EP3203084B1 - Fan wheel and blower unit - Google Patents

Description

The invention relates to a fan wheel for conveying a gaseous fluid, with a plurality of blades, which are arranged in a predeterminable angular division in an annular space volume around an axis of rotation and which are each fixed to carrier means with their axial, mutually opposite end regions, a first carrier means being a disk-shaped circular blank is formed coaxially to the axis of rotation and comprises a hub arrangement and wherein a second carrier means is designed as a ring coaxial to the axis of rotation and a spaced from the first carrier means is arranged a coaxial to the axis of rotation support plate which forms an annular gap with the first carrier means, the support disc of at least an inlet opening is penetrated, which enables a radially outward fluid flow in the annular gap. The invention further relates to a blower arrangement.

From the US 3,414,188 A an impeller with an inflow stabilizer is known which balances the fluid flow with a channel diffuser and is used in a centrifugal type rotary compressor. For this purpose, slots are formed in the side walls of flow separating vanes of a diffuser, which open into cavities within the vanes, the plurality of cavities communicating with a common one, closed by means of the openings in the diffuser wall trained distributors are connected and the fluid connections between the plurality of passages in the diffuser and the surrounding common distributor increases the operating range of the compressor, since pressure surges in one or more passages are quickly compensated for.

The DE 33 10 376 A discloses a radial fan with a spiral housing and a fan wheel rotatably mounted in the spiral housing, a lateral inflow opening being provided in the spiral housing, an air gap or intermediate space being present between the inner wall of the spiral housing opposite the inflow opening and the fan wheel, the air gap or intermediate space being radial Direction is sealed in the radial end region of the fan wheel.

From the EP 2 846 046 A1 A fan wheel for conveying a gaseous fluid is known, which has a plurality of blades, which are arranged at a constant angular division about an axis of rotation, at least one blade having an edge region and an inner region and a bead extending therebetween along a course curve and / or the edge region of a first Blade area and the inner region are determined by a second blade area, which are arranged and / or configured in a geometrically different manner.

The DE 10 2008 048 433 A1 discloses a radial fan with a closed fan wheel arranged in a housing, which can be connected via a hub to an output shaft of a motor, a first guide vane ring being arranged on one side of the fan wheel and a second guide vane ring being arranged on the side of the fan wheel facing away from it, wherein the second guide vane ring has a radial offset from the first guide vane ring towards the hub.

A fan wheel can be designed as a radial fan wheel, in particular with backward-curved blades, or also as a drum impeller, as can be seen, for example, in US Pat DE 1 628 336 A is known. Here, the drum impeller consists of a large number of narrow lamellae, which form the blades of the wheel and which are fastened between two end rings, the radius of which is substantially larger than the width of the lamellae, so that a drum-shaped construction is formed which is suitably connected to a Hub is connected, for example with the help of a circular plate which is attached to the fins at the center.

The object of the invention is to provide a fan wheel with improved aerodynamics and improved strength properties, and a blower arrangement with an enlarged range of uses.

This object is achieved according to a first aspect of the invention for a fan wheel of the type mentioned at the outset with the features of claim 1.

It is preferably provided that a space volume of the annular gap delimited by the first support means and by the support disk has an axial extent along the axis of rotation that is considerably smaller than the axial extent of the annular space volume that is determined by the two support means and in which the blades are arranged are. The axial extent of the annular gap along the axis of rotation is particularly preferably less than 20 percent, in particular less than 10 percent, of the axial extent of the annular space volume. This ensures that a fluid flow that flows through the annular gap in the radial direction toward the outside when the fan wheel rotates about the axis of rotation is considerably less than a fluid flow that flows through the annular space volume in the radial direction to the outside. As an example, it can be assumed that a mass flow of a main fluid flow through the annular space volume is at least 5 times, in particular at least 10 times larger than the mass flow of a secondary fluid flow through the annular gap. As an example, the fluid flow through the annular gap can be used to dissipate heat from a drive motor which is used to drive the fan wheel.

