Ventilator wheel

Abstract

The invention relates to a fan wheel (1) with a support part (2) and several blades (3) attached to the support part (2), wherein a hub (4) is attached to the support part (2) which is designed for coupling with a drive shaft and which defines an axis of rotation (5) oriented transversely to a front face (9) of the support part (2), wherein the blades (3) each have a first blade section (7) which is arranged in a space section (11) adjoining the front face (9) and which is fixed to a front face (9) of the support part (2). According to the invention, at least one blade (3) has a second blade section (8) which extends beyond a rear face (10) of the support part (2) facing away from the front face (9) into a space section (12) adjoining the rear face (10).

Description

[0001] The invention relates to a fan wheel with a support part and a plurality of blades attached to the support part, wherein a hub is attached to the support part, which hub is designed for coupling to a drive shaft and which determines an axis of rotation aligned transversely to a front side of the support part, wherein the blades each have a first blade section which is arranged in a space section adjacent to the front side and which is fixed to a front side of the support part.

[0002] From DE 10 2010 035 284 A1 an impeller for a radial fan is known with a plate-shaped disc and a ring arranged coaxially to the disc and axially spaced from the disc along a central axis, as well as a plurality of blades arranged between the disc and the ring, wherein the blades are in touching contact with the disc and with the ring at opposite end regions, wherein the blades are arranged in radially outer regions of the disc and the ring and form a blade ring and are each penetrated by at least one recess which runs parallel to the central axis over an entire longitudinal extent of the blade.

[0003] US 6 004 097 A discloses an exhaust fan for coal mills with an elongated, conical hub welded to the blades and engaging the rear shroud to eliminate air gaps along the rear of the fan assembly and to facilitate axial to radial directional changes of the coal flow. Two-piece blade assemblies are provided, including a lower blade welded directly to the hub and shrouds, a protective liner removably attached to the lower blades, and a plurality of recurved stiffening ribs welded to the rear undersides of the lower blades, the hub, and the shroud.

[0004] US 2002 0141888 A1 discloses a double-sided radial fan for drawing in cooling air, wherein a first airflow is drawn into one axial end of the device and directed over the outer surface of the device and a second airflow is drawn into an opposite axial end of the device and through the interior of the device before the second airflow is redirected over the outside of the device.

[0005] From DE 690 08 574 T2 a suction pump is known with a rotor arranged inside a housing which is connected to both a suction line and a discharge line and whose rotor is provided with a shaft and at least one disc which, on the suction side, has substantially radial blades which are recessed to leave a central space into which the extension of the suction line projects, wherein, on the outlet side, the disc is provided with a set of vanes forming a chamber which communicates with a line which, in turn, is connected to an external ventilation opening and encloses the drive belt drive and transmission mechanism which is connected to the drive pulley of the rotor.

[0006] US 6,705,837 B1 discloses a connecting sleeve attached to a support plate of a wear-resistant liner. The liner is secured to a rotor blade body by welding a thrust ring to a portion of the connecting sleeve that extends beyond a bore in the blade body. The liner can be replaced at a later time by burning off the welds connecting the thrust ring to the connecting sleeve.

[0007] US 2020 / 011343 A1 discloses a fan wheel comprising a first air plate, a second air plate, and a plurality of blades arranged between the first air plate and the second air plate. The first air plate comprises a central part and an air inlet arranged in the central part, wherein two adjacent blades each form an air channel. The plurality of blades each comprise an inlet section adjacent to the air inlet, an intermediate section, and an outlet section, wherein the thickness of the intermediate section is greater than the thickness of the inlet section and the thickness of the outlet section.

[0008] DE 10 2005 031197 A1 discloses a fan and a drive comprising a motor, a clutch and a gearbox, wherein a fan is provided for cooling the gearbox, wherein the fan is connected to a shaft of the gearbox or to a shaft connected to a shaft of the gearbox, wherein the fan comprises fan blades which cover an axial region which is different from the axial region which is covered by the connection between the fan and the shaft.

[0009] The object of the invention is to provide a fan wheel that combines low manufacturing costs with versatile applicability.

