a curved manner.
- Radial fan according to claim 1, characterised in that the at least one edge section (34) subject to incoming flow encloses an angle γ of at least 50° and at most 60°, preferably an angle γ of approximately 55°, with a radial direction.
- Radial fan according to claim 1 or 2, characterised in that the at least one edge section (34) subject to incoming flow is embodied in a concavely curved manner, wherein a straight connecting line between an outer and an inner end point encloses an angle γ of approx. 65° with a radial direction and wherein the opening (33, 50) has an area equally as large as an opening with an edge section (34) subject to incoming flow embodied in a straight manner, which encloses an angle γ = 55° with a radial direction.
- Radial fan according to one of the preceding claims, characterised in that each opening (33, 50) has precisely one edge section (34) subject to incoming flow and that each opening (33, 50) is assigned a guide channel (16) arranged on the side of the diffusor plate (13, 32, 48) opposite the impeller (2), wherein an inner wall of the guide channel (16) adjoins an inner end point (39) and an outer wall of the guide channel (16) adjoins an outer end point of the edge section (34) subject to incoming flow.
- Radial fan according to one of the preceding claims, characterised in that each opening (33, 50) has precisely one overflowed edge section (35, 49), wherein the inner end point (39) of the edge section (34) subject to incoming flow coincides with the inner end point (39) of the overflowed edge section (35, 49) and a continuation of the inner wall of the guide channel (16) is arranged along the overflowed edge section (35, 49) and an oblique ramp (43) is arranged from the outer end point of the overflowed edge section (35, 49) up to the entry opening (45) into the guide channel (16).
- Radial fan according to one of the preceding claims, characterised in that the at least one overflowed edge section (35, 49), at least in one subsection (47), runs obliquely to a radial direction, in particular encloses an angle θ of at least 50° with a radial direction.
- Radial fan according to one of the preceding claims, characterised in that the at least one overflowed edge section (35, 49), at least in one subsection (46, 47), is embodied in an arc-shaped manner.
- Radial fan according to claim 78, characterised in that the at least one overflowed edge section (49) has a subsection (46) which is embodied as a circular arc, the centre point of which lies on the axis of rotation (9).
- Radial fan according to one of the preceding claims, characterised in that the plurality of openings (33, 50) are evenly distributed along the periphery of the diffusor plate (13, 32, 48).
- Radial fan according to one of the preceding claims, characterised in that the outer end point of an edge section (34) subject to incoming flow of one opening (33, 50) is adjacent to the outer end point of an overflowed edge section (35, 49) of an adjacent opening (33, 50) or is congruent therewith.
- Radial fan according to one of the preceding claims, characterised in that the openings (33, 50) are arranged outside of the area of the diffusor plate (13, 32, 48) covered by the blades (7) of the impeller (2).
- Radial fan according to one of the preceding claims, characterised in that the diffusor plate (13, 32, 48) is embodied in one piece with the annular wall (14) or is joined to said annular wall (14) and as a result forms a baffle body.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102014208127.0A DE102014208127A1 (en) | 2014-04-30 | 2014-04-30 | Radial fan with improved leading edge geometry |
Publications (2)
Publication Number | Publication Date |
---|---|
EP2940311A1 EP2940311A1 (en) | 2015-11-04 |
EP2940311B1 true EP2940311B1 (en) | 2020-07-01 |
Family
ID=52997274
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP15163971.3A Active EP2940311B1 (en) | 2014-04-30 | 2015-04-17 | Radial fan with improved leading edge geometry |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP2940311B1 (en) |
DE (1) | DE102014208127A1 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107401517B (en) * | 2016-05-20 | 2023-12-05 | 阿美德格工业技术(上海)有限公司 | Air path structure of air flow device and air flow device |
CN111765123A (en) * | 2019-04-01 | 2020-10-13 | 博西华电器(江苏)有限公司 | Range hood's fan and range hood |
CN114704479B (en) * | 2022-04-12 | 2023-11-28 | 中国科学院空天信息创新研究院 | Centrifugal fan for stratosphere |
CN115788962A (en) * | 2022-11-22 | 2023-03-14 | 广东美的白色家电技术创新中心有限公司 | Electric fan and terminal equipment |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5990799A (en) * | 1982-11-16 | 1984-05-25 | Matsushita Electric Ind Co Ltd | Vacuum cleaner |
US5734214A (en) | 1995-11-09 | 1998-03-31 | Ametek, Inc. | Molded through-flow motor assembly |
