DE102015004200A1 - Radial fan with fan blades arranged on a base body - Google Patents

Abstract

Radial fan with arranged on a base body fan blades, each fan blade has an edge, in particular trailing edge, having at least one serrated edge portion.

Description

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

It is well known that a radial fan promotes axially incoming air in the radial direction.

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

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 arranged on a base fan blades,
wherein each fan blade has an edge, in particular one or the radial outer edge, which has at least one serrated edge portion.

The advantage here is that the fan is easy to manufacture, 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 serrated edge portion can be arranged at large radial distances, where high flow velocities can be achieved. Thus, the beneficial effect is enhanced.

Since the relative speed at the fan towards the environment increases with increasing radial distance, the jagged contour here works effectively.

In an advantageous embodiment, the serrated shape of the edge portion is executed by concatenated in the edge direction concave recesses. The advantage here is that the backflow can be reduced and the noise can be reduced.

In an advantageous embodiment, in each case a convex, rounded transition region of the fan blade is arranged in the edge direction between in each case two adjacent concave recesses. The advantage here is that the flow is even more laminar, that is less turbulent than in sharp-edged transition. In addition, the risk of injury when touched by people 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 a simple production is possible and a high efficiency in air conveying. In addition, the noise is very low.

In an advantageous embodiment, the circle radius of the concave recess is at least five times, in particular at least ten times greater, than the circle radius of the convex transition. The advantage here is that the recesses are more pronounced so the surveys, so transitions.

In an advantageous embodiment, the serrated edge portion extends over a portion of the leading edge of the fan blade, over the outer edge of the fan blade and at least a portion of the trailing edge of the fan blade. The advantage here is that the outer edge is executed jagged. Thus, the high flow rate region is jagged and thus forms less noise.

At the serrated edge portion, in particular at the portion of the leading edge, a backflow occurs. Thus, the serrated design counteracts the return flow and thus reduces the backflow losses. As a result, the efficiency of the fan is increased.

In an advantageous embodiment, the radial fan on a base body on which the fan blades are arranged,
the portion of the leading edge of the fan blade, the outer edge of the fan blade and / or the at least a portion of the trailing edge of the fan blade protrudes radially beyond the base body. The advantage here is that a simple production as injection molding is executable.

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 is effective as a radial fan and the fan blades are each just executable, this respective level containing the rotor shaft axis.

In an advantageous embodiment, the outer edge is designed jagged and extends in the axial direction. The advantage here is that the high flow rate range is designed jagged. Therefore, the backflow of the fan is reduced, thus achieving high efficiency.

In an advantageous embodiment, the serrated portion of the leading edge and / or the serrated portion of the trailing edge extends in a direction that is at least 30 ° to the direction of extension of the outer edge. The advantage here is that as long as possible, A high flow velocity exposed areas of the edge of the fan blade are jagged executable and thus the losses can be reduced.

In an advantageous embodiment, with increasing radial distance, each fan blade has an increasing axial width. The advantage here is that the delivery rate is high.

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

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

In an advantageous embodiment of the main body including fan blades is manufactured as a plastic injection molded part. The advantage here is that a simple production is executable.

In an advantageous embodiment, the fan blades of the radial fan are all the same running and / or are equally spaced from each other in the circumferential direction. The advantage here is that a simple production is executable.

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

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination possibilities of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or posing by comparison with the prior art task arise.

The invention will now be explained in more detail with reference to figures:

In the 1 is an inventive radial fan with fan blades 2 shown.

In the 2 an associated cross section is shown.

In the radial fan are the fan blades 2 on a base body 1 arranged. Preferably, fan blades 2 and basic body 1 in one piece, so one piece, executed. Particularly suitable is the production as a plastic injection molded part.

The radial fan is provided for non-rotatable connection with a rotor shaft of an electric motor.

The main body 1 has against the axial direction, ie to the rear, an increasing radial distance. At the axial front of the body 1 are the fan blades 2 arranged, in particular integrally formed.

Preferably, the main body 1 conical or at least has a conical section, in which the fan blades 2 at the base body 1 are attached.