[0010] This object is achieved for a fan wheel of the type mentioned at the outset with the features of claim 1. It is provided, inter alia, that at least one blade, preferably a plurality of blades, in particular all blades, has a second blade section which extends beyond a rear side of the support part facing away from the front side into a spatial section adjacent to the rear side.

[0011] Such a fan wheel can be used, for example, in a convection oven or a steam cooker and serves to generate an air flow. For this purpose, the fan wheel is fixed by the hub to a drive shaft of a drive motor, in particular an electric motor, and is set into a rotational movement about the rotation axis by the drive motor. Typically, the drive motor is arranged outside a cooking chamber and the drive shaft projects into the cooking chamber and the fan wheel is attached to it. Purely by way of example, the rear side of the fan wheel is arranged opposite a wall section of the cooking chamber extending between the drive motor and the fan wheel.

[0012] When the fan wheel is used in such an operating environment, the first blade sections ensure a first inflow of air when the fan wheel rotates about the axis of rotation, which is directed along the axis of rotation towards the front of the support part. This first inflow of air is accelerated radially outwards by the first blade sections when the fan wheel rotates. Furthermore, the second blade sections of the fan wheel enable an additional radial air flow, which can be fed from a space between the rear of the fan wheel and the adjacent wall section of the cooking chamber. This second inflow of air is accelerated radially outwards by the second blade sections when the fan wheel rotates.Thus, the fan wheel according to the invention has an improved conveying capacity compared to a conventional fan wheel which is not provided with second blade sections and ensures additional mixing of the amount of air taken in the cooking chamber.

[0013] The two spatial sections, which extend adjacent to the front side of the support part and adjacent to the rear side of the support part, can each be regarded as profile bodies extending along the axis of rotation, wherein the support part forms a dividing plane between the spatial section extending adjacent to the front side and the spatial section extending adjacent to the rear side.

[0014] By aligning the blades parallel to the rotation axis, significantly different forces are prevented from acting on the blades when the fan wheel is operated in the two different directions of rotation. Thus, a favorable fatigue strength can be assumed for the fan wheel even when the direction of rotation is frequently changed.

[0015] The extension of the first and second blade sections in the radial direction outwards beyond the support part ensures that the first and second blade sections have a high circumferential speed and thus an advantageous conveying capacity when the fan wheel rotates.

[0016] Preferably, an inwardly oriented first end face of the first blade section, arranged in a spatial section extending from the front side of the support part, assumes a first angle from an interval of 0 degrees to 90 degrees, in particular from an interval of 30 degrees to 60 degrees, to the axis of rotation. This orientation of the first end face ensures an advantageous flow onto the first blade section with regard to the air flowing in along the axis of rotation toward the front side of the support part and flowing outward in the radial direction.

[0017] In a further development of the invention, it is provided that an inwardly oriented second end face of the second blade section, arranged in a spatial section adjacent to the rear side of the support part, assumes a second angle from an interval of 0 degrees to 90 degrees, in particular from an interval of 30 degrees to 60 degrees, to the axis of rotation. This orientation of the second end face ensures an advantageous flow onto the second blade section with regard to the air flowing in along the axis of rotation toward the rear side of the support part and flowing outward in the radial direction.

[0018] In a further embodiment of the invention, it is provided that radially outwardly arranged outer surfaces of the blades are arranged on a diameter which is at least 25 percent, preferably at least 30 percent, in particular 40 percent, larger than an outer diameter of the carrier part.

[0019] According to the invention, the blades are arranged in blade planes that encompass the axis of rotation. This ensures a uniform flow across the blades regardless of the direction of rotation of the fan wheel, so that the fan wheel has the same aerodynamic efficiency for each of the two directions of rotation. It is particularly preferred that the blades be arranged on the support part at the same angular pitch with respect to the axis of rotation.

[0020] In a further embodiment of the invention, at least one fastening tab, oriented transversely to the blade plane, is formed, in particular integrally, on a first narrow side of the blade opposite the support part and is integrally connected to the support part. The fastening tab enables a stable, integral connection between the first blade section and the support part. This integral connection can be created, in particular, by soldering, brazing, electrical resistance welding, or laser welding.