It is expedient if the support disk is connected to the hub arrangement. This ensures an advantageous introduction of force and torque from the hub arrangement to the support disk, which ensures an advantageous flow of force in the fan wheel. In addition, the connection of the support disk to the hub arrangement simplifies the centering of the support disk required for an advantageous concentricity of the fan wheel.

It is advantageous if the support disk is connected directly to the first carrier means. As a result of this measure, the support disk and the first support means form a stable composite which, with a suitable design of the support disk and the first support means, leads to a considerable increase in the stability of the fan wheel, without the need for a considerably larger amount of material. This applies in particular when the first carrier means, which is typically formed as a stamped sheet-metal blank, in view of the connection to the support disk with a reduced one Material thickness is executed and the, preferably designed as a stamped sheet metal blank, has a material thickness which is similar to the material thickness of the first carrier means, in particular is identical to the material path of the first carrier means. It is preferably provided that the support disk and the first carrier are integrally connected to one another, for example by welding, in particular reader welding, and / or gluing.

According to the invention, projections, in particular beads, are formed on the support disk and / or on the first support means, each in the axial direction in the annular gap, which are fixed to an opposite surface of the support disk or the first support means. With such projections, which can already be formed during the manufacture of the support disk, which is typically designed as stamped sheet-metal blanks, or the first carrier means, in addition to a stabilizing effect for the respective component (first carrier center, support disk), an inexpensive and precise spacing of the two components from one another is also possible . The projections are preferably geometrically adapted with a front side facing the respectively opposite surface to a geometry of the opposite surface, which can preferably be flat. In this way, a large-area support of the projections on the opposite component is ensured, so that the desired stable bond between the support disk and the first carrier can be created.

In an advantageous development of the invention, it is provided that the projections are designed in the radial direction Show main extension. As a result, the projections have a double function which, in addition to the precise spacing and stable connection of the support disk and the first carrier means, also comprises a guiding action for the fluid flowing through the annular gap. By way of example, it is provided that the projections are arranged on radial lines which extend outward from the axis of rotation in the radial direction. Alternatively, it can be provided that the projections assume an offset and / or an acute angle with the radial lines or are at least partially curved.

The support disk is preferably penetrated by a plurality of inlet openings arranged at the same angular division from the axis of rotation, in particular congruently, between which radial spokes extend from the hub arrangement to a radially outer ring region of the support disk. The task of the inlet openings is to allow an axial inflow of fluid into the annular gap when the fan wheel rotates. In order to ensure an advantageous aerodynamic efficiency for the fluid flow in the annular gap, it is provided in particular that the inlet openings are congruent, that is to say geometrically congruent, and are arranged at the same angular division with respect to the axis of rotation. The inlet openings are each delimited in the circumferential direction by radial spokes, which are preferably web-shaped and in particular extend along radial lines that extend radially outward from the axis of rotation. It can further be provided that the inlet openings are bordered by a radially inner, circular segment-shaped edge and / or by a radially outer, circular segment-shaped edge. It is expedient if guide projections, in particular beads, of the first carrier means extend along the radial spokes up to the radially outer ring region, in particular up to a maximum diameter of the radially outer ring region. This ensures a fluid guide function for the fluid flow in the annular gap. Here, the fluid is always guided in an aerodynamically favorable manner with its flow movement starting from the inlet opening, which is formed in a radially inner region of the support disk, up to the radial exit from the annular gap with the aid of the respective guide projection.

Provision is preferably made for support projections, in particular beads, which are arranged on the first support means and / or on the support disk and are arranged between adjacent guide projections and extend in the radial direction over the radially outer ring region and are fixed on an opposite surface of the support disk or the first support means are. These support projections serve as additional guide means for the fluid flow in the annular gap and also contribute to the formation of a stable combination of the support disk and the first carrier means.

In a further embodiment of the invention, it is provided that the support disk has, in a radially outer area, an at least partially circular projection that extends in an axial direction opposite to the annular gap. The task of the at least partially circular projection is to stabilize the support disk. The arrangement of the radial circumferential projection in the radially outer region of the support disk enables an advantageous combination between the desired stabilizing effect and the smallest possible Impairment of the fluid flow in the annular gap can be achieved.

