Impeller with a seamless connection of the impeller blades to a disc body

Abstract

An impeller with impeller blades arranged around a rotational 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 rotational axis. Covering portions, between the impeller blades, determine the flow channels of the impeller.

Claims

1. An impeller comprising: a plurality of impeller blades, each impeller blade extending radially outward from a rotation axis of the impeller and arranged in a circumferential direction around the rotation axis of the impeller, each impeller blade including a leading edge and a trailing edge; a disc body connecting each impeller blade in the circumferential direction around the rotation axis of the impeller; a plurality of integral, seamless, and notch-free transitions, each transition provided at the trailing edge of the respective impeller blade, each transition rounded in a convex arc shape that extends from the disc body and continues along an arching or curvature of the trailing edge; and a plurality of covering portions formed between the transitions of adjacent impeller blades, each covering portion defining a flow channel of the impeller, wherein a radially outer portion of the disc body has an elliptical contour formed by each covering portion between adjacent impeller blades, the elliptical contour including the respective transition.

2. The impeller as set forth in claim 1, wherein the disc body forms an axial inlet opening of the impeller and delimits a radial blowout opening of the impeller.

3. The impeller as set forth in claim 1, wherein the impeller has a bottom disc forming a hub of the impeller, the hub forming an interface to a motor, wherein each impeller blade is attached to or formed on the bottom disc.

4. The impeller according to claim 3, wherein the disc body faces the bottom disc.

5. The impeller as set forth in claim 3, wherein each impeller blade extends over a blade length from the leading edge to the trailing edge, such that each impeller blade includes a front portion, a rear portion, and a transition portion, wherein the front portion extends from the leading edge toward the trailing edge, the rear portion, starting from the trailing edge, extends toward the leading edge, and the transition portion is formed between the front portion and the rear portion, and wherein the front portion and the rear portion are oppositely curved over a course between the disc body and the bottom disc.

6. The impeller as set forth in claim 5, wherein the front portion and the rear portion are embodied so as to be curved in opposite directions across a connection between the disc body and the bottom disc.

7. The impeller as set forth in claim 5, wherein each impeller blade is curved in an arc shape that extends between the disc body and the bottom disc.

8. The impeller as set forth in claim 5, wherein the front portion extends over at least 5%, preferably between 10-40% of the blade length.

9. The impeller as set forth in claim 5, wherein the rear portion extends over at least 5%, preferably between 10-40% of the blade length.

10. The impeller as set forth in claim 5, wherein the transition portion has a continuous progression along the blade length.

11. The impeller as set forth in claim 5, wherein the front portion is curved toward the rotation axis and the rear portion is curved away from the rotation axis.

12. The impeller as set forth in claim 3, wherein a radially outer portion of the bottom disc has an elliptical cross section, such that an edge of the radially outer portion of the bottom disc extends parallel or substantially parallel to the rotation axis.

13. The impeller as set forth in claim 1, wherein a curved V-shaped axial notch is formed on the disc body on an inlet side of the impeller above the trailing edge of the respective impeller blade.

14. The impeller as set forth in claim 1, wherein the impeller is a one-piece radial impeller or diagonal impeller.

Description

DRAWINGS

(1) 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:

(2) FIG. 1 is a perspective view of an impeller in a first exemplary embodiment.

(3) FIG. 2 is a side view of the impeller of FIG. 1.

(4) FIG. 3 is a perspective view of an impeller of a second exemplary embodiment.

(5) FIG. 4 is a side view of the impeller of FIG. 2.

(6) FIG. 5 is a perspective cross-sectional view of an impeller in another exemplary embodiment.

(7) FIG. 6 is a further perspective cross-sectional view of an impeller in another exemplary embodiment.