[0021] Furthermore, the invention provides that a ring part is arranged at a distance from the support part along the axis of rotation and that a rotational symmetry axis of the ring part is aligned coaxially with the axis of rotation, the first blade section being arranged between the support part and the ring part. The ring part stabilizes the blades against forces that occur in a circumferential direction of the support part and thus transversely to the largest surfaces of the blades during rotation of the fan wheel. Furthermore, the ring part serves to guide the flow in the radially outer region of the fan wheel. It is preferably provided that the first blade section is connected to the ring part, in particular by a material fit.

[0022] It is advantageous if the extension of the second blade section along the rotation axis corresponds to at least 50 percent of the distance between the support part and the ring part. This ensures that, during rotation of the fan wheel, the air flow provided by the second blade sections is sufficiently large to ensure favorable air circulation in the second spatial section.

[0023] Furthermore, the invention provides for the support part to be designed as a flat circular disk and / or for the ring part to be designed as a plane-parallel plate. This enables cost-effective production of the support part or the ring part, for example, by a cutting process (punching, punch-nibbling, waterjet cutting, laser cutting) from a sheet metal blank.

[0024] Preferably, a deviation between an inner diameter of an annular recess of the annular part and an outer diameter of the carrier part is less than 20 percent, preferably less than 10 percent, in particular less than 5 percent. This ensures advantageous flow guidance for the air flow generated by the first blade sections during rotation of the fan wheel.

[0025] In a further embodiment of the invention, it is provided that radially outwardly arranged outer surfaces of the blades are arranged on a diameter which is smaller than an outer diameter of the ring part.

[0026] It is advantageous if at least one second fastening tab, oriented transversely to the blade plane, is formed, in particular integrally, on a second narrow side of the blade opposite the ring part and is integrally connected to the ring part. This ensures an advantageous and stable connection between the first blade section and the ring part.

[0027] An advantageous embodiment of the invention is illustrated in the drawing. Figure 1 is a strictly schematic, perspective view from the front of a first embodiment of a fan wheel not according to the invention, Figure 2 is a perspective view from the front of a second embodiment of a fan wheel according to the invention, Figure 3 is a perspective view from the rear of the fan wheel according to the Figure 2 , Figure 4 a plan view of the front of the fan wheel according to the Figures 2 and 3, Figure 5 a top view of the rear of the fan wheel according to the Figures 2 to 4 , Figure 6 a side view of the fan wheel according to the Figures 2 to 5 Figure 7 is a perspective view of a blade for use with the fan wheel according to Figures 2 to 6 .

[0028] One in the Figure 1 The first embodiment of a fan wheel 1 shown, which is designed, for example, for use in a convection oven or steam cooker, comprises a carrier part 2 which, purely by way of example, is circular disk-shaped and a plurality of blades 3 attached to the carrier part 2. Furthermore, a hub 4 is attached to the carrier part 2 and is designed to secure the carrier part 2 to a drive shaft (not shown) of a drive motor, in particular an electric motor. The hub 4 defines an axis of rotation 5, wherein, purely by way of example, it is provided that the axis of rotation 5 is identical to a rotational axis of symmetry of the carrier part 2.

[0029] By way of example, it is provided that the total of six blades 3 are arranged at the same angular pitch and the same radial distance 6 from the rotation axis 5. Furthermore, it is provided that the blades 3 are each flat and are each arranged in a blade plane (not shown) that includes the rotation axis 5. In the fan wheel 1 according to the Figure 1 Due to the even number of blades 3, opposite blades 3 are arranged in a common blade plane (not shown).

[0030] The blades 3 are attached to the support part 2 in a manner not shown in detail, in particular by laser welding. Each of the blades 3 has a first blade section 7 and a second blade section 8. The first blade section 7 extends from a front side 9 of the support part 2 along the rotation axis 5 into a first spatial section 11. Furthermore, the second blade section 8, which is integrally connected to the first blade section 7, extends into a second spatial section 12, which extends from a rear side 10 of the support part 2.