In an advantageous development of the invention it is provided that a projection is formed on the blades in a radially outer region, the longest edge of which makes an acute angle with the axis of rotation. The purpose of this projection on the blade is to stabilize the radially outer region of the blade, which is exposed to the greatest fluid forces when the fan wheel is used in a blower arrangement. Furthermore, this projection can also be used to advantageously influence the fluid flow through the annular space volume, this fluid flow, the production of which is the main task of the fan wheel, being considerably greater than the fluid flow through the annular gap.

It is advantageous if the longest edge of the projection on the blade, in particular at least substantially, is aligned parallel to a connecting line between an outer edge of the first carrier means designed as a disc-shaped circular blank and an inner edge of the second carrier means designed as a ring. As a result, the fluid flow which, when the fan wheel rotates, passes through the annular space between the two carrier means and flows outward in the radial direction can be directed in the direction of the radially outer, circular exit gap of the annular gap and thus favor the fluid exit from the annular gap.

According to a second aspect of the invention, the object of the invention is achieved by a blower arrangement with a drive motor which has a drive shaft which is rotatably mounted on a motor housing comprises, as well as solved with a fan wheel according to any one of the preceding claims, wherein the fan wheel with the hub assembly is rotationally fixed to the drive shaft such that the support disc is arranged adjacent to the motor housing, so that when the fan wheel rotates about the axis of rotation, a fluid flow from the motor housing is effected in the direction of the support disc. As an example, the fan wheel is provided to provide a main fluid flow and a secondary fluid flow when rotating about the axis of rotation, the secondary fluid flow being able to be used, for example, to support heat dissipation from the drive motor.

Figur 1

eine perspektivische Vorderansicht eines Ventilatorrads, bei dem ein erstes Trägermittel als scheibenförmige Ronde und ein zweites Trägermittel als Ring jeweils koaxial zu einer Rotationsachse ausgebildet sind, wobei dem ersten Trägermittel eine koaxial zur Rotationsachse ausgebildete Stützscheibe zugeordnet ist und wobei zwischen den Trägermitteln in radialer Richtung ausgerichtete Schaufeln angeordnet sind,

Figur 2

eine perspektivische Schnittdarstellung des Ventilatorrads gemäß der Figur 1,

Figur 3

eine seitliche Schnittdarstellung des Ventilatorrads gemäß der Figur 1, und

Figur 4

eine perspektivische Rückansicht des Ventilatorrads gemäß der Figur 1.

An advantageous embodiment of the invention is shown in the drawing. It shows:

Figure 1

a perspective front view of a fan wheel, in which a first carrier means as a disc-shaped blank and a second carrier means as a ring are each formed coaxially with an axis of rotation, wherein the first carrier means is assigned a support disk formed coaxially with the axis of rotation and with blades aligned in the radial direction between the carrier means are arranged

Figure 2

a perspective sectional view of the fan wheel according to the Figure 1 ,

Figure 3

a side sectional view of the fan wheel according to the Figure 1 , and

Figure 4

a rear perspective view of the fan wheel according to the Figure 1 .

One in the Figures 1 to 4 Fan wheel 1, shown in different views, is provided for conveying a gaseous fluid, in particular air, and can be used, for example, in an oven, not shown, where it is set in rotation by a drive motor, not shown, about a rotation axis 2 in order to circulate the Air volume located in the oven.

The fan wheel 1 has, for example, a first carrier means designed as a disk-shaped circular blank 3 coaxial with the axis of rotation 2 and a second carrier means designed as a ring 4 coaxial with the axis of rotation 2, which are spaced along the axis of rotation 2 and arranged coaxially to one another. For example, the ring 4 is designed with respect to the axis of rotation 2 as a rotating body with a J-shaped profile and forms an inflow nozzle for a main fluid flow which, when the fan wheel 1 rotates about the axis of rotation 2 in the radial direction outwards between the two carrier means 3 and 4 is promoted.

