DE102015004200B4 - Radial fan with fan blades arranged on a base body - Google Patents

Abstract

Radial fan with fan blades arranged on a base body (1), each fan blade (2) having an edge, in particular a radial outer edge region, which has at least one serrated edge section. characterized in that the serrated edge section extends over a section of the front edge (3) of the fan blade (2), over the outer edge (4) of the fan blade (2) and at least a section of the rear edge (5) of the fan blade (2), with a backflow occurring at the serrated edge section, in particular at the section of the front edge (3), the radial fan having a base body (1) on which the fan blades (2) are arranged, the section of the front edge (3) of the fan blade (2), the outer edge (4) of the fan blade (2) and/or the at least one section of the rear edge (5) of the fan blade (2) protruding radially beyond the base body (1). the base body (1) has an increasing maximum Radial distance, wherein the fan blades (2) are arranged, in particular formed, on the axial front side of the base body (1).

Description

The invention relates to a radial fan with fan blades arranged on a base body.

It is well known that a radial fan moves axially flowing air in a radial direction.

From the DE 31 37 554 A1 The closest prior art is a centrifugal fan.

The invention is therefore based on the object of developing a fan with higher efficiency in a simple manner.

According to the invention, the object is achieved in the radial fan according to the features specified in claim 1.

Important features of the invention in the radial fan with fan blades arranged on a base body,
wherein each fan blade has an edge, in particular one or the radial outer edge, which has at least one jagged edge section.

The advantage here is that the fan is easy to produce, for example as an injection molded part, and causes less noise and, in addition, a higher efficiency of the air conveying effect can be achieved. The jagged edge section can be arranged at large radial distances where high flow velocities can be achieved. The beneficial effect is therefore increased.

Since the relative speed of the fan to the environment increases with increasing radial distance, the jagged contour is effective here.

In an advantageous embodiment, the jagged shape of the edge section is carried out by means of concave recesses lined up in the edge direction. The advantage here is that the backflow can be reduced and the noise can be reduced.

In an advantageous design, a convex, rounded transition area of the fan blade is arranged in the edge direction between two adjacent concave recesses. The advantage here is that the flow is even more laminar, i.e. less turbulent, than with a sharp-edged transition. In addition, the risk of injury when people touch it is reduced.

In an advantageous embodiment, the respective concave recess is circular and/or the respective convex transition is circular. The advantage here is that it is easy to manufacture and the air conveying is highly efficient. In addition, the noise level is very low.

In an advantageous embodiment, the circular radius of the concave recess is at least five times, in particular at least ten times, larger than the circular radius of the convex transition. The advantage here is that the recesses are more pronounced than the elevations, i.e. transitions.

In an advantageous embodiment, the jagged edge section extends over a section of the front edge of the fan blade, over the outer edge of the fan blade and at least a section of the rear edge of the fan blade. The advantage is that the outer edge is jagged. The area of high flow velocity is therefore jagged and therefore produces less noise.

A backflow occurs at the jagged edge section, in particular at the section of the front edge. The serrated design therefore counteracts the backflow and thus reduces the backflow losses. This increases the efficiency of the fan.

In an advantageous embodiment, the radial fan has a base body on which the fan blades are arranged,
the section of the front edge of the fan blade, the outer edge of the fan blade and/or at least one section of the rear edge of the fan blade protrudes radially beyond the base body. The advantage here is that it can be easily manufactured using injection molding.

In an advantageous embodiment, the base body has at least one conical section or is designed as a cone. The advantage here is that the fan works as a radial fan and the fan blades can each be designed to be flat, with this respective plane containing the rotor shaft axis.

In an advantageous embodiment, the outer edge is jagged and extends in the axial direction. The advantage here is that the area of high flow velocity is jagged. Therefore, the backflow of the fan is reduced and a high level of efficiency can be achieved.

In an advantageous embodiment, the jagged section of the front edge and/or the jagged section of the rear edge extends in a direction that is at least 30° to the extension direction of the outer edge. The advantage here is that areas of the edge of the fan blade that are exposed to high flow speeds can be designed to be jagged for as long as possible and thus the losses can be reduced.

In an advantageous design, each fan blade has an increasing axial width as the radial distance increases. The advantage here is that the air flow rate is high.

In an advantageous embodiment, the base body has an increasing maximum radial distance opposite to the axial direction,
in particular, the fan blades are arranged, in particular molded onto, the axial front side of the base body. The advantage here is that the base body, in conjunction with the fan blades, generates a high conveying effect.

In an advantageous embodiment, the radial distance difference between the base body and the outer edge of the respective fan blade increases in the opposite direction to the axial direction. The advantage here is that the funding effect is again high.

In an advantageous embodiment, the base body including fan blades is manufactured as a plastic injection molded part. The advantage here is that simple production can be carried out.

In an advantageous embodiment, the fan blades of the radial fan are all designed in the same way and/or are evenly spaced from one another in the circumferential direction. The advantage here is that simple production can be carried out.

In an advantageous design, each fan blade is flat. The advantage here is that the conveying effect in the radial direction is maintained regardless of the direction of rotation of the fan.

Further advantages arise from the subclaims. The invention is not limited to the combination of features in the claims. The person skilled in the art will recognize further useful combination options of claims and/or individual claim features and/or features of the description and/or the figures, in particular from the task and/or the task arising from comparison with the prior art.

