Patent Application
20210372426
This application claims priority to German Patent Application No. 102020114389.3 filed May 28, 2020. The entire disclosure of the above application is incorporated herein by reference.
The disclosure relates to an impeller with a seamless connection of the impeller blades to a disc body.
Impellers with impeller blades arranged between a bottom disc and a cover disc are known from the prior art. The impeller blades are connected in an abutting manner to the bottom disc and/or cover disc. Such impellers are disclosed in printed publication EP 2218917 B1, for example. The contours of the cover disc and/or bottom disc are implemented in different designs. However, there is always a notch at the abutting point of a connection between the impeller blades and the bottom disc and cover disc.
This notch is a critical area of the fan impellers both rheologically and mechanically, since, on the one hand, undesirable eddies form here, that have a negative effect on efficiency and noise generation, and, on the other hand, stresses in the glass wheels limit speed stability.
It is therefore the object of the disclosure to provide an impeller that is improved in terms of efficiency, noise generation, and speed stability.
This object is achieved by an impeller comprising impeller blades arranged around a rotation axis of the impeller. Integral, seamless, and notch-free transitions are formed into a disc body on at least one of their two axial sides. The disc body connects the impeller blades in the circumferential direction around the rotation axis. Covering portions, between the impeller blades, determine flow channels of the impeller.
According to the disclosure, an impeller has impeller blades that are arranged in a blade ring around a rotation axis of the impeller. The impeller blades form integral, seamless, and notch-free transitions into a disc body on at least one of their two axial sides. The disc body connects the impeller blades in the circumferential direction around the rotation axis. Covers portions, between the impeller blades, define the flow channels of the impeller.
The disc body thus simulates the cover disc that is known from the prior art, or optionally also the bottom disc. The impeller blades merge into the disc body integrally without a point of connection. Of course, it can also be viewed in such a way that the disc body merges accordingly into the impeller blades. Although there are one-piece impellers in the prior art, the connection between the impeller blades and the cover disc and the bottom disc each have a notch. Accordingly, no seamless transition is formed. In contrast, the disclosure determines a course between the impeller blades and the disc body(s) where no points of connection are provided, but rather seamless, notch-free transitions.
In one advantageous embodiment, in the impeller, when viewed from the side, the transitions from the impeller blades to the disc bodies are each rounded in an arc shape. Such a configuration is particularly favorable in terms of the efficiency, the noise generation, and the speed stability of the impeller.
Also advantageous in the case of the impeller is a configuration where, when the impeller is viewed from the side, the disc body has an elliptical contour in the portions between the impeller blades together with the transitions. In viewing the impeller from the side and looking at two adjacent impeller blades with the disc body connecting them, the two transitions between the impeller blades and the disc body portion, between the impeller blades, form a half-ellipse. The impeller blades then extend further axially to the oppositely situated disc body.
The disc body is preferably designed so that, on one side, it forms an axial inlet opening of the impeller and delimits a radial exhaust opening of the impeller. Thus, the disc body also assumes the function of the cover discs known from the prior art.
As described above, the disc body can simulate the bottom disc and/or cover disc known from the prior art. However, it is an advantageous embodiment of the impeller where the disc body simulates the cover disc and the impeller comprises a bottom disc with or forming a hub of the impeller. The hub forms the interface to the motor. The impeller blades are attached to or formed on the bottom disc.
In the case of the impeller, one further-developing embodiment makes a provision where the impeller blades each extend over a blade length from a blade leading edge to a blade trailing edge. The impeller blades are divided into a front portion, a rear portion and a transition portion. The front portion extends from the front edge of the blade toward the rear edge of the blade. The rear portion extends from the rear edge of the blade toward the front edge of the blade. The transition portion forms a transition between the front portion and the rear portion. The impeller blades in the front portion and the rear portion are embodied to be oppositely curved over the course between the disc body and the bottom disc.