Provided between the round blank 3 and the ring 4 with respect to the axis of rotation 2 are a plurality of blades 5 arranged in predeterminable, in particular constant, angular pitch, the largest surface 6 of which extends between the round blank 3 and the ring 4. By way of example only, it is provided that the largest surface 6 is flat and is arranged in a plane, not shown, which is delimited by the axis of rotation 2 and a radial line 7 extending transversely to the axis of rotation 2 in the radial direction. It is also provided purely by way of example that a projection 8 is formed on the largest surface 6, the longest edge 9 of which forms an acute angle 10 with the axis of rotation 2, as is the case here in the representation of the Figure 3 is indicated. Furthermore, it is provided by way of example that each blade 5 has a tab 15, 16, which is oriented transversely to the largest surface 6 and with which the blade 5 is flat, both on an axial end region 11 facing the round plate 3 and on an axial end region 12 facing the ring 4. in particular cohesively, is fixed to the circular blank 3 or the ring 4.

It is also provided purely by way of example that the longest edge 9 of the projection 8 is aligned at least substantially parallel to a connecting line 17 between a circular outer edge 18 of the round blank 3 and a circular inner edge 19 of the ring 4.

The circular disc 3 is assigned a support disk 20 which is formed coaxially to the axis of rotation 2 and which forms an annular gap 21 with the circular disc 3. Purely by way of example, the support disk 20 is designed as a rotating body with respect to the axis of rotation 2 and is provided with a plurality of inlet openings 22, which are arranged, for example, in the same angular division to the axis of rotation 2. It can be provided that all inlet openings 22 have an identical cross-sectional geometry and are therefore congruent. As an example, the inlet openings 22 are arranged on the support disk 20 such that radial spokes 23 are formed between the inlet openings 22, which limit the inlet openings 22 in the circumferential direction and which connect an annular inner region 24 of the support disk 20 to an annular outer region 25 of the support disk 20. The inner region of the support disk is connected in a force-transmitting manner to a hub arrangement 26, which in turn is connected to the circular blank 3 in a force-transmitting manner. The hub arrangement 26 is designed as a shaft coupling, for example rotationally fixed attachment of the fan wheel 1 is set up on a drive shaft, not shown.

By way of example only, a plurality of projections 27 and 28 facing the support disk 20 are formed on the round blank 3, which can be a stamped sheet-metal blank, which are implemented, for example, in the manner of beads. The projections 27 are guide projections which extend in the radial direction over almost the entire diameter of the round blank 3 and which are arranged such that they rest on the radial spokes 23 and the adjoining outer region 25 of the support disk 20. In contrast, the projections 28 are designed as support projections which, for example, rest only on the outer region 25 of the support disk 20. Both the guide projections 27 and the support projections 28 have end faces 29 facing the support disk 20, which lie flat against a surface 30 of the support disk 20 facing the round blank 3 and are fixed there, for example, in a materially integral manner, in particular by gluing or welding. The guide projections 27 and the support projections 28 thus determine the distance 31 between the round blank 3 and the support disk 20 and thus also the volume of the annular gap 21. The distance 31 is selected to be considerably smaller than a distance 34 between the round blank 3 and the ring 4. so that when the fan wheel 1 rotates about the axis of rotation 2, a (main) fluid flow caused by the blades 5, which flows in through the ring 4 in the axial direction and exits in the radial direction between the round plate 3 and ring 4, is considerably greater than is a (secondary) fluid flow through the annular gap 21, which enters through the inlet openings 22 in the axial direction and exits in the radial direction to the outside between the round blank 3 and the support disk 20.

As a purely exemplary example, both the guide projections 27 and the support projections 28 are aligned with a respective main extension along radial lines (not shown in more detail) which, starting from the axis of rotation 2, extend in the radial direction to the outside.

As from the representation of the Figures 2 and 4th can be removed, the support disk 20 has in a radially outer region a circular circumferential projection 32 which extends axially in a direction away from the round blank 3 and which is provided as an exemplary triangular shaped bead for stabilizing the support disk 20. For example, a concave depression is formed by the projection 32 when the rear side 33 of the fan wheel 1 is viewed, while the surface 30 of the support disk 20 facing the circular disc 3, with the exception of the projection 32, is of a flat design.

