WO2023025352A1

WO2023025352A1 - Fan wheel and fan having said fan wheel

Info

Publication number: WO2023025352A1
Application number: PCT/DE2022/100630
Authority: WO
Inventors: Klaus-Dieter Pfeffer
Original assignee: Pfeffer Klaus Dieter
Priority date: 2021-08-23
Filing date: 2022-08-22
Publication date: 2023-03-02
Also published as: DE102021121747A1; DE102021121747B4

Abstract

In a fan wheel (1) having a centrally located hub (2), which can be connected to a rotary shaft of a motor, a plurality of blades (3) extending radially from the hub (2) is provided, each blade (3) comprising a first and a second blade region (4, 5) connected by an at least partly helically extending transition region (6), and the first and second blade regions (4, 5) being at different angles of inclination to the axis of rotation of the hub (2) so that the air flows caused by the blade regions (4, 5) flow in opposite directions.

Description

FAN WHEEL AND FAN WITH THE SAME

The invention relates to a fan wheel with a centrally arranged hub, which can be connected to a rotating shaft of a motor, and a plurality of blades extending radially from the hub, each blade having a first and a second blade area connected by an at least partially helical transition area. Furthermore, the invention relates to a fan with a corresponding fan wheel.

Fans are known which are housed in electronic devices or machines such as refrigerators, air conditioners, microwave ovens, computers, televisions, printers or other electronic devices or machines and which provide air movement so that overheating is prevented.

Axial flow fans have a centrally located hub that is connected to a rotary shaft of a motor. Starting from the hub, a plurality of rotary vanes are usually arranged, which are arranged at equal distances around the outer peripheral surface of the hub and blow out air. The axial fan described, in which the axis of rotation of the impeller runs essentially parallel to the air flow, is the most common fan.

A double axial fan is known from DE 10 2008 031 084 A1, with a drive motor, with two counter-rotating impellers on the output shaft of the drive motor, the second of which surrounds the first in a ring and which are located within an inner tube and an outer tube concentrically surrounding it. The impellers lie concentrically as radially inner and outer impellers in a common radial plane, with the inner tube, the outer tube and the drive motor being connected by continuous radial spokes, such. The inner tube is divided inside the housing by a slot-shaped passage running around in the radial direction, in which a running ring lies, which connects the blades of the inner impeller to the blades of the outer impeller. The design of the impellers themselves and that of the transition area between the blades is severely restricted by the ring.

Such a double axial fan with a ring between the blades is also known from US Pat. No. 2,790,596 A.

Another fan is the diagonal fan, where the housing and the fan blades are conically shaped so that the air exits diagonally rather than axially. In addition, the radial fan is also used, in which the air is drawn in axially, in particular parallel to the drive axle, and deflected by 90° by rotating the radial impeller and blown out radially.

Blades for working machines for realizing a volume flow and an increase in pressure are known, which have an aerodynamically favorable shape, in particular a profiled or wing-like shape. This shape is intended to ensure that the flow is driven and no turbulence occurs on the blades that negatively affects the efficiency of the working machine. Such blades are known for example from DE 42 20 960 A1.

EP 0 761 982 B2 discloses a fan having a hub, a plurality of first blades extending radially outward from the hub to a blade support member, and a plurality of second blades extending radially outward from the support member.

The problem with the known fans or blades is that they generally only effect one direction of flow and, in addition, in order to achieve good efficiency, they have to run at high speeds, which, however, is associated with a high noise level. The object of the invention is to provide wings that can be used flexibly, which enable the construction of a compact fan and cause a large air circulation.

The object is solved by the features of claim 1 . Preferred developments are described in the dependent claims.

The object is achieved according to the invention in that a fan wheel is provided with a centrally arranged hub, which can be connected to a rotary shaft of a motor and a plurality of blades extending radially from the hub, each blade having a first and a second through an at least partially helical blade Transition area has connected blade area and the first and second blade area are at different angles of inclination to the axis of rotation of the hub, so that the air currents caused by the blade areas flow in opposite directions. Due to the design of the fan wheel according to the invention, basically two volume flows are moved, which have opposite directions. The first vane region causes an airflow with a direction opposite to the airflow caused by the second vane region. This can achieve hot air removal and efficient cooling.