In a variant of this impeller, the impeller blades in the front portion and the rear portion are embodied so as to be opposed, particularly curved three-dimensionally, across from a shortest connection between the disc body and the bottom disc.
In an advantageous embodiment, the impeller blades are curved in an arc shape. The arc-shaped path preferably has a constant or substantially constant arc radius.
One embodiment of the impeller is also advantageous where the front portion extends over at least 5%, preferably over 10-40% of the blade length. Similarly, it is advantageous where the rear portion extend over at least 5%, preferably over 10-40% of the blade length.
In the case of the impeller, the transition portion connects the front portion and the rear portion. In particular, the transition takes place in a steady progression along the length of the blade. The alternation of the curvature of the front portion and the rear portion, the opposing curvature in the front portion and the rear portion, is preferably implemented in the transition portion by a uniform progression.
One exemplary advantageous embodiment of the impeller, in terms of rheology, makes a provision where the front portion is curved toward the rotation axis and the rear portion is curved away from the rotation axis.
Furthermore, in one embodiment, the impeller bottom disc has an elliptical cross section on its radial outer edge portion. Thus, its radial outer edge runs parallel or substantially parallel to the rotation axis.
In an advantageous embodiment of the impeller, the impeller blades extend radially outward and around the rotation axis from the blade leading edge to the blade trailing edge. The impeller blades are thus curved forward or backward relative to the direction of rotation.
The impeller according to the disclosure is embodied particularly as a radial impeller or diagonal impeller. The impeller is preferably made of one piece, particularly of plastic. However, the use of multi-part impellers made of metal, particularly sheet metal, is also possible.
Other advantageous further developed embodiments of the disclosure are disclosed in the dependent claims and/or are described in more detail through the drawings in conjunction with the description of the preferred embodiment of the disclosure.
Other advantageous developments of the disclosure are characterized in the subclaims and/or depicted in greater detail below together with the description of the preferred embodiment of the disclosure with reference to the figures. In the drawing:
The transitions 7, from the impeller blades 2 to the integrally connected disc body 3, run seamlessly and without notches, with an arcuate contour of the blade trailing edge 6, being curved radially outward from the rotation axis RA, flowing over a rounded portion into the disc body 3. In the side view of the impeller 1 according to
The shape of the impeller blades 2 on the disc body 3 is repeated on all the impeller blades 2. Thus, the portions 9 between the individual impeller blades 2 together with the respective transitions 7 each form an elliptical contour in the form of a half ellipse, as can also be seen clearly in the side view according to
The impeller 1 also has the bottom disc 4 where the impeller blades are abuttingly joined in one piece along the connection 18. The impeller blades 2 run into the bottom disc at an angle relative to the rotation axis RA, see
The transition portion 11 has a steady progression along the blade length. Thus, the change in direction of the curvature of the impeller blades 2 from the front portion 10 to the rear portion 12 takes place uniformly over the entire axial height of the impeller blades 2 and without a step. According to
In the embodiment shown in
The disc body 3 is specially shaped in all exemplary embodiments. When viewed from radially inside to radially outside, it has a first portion 21 that extends axially parallel to the rotation axis RA and defines the intake opening 25. As seen in lateral cross section, this is followed by an arcuately curved progression that covers the impeller blades 2 and merges again in the radial outer edge portion 23 like a winglet in the axial direction parallel to the rotation axis RA. The disc body 3 thus undergoes a complete axial change of direction over its radial extension. The impeller blades 2 and the blade body 3 end together radially on the outside. Thus, the disc body 3 neither protrudes beyond the impeller blades 2 nor is it set back relative thereto.
The disclosure is not limited in its execution to the abovementioned preferred exemplary embodiments shown in the figures. On the contrary, the described variants are also included, particularly including the connection of the bottom disc as a disc body to the impeller blades 2 appropriately with transitions 7.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 114 389.3 | May 2020 | DE | national |