• In der 1 ist ein erfindungsgemäßer Radiallüfter mit Lüfterflügeln 2 gezeigt.
• In der 2 ist ein zugehöriger Querschnitt gezeigt.

The invention will now be explained in more detail using illustrations:

• In the 1 a radial fan according to the invention with fan blades 2 is shown.
• In the 2 an associated cross section is shown.

In the case of the radial fan, the fan blades 2 are arranged on a base body 1. Fan blades 2 and base body 1 are preferably designed in one piece, i.e. in one piece. Production as a plastic injection molded part is particularly suitable.

The radial fan is designed for a rotationally fixed connection to a rotor shaft of an electric motor.

The base body 1 has an increasing radial distance opposite to the axial direction, i.e. towards the rear. The fan blades 2 are arranged, in particular molded onto, the axial front side of the base body 1.

The base body 1 is preferably conical or has at least one conical section in which the fan blades 2 are attached to the base body 1.

The fan blades 2 are regularly spaced apart from one another in the circumferential direction. Each fan blade 2 is therefore at the same distance from the fan blade 2 closest to it in the circumferential direction.

Preferably, all fan blades 2 are shaped similarly.

With increasing radial distance, each fan blade 2 has an increasing axial width.

The wall thickness of each fan blade 2 is preferably constant.

When the radial fan rotates, the air flows against the axial direction and is conveyed in the radial direction.

An owl profile is formed on a section of the edge of each fan blade 2. This section extends over a section on the axial front edge 3 of the fan blade 2 over the radial outer edge 4 to the axial rear edge 5.

The rear edge 5 and also the outer edge 4 protrude radially beyond the base body 1.

The owl profile consists of round recesses, which are located on each edge in Kan line up in the direction of tension. The respective recess protrudes into the fan blade 2.

Each of the recesses preferably has a circular edge, with the transition from the edge of one recess to the next adjacent recess being rounded. Each recess is therefore concave, but the transition to the next adjacent recess is convex.

The magnitude of the radius of the convex transition is at least ten times smaller than the magnitude of the radius of the concave recess.

Viewed mathematically precisely, the term “circular” refers to a cross section through the fan blade 2, where the cutting plane includes the rotor shaft axis. In reality, when implementing the invention, the term “circular” describes a circular cylindrical section, the cylinder length of which corresponds to the wall thickness of the fan blade 2. The transition is also a cylinder section, the cylinder length of which corresponds to the wall thickness of the fan blade 2.

Using the owl profile described, not only are the noises dampened but the backflow of air is also reduced. This also means that less power loss can be achieved when the fan is operating.

The return flow of the radial fan occurs at the serrated front edge 3 of the fan blade. The serrations reduce the return flow losses and thus increase the efficiency.

Reference symbol list

1

Basic body, especially conical

2

Fan blades

3

leading edge

4

Outer edge

5

trailing edge

Claims (12)

Radial fan with fan blades arranged on a base body (1), each fan blade (2) having an edge, in particular a radial outer edge region, which has at least one jagged edge section. characterized in that the jagged edge section extends over a section of the front edge (3) of the fan blade (2), over the outer edge (4) of the fan blade (2) and at least a section of the rear edge (5) of the fan blade (2), wherein a backflow occurs on the jagged edge section, in particular on the section of the front edge (3), the radial fan having a base body (1) on which the fan blades (2) are arranged, the section of the front edge (3) of Fan blade (2), the outer edge (4) of the fan blade (2) and / or the at least one section of the rear edge (5) of the fan blade (2) protrudes radially beyond the base body (1). wherein the base body (1) has an increasing maximum radial distance counter to the axial direction, the fan blades (2) being arranged, in particular integrally formed, on the axial front side of the base body (1). Radial fan after Claim 1 , characterized in that the jagged shape of the edge section is carried out by means of concave recesses lined up in the edge direction, Radial fan according to at least one of the preceding claims, characterized in that a convex, rounded transition region of the fan blade (2) is arranged in the edge direction between each two adjacent concave recesses. Radial fan according to at least one of the preceding claims, characterized in that the respective concave recess is designed to be circular and/or the respective convex transition is designed to be circular. Radial fan according to at least one of the preceding claims, characterized in that the radius of the concave recess is at least five times, in particular at least ten times, larger than the radius of the convex transition. Radial fan according to at least one of the preceding claims, characterized in that the base body (1) has at least one conical section or is designed as a cone. Radial fan according to at least one of the preceding claims, characterized in that the outer edge (4) is jagged and extends in the axial direction. Radial fan according to at least one of the preceding claims, characterized in that the jagged section of the front edge (3) and/or the jagged led section of the rear edge (5) extends in a direction that has an angle of at least 30 ° to the direction of extension of the outer edge (4). Radial fan according to at least one of the preceding claims, characterized in that as the radial distance increases, each fan blade (2) has an increasing axial width. Radial fan according to at least one of the preceding claims, characterized in that the radial distance difference between the base body (1) and the outer edge (4) of the respective fan blade (2) increases counter to the axial direction. Radial fan according to at least one of the preceding claims, characterized in that the base body (1) together with fan blades is manufactured as a plastic injection-molded part. Radial fan according to at least one of the preceding claims, characterized in that the fan blades (2) of the radial fan are all designed in the same way and/or are evenly spaced from one another in the circumferential direction and/or that each fan blade (2) is designed to be flat.

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