In a preferred embodiment, the plurality of vanes are equally spaced about the hub. Depending on the application, the number of blades can be varied, it being advantageous if the number of blades is odd, since this can prevent imbalance. At their end facing the hub, the blades have connecting means which can be reversibly fastened in corresponding receptacles in the hub. This considerably simplifies the assembly and disassembly of the blades. It is preferred that the vanes are a one piece molding of metal or plastic. In particular, it is advantageous that the blades are produced by a 3D printing process that uses metal or plastic as the starting material. Using 3D printing processes, blades adapted to an application can be produced in a simple and cost-effective manner.

In a preferred embodiment, the fan wheel is a one-piece molded part made of metal or plastic. The complete fan wheel with the blades and the hub can consist of a molded part that is produced using a tool or a 3D printing process.

The transition area located between the blade areas is designed at least partially helically and characterizes the middle area of the blades.

In one configuration, the blades taper radially, starting from the transition area, up to the blade end or the hub. This means that the free end of the blades and the end oriented towards the hub have the smallest width in this configuration. Other configurations are widened towards the free end of the blades.

It has proven advantageous that the first and second blade area have a curved profile with concave inner surfaces. The outer surfaces can be correspondingly convex in shape. This allows air currents to be created without creating significant turbulence. The concave inner surfaces of the blade areas are particularly oriented in the direction of rotation of the fan wheel. The inner and outer surfaces of the blades can also be flat.

Furthermore, the invention relates to a fan with at least one fan wheel as explained above. The already explained advantages and configurations of the Fan wheel are to be applied analogously to the fan. Due to its efficient work performance, the fan can be part of an electronic device, for example, despite its compact design. For this purpose, the at least one fan wheel can be connected to a rotary drive, in that the hub is connected to a corresponding rotary shaft of an electric drive.

It is preferred that the fan has a cylindrical housing with a rotating shaft that runs in the middle and can be connected to a rotary drive, and that the at least one fan wheel forms an outer circumference that is spaced apart from the inner wall of the housing. The at least one fan wheel is driven via the rotary shaft, which can be connected to a rotary drive, and causes two opposing air flows. The rotary drive can, for example, be in the form of an electric motor and can be part of the housing or can be fastened to it. In particular, the cylindrical housing has an opening through which air can circulate in and out again.

Furthermore, it is advantageous for the fan to have a pot-shaped or hollow-sphere-shaped housing with only one opening and a rotary shaft that runs in the middle and can be connected to a rotary drive. Due to the design of the at least one fan wheel, air is sucked in from outside the housing through the second blade areas and blown out of the housing again via the first blade areas arranged near the hub. This results in efficient cooling of the housing or the housing wall. In order to protect the fan wheel or to prevent objects from penetrating, the opening of the pot-shaped or hollow-sphere-shaped housing can be covered with a grid-shaped housing cover. This also serves as protection against accidental contact to avoid injuries caused by reaching into it.

The inventive design of the blades is a

Creates air circulation that is suitable for various applications. For example, the fan wheel or fan can be used for cooling. Furthermore, the air circulation can be used for various applications. In this regard, it has proven to be advantageous if UV-C LEDs are arranged spaced apart on the inner wall of the housing and aligned in such a way, advantageously in such a way that no UV-C radiation radiates over the edge of the cup-shaped or hollow-spherical housing. The UV-C LEDs emit UV-C radiation that kills bacteria and viruses. The main advantage of the design of the housing is that the UV-C radiation does not radiate beyond the edge of the housing, thus preventing damage to the skin or eyes, for example. An easy-to-implement device is provided to achieve disinfection of air through a continuous exchange. The preferred embodiment can be used in buildings or vehicles, for example. In particular, the fan can be designed as an assembly that can include not only the fan but also the housing with the integrated UVC LEDs, a drive, a protection against accidental contact, corresponding electrical lines, a power supply and a control unit.