[0031] According to the invention, the first blade section 7 extends from a radially inner end region 15 beyond a diameter 20 of the carrier part 2 to a radially outer end region 16.

[0032] Furthermore, as in the invention, it is provided that the second blade section 8 extends radially outward from the diameter 20 of the carrier part 2 to the radially outer end region 16 of the first blade section 7. By way of example, it is provided that an outer edge 17 of the blade 3, which is determined by both the first blade section 7 and the second blade section 8, is aligned parallel to the rotation axis 5.

[0033] Furthermore, it is provided purely by way of example that an upper side 18 of the blade 3 and a lower side 19 of the blade 3 are aligned parallel to one another and transversely to the axis of rotation 5.

[0034] As the representation of the Figure 1can be removed, the first blade section 7 has a first length 21 in the direction of the rotation axis 5. Furthermore, the second blade section 8 has a second length 22 in the direction of the rotation axis 5. Purely by way of example, it is provided that the second length 22 is smaller than the first length 21, for example, approximately 80 percent of the first length.

[0035] For the blades 3 according to the illustration of the Figure 1 It is further provided purely by way of example that a radially inner first end face 25 of the first blade section 7 forms an acute angle 27 with the rotation axis 5, which preferably lies in an interval between 20 degrees and 70 degrees. It is further provided by way of example that a radially inner second end face 26 of the second blade section 8 forms an acute angle 28 with the rotation axis 5, which preferably lies in an interval between 20 degrees and 70 degrees.

[0036] Due to the design and arrangement of the blades 3 on the support part 2, the fan wheel 1 formed thereby can be operated with the same flow rates in a first direction of rotation about the rotation axis 5 and in a second direction of rotation about the rotation axis 5, which is opposite to the first direction of rotation. Regardless of the direction of rotation of the fan wheel 1, it can be assumed that when the fan wheel 1 rotates about the rotation axis 5, an air flow occurs in a radially inner region coaxial with the rotation axis and that the rotation of the fan wheel 1 accelerates the air in a radially outward direction.This applies both to a first air inflow 30, which flows along the rotation axis 5 from the first spatial section 11 in the direction of the front side 9 of the support part 2, and to a second air inflow 31, which flows along the rotation axis 5 from the second spatial section 12 in the direction of the front side 10 of the support part 2. These two air inflows 30, 31 are deflected and accelerated radially outwards by the blades 3 and mixed with one another in the region of the outer edge 17.

[0037] The second embodiment of a fan wheel 41, as shown in the Figures 2 to 6 shown, differs from the first embodiment of the fan wheel 1 according to the Figure 1by an additional ring part 42. The remaining structure of the fan wheel 41 is identical to the fan wheel 1, so that the same reference numerals are used for the fan wheel 41 as for the fan wheel 1 and a repeated description of components already described is omitted.

[0038] As the representation of the Figures 2 to 6 can be removed, the ring part 42 is attached to the upper side 18 of the blades 3. Purely by way of example, it is provided that an inner diameter 43 of the ring part 42 approximately corresponds to the diameter 20 of the carrier part 2. Furthermore, it is provided by way of example that an outer diameter 44 of the ring part 42 is slightly larger than a distance between outer edges 17 of two blades 3 that are arranged in the same blade plane (not shown). In addition, it can be provided that the second length 22 of the second blade section 8 corresponds to at least 50 percent of a distance 45 between the ring part 42 and the carrier part 2.

[0039] By way of example, it is provided that the ring part 42 is designed as a plane-parallel plate in the same way as the carrier part 2 and can thus be produced from a flat sheet metal plate (not shown) by a cutting process, for example laser cutting.

[0040] As the detailed presentation of the Figures 2 to 5 and the representation of a shovel 3 in the Figure 7can be removed, a plurality of fastening tabs 33, 34, aligned parallel to the front side 9 of the carrier part 2, are attached to the top side 18 of the first blade section 7 and to a bottom side 23 of the first blade section 7. The fastening tabs 33 assigned to the top side 18 are designed for a material-to-material fixing of the blade 3 to a rear side 47 of the ring part 42. The fastening tabs 34 assigned to the bottom side 23 of the first blade section 7 are designed for a material-to-material fixing of the blade 3 to the front side 9 of the carrier part 2. By way of example, it is provided that the fastening tabs 33, 34 are each substantially rectangular and are each aligned at a right angle to the first blade section 7.