The fan blades 2 are regularly spaced from one another in the circumferential direction. To each adjacent in the circumferential direction fan blades 2 So each fan blade has 2 the same distance.

Preferably, all fan blades 2 similarly shaped.

As the radial distance increases, each fan blade points 2 an increasing axial width.

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

Upon rotation of the radial fan, the air flows against the axial direction and is conveyed in the radial direction.

At a portion of the edge of each fan blade 2 is an owl profile formed. This section extends over a section on the axial leading edge 3 of the fan blade 2 over the radial outer edge 4 to the axial trailing edge 5 ,

This is the trailing edge 5 and also the outer edge 4 radially over the body 1 out.

The owl profile consists of round recesses, which adjoin one another at the respective edge in the edge direction. The respective recess protrudes into the fan blade 2 into it.

Each of the recesses is preferably bounded circular, wherein the transition is performed rounded from the boundary of a recess to the next adjacent recess. Thus, each recess is concave; the transition to the next adjacent recess but convex.

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

In mathematical terms, the term "circular" refers to a cross section through the fan blade 2 wherein the cutting plane includes the rotor shaft axis. In reality, in the implementation of the invention, the term "circular" describes a circular cylindrical portion, the cylinder length of the wall thickness of the fan blade 2 equivalent. Likewise, the transition is a cylinder section, the cylinder length of the wall thickness of the fan blade 2 equivalent.

By means of the described Eulenprofils not only the noise is damped but also reduces the backflowing air flow. Therefore, a lower power loss during operation of the fan can be achieved.

The return flow of the radial fan takes place at the serrated front edge 3 of the fan blade. The spikes reduce the backflow losses and thus increase the efficiency.

LIST OF REFERENCE NUMBERS

1

Basic body, in particular conical

2

fan blades

3

leading edge

4

outer edge

5

trailing edge

Claims (15)

Radial fan with fan blades arranged on a base body, characterized in that each fan blade has an edge, in particular a radial outer edge region, which has at least one serrated edge portion. Radial fan according to claim 1, characterized in that the serrated formation of the edge portion is carried out by means of concatenated concave recesses in the edge direction, Radial fan according to at least one of the preceding claims, characterized in that in the edge direction between each two adjacent concave recesses in each case a convex, rounded transition region of the fan blade is arranged. Radial fan according to at least one of the preceding claims, characterized in that the respective concave recess running circular and / or the respective convex transition is circular. Radial fan according to at least one of the preceding claims, characterized in that the circle radius of the concave recess at least five times, in particular at least ten times greater, than the radius of the circle of the convex transition. Radial fan according to at least one of the preceding claims, characterized in that the jagged running edge portion extends over a portion of the leading edge of the fan blade, over the outer edge of the fan blade and at least a portion of the trailing edge of the fan blade, in particular wherein the jagged executed edge portion, in particular the section of the leading edge, a backflow occurs. Radial fan according to at least one of the preceding claims, characterized in that the radial fan has a base body on which the fan blades are arranged, the portion of the leading edge of the fan blade, the outer edge of the fan blade and / or the at least a portion of the trailing edge of the fan blade radially over the Base body protrudes. Radial fan according to at least one of the preceding claims, characterized in that the base body 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 is designed jagged and extending in the axial direction. Radial fan according to at least one of the preceding claims, characterized in that the serrated portion of the leading edge and / or the serrated portion of the trailing edge extends in a direction which is at least 30 ° to the extension direction of the outer edge. Radial fan according to at least one of the preceding claims, characterized in that with increasing radial distance each fan blade has an increasing axial width. Radial fan according to at least one of the preceding claims, characterized in that the base body opposite to the axial direction has an increasing maximum radial distance, in particular wherein the fan blades are arranged, in particular molded, on the axial front side of the base body. Radial fan according to at least one of the preceding claims, characterized in that the radial distance difference between the main body and outer edge of the respective fan blade increases counter to the axial direction. Radial fan according to at least one of the preceding claims, characterized in that the base body including 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 of the radial fan are all of a similar design and / or evenly spaced from each other in the circumferential direction and / or that each fan blade is flat.

Images