The invention is explained in more detail below with reference to exemplary embodiments of the invention, which are illustrated in the drawing. Show it

FIG. 1 an embodiment of a preferred fan wheel, FIG. 2 designs of different blades (rotor blades), FIG. 3 an illustration of the air circulation caused by a fan wheel,

Figure 4A/4B is a perspective drawing of a preferred fan with housing,

Figure 5 shows a preferred fan with a housing cover and

FIG. 6 shows a preferred fan with UV-C LEDs. FIG. 1 shows an embodiment of a preferred fan wheel. The fan wheel 1 has a centrally arranged hub 2 which can be connected to a rotary shaft and from which a plurality of blades 3 extend radially outwards. The hub 2 can have a through hole or a blind hole, not shown, with which it can be connected to the rotary shaft of an electric rotary drive. The blades 3 can be produced in one piece as a molded part, for example using a 3D printing process. In order to connect the blades 3 to the hub 2, the blades 3 can have a connecting means at one end with which they can be reversibly fastened in corresponding receptacles in the hub 2. The connecting means can be designed, for example, as a latching or snap connection.

Furthermore, it can be advantageous if the complete fan wheel 1 including the blades 3 and hub 2 is provided in one piece as a molded part by a tooling or a 3D printing process. The fan wheel 1 or components thereof can be made of plastic or metal.

As can be seen clearly in FIG. 2, the blades 3 have a first blade area 4 (=R) arranged near the hub and a second blade area 5 (=L) arranged at the free end. Between the areas 4, 5 there is an at least partially and particularly preferably completely helical transition area 6 (=Z) which, depending on the design of the two blade areas 4, 5, is arranged shorter or longer or in the middle or outside the middle of the blade 3. Depending on the application, it can be advantageous to place the helically designed transition area 6 in such a way that an air flow flows inwards along the outside of a housing and is conveyed outwards in the middle (design L3, Z1, R1) - or in such a way that an air flow is sucked in centrally and discharged to the outside via a housing wall (configuration L1, Z1, R3). The helically designed transition region 6 can vary in length (Z1, Z2), also for production reasons, but is advantageously kept as short as possible. The length of the blade areas 4, 5, 6 of the embodiment according to the invention can be varied as required or as required.

Both blade areas 4, 5 are inclined to the axis of rotation of the hub 2, the inclination of the second blade area 5 to that of the first blade area 4 being different. This means that the second blade area 5 is at an angle of inclination to the first blade area 4. The angle of inclination between the two blade areas 4, 5 is advantageously approximately 90°.

Both blade areas 4, 5 have a curved aerodynamic profile with concave inner surfaces. The opposite outer surfaces of the two blade areas 4, 5 are in particular convex in shape. The concave inner surfaces of the blade areas 4, 5 are oriented in the direction of rotation when the fan wheel 1 rotates.

FIG. 3 shows an illustration of the air circulation caused by a fan wheel. The direction of rotation of the fan wheel 1 is indicated by an arrow and the flow directions of the air currents caused by the blade areas 4, 5 are also illustrated by arrows. The design of the blades 3 or the fan wheel 1 according to the invention has the effect that the first blade area 4 causes an air flow which has a direction which is opposite to the direction of the air flow caused by the second blade area 5 . As a result, essentially parallel counter-rotating air flows are caused, which basically bring about a continuous air flow, since the different pressures or flow speeds or temperatures between the outer and the inner air flow create a circulation. FIG. 3 shows an embodiment that shows the flow pattern for an application for cooling a centrally arranged component 7 illustrated by way of example. Here the cool air is drawn in from the outside in the middle and directed onto the hot component 7 . The heated air can be discharged to the outside.

FIG. 4A and FIG. 4B show an embodiment of a preferred fan with a fan wheel in a housing. The fan 8 has a pot-shaped or hemispherical housing 9 with an opening, which houses a fan wheel 1 . Depending on the application, there can also be several fan wheels in the housing 9 . The fan wheel 1 is arranged in the upper, wider area of the housing 9 and forms an outer peripheral surface which is slightly spaced from the inner wall of the housing 9 . The hub 2 of the fan wheel 1 is non-rotatably connected to a rotary shaft 10 arranged in the housing 9 or protruding through it, which in turn is driven by, for example, an electric motor (not shown) present in the housing 9 or attached to it. The direction of rotation of the fan wheel 1 and the direction of flow of the air are illustrated with arrows. For the sake of simplicity, FIG. 4B shows only one fan wheel with only two blades located opposite one another. The design of the blades has the effect that air is conveyed from the second blade areas 5 into the housing 9 and is blown out of the housing 9 again by the inner first blade areas 4 . As a result, the housing 9 can be cooled effectively.