Claims

1. Fan wheel (1; 42) with a support part (2) and several blades (3) attached to the support part (2), wherein a hub (4) is attached to the support part (2), which is designed for coupling with a drive shaft and which defines a rotational axis (5) aligned transversely to a front side (9) of the support part (2), wherein the blades (3) each have a first blade section (7), which is arranged in a space section (11) adjacent to the front side (9) and is fixed to a front side (9) of the support part (2), wherein the first blade section (7) extends from a radially inner end region (15) of the first blade section (7) beyond a diameter (20) of the support part (2) to a radially outer end region (16) of the first blade section (7), wherein at least one blade (3) has a second blade section (8) which extends beyond a rear side (10) of the support part (2) facing away from the front side (9) into a space section (12) adjacent to the rear side (10), wherein the second blade section (8) extends radially outwards from the diameter (20) of the support part (2) to the radially outer end region (16) of the first blade section (7), wherein a ring part (42) is arranged along the axis of rotation (5) at a distance from the support part (2) and an axis of rotational symmetry of the ring part (42) is aligned coaxially with the axis of rotation (5) and wherein the first blade section (7) is arranged between the support part (2) and the ring part (42), wherein the support part (2) is designed as a flat circular disc and / or the ring part (42) is designed as a flat parallel plate, characterised in that the blades (3) are arranged in blade planes which enclose the axis of rotation (3).

2. Fan wheel (1; 42) according to claim 1, characterised in that an inwardly facing first end face (25) of the first blade section (7), which is arranged in a space section (11) extending from the front side (9) of the support part (2), forms a first angle (27) from an interval of 0 degrees to 90 degrees, in particular from an interval of 30 degrees to 60 degrees, with the axis of rotation (5).

3. Fan wheel (1; 42) according to claim 1 or 2, characterised in that an inwardly aligned second end face (26) of the second blade section (8), arranged in a spatial section (12) adjacent to the rear side (10) of the support part (2), forms a second angle (28) from an interval of 0 degrees to 90 degrees, in particular from an interval of 30 degrees to 60 degrees, to the axis of rotation (5)4. Fan wheel (1; 42) according to one of claims 1 to 3, characterised in that radially outwardly arranged outer surfaces (17) of the blades (3) are arranged on a diameter which is at least 25 percent, preferably at least 30 percent, in particular 40 percent, greater than an outer diameter (20) of the support part (2).

5. Fan wheel (1; 42) according to one of the preceding claims, characterised in that at least one fastening lug (34) is arranged on a first narrow side (19) of the blade (3) opposite the support part (2), which fastening lug (34) is oriented transversely to the blade plane and is, in particular one-piece, connected in a material-locking manner to the support part (2).

6. Fan wheel (1; 42) according to claim 1, characterised in that an extension (22) of the second blade section (8) along the axis of rotation (5) corresponds to at least 50 percent of a distance between the support part (2) and the ring part (42) .

7. Fan wheel (1) according to claim 1, characterised in that a deviation between an inner diameter (43) of a ring recess of the ring part (42) and an outer diameter (20) of the support part (2) is less than 20 percent, preferably less than 10 percent, in particular less than 5 percent.

8. Fan wheel (1; 42) according to one of claims 1, 6 or 7, characterised in that radially outwardly arranged outer surfaces (17) of the blades (3) are arranged on a diameter which is smaller than an outer diameter (44) of the ring part (42).

9. Fan wheel (1; 42) according to one of the preceding claims, characterised in that at least one second fastening lug (33), in particular one-piece, is formed on a second narrow side (18) of the blade (3) opposite the ring part (42) and is aligned transversely to the blade plane, which second fastening lug (33) is connected to the ring part (42) in a material-locking manner.

Images