DETAILED DESCRIPTION

(8) FIGS. 1 and 2 show a first embodiment of an impeller 1 that is embodied as a radial impeller with a plurality of impeller blades 2 arranged in a blade ring around the rotation axis RA. The impeller blades 2 are curved in the circumferential direction around the rotation axis RA from the hub, starting from their respective blade leading edge 5 to their respective blade trailing edge 6, and extend radially outward over their respective blade length. On the axial inlet side, the impeller blades 2 each form integral, seamless and notch-free transitions 7 into the disc body 3. The transitions 7 connect the impeller blades 2 in the circumferential direction around the rotation axis RA in the manner of a cover disc and covers the portions 9 between the impeller blades 2. The disc body 3 forms the axial intake opening 25. The edge of the intake opening 25 is formed by a portion of the disc body 3 that extends parallel to the rotation axis RA. Flow channels 80 of the impeller 1 are defined between the respective impeller blades 2 and the disc body 3, forming radial blowout openings.

(9) 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 FIG. 2, it is easy to see how the transitions 7 are each rounded in an arc shape and continue a arching or curvature of the blade trailing edge 6. In this embodiment, the convex arching or curvature of the impeller blades 2 radially outward remains along the respective blade length from the blade leading edge 5 to the blade trailing edge 6, with respect to the rotation axis, in the same direction. Only the extent of the arching or curvature can change along the length of the blade.

(10) 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 FIG. 2. As a result, curved V-shaped axial notches 19 are formed on the disc body 3 on the inlet side.

(11) 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 FIG. 2. In its radial outer edge portion 22, the bottom disc 4 has an elliptical cross section and changes from an extension radially outward to an axial extension. Thus, the radial outer edge of the bottom disc 4 runs parallel or substantially parallel to the rotation axis RA.

(12) FIGS. 3 and 4 show a second exemplary embodiment where the features identical to those in the embodiment according to FIG. 1 are not repeated again but are regarded as having been disclosed through the present reference. The same reference symbols denote the same features. In contrast to the design of the impeller 1 from FIGS. 1 and 2, the arching or curvature of the impeller blades 2 is situated opposite the rotation axis RA, convexly oriented radially inward to the rotation axis. In this embodiment, the convex arching or curvature radially inward of the impeller blades 2 remains along the respective blade length from the blade leading edge 5 to the blade trailing edge 6, relative to the rotation axis RA, in the same direction. Only the extent of the arching or curvature can change along the length of the blade.

(13) FIG. 5 shows another exemplary embodiment of an impeller 1 in a lateral sectional view. The shape of the disc body 3 and the transitions 7, from the impeller blades 2 to the disc body 3, correspond to those of the exemplary embodiments in FIGS. 1-4. However, the arching or curvature of the impeller blades 2 differs from the rotation axis RA. According to FIG. 5, the impeller blades 2 at the blade leading edge 5 and the blade trailing edge 6 are embodied so as to be oppositely curved three-dimensionally over the course from the disc body 3 to the bottom disc 4. More precisely, the impeller blades 2 are divided into a front portion 10, rear portion 12 and transition portion 11. The front portion 10 extends from the blade leading edge 5 toward the blade trailing edge 6. The rear portion 12 extends from the blade trailing edge 6 toward the blade leading edge 5. The transition portion 11 forms a transition between the front portion 10 and the rear portion 12. The front portion 10 and the rear portion 12 each extend over approximately 30% of the total blade length. The transition portion 11 between them occupies the remainder.

(14) 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 FIG. 5, the impeller blades 2 are curved in the front portion 10 and the rear portion 12 in such a way that the impeller blades 2 in the front portion 10 and the rear portion 12 are curved three-dimensionally opposite a shortest connection between the disc body 3 and the bottom disc 4.

(15) In the embodiment shown in FIG. 5, the curvature occurs away from the rotation axis in the front portion 10 and toward the rotation axis in the rear portion 12. In the exemplary embodiment according to FIG. 6, it is exactly the opposite. The impeller blades 2 are curved toward the rotation axis in the front portion 10 and away from the rotation axis in the rear portion 12. The other features correspond to those from FIG. 5. The respective shortest connection between the bottom disc 4 and the disc body 3 is indicated by the straight line 8. Thus, the curvature in the rear portion 12 can be better grasped.

(16) 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.

(17) 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.

(18) 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.