JP3775542B2 (en) | 1998-01-29 | 2006-05-17 | 東芝テック株式会社 | Electric blower |
US6648613B2 (en) * | 2001-12-11 | 2003-11-18 | Ametek, Inc. | Fan blower assembly with one-piece air diffuser and bayonet-style end cap |
JP4596995B2 (en) | 2005-06-24 | 2010-12-15 | 日立アプライアンス株式会社 | Electric blower and vacuum cleaner equipped with the same |
JP4729599B2 (en) * | 2008-06-17 | 2011-07-20 | 日立アプライアンス株式会社 | Electric blower and vacuum cleaner equipped with the same |
-
2014
- 2014-04-30 DE DE102014208127.0A patent/DE102014208127A1/en not_active Ceased
-
2015
- 2015-04-17 EP EP15163971.3A patent/EP2940311B1/en active Active
Non-Patent Citations (1)
Title |
---|
None * |
Also Published As
Publication number | Publication date |
---|---|
EP2940311A1 (en) | 2015-11-04 |
DE102014208127A1 (en) | 2015-11-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE69925071T2 (en) | Centrifugal fan unit for a motor vehicle | |
EP2875718B1 (en) | Hand-held work device with a blowpipe | |
DE60125267T2 (en) | Method and device for expanding the operating area of a centrifugal compressor | |
EP2940311B1 (en) | Radial fan with improved leading edge geometry | |
EP2978976B1 (en) | Gearbox with a shaft | |
EP2716915B1 (en) | Housing for an axial ventilator | |
DE102018211808A1 (en) | Fan and control device for a fan | |
DE102007038405A1 (en) | Insert for fan motor arrangement | |
EP2740942A2 (en) | Medical or dental blower | |
EP0166174B1 (en) | Radial ventilator | |
DE3315477A1 (en) | DUST SEPARATOR | |
EP2808553B1 (en) | Electric motor with impeller wheel | |
DE102005012815A1 (en) | Radial blower housing, e.g. for automotive applications, has a flow duct whose size increases radially in a direction between the input wall and the rear side wall | |
EP2940310B1 (en) | Radial fan with improved overflow edge geometry | |
EP3617529B1 (en) | Fan frame of a motor vehicle | |
DE3514207A1 (en) | Dynamo having a rotor wheel for sucking in cooling air for motor vehicles | |
EP2465647A2 (en) | Hand tool machine with air circulation element | |
EP3450766A1 (en) | Fan for an electrical device | |
DE102005027460B4 (en) | Heat dissipating device | |
EP0845600A2 (en) | Side-channel machine | |
EP1122444A2 (en) | Radial fan and nozzle for a radial fan | |
EP3865711A1 (en) | Fan with cover plate on the rotor bell | |
DE102019134354A1 (en) | Electric motor device with an electric motor and an integral fan device | |
DE102014118210B4 (en) | Multi-flow turbomachine | |
DE3029507A1 (en) | Spiral flow type fan - has forward curved blades and stator passages profiled for quiet running and high pressure |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
17P | Request for examination filed |
Effective date: 20160504 |
|
RBV | Designated contracting states (corrected) |
Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20200225 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: REF Ref document number: 1286450 Country of ref document: AT Kind code of ref document: T Effective date: 20200715 Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D Free format text: LANGUAGE OF EP DOCUMENT: GERMAN |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 502015012894 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20201001 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20200701 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20201002 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20201001 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20201102 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20201101 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 502015012894 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
26N | No opposition filed |
Effective date: 20210406 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20210417 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210417 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20210430 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210417 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210430 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210430 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210417 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20201101 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MM01 Ref document number: 1286450 Country of ref document: AT Kind code of ref document: T Effective date: 20210417 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210430 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210417 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20150417 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20230417 Year of fee payment: 9 Ref country code: DE Payment date: 20230430 Year of fee payment: 9 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200701 |