Air is guided over the inside of the housing 9, which is equipped with the UV-C LEDs, for example, and is irradiated with UV-C, and the air that has been disinfected in this way is routed back out through the middle. It is advantageous to configure the speed in the low range in order to increase the residence time or the duration of exposure and thus the germicidal effect. Other advantages of the low speed: low power consumption, low noise level, no annoying draft. As shown by way of example in FIG. 5, the housing 9 can be provided with a housing cover 11 which is designed to be air-permeable. In this case, the housing cover 11 can be designed, for example, in the form of a lattice, ring or in some other way. On the one hand, the housing cover 11 prevents the fan wheel from being damaged. On the other hand, the risk of injury is minimized.

A design of a fan with UV-C LEDs is shown schematically in FIG. The pot-shaped fan 8 has a centrally arranged rotary shaft 10 which can be connected in a torque-proof manner to a hub of a fan wheel. In the fan 8, more precisely on its inner wall, UV-C LEDs 12 are arranged at a distance from one another. Due to the design of the blades, air is sucked into the housing 9, where it circulates past the inner wall and is conveyed out of the housing 9 again through the first blade areas. The contact time between air and UV-C LEDs 12 can be influenced by the speed of the fan wheel, sufficient air circulating even when the fan wheel rotates slowly. The air moved by the fan 8 is sterilized by the UV-C LEDs 12, ie bacteria, viruses or other germs present in the air are killed by the UV radiation. The fan 8 can be easily integrated into, for example, equipment, furniture, walls, floors, or ceilings in a vehicle or building, or placed as an independent device in, for example, a vehicle or building.

The low power consumption enables mains-independent operation using batteries, rechargeable batteries or solar panels.

Claims

PATENT CLAIMS Fan wheel (1) with a centrally arranged hub (2) which can be connected to a rotary shaft (10) of a motor and a plurality of blades (3) extending radially from the hub (2), each blade (3) having a first and has a second blade area (4, 5) connected by an at least partially helical transition area (6) and the first and second blade area (4, 5) are at different angles of inclination to the axis of rotation of the hub (2), so that the blade areas ( 4, 5) caused air currents to flow in opposite directions. Fan wheel (1) according to claim 1, characterized in that the plurality of blades (3) spaced equally from each other around the hub (2) are arranged. Fan wheel (1) according to claim 1 or 2, characterized in that the blades (3) are a one-piece molded part made of metal or plastic. Fan wheel (1) according to one of the preceding claims 1 or 2, characterized in that the fan wheel (1) is a one-piece molded part made of metal or plastic. Fan wheel (1) according to any one of the preceding claims, characterized in that the blades (3) at their the hub (2) end facing connecting means which are reversibly fastened in corresponding receptacles in the hub (2). Fan wheel (1) according to one of the preceding claims, characterized in that the blades (3) taper starting from the transition area (6) radially to the blade end or to the hub (2). Fan wheel (1) according to one of the preceding claims, characterized in that the blade areas (4, 5) have a different length. Fan wheel (1) according to one of the preceding claims, characterized in that the first and second blade area (4, 5) have a curved profile with concave inner surfaces. Fan wheel (1) according to one of the preceding claims, characterized in that the concave inner surfaces of the blade areas (4, 5) are oriented in the direction of rotation of the fan wheel (1). Fan wheel (1) according to any one of the preceding claims, characterized in that the angle of inclination between the first and second blade area (4, 5) is preferably 90 °. Fan (8) with at least one fan wheel (1) according to one or more of the preceding claims. Fan (8) according to Claim 11, characterized in that the fan (8) has a cylindrical housing (9) with a rotating shaft (10) running in the middle and which can be connected to a rotary drive, and the at least one fan wheel (1) forms an outer circumference, which is spaced from the inner wall of the housing (9). Fan (8) according to any one of claims 11 or 12, characterized in that the fan (8) is a pot-shaped or has a hollow spherical housing (9) with an opening and a rotary shaft (10) running in the middle and which can be connected to a rotary drive. Fan (8) according to one of the preceding claims 10 to 13, characterized in that on the inner wall of the housing (9) UV-C LEDs (12) are arranged at a distance and aligned in such a way that no IIV-C radiation over the edge of the pot-shaped or hollow spherical housing (9) radiates. Fan (8) according to one of the preceding claims 13 or 14, characterized in that the opening of the pot-shaped or hollow spherical housing (9) is covered with a grid-shaped housing cover (11).