The hub arrangement 26 enables the fan wheel 1 to be fixed in a rotationally fixed manner on a drive shaft, not shown, of a motor, in particular an electric motor. The fan wheel 1 is preferably arranged on the drive shaft such that the support disk 20 faces the motor, while the ring 4 faces away from the motor. As a result, when the fan wheel 1 rotates about the axis of rotation 2, in addition to the (main) fluid flow through the ring 4, a (secondary) fluid flow can be brought about through the annular gap 21, this (secondary) fluid flow, for example, heated air from the surroundings of the engine and can thus help cool the engine.

Claims (12)

1. Fan wheel for conveying a gaseous fluid, having a plurality of blades (5) which are arranged in a predeterminable angular division in an annular spatial volume about an axis of rotation (2) and which are each fixed with their axial, mutually opposite end regions (11, 12) to carrier means (3, 4), wherein a first carrier means (3) is constructed as a disc-shaped circular blank which is coaxial with the axis of rotation (2) and comprises a hub arrangement (26) and wherein a second carrier means (4) is constructed as a ring which is coaxial with the axis of rotation (2), wherein a support disc (20) is arranged at a distance from the first carrier means (3), which support disc (20) is coaxial with the axis of rotation (2) and forms an annular gap (21) with the first carrier means (3), and wherein the support disc (20) is penetrated by at least one inlet opening (22) which allows a radially outwardly directed fluid flow in the annular gap (21), characterised in that projections (27, 28) extending in the axial direction into the annular gap (21) are formed on the supporting disc (20) and/or on the first carrier means (3) respectively, which are fixed to an opposite surface (30) of the supporting disc (20) or of the first carrier means (3).
2. Fan wheel according to claim 1, characterized in that the supporting disk (20) is connected to the hub assembly (26) .
3. Fan wheel according to claim 1 or 2, characterized in that the supporting disk (20) is directly connected to the first carrier means (3).
4. Fan wheel according to claim 1, 2 or 3, characterized in that the projections (27, 28) are formed as beads.
5. Fan wheel according to claim 1, 2, 3 or 4, characterized in that the projections (27, 28) have a main extension in the radial direction.
6. Fan wheel according to one of the preceding claims, characterised in that the supporting disc (20) is penetrated by a plurality of inlet openings (22), which are arranged at the same angular pitch relative to the axis of rotation (2) and are in particular congruently formed, between which radial spokes (23) extend from the hub arrangement (26) to a radially outer annular region (25) of the supporting disc (20) .
7. Fan wheel according to claim 6, characterised in that guide projections (27), in particular beads, of the first support means (3) are extended along the radial spokes (23) up to the radially outer annular region (25), in particular up to a maximum diameter of the annular region (25).
8. Fan wheel according to claim 7, characterised in that supporting projections (28), in particular beads, are formed on the first carrier means (3) and/or on the supporting disk (20), each arranged between adjacent guide projections (27) and extending in the radial direction over the radially outer annular region (25), said supporting projections (28) being fixed to an opposite surface (30) of the supporting disk (20) or of the first carrier means (3).
9. Fan wheel according to one of the preceding claims, characterised in that the supporting disc (20) has, in a radially outer region, a projection (32) which is circularly circumferential at least in regions and which extends in an axial direction opposite to the annular gap (21).
10. Fan wheel according to one of the preceding claims, characterized in that a projection (8) is formed on each of the blades (5) in a radially outer region, the longest edge (9) of which projection (8) makes an acute angle (10) with the axis of rotation (2).
11. Fan wheel according to claim 10, characterised in that the longest edge (9) of the projection (8) on the blade (5) is aligned, in particular at least substantially, parallel to a connecting line (17) between an outer edge (18) of the first carrier means (3) formed as a disc-shaped round plate and an inner edge of the second carrier means (4) formed as a ring.
12. Blower arrangement with a drive motor, which comprises a drive shaft rotatably mounted on a motor housing, and with a fan wheel (1) according to one of the preceding claims, which is fixed to the drive shaft in a rotationally fixed manner with the hub arrangement (26) in such a way that the support disc (20) is arranged adjacent to the motor housing, so that a fluid flow is effected from the motor housing in the direction of the support disc (20) during a rotational movement of the fan wheel (1) about the axis of rotation (2).

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